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A Fortunate Universe: Life in a Finely Tuned Cosmos
Over the last forty years, scientists have uncovered evidence that if the Universe had been forged with even slightly different properties, life as we know it - and life as we can imagine it - would be impossible. Join us on a journey through how we understand the Universe, from its most basic particles and forces, to planets, stars and galaxies, and back through cosmic history to the birth of the cosmos. Conflicting notions about our place in the Universe are defined, defended and critiqued from scientific, philosophical and religious viewpoints. The authors' engaging and witty style addresses what fine-tuning might mean for the future of physics and the search for the ultimate laws of nature. Tackling difficult questions and providing thought-provoking answers, this volumes challenges us to consider our place in the cosmos, regardless of our initial convictions.
388 pages, Hardcover
First published August 7, 2016
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November 15, 2016
I came across Luke Barnes and his blog Letters to Nature when I was looking for expert commentary on New Atheist Victor Stenger's The Fallacy of Fine-Tuning, and was delighted to quote from him in my review. Now Barnes and his colleague Geraint Lewis have come out with their own book, which they wittily describe in the bibliography as "the antiparticle of Stenger's". There's no doubt as to who wins this fight. Stenger, who should be ashamed of himself, commits all the crimes that atheists like to lay at the door of their creationist enemies: he's rigid, dogmatic, humorless and startlingly dishonest. Barnes, in contrast, is scrupulous about sticking to the facts and not mentioning the G-word, as he disarmingly puts it, until he gets to the final chapter. Even then, he follows tradition and presents his case as a dialogue between himself and (as far as I can see, non-theist) coauthor. I'm raising his hand in triumph above the supine body of his opponent. It's Barnes, by a knockout.
For the benefit of people who came in halfway through this mini-epic, let me recap. The "Fine Tuning Problem", which has now been around for over forty years, is the claim that the laws of Nature appear to be carefully adjusted in order to make life possible. The basic ideas have been presented in several earlier popularisations, notably Rees's Just Six Numbers and Davies's The Goldilocks Enigma; but these books, unfortunately, didn't go into enough detail and failed to make the case as convincing as it could have been. Lewis and Barnes (henceforth, L&B) have been defending fine tuning for some time in both academic and public forums, and demonstrate fingertip familiarity with all the issues. They know where the most convincing evidence is; they also know how to answer all the standard objections.
The problem is that the best line of argument, the relative masses of the different quarks and leptons, is also one of the most technical ones, but L&B have found good ways to explain what's going on. Everything we see is made of protons, neutrons and electrons, and there are also vast numbers of invisible, very light neutrinos constantly streaming through us. The masses of the proton and the neutron are determined by the masses of the up and down quarks. It turns out that there are numerous strong constraints on the different masses. If things are pushed a little bit in one direction, you get a universe where there are only neutrons; in another, you get nothing but an exotic particle which in our real universe is very unstable; in a third direction, all the hydrogen gets used up in the first few minutes of the Big Bang and there is nothing left to power stars; in a fourth, too much mass leaks away from the initial concentrations and galaxies never form.
When you put it all together, there's hardly anything left, just a tiny area of the graph where we fortuituously happen to find ourselves. It is indeed mysterious. Of course, you can pick at this argument, and L&B devote a whole chapter to the numerous responses. Yes, it's hard to define exactly what life is and there are borderline cases like viruses, but this isn't the point. Nearly all the universes ruled out by the constraints are so fantastically inhospitable that the borderline cases are irrelevant. No life remotely like ours is going to exist in a universe that consists entirely of huge black holes, or of a thin soup of protons in which each particle is separated by trillions of light-years from its nearest neighbor. And yes, it is conceivable that there are forms of life totally unlike ours, but until someone at least suggests an in-principle mechanism by which such lifeforms could function, it's science-fiction rather than science. Lacking such creative suggestions, it seems quite reasonable to assume that life requires chemistry based on carbon, the only atom which allows formation of large, structured molecules. This creates further constraints, and makes our universe even more special.
My personal sympathies lie more in the atheist direction, but I think L&B are doing something admirable here. It doesn't matter that fine tuning is currently popular with theists like Francis S. Collins (The Language of God) or Richard Swinburne (Is There a God?). It doesn't matter that one of them (Barnes) appears to be a theist himself. What matters is that they're doing their best to look impartially at the evidence and see where it leads them. They are in good company. William Paley's carefully observed Natural Theology inspired Darwin to discover evolution; Georges Lemaître, with his clever interpretation of Hubble's redshift measurements, provided the initial basis for the Big Bang theory. In both cases, good scientists who happened to be theists got a subject moving in a new and fabulously productive direction because they were not afraid to say they'd found something strange that needed an explanation. We don't know if fine tuning is going to be equally successful. But it's always nice to see people who think data is more important than political correctness.
For the benefit of people who came in halfway through this mini-epic, let me recap. The "Fine Tuning Problem", which has now been around for over forty years, is the claim that the laws of Nature appear to be carefully adjusted in order to make life possible. The basic ideas have been presented in several earlier popularisations, notably Rees's Just Six Numbers and Davies's The Goldilocks Enigma; but these books, unfortunately, didn't go into enough detail and failed to make the case as convincing as it could have been. Lewis and Barnes (henceforth, L&B) have been defending fine tuning for some time in both academic and public forums, and demonstrate fingertip familiarity with all the issues. They know where the most convincing evidence is; they also know how to answer all the standard objections.
The problem is that the best line of argument, the relative masses of the different quarks and leptons, is also one of the most technical ones, but L&B have found good ways to explain what's going on. Everything we see is made of protons, neutrons and electrons, and there are also vast numbers of invisible, very light neutrinos constantly streaming through us. The masses of the proton and the neutron are determined by the masses of the up and down quarks. It turns out that there are numerous strong constraints on the different masses. If things are pushed a little bit in one direction, you get a universe where there are only neutrons; in another, you get nothing but an exotic particle which in our real universe is very unstable; in a third direction, all the hydrogen gets used up in the first few minutes of the Big Bang and there is nothing left to power stars; in a fourth, too much mass leaks away from the initial concentrations and galaxies never form.
When you put it all together, there's hardly anything left, just a tiny area of the graph where we fortuituously happen to find ourselves. It is indeed mysterious. Of course, you can pick at this argument, and L&B devote a whole chapter to the numerous responses. Yes, it's hard to define exactly what life is and there are borderline cases like viruses, but this isn't the point. Nearly all the universes ruled out by the constraints are so fantastically inhospitable that the borderline cases are irrelevant. No life remotely like ours is going to exist in a universe that consists entirely of huge black holes, or of a thin soup of protons in which each particle is separated by trillions of light-years from its nearest neighbor. And yes, it is conceivable that there are forms of life totally unlike ours, but until someone at least suggests an in-principle mechanism by which such lifeforms could function, it's science-fiction rather than science. Lacking such creative suggestions, it seems quite reasonable to assume that life requires chemistry based on carbon, the only atom which allows formation of large, structured molecules. This creates further constraints, and makes our universe even more special.
My personal sympathies lie more in the atheist direction, but I think L&B are doing something admirable here. It doesn't matter that fine tuning is currently popular with theists like Francis S. Collins (The Language of God) or Richard Swinburne (Is There a God?). It doesn't matter that one of them (Barnes) appears to be a theist himself. What matters is that they're doing their best to look impartially at the evidence and see where it leads them. They are in good company. William Paley's carefully observed Natural Theology inspired Darwin to discover evolution; Georges Lemaître, with his clever interpretation of Hubble's redshift measurements, provided the initial basis for the Big Bang theory. In both cases, good scientists who happened to be theists got a subject moving in a new and fabulously productive direction because they were not afraid to say they'd found something strange that needed an explanation. We don't know if fine tuning is going to be equally successful. But it's always nice to see people who think data is more important than political correctness.
January 27, 2025
Earth is famously known as a Goldilocks planet -- if it were slightly further from the sun or slightly closer to it, life (as we know it) could not exist, but rather the conditions had to be ‘just right.’ But what about a Goldilocks universe? Is there something about our universe, about its physical constants and parameters, that are equally tricky to line up, or could these forces -- say, the cosmological constant, the weight of quarks relative to electrons, the ratio of the strong force to gravity -- differ and still result in basically the same universe? How many combinations of the basic physical constants would lead to a universe that can support human life (also called “an anthropic universe”), or any life at all? Which numerical values for these parameters would allow for a universe with planets, galaxies, heavy elements, etc., or even just chemistry or star formation -- rather than, say, a cloud of helium protons, or a series of black holes, or a universe that immediately collapses after the Big Bang? How much ‘leeway’ is there for the fundamental physical constants of the universe?
PART 1: A VERY BIG NUMBER
The answer to this question is probably the most interesting discovery in the history of natural science, and certainly the most interesting empirical fact discovered in the past few decades. Of the 55 physical constants that have been studied and verified experimentally by physicists using high-end research instrumentation -- leaving aside the physical constants yet to be discovered, of which there are likely very many -- it turns out that there is essentially zero leeway for these basic parameters, and that the universe appears to have been EXTREMELY fine-tuned for the existence of human life.
At the very least, given all possible values for these parameters that still ‘work’ within physics as we know it, the odds of just a couple dozen of these parameters happening to line up is at least 10^10^100 to 1, a number so big that if we wrote a zero on every atom in the universe, there would not be enough atoms upon which to write the zeroes, and we would need all the atoms from an additional 10^20 universes.
This set of empirical facts has, as one might imagine, drawn the attention of various physicists. Many of the most interesting papers on this topic (specifically, on anthropic explanations of the cosmological constant) have been written by Steven Weinberg, a Nobel Prize winner, one of the main architects of the Standard Model of particle physics, and arguably the leading theoretical particle physicist in the world. See also:
Frank Wilczek:
Stephen Hawking:
Andrei Linde:
Leonard Susskind:
Of the 55 relevant features of the universe that could be mentioned, the most strongly fine-tuned are:
— gravitational attraction constant
— fine-structure constant
— strong/weak force coupling constants
— unit charge and rest mass of protons/electrons
— minimum mass in the universe
— total visible rest mass in the universe
— Boltzmann's constant
— Hubble constant
— cosmological constant
— cosmic photon/proton ratio
— permittivity of free space
— triple-alpha process
— vacuum expectation value of the Higgs field
Not only are all of these physical parameters fine-tuned to an astonishingly precise degree to create any universe that is even remotely possible for the development of life, they all also had to interlock in a precisely coordinated way.
(1) The strongest example of fine-tuning is the cosmological constant (energy density of space / vacuum energy / rate of acceleration of the universe), which was found in 1998 to be fine-tuned to a value of 1 in 10^120. If this were any different from precisely that number – that is to say, higher or lower by a value of 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001 – then the universe would be a diffuse soup of hydrogen/helium gas and life could not exist.
(2) If we create a graph where we place the fine structure constant on the X axis, and the gravitational constant on the Y axis, and plot all possible values, the region of the graph where stars can exist is less than one part in 10^35 of the plot.
(3) If gravitational force were one part in 10^36 weaker or stronger, stars/planets would not exist; to put this another way, if on Earth, for every trillion trillion trillion photons and electrons we added a single extra electron, the combined repulsion of those extra electrons would be stronger than the attraction of gravity, and this would preclude the existence of the Earth (or of any gravitationally bound structure in the universe).
(4) If gravity or electromagnetism were 1 part in 10^39 different, then all stars would be red dwarfs (if gravity were slightly weaker) or all stars would be blue giants (if EM were slightly stronger), thus not giving life time to form.
(5) If the weak force constant were one part in 10^12 weaker or stronger, then supernovas could not occur (and therefore heavier elements could not be formed); if weak interaction were barely weaker, neutrinos could not exert enough pressure on the outer envelope of the stars to cause the supernova; if stronger, neutrinos would be trapped inside the core.
(6) The amount/density of matter in the universe one second after the Big Bang was 10^24 kg per cubic meter. If this had been a single kilogram per cubic meter higher, the universe would have collapsed by now; if it were a single kilogram per cubic meter lower, stars would not have formed.
(7) The six types of quarks are precisely 4.5, 9.4, 190, 2,495, 8,180, and 338,960 times heavier than electrons, while the muon and tau neutrinos are 206.768284 and 3477.15 times heavier. If any of these ratios were very, very slightly different, chemistry would not exist, and the universe would be a cloud of featureless neutrons.
PART 2: SO YOU'RE TELLING ME THERE'S A CHANCE?
The two most common critiques of fine-tuning are as follows:
(1) The fine-tuned ratios of various natural constants will be explained by future research; i.e., the strong/weak forces will have to exist at precisely that ratio because of a deeper underlying principle that explains them both, a simpler explanation.
(2) Of course a universe that we observe would be suited for human life; we're here to observe it! We just got incredibly lucky, and who knows why; or maybe there are infinite universes, and thus one of them would inevitably contain human life.
I'll address (1) first. In all likelihood, anyone making this argument has failed to grasp the numbers involved. It is 100% possible – in fact, quite probable – that various constants will be shown to be unified at a deeper level, but there are a LOT of constants in a LOT of different areas of cosmology and physics, and they are all very, very, VERY fine-tuned. Even if we narrow down the 55 parameters to 25, or 8, or 5, those will still be a 1 in 10^3,750 chance, 1 in 10^729 chance, and so on, and this will still be an empirical fact that demands an explanation. No matter the precise relation or number of these constants, it would still be a massive coincidence that this happened to be a combination that allows for human life, given that the math/equations do just fine with a wide variety of different conditions (i.e., physics 'works' without EM force, without strong nuclear force, etc.). This smaller group of parameters would have to line up for both human life and for that theory to work, and they just happen to be the exact same extremely fine-tuned relationships?
Now for (2), which seems common-sensical at first, but falls apart under further scrutiny. Let's begin with an analogy.
Bob and Jane are playing poker. Bob is dealing, and is dealt a thousand royal flushes in a row (the rarest and strongest hand in poker), while Jane is dealt two-pair, one-pair, 9-high, etc., and loses every pot. Bob can see that Jane is getting a bit suspicious, and says: “No, no, Jane, don’t you know how probability works? Technically every combination of cards in a shuffled deck is equally likely, and we just happen to have played with a series of decks where I received a thousand royal flushes in a row. Sometimes coincidences happen!” Jane, however, is not convinced, and thinks that perhaps she needs to do some Bayesian analysis; taking into account the empirical fact of the hands as dealt, Jane will now need to revise her earlier assumption that Bob was dealing fairly, versus the probability that he is cheating. No sane person would accept Bob’s explanation.
The fact that we’re here to observe our own fine-tuned universe (necessarily) is also irrelevant. An example commonly used in the scholarly literature is Locke’s firing squad argument. Let’s say that you’re about to be executed by a firing squad consisting of a hundred expert marksmen; for a fine-tuned universe it would really be more like 10^10^100 marksmen, but let’s stick with 100. You close your eyes, ready for death, and . . . all the bullets miss. You’re standing there, somehow alive, with a hundred bullets lodged into the wall behind you. You should not be surprised that you do not observe you are dead (as you wouldn’t be there to observe otherwise!), but you should still be surprised that you lived. You would seek some further reason for your luck, and no sane person would accept the conclusion that 10^10^100 expert marksmen just happened to miss.
And if you don't believe some random guy on the internet, then at least believe the various Nobel Prize winners that I quoted above, prominent physicists at top universities who understand Bayesian reasoning and have rightly figured out that "hey we got super lucky!" is not a sufficient response.
Skeptics of anthropic coincidences also try to get around fine-tuning by using a slightly different formulation of the point above: “Maybe there are infinite universes and we just happen to be in the one where I get a thousand royal flushes?"
I was surprised, and honestly kind of shocked, to find out that all of the multiverse theories you may have vaguely heard of -- Everett-DeWitt’s many-worlds interpretation of quantum mechanics, Linde’s chaotic inflationary multiverse, Susskind’s interpretation of string theory, etc. -- all these theories were, for the most part (and entirely, for Linde/Susskind) formulated specifically due to discomfort with the clearly fine-tuned nature of the universe, and not for any scientific/experimental/actual reason.
