What do you think?
Rate this book
The Inflationary Universe: The Quest for a New Theory of Cosmic Origins
This is the compelling, first-hand account of Alan Guth’s paradigm-breaking discovery of the origins of the universe—and of his dramatic rise from young researcher to physics superstar. Guth’s startling theory—widely regarded as one of the most important contributions to science during the twentieth century—states that the big bang was set into motion by a period of hyper-rapid “inflation,” lasting only a billion-trillion-billionth of a second. The Inflationary Universe is the passionate story of one leading scientist’s effort to look behind the cosmic veil and explain how the universe began.
358 pages, Paperback
First published January 1, 1997
38 people are currently reading
3303 people want to read
About the author
Alan Guth
5 books57 followersTheory of known American theoretical physicist Alan Harvey Guth of the inflationary universe modifies the scientific Big Bang theory, describing the origin of all space, time, matter, and energy, 13.7 billion years ago, from the violent expansion of a singular point of extremely high density and temperature.
This cosmologist researched early applicability of elementary particles. He, served as Victor Weisskopf professor of Physics at the Massachusetts Institute of Technology.
He graduated from Massachusetts Institute of Technology in 1968 and stayed to receive a master's and a doctorate also.
This junior particle physicist first developed the cosmic idea in 1979 at Cornell and gave his first seminar on the subject in January 1980. Moving to Stanford University, Guth formally proposed in 1981 that the a positive vacuum energy density (negative pressure) drove a phase of exponential expansion through which nascent universe passed. The results of the Wilkinson Microwave Anisotropy Probe in 2006 made the very compelling cosmic case. Measurements by the Background Imaging of Cosmic Extragalactic Polarization and Keck array telescope give support to the cosmic idea, on 17 March 2014, the findings of the B-mode polarization signature gave confirmation.
In the past, Guth studied lattice gauge theory, magnetic monopoles and instantons, Gott time machines, and a number of other topics in theoretical physics. Much of current work includes extrapolating density fluctuations, arising from various versions of inflation, to test against observations and investigating inflation in "brane world" models.
So far, he wrote sixty technical papers, related to the effects and interactions with particle physics. He won many awards and medals, including the medal of the international center for theoretical physics, Trieste, Italy, with Andrei Linde and Paul Steinhardt and the Eddington medal in 1996, and the British Institute of Physics awarded the Isaac Newton medal of 2009.
The Boston Globe organized the award for the messiest office in 2005. Colleagues, who expected the award to shame Guth into tidying his office, entered him, who quite proudly won the award.
In July 2012, he was an inaugural awardee of the fundamental physics prize, the creation of physicist and internet entrepreneur, Yuri Milner.
More: http://web.mit.edu/physics/people/fac...
http://www.amazon.com/s/ref=ntt_athr_...
This cosmologist researched early applicability of elementary particles. He, served as Victor Weisskopf professor of Physics at the Massachusetts Institute of Technology.
He graduated from Massachusetts Institute of Technology in 1968 and stayed to receive a master's and a doctorate also.
This junior particle physicist first developed the cosmic idea in 1979 at Cornell and gave his first seminar on the subject in January 1980. Moving to Stanford University, Guth formally proposed in 1981 that the a positive vacuum energy density (negative pressure) drove a phase of exponential expansion through which nascent universe passed. The results of the Wilkinson Microwave Anisotropy Probe in 2006 made the very compelling cosmic case. Measurements by the Background Imaging of Cosmic Extragalactic Polarization and Keck array telescope give support to the cosmic idea, on 17 March 2014, the findings of the B-mode polarization signature gave confirmation.
In the past, Guth studied lattice gauge theory, magnetic monopoles and instantons, Gott time machines, and a number of other topics in theoretical physics. Much of current work includes extrapolating density fluctuations, arising from various versions of inflation, to test against observations and investigating inflation in "brane world" models.
So far, he wrote sixty technical papers, related to the effects and interactions with particle physics. He won many awards and medals, including the medal of the international center for theoretical physics, Trieste, Italy, with Andrei Linde and Paul Steinhardt and the Eddington medal in 1996, and the British Institute of Physics awarded the Isaac Newton medal of 2009.
The Boston Globe organized the award for the messiest office in 2005. Colleagues, who expected the award to shame Guth into tidying his office, entered him, who quite proudly won the award.