To be clear, in most cases, these physicists started inventing fanciful theories that allowed for an infinity of universes -- a completely theoretical, imaginary infinity of universes that cannot be detected by any empirical method whatsoever and therefore have NOTHING TO DO WITH SCIENCE, WTF -- to explain away one universe that they didn't want to look designed. There is no overarching law that explains scientifically why all these kinds of universe would exist. The semantic content of “maybe there are infinite universes?” is “I am made uncomfortable by fine-tuning”; it's ad hoc pseudo-science, a metaphysical guess. And, of course, having physical laws that lead to the existence of domains of a sufficiently rich variety to make life inevitable would itself qualify as an anthropic coincidence that demands explanation.
I also just want to quickly note that the argument for fine-tuning -- or rather, the fact of it -- is not an argument for Intelligent Design or for God’s existence (though of course fine-tuning is not exactly bad news for theologians!). Anthropic coincidences in physics, as a field, began in physics journals and has largely remained there; there are a few ID theorists who have mentioned this topic in essays, but fine-tuning could just as easily mean that we're living in a computer simulation (an argument that I once thought was total bullshit, but possibly not), or that our physical universe was created by an unimaginably powerful alien species, etc. Fine-tuning does not say anything positively or negatively about religion or a creator God, at all -- though it's fair to say that it strengthens design arguments for God's existence (in Swinburne, Barr, et al.).
ENTROPY AND ORDER
Einstein’s statement that “the most incomprehensible thing about the world is that it is comprehensible” is not just a charming quotation to put on a coffee mug, but is in fact a very serious point. As he put it: "There is an order in the objective world of a high degree which one has no a-priori right to expect. This is the 'miracle' which grows increasingly persuasive with the increasing development of knowledge." It is not commonly realized that the laws of nature are not like laws of logic or math, which have to be true. The laws of nature could be very different, and they also don't need to be consistent; the boiling point of water could fluctuate on a daily basis. We do not just live in a universe that is very fine-tuned; we also live in a universe with a great deal of order, an unnecessarily extravagant amount of order that demands an explanation, especially given how chaotic/entropic nature is on a local scale.
The fact that the anthropic fine-tuned universe also has a low-entropy beginning for no discernible physical reason -- in a universe that tends toward entropy! -- similarly demands an explanation. It is an underappreciated aspect of the history of science that the Big Bang initially made most physicists very uncomfortable, because it made no sense that the universe would begin with infinitely low entropy. Most scientists (including Einstein, who rejected the idea of the Big Bang in 1916 even though his equations required it) started with the assumption that the universe had existed eternally and had an infinite number of ‘tries’ to bring about our current configuration, which would make it less special/fine-tuned that we existed. But if something makes a sudden appearance, it demands an explanation: possibly even more so than fine-tuning, given that infinitely low entropy (according to the second law of thermodynamics) would be an infinitely unlikely state, and infinity is a very big number! Even bigger than, say, 10^10^100.
* * *
N.B., this review relies on various writings by physicists and philosophers; Lewis/Barnes, of course, but also various other books and articles on the topic. I tried to put everything in my own words, but my notes were blended together with various quotations and I’m honestly not sure, probably ~90% is my own writing? Anyway, the ideas/critiques can be found in some form or another primarily within:
https://www.goodreads.com/book/show/3...
https://www.goodreads.com/book/show/7...
https://www.goodreads.com/book/show/2...
https://www.goodreads.com/book/show/8...
https://www.goodreads.com/book/show/2...
https://www.goodreads.com/book/show/1...
PART 1: A VERY BIG NUMBER
The answer to this question is probably the most interesting discovery in the history of natural science, and certainly the most interesting empirical fact discovered in the past few decades. Of the 55 physical constants that have been studied and verified experimentally by physicists using high-end research instrumentation -- leaving aside the physical constants yet to be discovered, of which there are likely very many -- it turns out that there is essentially zero leeway for these basic parameters, and that the universe appears to have been EXTREMELY fine-tuned for the existence of human life.
At the very least, given all possible values for these parameters that still ‘work’ within physics as we know it, the odds of just a couple dozen of these parameters happening to line up is at least 10^10^100 to 1, a number so big that if we wrote a zero on every atom in the universe, there would not be enough atoms upon which to write the zeroes, and we would need all the atoms from an additional 10^20 universes.
This set of empirical facts has, as one might imagine, drawn the attention of various physicists. Many of the most interesting papers on this topic (specifically, on anthropic explanations of the cosmological constant) have been written by Steven Weinberg, a Nobel Prize winner, one of the main architects of the Standard Model of particle physics, and arguably the leading theoretical particle physicist in the world. See also:
Frank Wilczek:
“Life appears to depend upon delicate coincidences that we have not been able to explain. The broad outlines of that situation have been apparent for many decades. When less was known, it seemed reasonable to hope that better understanding of symmetry and dynamics would clear things up. Now that hope seems much less reasonable. The happy coincidences between life's requirements and nature's choices of parameter values . . . might be just a series of flukes, but one could be forgiven for beginning to suspect that something deeper is at work.”
Stephen Hawking:
“Most of the fundamental constants in our theories appear fine-tuned in the sense that if they were altered by only modest amounts, the universe would be qualitatively different, and in many cases unsuitable for the development of life. . . . The emergence of the complex structures capable of supporting intelligent observers seems to be very fragile.”
Andrei Linde:
“The existence of an amazingly strong correlation between our own properties and the values of many parameters of our world, such as the masses and charges of electron and proton, the value of the gravitational constant, the amplitude of spontaneous symmetry breaking in the electroweak theory, the value of the vacuum energy, and the dimensionality of our world, is an experimental fact requiring an explanation.”
Leonard Susskind:
"The universe is an extraordinary place that appears to be fantastically well designed for our own existence. This specialness is not something that we can attribute to lucky accidents, which is far too unlikely. The apparent coincidences cry out for an explanation."
Of the 55 relevant features of the universe that could be mentioned, the most strongly fine-tuned are:
— gravitational attraction constant
— fine-structure constant
— strong/weak force coupling constants
— unit charge and rest mass of protons/electrons
— minimum mass in the universe
— total visible rest mass in the universe
— Boltzmann's constant
— Hubble constant
— cosmological constant
— cosmic photon/proton ratio
— permittivity of free space
— triple-alpha process
— vacuum expectation value of the Higgs field
Not only are all of these physical parameters fine-tuned to an astonishingly precise degree to create any universe that is even remotely possible for the development of life, they all also had to interlock in a precisely coordinated way.
(1) The strongest example of fine-tuning is the cosmological constant (energy density of space / vacuum energy / rate of acceleration of the universe), which was found in 1998 to be fine-tuned to a value of 1 in 10^120. If this were any different from precisely that number – that is to say, higher or lower by a value of 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001 – then the universe would be a diffuse soup of hydrogen/helium gas and life could not exist.
(2) If we create a graph where we place the fine structure constant on the X axis, and the gravitational constant on the Y axis, and plot all possible values, the region of the graph where stars can exist is less than one part in 10^35 of the plot.
(3) If gravitational force were one part in 10^36 weaker or stronger, stars/planets would not exist; to put this another way, if on Earth, for every trillion trillion trillion photons and electrons we added a single extra electron, the combined repulsion of those extra electrons would be stronger than the attraction of gravity, and this would preclude the existence of the Earth (or of any gravitationally bound structure in the universe).
(4) If gravity or electromagnetism were 1 part in 10^39 different, then all stars would be red dwarfs (if gravity were slightly weaker) or all stars would be blue giants (if EM were slightly stronger), thus not giving life time to form.
(5) If the weak force constant were one part in 10^12 weaker or stronger, then supernovas could not occur (and therefore heavier elements could not be formed); if weak interaction were barely weaker, neutrinos could not exert enough pressure on the outer envelope of the stars to cause the supernova; if stronger, neutrinos would be trapped inside the core.
(6) The amount/density of matter in the universe one second after the Big Bang was 10^24 kg per cubic meter. If this had been a single kilogram per cubic meter higher, the universe would have collapsed by now; if it were a single kilogram per cubic meter lower, stars would not have formed.
(7) The six types of quarks are precisely 4.5, 9.4, 190, 2,495, 8,180, and 338,960 times heavier than electrons, while the muon and tau neutrinos are 206.768284 and 3477.15 times heavier. If any of these ratios were very, very slightly different, chemistry would not exist, and the universe would be a cloud of featureless neutrons.
PART 2: SO YOU'RE TELLING ME THERE'S A CHANCE?
The two most common critiques of fine-tuning are as follows:
(1) The fine-tuned ratios of various natural constants will be explained by future research; i.e., the strong/weak forces will have to exist at precisely that ratio because of a deeper underlying principle that explains them both, a simpler explanation.
(2) Of course a universe that we observe would be suited for human life; we're here to observe it! We just got incredibly lucky, and who knows why; or maybe there are infinite universes, and thus one of them would inevitably contain human life.
I'll address (1) first. In all likelihood, anyone making this argument has failed to grasp the numbers involved. It is 100% possible – in fact, quite probable – that various constants will be shown to be unified at a deeper level, but there are a LOT of constants in a LOT of different areas of cosmology and physics, and they are all very, very, VERY fine-tuned. Even if we narrow down the 55 parameters to 25, or 8, or 5, those will still be a 1 in 10^3,750 chance, 1 in 10^729 chance, and so on, and this will still be an empirical fact that demands an explanation. No matter the precise relation or number of these constants, it would still be a massive coincidence that this happened to be a combination that allows for human life, given that the math/equations do just fine with a wide variety of different conditions (i.e., physics 'works' without EM force, without strong nuclear force, etc.). This smaller group of parameters would have to line up for both human life and for that theory to work, and they just happen to be the exact same extremely fine-tuned relationships?
Now for (2), which seems common-sensical at first, but falls apart under further scrutiny. Let's begin with an analogy.
Bob and Jane are playing poker. Bob is dealing, and is dealt a thousand royal flushes in a row (the rarest and strongest hand in poker), while Jane is dealt two-pair, one-pair, 9-high, etc., and loses every pot. Bob can see that Jane is getting a bit suspicious, and says: “No, no, Jane, don’t you know how probability works? Technically every combination of cards in a shuffled deck is equally likely, and we just happen to have played with a series of decks where I received a thousand royal flushes in a row. Sometimes coincidences happen!” Jane, however, is not convinced, and thinks that perhaps she needs to do some Bayesian analysis; taking into account the empirical fact of the hands as dealt, Jane will now need to revise her earlier assumption that Bob was dealing fairly, versus the probability that he is cheating. No sane person would accept Bob’s explanation.
The fact that we’re here to observe our own fine-tuned universe (necessarily) is also irrelevant. An example commonly used in the scholarly literature is Locke’s firing squad argument. Let’s say that you’re about to be executed by a firing squad consisting of a hundred expert marksmen; for a fine-tuned universe it would really be more like 10^10^100 marksmen, but let’s stick with 100. You close your eyes, ready for death, and . . . all the bullets miss. You’re standing there, somehow alive, with a hundred bullets lodged into the wall behind you. You should not be surprised that you do not observe you are dead (as you wouldn’t be there to observe otherwise!), but you should still be surprised that you lived. You would seek some further reason for your luck, and no sane person would accept the conclusion that 10^10^100 expert marksmen just happened to miss.
And if you don't believe some random guy on the internet, then at least believe the various Nobel Prize winners that I quoted above, prominent physicists at top universities who understand Bayesian reasoning and have rightly figured out that "hey we got super lucky!" is not a sufficient response.
Skeptics of anthropic coincidences also try to get around fine-tuning by using a slightly different formulation of the point above: “Maybe there are infinite universes and we just happen to be in the one where I get a thousand royal flushes?"
I was surprised, and honestly kind of shocked, to find out that all of the multiverse theories you may have vaguely heard of -- Everett-DeWitt’s many-worlds interpretation of quantum mechanics, Linde’s chaotic inflationary multiverse, Susskind’s interpretation of string theory, etc. -- all these theories were, for the most part (and entirely, for Linde/Susskind) formulated specifically due to discomfort with the clearly fine-tuned nature of the universe, and not for any scientific/experimental/actual reason.
To be clear, in most cases, these physicists started inventing fanciful theories that allowed for an infinity of universes -- a completely theoretical, imaginary infinity of universes that cannot be detected by any empirical method whatsoever and therefore have NOTHING TO DO WITH SCIENCE, WTF -- to explain away one universe that they didn't want to look designed. There is no overarching law that explains scientifically why all these kinds of universe would exist. The semantic content of “maybe there are infinite universes?” is “I am made uncomfortable by fine-tuning”; it's ad hoc pseudo-science, a metaphysical guess. And, of course, having physical laws that lead to the existence of domains of a sufficiently rich variety to make life inevitable would itself qualify as an anthropic coincidence that demands explanation.
I also just want to quickly note that the argument for fine-tuning -- or rather, the fact of it -- is not an argument for Intelligent Design or for God’s existence (though of course fine-tuning is not exactly bad news for theologians!). Anthropic coincidences in physics, as a field, began in physics journals and has largely remained there; there are a few ID theorists who have mentioned this topic in essays, but fine-tuning could just as easily mean that we're living in a computer simulation (an argument that I once thought was total bullshit, but possibly not), or that our physical universe was created by an unimaginably powerful alien species, etc. Fine-tuning does not say anything positively or negatively about religion or a creator God, at all -- though it's fair to say that it strengthens design arguments for God's existence (in Swinburne, Barr, et al.).
ENTROPY AND ORDER
Einstein’s statement that “the most incomprehensible thing about the world is that it is comprehensible” is not just a charming quotation to put on a coffee mug, but is in fact a very serious point. As he put it: "There is an order in the objective world of a high degree which one has no a-priori right to expect. This is the 'miracle' which grows increasingly persuasive with the increasing development of knowledge." It is not commonly realized that the laws of nature are not like laws of logic or math, which have to be true. The laws of nature could be very different, and they also don't need to be consistent; the boiling point of water could fluctuate on a daily basis. We do not just live in a universe that is very fine-tuned; we also live in a universe with a great deal of order, an unnecessarily extravagant amount of order that demands an explanation, especially given how chaotic/entropic nature is on a local scale.
The fact that the anthropic fine-tuned universe also has a low-entropy beginning for no discernible physical reason -- in a universe that tends toward entropy! -- similarly demands an explanation. It is an underappreciated aspect of the history of science that the Big Bang initially made most physicists very uncomfortable, because it made no sense that the universe would begin with infinitely low entropy. Most scientists (including Einstein, who rejected the idea of the Big Bang in 1916 even though his equations required it) started with the assumption that the universe had existed eternally and had an infinite number of ‘tries’ to bring about our current configuration, which would make it less special/fine-tuned that we existed. But if something makes a sudden appearance, it demands an explanation: possibly even more so than fine-tuning, given that infinitely low entropy (according to the second law of thermodynamics) would be an infinitely unlikely state, and infinity is a very big number! Even bigger than, say, 10^10^100.
* * *
N.B., this review relies on various writings by physicists and philosophers; Lewis/Barnes, of course, but also various other books and articles on the topic. I tried to put everything in my own words, but my notes were blended together with various quotations and I’m honestly not sure, probably ~90% is my own writing? Anyway, the ideas/critiques can be found in some form or another primarily within:
https://www.goodreads.com/book/show/3...
https://www.goodreads.com/book/show/7...
https://www.goodreads.com/book/show/2...
https://www.goodreads.com/book/show/8...
https://www.goodreads.com/book/show/2...
https://www.goodreads.com/book/show/1...
July 6, 2022
The question is why the laws of physics/cosmology are what they are; and in particular why their constants take specific and life-friendly values? The possible answers to this "fine-tuning" problem, provided mainly in a what-if multiverse domain, seem to be the new battleground between atheists and creationists; with the scientific cosmologists in the middle as neutral and objective observers. The book is great in explaining a lot of past and current theories, along with their assumptions and implications.
However, here is a different take on the issue. Starting with Galileo and Newton, the mathematical equations encountered in physics are anticipatory projections of nature as a domain of calculable objects. As such, constants encountered in these mathematical equations are nothing more than just remainders. In this “objective” ontology, the certitude of calculable objects defines the truth, and this in turn defines the real. Real, understood as extension, is the same as existence in this ontology. The subject with all his representations and theories opposes these objects, and in his assault on nature implicitly provides the criterion for what truly exists. Consequently, the so-called “anthropic principle” is unavoidable and pops up in different forms in these theories. This ontology brings the associated and inevitable issues of: truth understood as correspondence, the proofs and disproofs for the existence of God, the existence or non-existence of the real world, the suspicion of living inside a simulation, the abstract/mathematical time as measured by a clock and direction-free, the speculative scientist running into all kind of antinomies, the generic subjectivity presented as the “critical conscience” of science, and so on.
However, here is a different take on the issue. Starting with Galileo and Newton, the mathematical equations encountered in physics are anticipatory projections of nature as a domain of calculable objects. As such, constants encountered in these mathematical equations are nothing more than just remainders. In this “objective” ontology, the certitude of calculable objects defines the truth, and this in turn defines the real. Real, understood as extension, is the same as existence in this ontology. The subject with all his representations and theories opposes these objects, and in his assault on nature implicitly provides the criterion for what truly exists. Consequently, the so-called “anthropic principle” is unavoidable and pops up in different forms in these theories. This ontology brings the associated and inevitable issues of: truth understood as correspondence, the proofs and disproofs for the existence of God, the existence or non-existence of the real world, the suspicion of living inside a simulation, the abstract/mathematical time as measured by a clock and direction-free, the speculative scientist running into all kind of antinomies, the generic subjectivity presented as the “critical conscience” of science, and so on.
March 30, 2019
The Fortunate Universe is a unique way of describing how weird, unreal, irrational and perhaps unnecessary the existence is at the most fundamental levels for modern age scientists, cosmologists, geneticists and followers of any rational studies.
The subject permits the authors to cover the key concepts of particle physics, relativity, quantum mechanics, cosmology, earth sciences and genetics in a refreshing and novel way. It does not compel the authors to cover the topics in the usual chronological fashion that one sees in most popular science books. As a result, the authors can focus on the knowledge as it exists now, rather than scientists or the path to various discoveries (largely). The discussions focus on the oddities - like the value of various parameters in standard equations, for instance - in these fields rather than their most obvious and well-discussed conclusions.
And yet, the book suffers from some flaws in the design, and the topic itself. To start with, the book moves extremely rapidly. The authors do not delve sufficient time on almost any topics, and they raise many philosophical, teleological, theological and scientific issues with almost all ending incompletely and unsatisfactorily. The book should have been at least a double its current size to do justice to even a fraction of the issues covered.
The authors have provided extended chapters at the end to rebuff many - and in their eyes, almost all - arguments that might arise against the fine-tuning concept and what it might imply. These chapters partially address some problems this reviewer lists below but even where they exist, most rebuttals are not only inadequate/wrong. Most importantly, the entire fine-tuning argument lacks the perspective that almost any existence of our kind could not have looked probable or anything but fine-tuned.
Let’s begin at the beginning. Existence is irrational. Someone could have said “who ordered it” about it; it is unnecessary given we cannot remotely imagine the objective or the need that caused us in any standard scientific or even God-made-it theories.
If certain existential realities evolve as per rules, that is another level of arbitrariness, only compounded by yet another one that these rules appear somewhat, even if not wholly, describable in the language of Math. Now, Math itself is ungodly messy and chaotic in its dealing with interactions between even three particles following simplest of rules, let alone those numbering crazy orders of ten and with complex mathematical rules like general relativity or wave equations for interactions. With all our knowledge and computing power, we cannot fully describe the fluid down a narrow capillary because all interaction Math is inherently unstable even before probabilities and irrational constants.
The book ignores all this. And, the book ignores another chaos generating mechanism later - the path dependency. One could restate the Butterfly effect: a tiny quantum variation in the actualisation during inflation and the matter might not have existed. Slightly different gravitational wrinkles within the first second and certain galaxies that gave rise to the matter in the Sun eventually might not have existed. From the first creation of the life-form/cell, the endosymbiosis, the forces that led to the right Oxidization of the Earth’s environment, the extinctions that paved the ways for the homo sapiens to dominate - there are zillions of non-Standard equations’ parametric coincidences that could appear exquisitely fine-tuned to anyone wearing the tinted glasses and being thankful for our “fortunate” current point in time.
The authors largely focus on only one kind of “fine-tuning”: the one in the Standard Model, or its slightly larger variants that try to include the Relativity.
Wikipedia has a good definition of this “fine-tuning”: “In theoretical physics, fine-tuning is the process in which parameters of a model must be adjusted very precisely in order to fit with certain observations.” This part is extremely well covered in the book. There is a lot that would leave one’s mouth agape including those well-read on the model’s quixotic parameters. The authors can provide great information and differentiated insights throughout the book with descriptions of scientific theories from a singular viewpoint of discovering their existential oddities.
Yet, as this reviewer sees it, the authors miss the point that the oddities are almost an obvious outcome of the irrationality of the existence. In some other universe, the parameters might be different, leading to wholly other types of matter, forces, their interactions and life. In certain other hypothetical world, the rules or equations forming multi-verses could be different. And, there could be worlds where rules are in a different type of objective language that is not Math and one we cannot even imagine with our faculties.
The main point is whether we humans can even contemplate an intelligent existence where the reality would not look a happenstance to its inhabitants. Within certain narrow frameworks, things could look normal - like the way the motion does when one is using Relativity equations, but this cannot be all and the whole if there is an intelligent life studying it from within.
All that said, the subject and the approach are fascinating. I would have loved if the authors had taken far more time discussing what they set out to.
The subject permits the authors to cover the key concepts of particle physics, relativity, quantum mechanics, cosmology, earth sciences and genetics in a refreshing and novel way. It does not compel the authors to cover the topics in the usual chronological fashion that one sees in most popular science books. As a result, the authors can focus on the knowledge as it exists now, rather than scientists or the path to various discoveries (largely). The discussions focus on the oddities - like the value of various parameters in standard equations, for instance - in these fields rather than their most obvious and well-discussed conclusions.
And yet, the book suffers from some flaws in the design, and the topic itself. To start with, the book moves extremely rapidly. The authors do not delve sufficient time on almost any topics, and they raise many philosophical, teleological, theological and scientific issues with almost all ending incompletely and unsatisfactorily. The book should have been at least a double its current size to do justice to even a fraction of the issues covered.
The authors have provided extended chapters at the end to rebuff many - and in their eyes, almost all - arguments that might arise against the fine-tuning concept and what it might imply. These chapters partially address some problems this reviewer lists below but even where they exist, most rebuttals are not only inadequate/wrong. Most importantly, the entire fine-tuning argument lacks the perspective that almost any existence of our kind could not have looked probable or anything but fine-tuned.
Let’s begin at the beginning. Existence is irrational. Someone could have said “who ordered it” about it; it is unnecessary given we cannot remotely imagine the objective or the need that caused us in any standard scientific or even God-made-it theories.
If certain existential realities evolve as per rules, that is another level of arbitrariness, only compounded by yet another one that these rules appear somewhat, even if not wholly, describable in the language of Math. Now, Math itself is ungodly messy and chaotic in its dealing with interactions between even three particles following simplest of rules, let alone those numbering crazy orders of ten and with complex mathematical rules like general relativity or wave equations for interactions. With all our knowledge and computing power, we cannot fully describe the fluid down a narrow capillary because all interaction Math is inherently unstable even before probabilities and irrational constants.
The book ignores all this. And, the book ignores another chaos generating mechanism later - the path dependency. One could restate the Butterfly effect: a tiny quantum variation in the actualisation during inflation and the matter might not have existed. Slightly different gravitational wrinkles within the first second and certain galaxies that gave rise to the matter in the Sun eventually might not have existed. From the first creation of the life-form/cell, the endosymbiosis, the forces that led to the right Oxidization of the Earth’s environment, the extinctions that paved the ways for the homo sapiens to dominate - there are zillions of non-Standard equations’ parametric coincidences that could appear exquisitely fine-tuned to anyone wearing the tinted glasses and being thankful for our “fortunate” current point in time.
The authors largely focus on only one kind of “fine-tuning”: the one in the Standard Model, or its slightly larger variants that try to include the Relativity.
Wikipedia has a good definition of this “fine-tuning”: “In theoretical physics, fine-tuning is the process in which parameters of a model must be adjusted very precisely in order to fit with certain observations.” This part is extremely well covered in the book. There is a lot that would leave one’s mouth agape including those well-read on the model’s quixotic parameters. The authors can provide great information and differentiated insights throughout the book with descriptions of scientific theories from a singular viewpoint of discovering their existential oddities.
Yet, as this reviewer sees it, the authors miss the point that the oddities are almost an obvious outcome of the irrationality of the existence. In some other universe, the parameters might be different, leading to wholly other types of matter, forces, their interactions and life. In certain other hypothetical world, the rules or equations forming multi-verses could be different. And, there could be worlds where rules are in a different type of objective language that is not Math and one we cannot even imagine with our faculties.
The main point is whether we humans can even contemplate an intelligent existence where the reality would not look a happenstance to its inhabitants. Within certain narrow frameworks, things could look normal - like the way the motion does when one is using Relativity equations, but this cannot be all and the whole if there is an intelligent life studying it from within.
All that said, the subject and the approach are fascinating. I would have loved if the authors had taken far more time discussing what they set out to.
November 26, 2022
This is one of perhaps many books that try to convey to the lay reader the issue of fine-tuning in cosmology and the various conjectures (and worse than conjectures) that try to explain fine-tuning. The issue of fine-tuning is this: we know a bunch of physical laws (equations). Most of them have some constants. They have to be experimentally measured. We have no reason to believe these values have to be what they are. It's conceivable some other values are equally plausible. But if you start to hypothetically change these values, you soon realize that the resulting universe is unlikely to permit life. In other words, these values are suspiciously fine-tuned to permit intelligent life like us. Much of the book explains why when a particular value is very different life is unlikely to exist.
When you put all this information together, the natural question is why. Then a number of conjectures (I'm using the word to mean something weaker than hypothesis) about it are explained. For example, there may be multiple or even infinite number of universes (in space, in time). Some are life-permitting such as ours, others sterile. Obviously we are only possible in the subset that permit life. As another example, they even brought up the tiring argument of God from the theists. They even acknowledge that there are modern, revised God in retreat from science, but claim this time it's different. (No it's not. Their argument is just as tautological as the Flying Spaghetti Monster.) We could also be in a simulation from a "higher being", which is only slightly less tautological but a bit more relatable to us. But I make the assumption that the authors are merely messengers (though Barnes spent way too many pages in philosophical nonsense to pass as a disinterested messenger).
When you put all this information together, the natural question is why. Then a number of conjectures (I'm using the word to mean something weaker than hypothesis) about it are explained. For example, there may be multiple or even infinite number of universes (in space, in time). Some are life-permitting such as ours, others sterile. Obviously we are only possible in the subset that permit life. As another example, they even brought up the tiring argument of God from the theists. They even acknowledge that there are modern, revised God in retreat from science, but claim this time it's different. (No it's not. Their argument is just as tautological as the Flying Spaghetti Monster.) We could also be in a simulation from a "higher being", which is only slightly less tautological but a bit more relatable to us. But I make the assumption that the authors are merely messengers (though Barnes spent way too many pages in philosophical nonsense to pass as a disinterested messenger).
December 30, 2017
This is one of the best treatments of The Fine-Tuning of the universe I've ever come across. As anyone who follows Cerebral Faith and has read my most recent blog post knows, The Fine-Tuning Argument is one of my top 5 favorite arguments for God's existence. This book caught my eye because it's an entire book devoted to this subject, and I downloaded it hoping to become even more knowledgeable on the subject.
The majority of the book is devoted to the science of fine-tuning. By that, I mean the actual constants (The Strong Nuclear Force, The Weak Nuclear Force, Gravity, Electromagnetism, The Cosmological Constant) and quantities (e.g the level of low entropy in the early universe), and what would follow if these parameters had been off by a little bit. Only two chapters near the end of the book are devoted to making a design inference and addressing atheistic responses to the FT argument. I was glad for this because the actual nuts-and-bolts of the fine-tuning is what I was seeking to further educate myself on.
The book is geared toward a lay audience, so the language that's employed shouldn't be too difficult for anyone with a high school education.
Not only is this book educational, but it's lively. The authors have a sense of humor that can be found in multiple places in the book (even the footnotes!).
If you love science, or if you're studying natural theology, get this book.
The majority of the book is devoted to the science of fine-tuning. By that, I mean the actual constants (The Strong Nuclear Force, The Weak Nuclear Force, Gravity, Electromagnetism, The Cosmological Constant) and quantities (e.g the level of low entropy in the early universe), and what would follow if these parameters had been off by a little bit. Only two chapters near the end of the book are devoted to making a design inference and addressing atheistic responses to the FT argument. I was glad for this because the actual nuts-and-bolts of the fine-tuning is what I was seeking to further educate myself on.
The book is geared toward a lay audience, so the language that's employed shouldn't be too difficult for anyone with a high school education.
Not only is this book educational, but it's lively. The authors have a sense of humor that can be found in multiple places in the book (even the footnotes!).
If you love science, or if you're studying natural theology, get this book.
October 9, 2022
I decided to read this book because the topic is just fun, and reading the book gives me a playground for exploring it.
To some extent the book itself is written in the same vein. Lewis and Barnes are two cosmologists who are fascinated by the topic, knowledgeable about the ins and outs of the physics and astrophysics behind it, and they allow themselves to explore in an unbounded way, crossing the boundaries into areas scientists are often squeamish about.
It’s presented within a framing dialogue between the two authors, emphasizing that exploratory and informal tone.
“Fine-tuning” in this context refers to how precisely the values of the constants of physics and cosmology, out of all of the possible values those constants could have, are suited to the development of galaxies, stars, planets, and the chemistry of complex life. We, in other words, seem unlikely to be possible, given all the universes that could have been. Why is the universe so well-suited to complex, intelligent life such as us?
Two thirds of the book deal with how remarkably precise this fine tuning is, and how different the universe would be if those constants — such as the strength of the fundamental forces (gravity, electromagnetism, the strong and weak nuclear forces), the masses of fundamental particles, the apparent initial conditions of the universe — had they been other than what they are.
Scientists don’t like unexplained facts. They want explanations for the values of those constants. Lewis and Barnes quote Einstein — ”I would like to state a theorem which at present can not be based upon anything more than upon a faith in the simplicity, i.e. intelligibility, of nature: there are no arbitrary constants . . .”
And any inclination to go for the gold, to say that the universe is as it is in order to produce complex, intelligent life . . . . no. Scientists commit themselves to a description of the universe that is not dependent on goals or purposes. Better a universe that just happens than one that pursues a plan or a purpose.
Lewis and Barnes push the point through many examples, themselves edifying discussions of concepts and themes in modern cosmology. What happens, they ask, if we fiddle with the dials? If we change some of those constants.
Part of the trick is that we imagine such changes as a slight increase in the strength of gravity as something that would make us heavier, or maybe make our planet’s orbit around the sun smaller, or some other adjustment to the familiar.
But that’s not the way it works. Increasing the strength of gravity affects the ability of matter to clump together in any way, anywhere. Stars would be larger, hotter, and shorter lived. That affects the production of heavier elements (heavier than hydrogen). That affects the availability of heavier elements for chemical reactions. And so on, and so on. Chains of effects that transform the familiar universe into something radically different.
The differences between those universes and our own are not small. Those are universes in which, as Lewis and Barnes say, “The extremes . . . are disintegrating atoms, the cessation of all chemical reactions, the crush of a black hole, and the eternal loneliness of life in a universe where particles collide every trillion years or so.”
This is to say nothing of messing with the cosmological constant — the poorly understood factor that accounts for both the fact that the universe’s expansion is accelerating and the fact that is not accelerating (and has not accelerated) so fast that galaxies, stars, and planets never form.
Or the value for Q, the “lumpiness” of the initial universe. Q is currently estimated at 1 in 100,000, meaning that the density of the initial universe at any point varies from the universe’s overall average value by only 1 part in 100,000. If that weren’t the case, if the lumpiness of the universe weren’t so well fine-tuned, we’d either get a very smooth, flat, universe with no galaxies, no stars, no planets, or one with all of its matter locked into incredibly massive objects (black holes).
Or just make it simple. A universe in which matter and anti-matter are symmetrical, where there is just as much of one as the other. In the very early, dense universe, they interact, they mutually annihilate. No matter left to make anything at all.
Lewis and Barnes don’t even stop there. They go on to more abstract contingencies in the nature of the universe, including orderliness itself. A universe without order is one in which there are no patterns, just randomness.
The best part of the book, for me, starts about two-thirds of the way through, where we get to the “So what?” discussion.
I’ve been aware of the fine-tuning problem since Barrow and Tipler’s 1986 book, The Anthropic Cosmological Principle (in fact, I'm putting this book next to that one on the shelf). At the time, it was hard to know how seriously to take the problem (much less the solutions that Barrow and Tipler floated). And that seemed true for the physics and cosmology worlds as well — it didn’t seem like a scientific problem so much as an invitation to wild speculation.
But the fine-tuning problem has grown up now, and both scientists and others do pay attention. It raises questions about the status of physical theory today, its scope, its future direction, and the proper scope and limits of scientific explanation.
Lewis and Barnes collect reactions they have experienced to the fine-tuning problem, both from scientific colleagues and non-scientist audiences, into “A Dozen (or So) Reactions to Fine-Tuning” in their chapter 7. Actually, since they designate the reactions by letters from “a” to “o”, there are definitely more than a dozen.
Those reactions vary from naturalistic to religious. They include reactions that I’ve played with myself, especially (a) “coincidence” — that the facts just are as they are, and they provide for complex, intelligent life, or else we wouldn’t be here to talk about it.
And (g) that all possible universes are, taken singly, unlikely, this one no more nor less than any of the others. One of them had to exist, and, no matter which, it would be an unlikely one.
And (j) — “life chauvinism,” that we bias our perspective to an investigation of the relationship between the constants and the development of creatures like ourselves, when we could just as well formulate a fine-tuning problem relating to any number of other things only possible in a universe like ours. Or, for that matter, if the universe was in fact entirely populated by black holes, wouldn’t that pose a fine-tuning problem itself (granted with no one to articulate it)?
Lewis and Barnes provide responses to all of these reactions, and even if they don’t always completely satisfy, they at least take the thinking deeper.
As for their own reactions, they aren’t offering a conclusion. As I said, they are more “at play” in the discussion than pushing a resolution. But they do have inclinations.
Lewis is sympathetic with a multiverse solution. In various multiverse theories, other values for those constants are realized, just in universes other than our own. The fact that we live in a universe hospitable to life like our own is not surprising — it couldn’t be otherwise. There is no coincidence, and no unlikely fine-tuning involved. There are many universes. Some are full of black holes. Some are endless expanses of thinly spread hydrogen atoms. And some, like ours, contain intelligent creatures.
There are certainly numerous multiverse theories out there, and Lewis cites cosmic inflation as one avenue to go down to explain the origins of multiple, non-interacting universes with differing constants. Note that not just any multiverse theory will do — Everettian multiverse (or “many worlds”) theory, for example, does not help, as it relies upon relatively standard quantum physics with established values for its constants.
You might object that using cosmic inflation to explain multiverse theory to explain fine-tuning is using something poorly understood to explain something even more poorly understood to explain the pretty much completely not-understood, but, hey, sometimes a Hail Mary is a good call.
Barnes seems to favor an extension of their response to reaction (a) — that “coincidence” is not an acceptable endpoint for theorizing. In the closing parts of their dialogue, Barnes says, “The moral: when a theory requires very precise but unexplained postulates to explain the data, it might be a clue. Perhaps we should be looking for a deeper theory in which the postulate is explained, or exists naturally.”
That is, what we lack is a more fundamental physics than what we have today. Yes, today the constants are unaccounted for facts, but there remains a “gap between the laws-as-we-know-them and the ultimate laws of nature.” Fine-tuning points toward the need for more fundamental, more ultimate theory.
The best thing about the book is its lack of conclusions. This is a topic ripe for speculation and creative thought. Scientists should do more of that. And they should, as Lewis and Barnes do from time to time, bring in concerns and insights from other disciplines, especially philosophical thought and, yes, even religious thought. Why not? Science has no monopoly on knowledge or insight.
As for readability, I have to say the book is uneven. Sometimes it flows easily — it doesn’t depend on formulas or mathematical sophistication, although some of that is there if you want to chase it. Conceptually, some topics, e.g., supersymmetry, are just complex, and you’re not going to come away understanding them if you didn’t come in already pretty well-equipped. But the whole doesn’t depend on the reader understanding every little piece of physics surveyed along the way.
Don’t worry about it. Just play.
To some extent the book itself is written in the same vein. Lewis and Barnes are two cosmologists who are fascinated by the topic, knowledgeable about the ins and outs of the physics and astrophysics behind it, and they allow themselves to explore in an unbounded way, crossing the boundaries into areas scientists are often squeamish about.
It’s presented within a framing dialogue between the two authors, emphasizing that exploratory and informal tone.
“Fine-tuning” in this context refers to how precisely the values of the constants of physics and cosmology, out of all of the possible values those constants could have, are suited to the development of galaxies, stars, planets, and the chemistry of complex life. We, in other words, seem unlikely to be possible, given all the universes that could have been. Why is the universe so well-suited to complex, intelligent life such as us?
Two thirds of the book deal with how remarkably precise this fine tuning is, and how different the universe would be if those constants — such as the strength of the fundamental forces (gravity, electromagnetism, the strong and weak nuclear forces), the masses of fundamental particles, the apparent initial conditions of the universe — had they been other than what they are.
Scientists don’t like unexplained facts. They want explanations for the values of those constants. Lewis and Barnes quote Einstein — ”I would like to state a theorem which at present can not be based upon anything more than upon a faith in the simplicity, i.e. intelligibility, of nature: there are no arbitrary constants . . .”
And any inclination to go for the gold, to say that the universe is as it is in order to produce complex, intelligent life . . . . no. Scientists commit themselves to a description of the universe that is not dependent on goals or purposes. Better a universe that just happens than one that pursues a plan or a purpose.
Lewis and Barnes push the point through many examples, themselves edifying discussions of concepts and themes in modern cosmology. What happens, they ask, if we fiddle with the dials? If we change some of those constants.
Part of the trick is that we imagine such changes as a slight increase in the strength of gravity as something that would make us heavier, or maybe make our planet’s orbit around the sun smaller, or some other adjustment to the familiar.
But that’s not the way it works. Increasing the strength of gravity affects the ability of matter to clump together in any way, anywhere. Stars would be larger, hotter, and shorter lived. That affects the production of heavier elements (heavier than hydrogen). That affects the availability of heavier elements for chemical reactions. And so on, and so on. Chains of effects that transform the familiar universe into something radically different.
The differences between those universes and our own are not small. Those are universes in which, as Lewis and Barnes say, “The extremes . . . are disintegrating atoms, the cessation of all chemical reactions, the crush of a black hole, and the eternal loneliness of life in a universe where particles collide every trillion years or so.”
This is to say nothing of messing with the cosmological constant — the poorly understood factor that accounts for both the fact that the universe’s expansion is accelerating and the fact that is not accelerating (and has not accelerated) so fast that galaxies, stars, and planets never form.
Or the value for Q, the “lumpiness” of the initial universe. Q is currently estimated at 1 in 100,000, meaning that the density of the initial universe at any point varies from the universe’s overall average value by only 1 part in 100,000. If that weren’t the case, if the lumpiness of the universe weren’t so well fine-tuned, we’d either get a very smooth, flat, universe with no galaxies, no stars, no planets, or one with all of its matter locked into incredibly massive objects (black holes).
Or just make it simple. A universe in which matter and anti-matter are symmetrical, where there is just as much of one as the other. In the very early, dense universe, they interact, they mutually annihilate. No matter left to make anything at all.
Lewis and Barnes don’t even stop there. They go on to more abstract contingencies in the nature of the universe, including orderliness itself. A universe without order is one in which there are no patterns, just randomness.
The best part of the book, for me, starts about two-thirds of the way through, where we get to the “So what?” discussion.
I’ve been aware of the fine-tuning problem since Barrow and Tipler’s 1986 book, The Anthropic Cosmological Principle (in fact, I'm putting this book next to that one on the shelf). At the time, it was hard to know how seriously to take the problem (much less the solutions that Barrow and Tipler floated). And that seemed true for the physics and cosmology worlds as well — it didn’t seem like a scientific problem so much as an invitation to wild speculation.
But the fine-tuning problem has grown up now, and both scientists and others do pay attention. It raises questions about the status of physical theory today, its scope, its future direction, and the proper scope and limits of scientific explanation.
Lewis and Barnes collect reactions they have experienced to the fine-tuning problem, both from scientific colleagues and non-scientist audiences, into “A Dozen (or So) Reactions to Fine-Tuning” in their chapter 7. Actually, since they designate the reactions by letters from “a” to “o”, there are definitely more than a dozen.
Those reactions vary from naturalistic to religious. They include reactions that I’ve played with myself, especially (a) “coincidence” — that the facts just are as they are, and they provide for complex, intelligent life, or else we wouldn’t be here to talk about it.
And (g) that all possible universes are, taken singly, unlikely, this one no more nor less than any of the others. One of them had to exist, and, no matter which, it would be an unlikely one.
And (j) — “life chauvinism,” that we bias our perspective to an investigation of the relationship between the constants and the development of creatures like ourselves, when we could just as well formulate a fine-tuning problem relating to any number of other things only possible in a universe like ours. Or, for that matter, if the universe was in fact entirely populated by black holes, wouldn’t that pose a fine-tuning problem itself (granted with no one to articulate it)?
Lewis and Barnes provide responses to all of these reactions, and even if they don’t always completely satisfy, they at least take the thinking deeper.
As for their own reactions, they aren’t offering a conclusion. As I said, they are more “at play” in the discussion than pushing a resolution. But they do have inclinations.
Lewis is sympathetic with a multiverse solution. In various multiverse theories, other values for those constants are realized, just in universes other than our own. The fact that we live in a universe hospitable to life like our own is not surprising — it couldn’t be otherwise. There is no coincidence, and no unlikely fine-tuning involved. There are many universes. Some are full of black holes. Some are endless expanses of thinly spread hydrogen atoms. And some, like ours, contain intelligent creatures.
There are certainly numerous multiverse theories out there, and Lewis cites cosmic inflation as one avenue to go down to explain the origins of multiple, non-interacting universes with differing constants. Note that not just any multiverse theory will do — Everettian multiverse (or “many worlds”) theory, for example, does not help, as it relies upon relatively standard quantum physics with established values for its constants.
You might object that using cosmic inflation to explain multiverse theory to explain fine-tuning is using something poorly understood to explain something even more poorly understood to explain the pretty much completely not-understood, but, hey, sometimes a Hail Mary is a good call.
Barnes seems to favor an extension of their response to reaction (a) — that “coincidence” is not an acceptable endpoint for theorizing. In the closing parts of their dialogue, Barnes says, “The moral: when a theory requires very precise but unexplained postulates to explain the data, it might be a clue. Perhaps we should be looking for a deeper theory in which the postulate is explained, or exists naturally.”
That is, what we lack is a more fundamental physics than what we have today. Yes, today the constants are unaccounted for facts, but there remains a “gap between the laws-as-we-know-them and the ultimate laws of nature.” Fine-tuning points toward the need for more fundamental, more ultimate theory.
The best thing about the book is its lack of conclusions. This is a topic ripe for speculation and creative thought. Scientists should do more of that. And they should, as Lewis and Barnes do from time to time, bring in concerns and insights from other disciplines, especially philosophical thought and, yes, even religious thought. Why not? Science has no monopoly on knowledge or insight.
As for readability, I have to say the book is uneven. Sometimes it flows easily — it doesn’t depend on formulas or mathematical sophistication, although some of that is there if you want to chase it. Conceptually, some topics, e.g., supersymmetry, are just complex, and you’re not going to come away understanding them if you didn’t come in already pretty well-equipped. But the whole doesn’t depend on the reader understanding every little piece of physics surveyed along the way.
Don’t worry about it. Just play.
June 11, 2017
Alternate history stories are popular. You take an established fact of history and ask a question: 'What If?' What if we changed some element of history? How would things be different? This book does something similar in the field of physics. It looks at our current understanding of the universe and asks the same question: 'What If?' What if the universe were expanding at a faster rate than it currently is? What would be the consequences for the universe (and by extension, what would be the consequences for you and me?) Would we even be around to note it? What if the universe were expanding at a slower rate than it currently is? What would happen then? Roughly the first two thirds of this book considers questions like that. What if the mass of the particles had been different? What if the the relative strength of the fundamental forces had been different? What if the initial conditions of the early universe had been different? After awhile, a picture begins to emerge. The universe exists in a very narrow range where life can flourish. If you were twiddling knobs to set the parameters for a hospitable universe in your universe building machine, you couldn't just spin them like the showcase showdown wheel on the Price Is Right and hope they land where you want them to. Every dial has to land in a specific place and so many things are dependent on so many other things that changing one thing over here affects three other things over there. Otherwise you have no galaxies, stars, planets, atoms, molecules and no life.
It is worth noting that this book may have a distinct advantage over other books on fine-tuning. The two authors are on different sides of the ideological fence, one being a theist and the other an atheist. Perhaps, like matter and anti-matter, the presence of one cancelled out any potential slanting of the facts by the other and we arrive at an objective assessment of the science. Indeed, the bulk of the book is just an assessment of the facts. It isn't until two thirds of the way into the book that we get to possible implications and explanations of fine-tuning. The second section of the book examines reactions to the idea that the universe is fine-tuned. The authors set the stage somewhat colourfully by describing the aftermath of talks they give at astronomy seminars:
'The fine-tuning for life is unique in our experience for the strength of the opinions expressed. In both popular and professional settings, disagreements often become noisy arguments. Even those who don't think fine-tuning means anything simply must explain enthusiastically to everyone, in great detail, why it doesn't mean anything.
Fine-tuning also evokes a terrific range of responses. Most of the audience agrees that this is an unusual kind of fact, and one that mustn't be allowed to ramble free and unexplained. It must be put firmly in its place, either in the service of some conclusion or quarantined away from all such conclusions.
The problem is that different members of the audience can't agree on its proper place. Our neat question-and-answer session following a talk devolves into a town hall meeting . Questions to the speaker are intercepted by the front row, defended on the left, heckled by the back row, and so on. We just light the fuse and enjoy the fireworks.'
Among those reactions:
It’s Just a Coincidence
We’ve Only Observed One Universe
Low-Probability Events Happen All the Time
Fine-Tuning Has Been Disproved By (Insert Name Here)
Evolution Will Find a Way
How Can the Universe Be ‘Fine-Tuned’ When It Is Mostly Inhospitable To Life?
This Universe Is Just As Unlikely As Any Other Universe
How Do We Know What Would Happen In Other Universes? Go Do the Experiment!
Fine-Tuners Turn Only One Dial at a Time
Life Chauvinism - Why Think That Life is Special?
We Don’t Even Have a Good Definition of Life
There Could Be Other Forms of Life
The Anthropic Principle Explains Our Existence
Whence the Possibilities?
Whence the Probabilities?
A final section takes the form of a socratic dialogue between the two authors where they discuss possible explanations of the fine-tuned universe: the universe just is, a deeper understanding of physics will provide an explanation, our universe is one among many such universes, some of which were not so fortunate as ours, God, and the possibility the universe is a simulation.
I suppose this might be the point at which some people might make an inference to the best explanation. I'll put my money on God. There are plenty enough things I can cast a critical eye over when it comes to the topic of God and things that lie beyond the realms of sensory data but this is not one of them. The vast number of coincidences needed for the universe to be here are.... well, I suppose a fitting adjective given the subject matter might be astronomical. I always come back to this same conclusion.
This book is well worth reading. A little bit of humour, a smattering of pop culture science fiction references, and a lot to digest. It also includes a further reading section divided up into popular and academic levels. It will probably give the interested reader something to think about no matter what their own opinions and beliefs on the matter are.
Last word to the authors: 'The message: messing with the make-up of the Universe can have a disastrous effect on the emergence of complex life like you and me, and especially the physical conditions that underlie life, such as usable energy and organic chemistry. Our conclusion is that the fundamental properties of the universe appear to be fine-tuned for life. We need a cosmos that expands not too fast and not too slow, that forms structure, with a mix of stable elements that can form stars, planets, and cells with the right mix of forces for stars to burn for billions of years, with plenty of carbon and oxygen, with a low-entropy past and free energy into the future, with a life-supporting number of dimensions, and even with mathematically elegant and discoverable laws.'
It is worth noting that this book may have a distinct advantage over other books on fine-tuning. The two authors are on different sides of the ideological fence, one being a theist and the other an atheist. Perhaps, like matter and anti-matter, the presence of one cancelled out any potential slanting of the facts by the other and we arrive at an objective assessment of the science. Indeed, the bulk of the book is just an assessment of the facts. It isn't until two thirds of the way into the book that we get to possible implications and explanations of fine-tuning. The second section of the book examines reactions to the idea that the universe is fine-tuned. The authors set the stage somewhat colourfully by describing the aftermath of talks they give at astronomy seminars:
'The fine-tuning for life is unique in our experience for the strength of the opinions expressed. In both popular and professional settings, disagreements often become noisy arguments. Even those who don't think fine-tuning means anything simply must explain enthusiastically to everyone, in great detail, why it doesn't mean anything.
Fine-tuning also evokes a terrific range of responses. Most of the audience agrees that this is an unusual kind of fact, and one that mustn't be allowed to ramble free and unexplained. It must be put firmly in its place, either in the service of some conclusion or quarantined away from all such conclusions.
The problem is that different members of the audience can't agree on its proper place. Our neat question-and-answer session following a talk devolves into a town hall meeting . Questions to the speaker are intercepted by the front row, defended on the left, heckled by the back row, and so on. We just light the fuse and enjoy the fireworks.'
Among those reactions:
It’s Just a Coincidence
We’ve Only Observed One Universe
Low-Probability Events Happen All the Time
Fine-Tuning Has Been Disproved By (Insert Name Here)
Evolution Will Find a Way
How Can the Universe Be ‘Fine-Tuned’ When It Is Mostly Inhospitable To Life?
This Universe Is Just As Unlikely As Any Other Universe
How Do We Know What Would Happen In Other Universes? Go Do the Experiment!
Fine-Tuners Turn Only One Dial at a Time
Life Chauvinism - Why Think That Life is Special?
We Don’t Even Have a Good Definition of Life
There Could Be Other Forms of Life
The Anthropic Principle Explains Our Existence
Whence the Possibilities?
Whence the Probabilities?
A final section takes the form of a socratic dialogue between the two authors where they discuss possible explanations of the fine-tuned universe: the universe just is, a deeper understanding of physics will provide an explanation, our universe is one among many such universes, some of which were not so fortunate as ours, God, and the possibility the universe is a simulation.
I suppose this might be the point at which some people might make an inference to the best explanation. I'll put my money on God. There are plenty enough things I can cast a critical eye over when it comes to the topic of God and things that lie beyond the realms of sensory data but this is not one of them. The vast number of coincidences needed for the universe to be here are.... well, I suppose a fitting adjective given the subject matter might be astronomical. I always come back to this same conclusion.
This book is well worth reading. A little bit of humour, a smattering of pop culture science fiction references, and a lot to digest. It also includes a further reading section divided up into popular and academic levels. It will probably give the interested reader something to think about no matter what their own opinions and beliefs on the matter are.
Last word to the authors: 'The message: messing with the make-up of the Universe can have a disastrous effect on the emergence of complex life like you and me, and especially the physical conditions that underlie life, such as usable energy and organic chemistry. Our conclusion is that the fundamental properties of the universe appear to be fine-tuned for life. We need a cosmos that expands not too fast and not too slow, that forms structure, with a mix of stable elements that can form stars, planets, and cells with the right mix of forces for stars to burn for billions of years, with plenty of carbon and oxygen, with a low-entropy past and free energy into the future, with a life-supporting number of dimensions, and even with mathematically elegant and discoverable laws.'
February 7, 2017
Rarely am I inclined to give a 5 star rating to a book, but, I believe this one is deserving. Lewis & Barnes provide an engaging introduction to the fine-tuning problem, providing coherent, yet simple explanations of some of the most persuasive examples. The authors are candid and intellectually honest, sharing their own doubts about fine-tuning and previously endorsed examples that ultimately didn't pan out. The ending chapters effectively summarized the data and surveyed several common rejoinders to fine-tuning with responses. The very end provides a surprisingly sophisticated (given the authors' stations as cosmologists) philosophical discussion on the impact of fine tuning in the teleological argument. The footnotes are absolute gems and the bibliography/reco reading is exemplary. My main complaints: the discussion on objective Bayesianism needed an additional 20 pages, the graphics had a hideous font, and Fig. 3 isn't a "Scheckmate".
4.8/5
4.8/5
July 23, 2022
The book deals with a fairly old problem in Physics, and to some extent, Philosophy. The problem is, why do we live in a universe which allows the existence of life and us? Since the beginning of modern science, it has been clear that a number of things have to be just so for a planet like earth to exist that can generate and nurture life. While the problem was always there, the details of the problem changed over time. Initially, many things seemed to be necessary to support life. As science progressed, we had fewer and fewer independent physical laws, and a cleaner and simpler picture of the universe was emerging. Today, most of the universe can be explained by a small number of generalized laws that can be written in just a few pages of mathematical equations. This is a remarkable achievement in just a few hundred years.
However, as the book explains, these laws depend upon a handful of numbers that cannot be predicted by our theories and must be measured in nature. The problem is, if we try to imagine slightly different values of these constants, we realize that the resulting universe cannot sustain any complex structures which are essential for life. In most cases, the resulting universes would not even have chemistry or even any elements beyond Hydrogen. This is known as the "fine tuning" problem. That is, why do we live in a universe where the values of these constants are in the tight regions that make life possible. Of course, there is the argument that had it not been so, then we would not have existed to ask this question. However, this anthropic argument is somehow aesthetically unpleasing.
There are many potential solutions, but the book tries to show why all of them either shift the problem rather than solve it, or are logically weak. In the end, it also discusses the theistic angle and discusses how the existence of a God could be one potential explanation. They also discussed some of the Matrix-like ideas where the universe we live in is just a numerical simulation.
What I found a little strange is the authors were completely dismissive of String Theory, which promises to offer a parameter-free theory of the universe. True, this theory got into a lot of problems and seems to be less promising than it initially looked. However, if we could come up with a theory that came close to it, why would we be so hopeless about other such theories. After all, String Theory is just a few decades old. Based on the tremendous success of modern Physics over the last 200 years, I think it is a little too hasty to give up on it after the first failure and go for entirely speculative alternatives such as God or a simulation.
However, if this topic interests you, this is the best book I have read that explores this problem thoroughly and in a balanced tone.
However, as the book explains, these laws depend upon a handful of numbers that cannot be predicted by our theories and must be measured in nature. The problem is, if we try to imagine slightly different values of these constants, we realize that the resulting universe cannot sustain any complex structures which are essential for life. In most cases, the resulting universes would not even have chemistry or even any elements beyond Hydrogen. This is known as the "fine tuning" problem. That is, why do we live in a universe where the values of these constants are in the tight regions that make life possible. Of course, there is the argument that had it not been so, then we would not have existed to ask this question. However, this anthropic argument is somehow aesthetically unpleasing.
There are many potential solutions, but the book tries to show why all of them either shift the problem rather than solve it, or are logically weak. In the end, it also discusses the theistic angle and discusses how the existence of a God could be one potential explanation. They also discussed some of the Matrix-like ideas where the universe we live in is just a numerical simulation.
What I found a little strange is the authors were completely dismissive of String Theory, which promises to offer a parameter-free theory of the universe. True, this theory got into a lot of problems and seems to be less promising than it initially looked. However, if we could come up with a theory that came close to it, why would we be so hopeless about other such theories. After all, String Theory is just a few decades old. Based on the tremendous success of modern Physics over the last 200 years, I think it is a little too hasty to give up on it after the first failure and go for entirely speculative alternatives such as God or a simulation.
However, if this topic interests you, this is the best book I have read that explores this problem thoroughly and in a balanced tone.
September 8, 2019
This is a great book! It’s insane the way the universe works, isn’t it? So I’m not a particle physicist and the last physics I leaned was >15 years ago. As a result it was a slow read as I absorbed the universe-worth of info. But the little jokes and funny footnotes the authors threw in made it so much more enjoyable. My main complaint is the philosophical discussion at the end; not so much its presence or even the arguments the authors were making but the format as a scripted conversation. A page or two like that is ok but this went on a long time and for me was very distracting. As a result the most difficult part of the book for me to process was made harder and it became a bit of a chore to get through. Overall it was so informative and so fun that I highly recommend to all with even a passing interest in the universe and the reasons for its existence in this way.
August 6, 2017
About two-third physics and chemistry. Carbon, neutrinos, inflation in the early universe, what Albert Einstein thought was his biggest mistake, what would make a universe dull, and more. All discussing what tweaking the free parameters would do to this universe and life in it. Much clarification of the Weak and Strong Anthropic Principles.
And then discussing questions this would raise, including the philosophical ones.
And then discussing questions this would raise, including the philosophical ones.
December 8, 2016
Here I sit, on the surface of this small rocky planet, the result of a cosmic gamble that makes winning EuroMillions look like a dead certainty. Daydreaming about 'a theory of everything', from which the Universe will emerge fully formed.
April 16, 2020
“Well, that escalated quickly. I mean, that really got out of hand fast. We were just wondering what would happen if the Universe were different. We ended up wandering through most of physics and cosmology, stopped by probability theory, dipped into mathematics, stumbled inexpertly through some philosophy, and even tried to put a multiverse in a computer.”
This had to have been a difficulty book to write, and I think the above quote from the final chapter sums it up well (including the Anchorman quote, which gives an idea of the humor the authors weave in at every opportunity, sometimes to better effect than others). How does one decide how much technical knowledge is necessary for a lay audience to appreciate what “fine-tuning” means, without losing most of them in the process? Every chapter seemed to cover an incredible amount of material while still only barely scratching the surface of the theories involved. The fact that the book is coherent at all under those circumstances is pretty remarkable. In fact, it’s pretty good and readable, largely because the authors realize this is an introduction to fine-tuning rather than the final word on the subject. In that vein, they’ve included copious recommendations for further reading as well as a long list of references.
This book contains more than technical material, however. The best part, in my opinion, is the discussion between the authors (framed as a dialogue) introducing the topic, and later summarizing and thinking about how to go about explaining the phenomena we observe. And it’s great - it’s clear for example that one of the authors is convinced that theism is the ultimate explanation of fine-tuning, while the other is not. And yet the dialogue is respectful, thought-provoking, and humble.
I’d recommend for anyone who wants to know more about the scientific evidence for fine-tuning in the Universe.
This had to have been a difficulty book to write, and I think the above quote from the final chapter sums it up well (including the Anchorman quote, which gives an idea of the humor the authors weave in at every opportunity, sometimes to better effect than others). How does one decide how much technical knowledge is necessary for a lay audience to appreciate what “fine-tuning” means, without losing most of them in the process? Every chapter seemed to cover an incredible amount of material while still only barely scratching the surface of the theories involved. The fact that the book is coherent at all under those circumstances is pretty remarkable. In fact, it’s pretty good and readable, largely because the authors realize this is an introduction to fine-tuning rather than the final word on the subject. In that vein, they’ve included copious recommendations for further reading as well as a long list of references.
This book contains more than technical material, however. The best part, in my opinion, is the discussion between the authors (framed as a dialogue) introducing the topic, and later summarizing and thinking about how to go about explaining the phenomena we observe. And it’s great - it’s clear for example that one of the authors is convinced that theism is the ultimate explanation of fine-tuning, while the other is not. And yet the dialogue is respectful, thought-provoking, and humble.
I’d recommend for anyone who wants to know more about the scientific evidence for fine-tuning in the Universe.
February 20, 2019
This is an excellent book. I believe it is the best book on fine tuning and cosmology that I have ever read. In my view it completely displaces Hawking’s “A Brief History of Time”. The two authors provide an excellent balance to the arguments. They go out of their way not to push a philosophical agenda (neither theism nor atheistic naturalism). The Physics was beautiful and enjoyable to read. Then at the end of the book the two authors, who at least pretend to be a theist and an atheist, discuss the philosophical ramifications of fine tuning, including topics such as the multiverse and God. The give and take of the authors were pleasant and respectful. I can recommend this book to anyone who is interested in cosmology and fine tuning.
June 4, 2017
A scientific viewpoint of the fine-tuning of the laws of science, and its implications for the inner workings of the Universe are examined. The Universe is a beautiful place, but we have no idea why we are here. The existence of life in our Universe is a suspicious fact. It requires a range of precise coincidences. Science cannot state that we are insignificant since there isn't a telescope that measures importance. While science offers a hierarchy of explanation, the anthropic principle doesn’t explain why a life-permitting universe exists. One aspect of our laws that looks particularly incomplete is the presence of numbers – free parameters – in the equations themselves and in the solutions to these equations. The argument from design, or teleological, argument is part of the Western philosophical tradition, and is one of a host of arguments for the existence of God.
July 31, 2020
The trouble with books of this ilk is that I barely follow the science. Based on Lewis and Barnes's argument, I feel confident enough to at least say this. The appearance of design (fine tuning) is strong enough, and the counterarguments are bizarre enough, that I'm skeptical of the skeptics. When you consider how much had to go incomprehensibly perfect for us to even exist to ponder it, the smart money is with design.
January 31, 2019
If you're in the tiniest bit interested in a few things that keep the coauthors up at night, then go ahead and read it. You won't be disappointed.
March 24, 2021
I was promised that this is a "witty" book, and I suppose if the reader is 12 years old then indeed the puerile "wit" meets that lowly standard.
The writers stated the facts correctly within a few pages at the start of the book, and then spiraled out of control for the rest of the book; the universe is *NOT* "fined tuned for life," and the writers correctly explained why... and then offered bizarre and unnecessary guesses at why the universe appears "fine tuned for life." The self-contradiction is more then a little creepy.
This universe has been "fine tuned" for atoms to exist, not life; some particle physicists have concluded that there are an infinite number of similar universes, as well as a larger infinity of other universes. Every universe that exists will appear "fine tuned" *BECAUSE* they exist: if a universe has similar atoms than this universe, they will evolve life: atoms behave exactly the same if they are the same type of atoms regardless of the universe they are in.
The book included occult superstition as one of its topics to explain "why" he/they believes this universe is "fine tuned." That appears to be the only "evidence" presented--- a mere opinion based upon emotion and his bizarre desire to believe this universe is "fine tuned."
We observe other universes attached to this one (i.e., black holes); we observe matter and energy coming into this universe from its parent universe. We do not observe any evidence that this universe is "fine tuned for life" because we only observe life in one universe.
An intelligent person would have known this.
The writers stated the facts correctly within a few pages at the start of the book, and then spiraled out of control for the rest of the book; the universe is *NOT* "fined tuned for life," and the writers correctly explained why... and then offered bizarre and unnecessary guesses at why the universe appears "fine tuned for life." The self-contradiction is more then a little creepy.
This universe has been "fine tuned" for atoms to exist, not life; some particle physicists have concluded that there are an infinite number of similar universes, as well as a larger infinity of other universes. Every universe that exists will appear "fine tuned" *BECAUSE* they exist: if a universe has similar atoms than this universe, they will evolve life: atoms behave exactly the same if they are the same type of atoms regardless of the universe they are in.
The book included occult superstition as one of its topics to explain "why" he/they believes this universe is "fine tuned." That appears to be the only "evidence" presented--- a mere opinion based upon emotion and his bizarre desire to believe this universe is "fine tuned."
We observe other universes attached to this one (i.e., black holes); we observe matter and energy coming into this universe from its parent universe. We do not observe any evidence that this universe is "fine tuned for life" because we only observe life in one universe.
An intelligent person would have known this.
June 1, 2024
A PRESENTATION OF THE SCIENTIFIC VIEWPOINT FOR “FINE-TUNING” OF THE LAWS OF SCIENCE
The authors wrote in the Preface to this 2016 book, “over the past few centuries, we’ve come to discover how we came to be so nicely suited to conditions on Earth. Our physical properties… result from life continually changing and evolving over the pas 3.5 billion years, adapting to the conditions that surround us. The realization that the Earth is not unique changes our view of our place in the Universe… we have found that … the Earth is just one of a myriad of planets, and the Sun is but a boringly typical star. Our place in the Universe is… in no way unique. [But] Peering more deeply… [and] examining the basic make-up of the Universe, reveals that we are not as mediocre as it seems. The fundamental particles from which everything is constructed, and the fundamental forces that dictate interactions, appear to be fine-tuned for life… At every level, we find that our Universe’s ability to create and sustain life forms is rare and remarkable… The goal of this book is to present the scientific viewpoint of the fine-tuning of the laws of science, and delve into its implications for the inner workings of the Universe.”
In the first chapter, they note, “we can ask hypothetical questions about the Universe. Specifically, how different would the Universe have been if it were born with a different set of fundamental properties? These hypothetical universes may not be significantly different form our own, and so we could guess that they too would be hospitable to human life. Or they could be radically different, but still allow an alternative form of life. But what if almost all of the possible universes are sterile, with conditions too simple or extreme for life of any conceivable type to arise? Then we are faced with a conundrum. Why, in the almost infinite sea of possibilities, was our Universe born with the conditions that allow life to arise? That is the subject of this book.” (Pg. 1-2)
They state, “So far as we know, there are many ways that the Universe could have been born… The wealth of free energy we have from our low-entropy start is quite surprising given what could have been. We should keep asking: why?... it is important to realize that it is not only the fundamental properties of the physical laws… that are finely balanced. Thanks to the ultimate dose of beginner’s luck, our Universe was endowed with ample free energy for driving the processes that allowed us to be here. The question of fine-tuning applies not only to the cosmos we see around us, but also to whatever would up the clockwork of the Universe in the first place.” (Pg. 128) They add, “With so many potential ways the Universe could have been, we cannot ignore the apparent specialness of our existence. So what are we to make of this?” (Pg. 236)
About the claim that recent scientists have debunked the notion of fine-tuning, they comment, “[The] calculations have bene refined using cutting-edge models and methods. Sometimes, new options for life have opened up, and sometimes life has turned out to be more fine-tuned than previously thought. On balance, the fine-tuning of the Universe for life has stood up well under the scrutiny of physicists.” (Pg. 241)
About the possibility of other forms of life, they argue, “The discovery of other possible forms of life is not enough to overturn fine-tuning. We would need to discover alternative forms of life that could exist in any old universe including the vast wasteland what we discarded as uninhabitable. No such forms of life have been proposed. Furthermore, if life is so easy, why does life as we know it rely on such extraordinarily complicated organic chemistry?” (Pg. 267)
They say of the Multiverse hypothesis, “the multiverse… cannot be directly detected. If the multiverse exists, we will never get information from the other universes. They could all disappear tomorrow and we’d never know… Also, the pieces borrowed from modern physics aren’t particularly secure. While inflation has made successful predictions, its mechanism is not known… there is zero experimental evidence for string theory and even less for the string theory landscape. The theory is so difficult that few of its predictions are secure.” (Pg. 321)
They present a “dialogue” between “Geraint” and “Luke”: “[Luke:] theism postulates that God created and sustains the universe in a way that is consistent, rational and discoverable. Discovering those laws allows us to understand and even predict physical phenomena… God is not presented here as a competitor to any scientific theory. Theism’s rival is naturalism, not science, and theism offers an explanation where naturalism offers NONE… So the success of science looks the same on naturalism and theism. The ultimate laws of nature are just as contingent on both, given the great mathematical morass of possible laws… The success of science is not the success of naturalism. The predictions of naturalism are not the predictions of science.” (Pg. 336-337)
“Luke” adds: “physicists have considered the consequences of varying the values of these parameters. The result is often swift disaster: seemingly small changes in the parameters lead to … detrimental changes in a universe’s ability to create and support the complexity needed by life… all this talk of the ultimate laws of nature and the deepest level of explanation that science can hope to provide sends us toward some famously ‘big’ questions: why does anything at all exist?... According to naturalism, these questions are unanswerable---you’ll just have to convince yourself that you didn’t REALLY want an answer anyway. According to theism, a PERFECT being can answer those deep questions. Its necessary existence explains why anything exists.” (Pg. 353)
“Geraint” replies, “I think I still stick with the multiverse. Our is but one of a vast sea of universes, and each with differing laws of physics and properties of matter, set at their birth through some cosmic roll of the dice. As we have seen, almost all of these universes are sterile, empty or soon-to-collapse. But, of course, we find ourselves in one of the extremely few universes that can support life---the anthropic principle in action.” (Pg. 353-354)
This is an interesting presentation of the evidence for “fine-tuning,” that will be of great interest to those studying the topic.
The authors wrote in the Preface to this 2016 book, “over the past few centuries, we’ve come to discover how we came to be so nicely suited to conditions on Earth. Our physical properties… result from life continually changing and evolving over the pas 3.5 billion years, adapting to the conditions that surround us. The realization that the Earth is not unique changes our view of our place in the Universe… we have found that … the Earth is just one of a myriad of planets, and the Sun is but a boringly typical star. Our place in the Universe is… in no way unique. [But] Peering more deeply… [and] examining the basic make-up of the Universe, reveals that we are not as mediocre as it seems. The fundamental particles from which everything is constructed, and the fundamental forces that dictate interactions, appear to be fine-tuned for life… At every level, we find that our Universe’s ability to create and sustain life forms is rare and remarkable… The goal of this book is to present the scientific viewpoint of the fine-tuning of the laws of science, and delve into its implications for the inner workings of the Universe.”
In the first chapter, they note, “we can ask hypothetical questions about the Universe. Specifically, how different would the Universe have been if it were born with a different set of fundamental properties? These hypothetical universes may not be significantly different form our own, and so we could guess that they too would be hospitable to human life. Or they could be radically different, but still allow an alternative form of life. But what if almost all of the possible universes are sterile, with conditions too simple or extreme for life of any conceivable type to arise? Then we are faced with a conundrum. Why, in the almost infinite sea of possibilities, was our Universe born with the conditions that allow life to arise? That is the subject of this book.” (Pg. 1-2)
They state, “So far as we know, there are many ways that the Universe could have been born… The wealth of free energy we have from our low-entropy start is quite surprising given what could have been. We should keep asking: why?... it is important to realize that it is not only the fundamental properties of the physical laws… that are finely balanced. Thanks to the ultimate dose of beginner’s luck, our Universe was endowed with ample free energy for driving the processes that allowed us to be here. The question of fine-tuning applies not only to the cosmos we see around us, but also to whatever would up the clockwork of the Universe in the first place.” (Pg. 128) They add, “With so many potential ways the Universe could have been, we cannot ignore the apparent specialness of our existence. So what are we to make of this?” (Pg. 236)
About the claim that recent scientists have debunked the notion of fine-tuning, they comment, “[The] calculations have bene refined using cutting-edge models and methods. Sometimes, new options for life have opened up, and sometimes life has turned out to be more fine-tuned than previously thought. On balance, the fine-tuning of the Universe for life has stood up well under the scrutiny of physicists.” (Pg. 241)
About the possibility of other forms of life, they argue, “The discovery of other possible forms of life is not enough to overturn fine-tuning. We would need to discover alternative forms of life that could exist in any old universe including the vast wasteland what we discarded as uninhabitable. No such forms of life have been proposed. Furthermore, if life is so easy, why does life as we know it rely on such extraordinarily complicated organic chemistry?” (Pg. 267)
They say of the Multiverse hypothesis, “the multiverse… cannot be directly detected. If the multiverse exists, we will never get information from the other universes. They could all disappear tomorrow and we’d never know… Also, the pieces borrowed from modern physics aren’t particularly secure. While inflation has made successful predictions, its mechanism is not known… there is zero experimental evidence for string theory and even less for the string theory landscape. The theory is so difficult that few of its predictions are secure.” (Pg. 321)
They present a “dialogue” between “Geraint” and “Luke”: “[Luke:] theism postulates that God created and sustains the universe in a way that is consistent, rational and discoverable. Discovering those laws allows us to understand and even predict physical phenomena… God is not presented here as a competitor to any scientific theory. Theism’s rival is naturalism, not science, and theism offers an explanation where naturalism offers NONE… So the success of science looks the same on naturalism and theism. The ultimate laws of nature are just as contingent on both, given the great mathematical morass of possible laws… The success of science is not the success of naturalism. The predictions of naturalism are not the predictions of science.” (Pg. 336-337)
“Luke” adds: “physicists have considered the consequences of varying the values of these parameters. The result is often swift disaster: seemingly small changes in the parameters lead to … detrimental changes in a universe’s ability to create and support the complexity needed by life… all this talk of the ultimate laws of nature and the deepest level of explanation that science can hope to provide sends us toward some famously ‘big’ questions: why does anything at all exist?... According to naturalism, these questions are unanswerable---you’ll just have to convince yourself that you didn’t REALLY want an answer anyway. According to theism, a PERFECT being can answer those deep questions. Its necessary existence explains why anything exists.” (Pg. 353)
“Geraint” replies, “I think I still stick with the multiverse. Our is but one of a vast sea of universes, and each with differing laws of physics and properties of matter, set at their birth through some cosmic roll of the dice. As we have seen, almost all of these universes are sterile, empty or soon-to-collapse. But, of course, we find ourselves in one of the extremely few universes that can support life---the anthropic principle in action.” (Pg. 353-354)
This is an interesting presentation of the evidence for “fine-tuning,” that will be of great interest to those studying the topic.
July 8, 2020
This is a lot of fun if you like astrophysics. Lewis and co-author Luke Barnes examine every detail of the universe from the tiniest particles and forces to the most massive and powerful, and scramble all the dials on the numbers of the constants that exist in our universe (atomic weights, the magnitude of a force) to examine how rare it is that a universe exists that supports intelligent observers (humans). Turns out, even minor alterations to fixed constants in our universe yield universes that cannot sustain life. The last section of the book is a dialogue between Lewis and Barnes about the meaning of this apparent fine tuning. Is it merely "a brute fact" of naturalism that we are here? Is our universe one of billions in a multiverse, each of those universes with different "readings" on the cosmological constant dials. Is the universe a computer simulation run by some super-intelligent teenager in yet another universe? Or is it fine tuned because a good God designed it that way? The authors don't agree on the answer, which makes this a richer read. Also, many of the footnotes are informative, and others are hilarious. The authors had as much fun writing this book as I had reading it.
November 30, 2016
Luke Barnes has always been my go-to-guy on the concept of the fine-tuning of the universe, and having read his previous papers on the issue, especially those refuting Stenger, I was particularly looking forward to this. Barnes and Lewis discuss the issue of fine-tuning for the lay reader for most of the books, making apt use of analogies in order to hammer home that the universe IS fine tuned for life, and in the last section, Barnes, the Christian, and Lewis, the atheist, settle down for discussion of WHY there is fine tuning. Both put forward their case with respect for the other's point of view, which is something I rarely see nowadays. In the end, I felt Barnes had the better case, but Lewis' idea of the universe being born into lumps of matter that spread out with each lump having different laws (with some vanishing and some expanding too fast for stars to form), was an interesting one. It effectively meant the multiverse is comprised of PARTS of the initial universe-creating event. They do not agree in the end, but end on a cordial note. If only all argument ended that way...
December 31, 2016
About the Authors
Geraint F. Lewis is a Professor of Astrophysics and head of the Gravitational Astrophysics Group at the Sydney Institute for Astronomy, part of the University of Sydney’s School of Physics. Luke A. Barnes is a postdoctoral researcher at the Sydney Institute for Astronomy, University of Sydney, where his focus is on cosmology, galaxy formation, and the fine-tuning of the Universe for life. Given the authors’ education, present research, public engagements and sharp interest in the subject of the Universe’s fine-tuning for life, they are well qualified to dig into deciphering the laws of nature and initial conditions of the Universe. Lewis, admittedly, first took on the challenge of writing this book out of a long-held desire to pen one. Lewis invited Barnes to be his co-author, an appropriate choice given the latter’s keen interest in cosmological fine-tuning. Being heavily invested in cosmology, the authors are motivated to set forth a coherent exposition of the Universe’s fine-tuning for life, all the while supplying the reader with valuable lessons on the most up to date physics.
Summary
What would happen if one were to tinker with the properties of the fundamental particles from which everything is constructed or the fundamental forces that dictate physical interactions? The surprising answer is that it would leave the Universe dead and sterile. In A Fortunate Universe, Lewis and Barnes seek “to present the scientific viewpoint of the fine-tuning of the laws of science, and delve into its implications for the inner workings of the Universe.” The authors note that far from getting closer to resolving the question of fine-tuning as cosmological research advances, the problem only grows in magnitude and complexity. This “elephant in the room” draws interest not only from cosmologists, but philosophers, theologians, physicists of all types and even regular Janes and Joes not directly involved in academia. It is to this mystery that Lewis and Barnes direct their efforts, a mystery that points to a deeper question, “Why are we here?”
A Fortunate Universe consists of eight chapters divided roughly into three sections. Chapter 1 (“A Conversation on Fine-Tuning”) sets the stage for the topic of the book in which following chapters give a detailed explanation and discussion. Chapters 2-6 (“I’m Only Human!”, “Can You Feel the Force?”, “Energy and Entropy”, “The Universe Is Expanding”, and “All Bets Are Off!”) form its scientific grounding from which the current idea of the Universe as finely-tuned is derived. Chapters 7 and 8 (“A Dozen (or So) Reactions to Fine-Tuning” and “A Conversation Continued”) present the common reactions as well as the authors’ favorite explanations as to the mystery of why the Universe’s conditions are just right so as to allow such amazing complexity, including life. The following contains a more detailed summary of the material contained in A Fortunate Universe.
Part I: What is Fine-Tuning?
The 20th century witnessed the unveiling of much of the Universe’s fundamental forces and building blocks. While there is admittedly a lot left undiscovered, there has emerged a question that looms large over science in general and the work of physicists in particular, “Why, in the almost infinite sea of possibilities, was our Universe born with the conditions that allow life to arise?” It is to this issue the book is devoted.
In chapter one Lewis and Barnes state that fine-tuning is “a technical term borrowed from physics, and refers to the contrast between a wide range of possibilities and a narrow range of a particular outcome or phenomenon.” It implies “a sensitivity of an outcome to some input parameters or assumptions.” Fine-tuning for life is a subset of the above physics fine-tuning in which the outcome is life. The fine-tuning for life problem is “the realization that if the laws of physics were different, even just by a little bit, life would not exist.”
Part II: How is the Universe Fine-Tuned?
Chapter two features the authors taking the reader down in scale from that of the human body to the level of protons, neutrons, and electrons. As one digs deeper into the smaller details of life, “biology becomes chemistry and chemistry becomes physics . . . .” Lewis and Barnes state, “The secrets of life were laid bare by molecular biology. Molecular machinery churns and grinds within every one of us.” Beneath the atoms (which compose molecules) lie the even smaller fundamental particles such as the individual types of quarks and leptons. Playing with their properties, like small changes in their mass, would prove disastrous to the Universe. “Their properties might seem like mere textbook technicalities, and yet their role in how the Universe plays out is enormous. The smallest ingredients of the universe dramatically affect its bigger structures, especially the chemistry of life.”
The fundamental forces of nature are addressed in chapter three. In the Universe, there are merely four forces: the strong nuclear force, the weak nuclear force, electromagnetism, and gravity. What if one were to change the values of these forces? “With some tweaking of the free parameters of the Standard Model of particle physics, we could create a universe in which there was no energy gap between chemical and nuclear. If you left your cake in the oven for too long, you might end up with a burnt cake, or you might end up with a lump of lead.” The relative power and number of forces in the Universe are just so as to provide the stability to allow the life and the existence of a variety of elements and chemical interactions.
In chapter four, Lewis and Barnes discuss “the other principles that animate life in the Universe: energy and entropy.” Life needs energy to operate, and it needs energy in a useful form. “A system with low entropy has energy that can be extracted and converted into another form. By contrast, the energy of high-entropy systems is stuck, unable to be tapped.” The Universe started with an amazingly low amount of entropy which carried with it a treasure trove of free energy. It could have started in many ways that entailed a high entropy state; instead, the “Universe was endowed with ample free energy for driving the processes that allowed us to be here.” The question naturally follows: why?
The focus of the story in chapter five is zoomed out to the entirety of the Universe itself. When we do, we find a scandal: “[t]he mathematical structure of cosmology is deceptively simple!” As to the energy content of the Universe, it appears to be fine-tuned. “If our Universe had had a differing mixture of dark energy and matter to the one we observe, its evolutionary history would have been dramatically different. With dark energy, a universe is rather easy to ruin.” Not only is the mixture of matter and energy in the Universe “just right,” so is the (effective) cosmological constant; if its value were a little higher or a little lower, the Universe would lose its underlying structure and order.
Chapter six features the authors considering a change not in the constants of nature or initial state of the Universe as in the previous chapters but in the laws of nature themselves. Quantum mechanics influences only the very small, stabilizing atoms, while everything larger is predictable - something one needs for life in order to store and process information. If, for example, the scale of activity for quantum mechanics were larger there would not be the predictability and order to allow for life forms. As another thought experiment, what if our Universe was without symmetry, and so without conservation laws? It “would be chaos. There would be no simple laws to be discovered beneath the complex events around us.” On the other hand, what if there were no matter/antimatter asymmetry? In that case, “our Universe would be nothing but a cooling sea of radiation, completely devoid of the particles that make nuclei and atoms. This is a wonderfully clear case of a life-prohibiting universe - there’s no structure at all!” Similarly, if the Universe had a different number of spatial and temporal dimensions, “the prospect for complex life arising would have been severely diminished if not downright impossible.” To sum up, the laws of nature in the Universe “reflect the order and stability that allow life to exist.”
Part III: Why is the Universe Fine-Tuned?
Over years of presenting on the topic of cosmic fine-tuning, Lewis and Barnes have encountered many common and (despite the passion evoked) misguided reactions. These are as follows:
It’s Just a Coincidence
We’ve Only Observed One Universe
Low-Probability Events Happen All the Time
Fine-Tuning Has Been Disproved By (Insert Name Here)
Evolution Will Find a Way
How Can the Universe Be ‘Fine-Tuned’ When It Is Mostly Inhospitable To Life?
This Universe Is Just As Unlikely As Any Other Universe
How Do We Know What Would Happen In Other Universes? Go Do the Experiment!
Fine-Tuners Turn Only One Dial at a Time
Life Chauvinism - Why Think That Life is Special?
We Don’t Even Have a Good Definition of Life
There Could Be Other Forms of Life
The Anthropic Principle Explains Our Existence
Whence the Possibilities?
Whence the Probabilities?
The above objections are dealt with fairly easily in chapter seven, while the more plausible explanations are left for the eighth chapter.
In their final chapter, the authors give what they take to be the more robust potential explanations for the fine-tuning of the Universe. The first, the so-called “Lady Gaga Defence,” is to say “the Universe just is and that’s all there is to it,” but that’s more like ignoring the question than answering it. The second is that we just need more and deeper knowledge of the physics of the Universe, but even the existence of unknown theories that simplify physics cannot discount the fact that the Universe is fine-tuned for life. What about the Multiverse theory? Maybe the Universe is not unique after all. Nevertheless, the Multiverse theory itself has major hurdles to overcome such as the problem of Boltzmann Brains and lack of any empirical support. What if the answer is beyond the limits of scientific study? God as creator would account for the existence of life in the Universe, because He would have intended it that way. Another strength of this answer is that it’s not an ad hoc explanation to the problem of fine-tuning; the nature of God and His role as creator and designer of the Universe have been studied, critiqued and discussed for over a millennia. While Barnes favors this explanation, Lewis does not, proposing the possibility of a “Simulated Universe.” What if the Universe is fine tuned because it was programmed to be that way? This last option is more plausible to Lewis than Barnes. In the end, what cannot be denied is that our Universe is incredibly fine-tuned for life.
Evaluation
Strengths
There is much to say in favor of A Fortunate Universe. While learning about the fine-tuning of the Universe for life, the reader is provided with a basic primer on current physics - something I found invaluable. The authors are cosmologists and have interacted with their subject at length; thus, the story they tell is credible. Additionally, Lewis and Barnes do well to make the content interesting and readable via use of the mode of dialogue as well as occasional humor. My favorite line (rather timely given the release of the new Star Wars movies this month and last year) was made in the context of variations of life as we know it: “Chewbacca, while adorable, is a combination of a human, a dog, and a crossbow.” This gave me a chuckle, and similar comedic prose tends to keep readers engaged.
The authors are to be commended for not only giving robust and detailed evidence in favor of cosmological fine-tuning but also for addressing the most common objections and discussing the most plausible explanations. In other words, their treatment of the “why” question was handled in a fair, honest and thorough manner. Perhaps because the writers themselves represent differing worldviews, no favoritism is shown toward an atheistic or theistic reading of the evidence. All options are laid on the table for examination.
Robin Collins of Messiah College lays his finger on another aspect of A Fortunate Universe that is praiseworthy. He opines that the book “is among the two most philosophically sophisticated treatments” of the fine-tuning of the Universe. I must agree with Collins that the authors do not stumble (as many writers from the same profession do) amongst the hills and valleys of philosophical discourse. Finally, it must be mentioned that the diagrams and visual maps provided were of great benefit to my comprehension of the more heady concepts in physics. To anyone not well-versed in modern physics, these visual aids were essential and most welcome.
Weaknesses
What may be said by way of critique about A Fortunate Universe? The helpful use of visual aids and the writing style of dialogue might have been expanded. As to the latter, the back and forth between the two writers was a little “canned,” yet this kept the discussion civil and instructive. I found Lewis’ response to Barnes’ argument for God as the explanation for fine-tuning to be somewhat weak, but (in Lewis’ defense) it is a common and probably the strongest possible counterargument. As discovered from perusing other book reviews of A Fortunate Universe, there are skeptics of theism who strongly disagree with the conclusions reached in this book concerning the fine-tuning of the Universe for life, but their objections more likely reveal a weakness in their underlying belief system than in the tightly logical reasoning of the authors.
Goal Achievement
The authors’ thesis is chiefly that our Universe is finely-tuned for life. To this end a veritable mountain of evidence is provided. Lewis and Barnes make a slam-dunk case for the incredible preciseness of the laws of nature and initial conditions of the Universe so as to allow not only beauty and complexity but life itself. As such, the authors have succeeded in proving their thesis and opening up for conversation the question of why this is so.
Recommendation
A Fortunate Universe draws conclusions that affect a broad audience, namely everyone, yet its technical nature would be a bit daunting for most. However, for philosophers, theologians, scientists, and even untrained science enthusiasts, this book is not only helpful and engaging but, I would say, a necessary read. The big question of “Why are we here?” receives support as being valid from the scientific data presented in this book that our Universe is especially fit for life. As far as presenting thorough evidence and carefully crafted argumentation, A Fortunate Universe surpasses many others of the science genre. Hence, I recommend this book to those particularly fascinated by cosmological fine-tuning as well as those interested generally in science or religion.
Geraint F. Lewis is a Professor of Astrophysics and head of the Gravitational Astrophysics Group at the Sydney Institute for Astronomy, part of the University of Sydney’s School of Physics. Luke A. Barnes is a postdoctoral researcher at the Sydney Institute for Astronomy, University of Sydney, where his focus is on cosmology, galaxy formation, and the fine-tuning of the Universe for life. Given the authors’ education, present research, public engagements and sharp interest in the subject of the Universe’s fine-tuning for life, they are well qualified to dig into deciphering the laws of nature and initial conditions of the Universe. Lewis, admittedly, first took on the challenge of writing this book out of a long-held desire to pen one. Lewis invited Barnes to be his co-author, an appropriate choice given the latter’s keen interest in cosmological fine-tuning. Being heavily invested in cosmology, the authors are motivated to set forth a coherent exposition of the Universe’s fine-tuning for life, all the while supplying the reader with valuable lessons on the most up to date physics.
Summary
What would happen if one were to tinker with the properties of the fundamental particles from which everything is constructed or the fundamental forces that dictate physical interactions? The surprising answer is that it would leave the Universe dead and sterile. In A Fortunate Universe, Lewis and Barnes seek “to present the scientific viewpoint of the fine-tuning of the laws of science, and delve into its implications for the inner workings of the Universe.” The authors note that far from getting closer to resolving the question of fine-tuning as cosmological research advances, the problem only grows in magnitude and complexity. This “elephant in the room” draws interest not only from cosmologists, but philosophers, theologians, physicists of all types and even regular Janes and Joes not directly involved in academia. It is to this mystery that Lewis and Barnes direct their efforts, a mystery that points to a deeper question, “Why are we here?”
A Fortunate Universe consists of eight chapters divided roughly into three sections. Chapter 1 (“A Conversation on Fine-Tuning”) sets the stage for the topic of the book in which following chapters give a detailed explanation and discussion. Chapters 2-6 (“I’m Only Human!”, “Can You Feel the Force?”, “Energy and Entropy”, “The Universe Is Expanding”, and “All Bets Are Off!”) form its scientific grounding from which the current idea of the Universe as finely-tuned is derived. Chapters 7 and 8 (“A Dozen (or So) Reactions to Fine-Tuning” and “A Conversation Continued”) present the common reactions as well as the authors’ favorite explanations as to the mystery of why the Universe’s conditions are just right so as to allow such amazing complexity, including life. The following contains a more detailed summary of the material contained in A Fortunate Universe.
Part I: What is Fine-Tuning?
The 20th century witnessed the unveiling of much of the Universe’s fundamental forces and building blocks. While there is admittedly a lot left undiscovered, there has emerged a question that looms large over science in general and the work of physicists in particular, “Why, in the almost infinite sea of possibilities, was our Universe born with the conditions that allow life to arise?” It is to this issue the book is devoted.
In chapter one Lewis and Barnes state that fine-tuning is “a technical term borrowed from physics, and refers to the contrast between a wide range of possibilities and a narrow range of a particular outcome or phenomenon.” It implies “a sensitivity of an outcome to some input parameters or assumptions.” Fine-tuning for life is a subset of the above physics fine-tuning in which the outcome is life. The fine-tuning for life problem is “the realization that if the laws of physics were different, even just by a little bit, life would not exist.”
Part II: How is the Universe Fine-Tuned?
Chapter two features the authors taking the reader down in scale from that of the human body to the level of protons, neutrons, and electrons. As one digs deeper into the smaller details of life, “biology becomes chemistry and chemistry becomes physics . . . .” Lewis and Barnes state, “The secrets of life were laid bare by molecular biology. Molecular machinery churns and grinds within every one of us.” Beneath the atoms (which compose molecules) lie the even smaller fundamental particles such as the individual types of quarks and leptons. Playing with their properties, like small changes in their mass, would prove disastrous to the Universe. “Their properties might seem like mere textbook technicalities, and yet their role in how the Universe plays out is enormous. The smallest ingredients of the universe dramatically affect its bigger structures, especially the chemistry of life.”
The fundamental forces of nature are addressed in chapter three. In the Universe, there are merely four forces: the strong nuclear force, the weak nuclear force, electromagnetism, and gravity. What if one were to change the values of these forces? “With some tweaking of the free parameters of the Standard Model of particle physics, we could create a universe in which there was no energy gap between chemical and nuclear. If you left your cake in the oven for too long, you might end up with a burnt cake, or you might end up with a lump of lead.” The relative power and number of forces in the Universe are just so as to provide the stability to allow the life and the existence of a variety of elements and chemical interactions.
In chapter four, Lewis and Barnes discuss “the other principles that animate life in the Universe: energy and entropy.” Life needs energy to operate, and it needs energy in a useful form. “A system with low entropy has energy that can be extracted and converted into another form. By contrast, the energy of high-entropy systems is stuck, unable to be tapped.” The Universe started with an amazingly low amount of entropy which carried with it a treasure trove of free energy. It could have started in many ways that entailed a high entropy state; instead, the “Universe was endowed with ample free energy for driving the processes that allowed us to be here.” The question naturally follows: why?
The focus of the story in chapter five is zoomed out to the entirety of the Universe itself. When we do, we find a scandal: “[t]he mathematical structure of cosmology is deceptively simple!” As to the energy content of the Universe, it appears to be fine-tuned. “If our Universe had had a differing mixture of dark energy and matter to the one we observe, its evolutionary history would have been dramatically different. With dark energy, a universe is rather easy to ruin.” Not only is the mixture of matter and energy in the Universe “just right,” so is the (effective) cosmological constant; if its value were a little higher or a little lower, the Universe would lose its underlying structure and order.
Chapter six features the authors considering a change not in the constants of nature or initial state of the Universe as in the previous chapters but in the laws of nature themselves. Quantum mechanics influences only the very small, stabilizing atoms, while everything larger is predictable - something one needs for life in order to store and process information. If, for example, the scale of activity for quantum mechanics were larger there would not be the predictability and order to allow for life forms. As another thought experiment, what if our Universe was without symmetry, and so without conservation laws? It “would be chaos. There would be no simple laws to be discovered beneath the complex events around us.” On the other hand, what if there were no matter/antimatter asymmetry? In that case, “our Universe would be nothing but a cooling sea of radiation, completely devoid of the particles that make nuclei and atoms. This is a wonderfully clear case of a life-prohibiting universe - there’s no structure at all!” Similarly, if the Universe had a different number of spatial and temporal dimensions, “the prospect for complex life arising would have been severely diminished if not downright impossible.” To sum up, the laws of nature in the Universe “reflect the order and stability that allow life to exist.”
Part III: Why is the Universe Fine-Tuned?
Over years of presenting on the topic of cosmic fine-tuning, Lewis and Barnes have encountered many common and (despite the passion evoked) misguided reactions. These are as follows:
It’s Just a Coincidence
We’ve Only Observed One Universe
Low-Probability Events Happen All the Time
Fine-Tuning Has Been Disproved By (Insert Name Here)
Evolution Will Find a Way
How Can the Universe Be ‘Fine-Tuned’ When It Is Mostly Inhospitable To Life?
This Universe Is Just As Unlikely As Any Other Universe
How Do We Know What Would Happen In Other Universes? Go Do the Experiment!
Fine-Tuners Turn Only One Dial at a Time
Life Chauvinism - Why Think That Life is Special?
We Don’t Even Have a Good Definition of Life
There Could Be Other Forms of Life
The Anthropic Principle Explains Our Existence
Whence the Possibilities?
Whence the Probabilities?
The above objections are dealt with fairly easily in chapter seven, while the more plausible explanations are left for the eighth chapter.
In their final chapter, the authors give what they take to be the more robust potential explanations for the fine-tuning of the Universe. The first, the so-called “Lady Gaga Defence,” is to say “the Universe just is and that’s all there is to it,” but that’s more like ignoring the question than answering it. The second is that we just need more and deeper knowledge of the physics of the Universe, but even the existence of unknown theories that simplify physics cannot discount the fact that the Universe is fine-tuned for life. What about the Multiverse theory? Maybe the Universe is not unique after all. Nevertheless, the Multiverse theory itself has major hurdles to overcome such as the problem of Boltzmann Brains and lack of any empirical support. What if the answer is beyond the limits of scientific study? God as creator would account for the existence of life in the Universe, because He would have intended it that way. Another strength of this answer is that it’s not an ad hoc explanation to the problem of fine-tuning; the nature of God and His role as creator and designer of the Universe have been studied, critiqued and discussed for over a millennia. While Barnes favors this explanation, Lewis does not, proposing the possibility of a “Simulated Universe.” What if the Universe is fine tuned because it was programmed to be that way? This last option is more plausible to Lewis than Barnes. In the end, what cannot be denied is that our Universe is incredibly fine-tuned for life.
Evaluation
Strengths
There is much to say in favor of A Fortunate Universe. While learning about the fine-tuning of the Universe for life, the reader is provided with a basic primer on current physics - something I found invaluable. The authors are cosmologists and have interacted with their subject at length; thus, the story they tell is credible. Additionally, Lewis and Barnes do well to make the content interesting and readable via use of the mode of dialogue as well as occasional humor. My favorite line (rather timely given the release of the new Star Wars movies this month and last year) was made in the context of variations of life as we know it: “Chewbacca, while adorable, is a combination of a human, a dog, and a crossbow.” This gave me a chuckle, and similar comedic prose tends to keep readers engaged.
The authors are to be commended for not only giving robust and detailed evidence in favor of cosmological fine-tuning but also for addressing the most common objections and discussing the most plausible explanations. In other words, their treatment of the “why” question was handled in a fair, honest and thorough manner. Perhaps because the writers themselves represent differing worldviews, no favoritism is shown toward an atheistic or theistic reading of the evidence. All options are laid on the table for examination.
Robin Collins of Messiah College lays his finger on another aspect of A Fortunate Universe that is praiseworthy. He opines that the book “is among the two most philosophically sophisticated treatments” of the fine-tuning of the Universe. I must agree with Collins that the authors do not stumble (as many writers from the same profession do) amongst the hills and valleys of philosophical discourse. Finally, it must be mentioned that the diagrams and visual maps provided were of great benefit to my comprehension of the more heady concepts in physics. To anyone not well-versed in modern physics, these visual aids were essential and most welcome.
Weaknesses
What may be said by way of critique about A Fortunate Universe? The helpful use of visual aids and the writing style of dialogue might have been expanded. As to the latter, the back and forth between the two writers was a little “canned,” yet this kept the discussion civil and instructive. I found Lewis’ response to Barnes’ argument for God as the explanation for fine-tuning to be somewhat weak, but (in Lewis’ defense) it is a common and probably the strongest possible counterargument. As discovered from perusing other book reviews of A Fortunate Universe, there are skeptics of theism who strongly disagree with the conclusions reached in this book concerning the fine-tuning of the Universe for life, but their objections more likely reveal a weakness in their underlying belief system than in the tightly logical reasoning of the authors.
Goal Achievement
The authors’ thesis is chiefly that our Universe is finely-tuned for life. To this end a veritable mountain of evidence is provided. Lewis and Barnes make a slam-dunk case for the incredible preciseness of the laws of nature and initial conditions of the Universe so as to allow not only beauty and complexity but life itself. As such, the authors have succeeded in proving their thesis and opening up for conversation the question of why this is so.
Recommendation
A Fortunate Universe draws conclusions that affect a broad audience, namely everyone, yet its technical nature would be a bit daunting for most. However, for philosophers, theologians, scientists, and even untrained science enthusiasts, this book is not only helpful and engaging but, I would say, a necessary read. The big question of “Why are we here?” receives support as being valid from the scientific data presented in this book that our Universe is especially fit for life. As far as presenting thorough evidence and carefully crafted argumentation, A Fortunate Universe surpasses many others of the science genre. Hence, I recommend this book to those particularly fascinated by cosmological fine-tuning as well as those interested generally in science or religion.
June 5, 2020
This book addresses one of the BIG questions - the fine-tuning question - Why is the Universe just right for the formation of complex, intelligent beings? Like some of other big questions, it is possible that you may be already formulating an answer to this question in your own mind. That’s okay. Regardless of your initial convictions, read on, finish this review, then read the book, A fortunate Universe, then follow the conversation, you will not be disappointed! The aim of the authors is to present the scientific viewpoint of the fine-tuning of the laws of science, and delve into the inner workings of the Universe. The authors, astrophysicists Geraint Lewis and Luke Barnes from the University of Sydney, achieve this with wit and aplomb.
To be honest they had me at the opening chapter - any book that starts and finishes with a dialogue format, has my attention - provided it is done well. My favorite science book is Galileo’s 1632 masterpiece Dialogue concerning two chief world systems, a tough act to follow in any language. The opening and closing dialogues in A fortunate Universe are well done, although missing the third interlocutor of the Dialogue it is a captivating introduction and ‘continuation of the conversation’ wrap-up of the questions and arguments to date. Their arguments and the presentation of them, are good reading.
Perhaps you already have a strong opinion on this? Risk leaping to Chapter 7 (aptly titled, A dozen (or so) reactions to fine-tuning) and see if your explanation gets an airing in this very informative ‘short’ and ‘long’ answer format to opinions and explanations the authors have collected from professional and popular audiences over the years. I found my opening intuitive opinion disposed of succinctly as Reaction (g): This universe is just as unlikely as any other universe. Fortunately I had read the book from the start so was not at all disconcerted to have my opinion bubble so neatly burst. That really is the best way to go - the book feels like a well constructed conversation on fine-tuning. Like Galileo’s Dialogue, the conversation ranges widely, you incidentally learn a lot about the physics of the universe and the philosophy of science, while still framed around a seemingly easy question.
The book takes the reader through what it is to be human; the chemistry and biology of life, quickly getting to the modern physics of fundamental particles. From there they discuss fundamental forces, entropy and energy and then the Universe in its entirety. The authors then shake it all up and show that how unlikely our universe is by messing with the strengths of the forces and the initial conditions of the Universe. They then go wild altering space and time and asking ‘Does life have a chance in any of these unfamiliar arenas?’ Without spoiling their thunder - the answer is - well no, it seems that changes lead to ‘a universe that could have been different, so very dead and sterile’. This book presents the challenges too, and neatly disposes of glib responses too the apparent specialness of our existence. The science is sound, the philosophy is good, the writing is (geekily) witty and entertaining without descending to annoying glibness or employing a condescending tone. It will capture your attention and challenge your thinking - can’t think of better reasons to suggest a book.
This book review was first published here: https://dragonlaughing.tumblr.com/pos...
This book was a review copy provided to me by Cambridge University Press (Melbourne). The review is my own opinion.
To be honest they had me at the opening chapter - any book that starts and finishes with a dialogue format, has my attention - provided it is done well. My favorite science book is Galileo’s 1632 masterpiece Dialogue concerning two chief world systems, a tough act to follow in any language. The opening and closing dialogues in A fortunate Universe are well done, although missing the third interlocutor of the Dialogue it is a captivating introduction and ‘continuation of the conversation’ wrap-up of the questions and arguments to date. Their arguments and the presentation of them, are good reading.
Perhaps you already have a strong opinion on this? Risk leaping to Chapter 7 (aptly titled, A dozen (or so) reactions to fine-tuning) and see if your explanation gets an airing in this very informative ‘short’ and ‘long’ answer format to opinions and explanations the authors have collected from professional and popular audiences over the years. I found my opening intuitive opinion disposed of succinctly as Reaction (g): This universe is just as unlikely as any other universe. Fortunately I had read the book from the start so was not at all disconcerted to have my opinion bubble so neatly burst. That really is the best way to go - the book feels like a well constructed conversation on fine-tuning. Like Galileo’s Dialogue, the conversation ranges widely, you incidentally learn a lot about the physics of the universe and the philosophy of science, while still framed around a seemingly easy question.
The book takes the reader through what it is to be human; the chemistry and biology of life, quickly getting to the modern physics of fundamental particles. From there they discuss fundamental forces, entropy and energy and then the Universe in its entirety. The authors then shake it all up and show that how unlikely our universe is by messing with the strengths of the forces and the initial conditions of the Universe. They then go wild altering space and time and asking ‘Does life have a chance in any of these unfamiliar arenas?’ Without spoiling their thunder - the answer is - well no, it seems that changes lead to ‘a universe that could have been different, so very dead and sterile’. This book presents the challenges too, and neatly disposes of glib responses too the apparent specialness of our existence. The science is sound, the philosophy is good, the writing is (geekily) witty and entertaining without descending to annoying glibness or employing a condescending tone. It will capture your attention and challenge your thinking - can’t think of better reasons to suggest a book.
This book review was first published here: https://dragonlaughing.tumblr.com/pos...
This book was a review copy provided to me by Cambridge University Press (Melbourne). The review is my own opinion.
October 8, 2020
A Fortunate Universe: Life in a Finely Tuned Cosmos by Geraint F. Lewis and Luke A. Barnes is a book about the cosmos for those looking for a bit more than a Discovery Channel series on the universe. Lewis is a Welsh astrophysicist, who is best known for his work on dark energy, gravitational lensing, and galactic cannibalism. Barnes is a postdoctoral researcher at the Sydney Institute for Astronomy, University of Sydney. He works on cosmology, galaxy formation, and the fine-tuning of the universe for life.
The universe has gotten a lot more complicated over the years, but much more accessible. Science shows on television, the internet, and since the 1980s, science books that were not just filled with equations. Einstein used thought experiments as well as Schrödinger. Feynman used diagrams to represent extremely complex mathematical equations. Stephen Hawkings had a best-selling book on science (with only one equation). I remember reading a non-mathematical Quantum Mechanics book back in the mid-1980s that opened up a whole new world to me. The popularization of quantum mechanics and cosmology allowed people with an interest in science to follow along and grasp the post-Newtonian universe.
Lewis and Barnes discuss the universe with all the familiar forces and particles. They, however, look at how our universe is "tuned." They examine what small changes in forces and particles achieve. What would happen to the universe if the strong nuclear force and gravity were at different values? Could stars form? What would their lifecycles be like? Radiation is a serious problem for living beings, but would a universe without radiation support life? The earth would just be a cold dead rock. Radiation keeps the core hot and the magnetic field active. Perhaps the most important aspect of life in the universe is carbon. Carbon is formed inside of stars but by much more than simple fusion.
My background is not in science but I could follow along fairly easily throughout most of the book. There were a few places that I needed to reread or lookup in an external source but, for the most part, the writing was very understandable. The explanations are complete and understandable. Personally, I tend to forget how the weak nuclear force works, but I came away well informed. The writing style is engaging and thought provoking, and although the workings of the universe make rocket science look like child’s play, the writer’s can be entertaining. They also like to drop musical references in their writing.
In addition to what we know about the universe and what changing a variable might accomplish the book discusses what we don’t know and some problems with what we don’t know. The authors tell what happens when theories get stretched too far. In one place the authors discuss the number of 10^120. It’s large number so large in fact that it is nearly impossible. Impossible many times over when discussing the number of protons in the universe. Higgs, dark matter and dark energy, as well as singularities, are part of the discussion and keep the writing current. The authors start and end the book in a discussion format. It provides a good introduction and closes the book well taking in a final discussion of if the universe is so tuned for life could it have been created or designed. A particularly well-chosen closing to what very much seems like a Goldilocks Universe.
The universe has gotten a lot more complicated over the years, but much more accessible. Science shows on television, the internet, and since the 1980s, science books that were not just filled with equations. Einstein used thought experiments as well as Schrödinger. Feynman used diagrams to represent extremely complex mathematical equations. Stephen Hawkings had a best-selling book on science (with only one equation). I remember reading a non-mathematical Quantum Mechanics book back in the mid-1980s that opened up a whole new world to me. The popularization of quantum mechanics and cosmology allowed people with an interest in science to follow along and grasp the post-Newtonian universe.
Lewis and Barnes discuss the universe with all the familiar forces and particles. They, however, look at how our universe is "tuned." They examine what small changes in forces and particles achieve. What would happen to the universe if the strong nuclear force and gravity were at different values? Could stars form? What would their lifecycles be like? Radiation is a serious problem for living beings, but would a universe without radiation support life? The earth would just be a cold dead rock. Radiation keeps the core hot and the magnetic field active. Perhaps the most important aspect of life in the universe is carbon. Carbon is formed inside of stars but by much more than simple fusion.
My background is not in science but I could follow along fairly easily throughout most of the book. There were a few places that I needed to reread or lookup in an external source but, for the most part, the writing was very understandable. The explanations are complete and understandable. Personally, I tend to forget how the weak nuclear force works, but I came away well informed. The writing style is engaging and thought provoking, and although the workings of the universe make rocket science look like child’s play, the writer’s can be entertaining. They also like to drop musical references in their writing.
In addition to what we know about the universe and what changing a variable might accomplish the book discusses what we don’t know and some problems with what we don’t know. The authors tell what happens when theories get stretched too far. In one place the authors discuss the number of 10^120. It’s large number so large in fact that it is nearly impossible. Impossible many times over when discussing the number of protons in the universe. Higgs, dark matter and dark energy, as well as singularities, are part of the discussion and keep the writing current. The authors start and end the book in a discussion format. It provides a good introduction and closes the book well taking in a final discussion of if the universe is so tuned for life could it have been created or designed. A particularly well-chosen closing to what very much seems like a Goldilocks Universe.
December 14, 2020
I really enjoyed this book, though at times it was very technical, even for me.
Throughout the first part of the book they explore the case for the fine-tuning of the universe, and they do so very thoroughly. This is the point where it sometimes gets quite technical but even if someone does not get the details, one can still understand the overall thrust of their argument.
Then they spend a chapter responding to a number of critiques of fine-tuning, and this chapter is very helpful because the dozen or so critiques that they bring up a very common and their answers for the most part of very good. There are a few times where I think they could have improved their answers with another argument, but overall it was good.
What I appreciated about the last couple of chapters is that they took seriously the major attempts to explain fine-tuning: they fully explored a naturalism answer which is the Multiverse and they fully explored theisms answer. They were honest about both of those answers and gave the best case for each of them. They did not try to set up one or the other as a strawman, but gave the strengths of both. I also like how they talked about how we need to walk around in the shoes so to speak of each worldview and explanation and see if it fits with the reality, our experiences, and our intuitions. They also explored a couple of others like the simulation hypothesis, but they do not give us much time to those.
In the end, it seems that these two authors disagree on what is the best explanation for fine-tuning. It seems that one of them likely thinks that theism is the best explanation and the other thinks that some version of the Multiverse is. Yet both wrote the book together and work together as friends and colleagues at the University of Sydney. Such a partnership while standing a different worldviews is pretty rare, but it is very refreshing to see.
Throughout the first part of the book they explore the case for the fine-tuning of the universe, and they do so very thoroughly. This is the point where it sometimes gets quite technical but even if someone does not get the details, one can still understand the overall thrust of their argument.
Then they spend a chapter responding to a number of critiques of fine-tuning, and this chapter is very helpful because the dozen or so critiques that they bring up a very common and their answers for the most part of very good. There are a few times where I think they could have improved their answers with another argument, but overall it was good.
What I appreciated about the last couple of chapters is that they took seriously the major attempts to explain fine-tuning: they fully explored a naturalism answer which is the Multiverse and they fully explored theisms answer. They were honest about both of those answers and gave the best case for each of them. They did not try to set up one or the other as a strawman, but gave the strengths of both. I also like how they talked about how we need to walk around in the shoes so to speak of each worldview and explanation and see if it fits with the reality, our experiences, and our intuitions. They also explored a couple of others like the simulation hypothesis, but they do not give us much time to those.
In the end, it seems that these two authors disagree on what is the best explanation for fine-tuning. It seems that one of them likely thinks that theism is the best explanation and the other thinks that some version of the Multiverse is. Yet both wrote the book together and work together as friends and colleagues at the University of Sydney. Such a partnership while standing a different worldviews is pretty rare, but it is very refreshing to see.
November 7, 2017
This was a bit of a chore to read but not necessarily in a bad way. I made my way through it 10-20 pages per day with sufficient time to allow my brain and eyes to rest. While there is some advanced math in these pages, I would say that it is mostly accessible to anybody with sufficient exposure to high school physics/chemistry. Some of the philosophical stuff in the last two chapters was a bit harder to follow; perhaps because I was ready to be done with this title. A tiny bit of overlap with Dawkin's The God Delusion which I've coincidentally been working through these last couple weeks. Minor niggling point: there are several (at least 4 or 5) typos in this book like "out" vs. "our". These are fairly distracting when you're trying to parse a lengthy block of text. Hopefully these are cleaned up in a revised edition.
July 31, 2022
A pretty in-depth review of the various physical properties of the universe that appear to be fine-tuned to allow for life. Interesting if you have an interest in cosmological sciences and physics. Ultimately, however, it's not going to "settle" any debates between those who are strictly naturalists and those who believe in a Creator. Most people are going to consider this to be a very, very "dry" read. If you've successfully tackled books by Stephen Hawking, Michio Kaku, Brian Greene and the like, you'll be better able to understand the physics presented and the information presented here will have more of a "Ah! Now I see!" kind of effect. (These are authors I've been reading for decades now and I've always been fascinated by string theory and cosmology separately.) If, on the other hand, you are looking at this book from a Christian apologetics standpoint, you aren't likely to gain much in order to have productive conversations with your strongly atheistic friends.
May 23, 2018
The biggest positive surprise on my reading list! In a nutshell, the book touches on the apparent fine-tuning of our Universe. First chapters are the crash course in modern physics- Barnes and Lewis are doing a remarkable job of explaining it in layman's terms without any complex maths. Final chapters are somehow at the intersection of science, philosophy and theology -- it's a fascinating and respectful dialogue between two competent scientists with different explanations for the fine-tuning and both authors give compelling arguments in favour of their hypotheses (Lewis is an atheist who favors a multiverse hypothesis, whereas Barnes views fine-tuning as a leading argument for the existence of God). Highly recommended!
May 24, 2023
If there's one thing that's clear, it's that we're incredibly lucky to be alive. Why is it that we live in a universe apparently so fine tuned to allow the conditions for galaxies, stars, planets and us, to exist? This book looks at what it takes to create a universe, let alone one that can produce life, and how such a universe might look were the initial conditions only a little different (Spoiler warning: probably not good!). Written in a personable, reader friendly style which helps to explain the sometimes hard science that needs to be in there, the layman can hopefully grasp the thinking behind the authors' conjectures. An absolutely fascinating read.
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