In July 2012, he was an inaugural awardee of the fundamental physics prize, the creation of physicist and internet entrepreneur, Yuri Milner.
More: http://web.mit.edu/physics/people/fac...
http://www.amazon.com/s/ref=ntt_athr_...
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 30 of 44 reviews
August 17, 2014
[Original review: July 2012]
Yesterday evening, I was sitting with the local knitting group and reading the last few pages of Guth's book. "Should I actually believe this?" I bemusedly asked the two CERN physicists sitting on either side of me. "HELL NO!" said T, after glancing at the cover. "Inflation?? I HATE IT!!! It's why I gave up cosmology and went into nuclear physics! That's real science!" But A had a more positive opinion. "Well," she shrugged, "it's part of the standard Big Bang model. How else are you going to make sense of the observational data?" Then they both hastened to add that I shouldn't take seriously anything they'd said, they weren't experts, not their field. In fact, they didn't know. I wondered if they thought that would be a typical reaction, were I to ask other professional scientists. Would everyone say they didn't know, unless the question concerned the tiny area where they were an acknowledged world-class expert? A thought about it. "Probably," she said. So, ah, to summarise, no one except a handful of experts understands our current theories about the origins of the universe well enough to say whether they make sense, but Alan Guth, the guy who kicked it off, has written a book about how we got here. I personally found it very helpful and feel I grasp the idea of "inflation" far better than I did a week ago: the brief summaries I'd seen elsewhere had left me cold, but seeing how the ideas developed over time put them into perspective and made them less outlandish.
Though I still have real trouble believing this stuff; it seems impossibly speculative, even if it does "explain" important things, in particular the flatness and uniformity of the universe, and the slight unevenness in the Cosmic Microwave Background Radiation (CMBR) that later turned into galaxies. Guth describes his key insight from 1980 and the developments following on from it. You project the history of the universe backwards in time, and it gets hotter and denser the further back you go. At some point, about 10^-35 seconds after the beginning of time, things are so hot that the three non-gravitational forces - electromagnetism, and the strong and weak nuclear forces - all become the same force. But then, winding the clock forwards again, the universe cools down, and they split up into the three forces we see today. In the process of doing so, there could have been an intermediate state, a "false vacuum", where the universe was filled with the enormous energy released by the splitting up of the three forces. This energy would have caused it to expand exponentially, making it uniform and flat; quantum fluctuations would account for the minor unevennesses we have found in the CMBR.
This is indeed the standard story, but I am shocked to see how many assumptions you need in order to make it work. There is a bunch of "Grand Unified Theories" explaining how the three forces can be unified into one, but the energies needed to test them are over a billion times higher than anything we can create in our current accelerators. The potential curve which determines how the energy level falls during the splitting of the forces needs to have a very specific shape in order to get results that match the data. Originally, the idea was that the field mediating the energy was going to be the Higgs field, which we know something about; but in fact the Higgs field turns out not to have the right properties, so a new field was required. (By the way, this seems to be why the Higgs is often called "the God Particle"; people thought for a while that it had created the universe, but they later changed their minds). The universe has to be locally flat enough before inflation started, which involves some kind of theory of quantum gravity. All these theories are speculative.
I can't help being reminded of medieval cosmologies. Back then, astronomers tweaked systems of cycles and epicycles to make them fit the observed notions of the planets. Now, they tweak the potential curves of the inflaton field to make it fit the patterns found in the CMBR. No one had ever seen a crystal sphere, and no one has ever seen an inflaton; perhaps they are equally mythical. But careful analysis of the crystal spheres eventually produced better theories, and I'm guessing the same thing will happen here, given time. Why is there never a Newton around when you need one?
_________________________________
People who have read this book might want to look carefully at Appendix B and compare it with this paper by J.D. Norton. It certainly seems to me that the 1895 result from Seeliger quoted by Norton completely invalidates Guth's argument, and in fact leaves him looking rather silly. But see if you agree.
_________________________________
[Update: Aug 17 2014]
Check out Takahiro Terada's one-minute YouTube video Single Superfield Inflation: The Trailer, which I just saw on Sean Carroll's Preposterous Universe blog. It's amazing.
Yesterday evening, I was sitting with the local knitting group and reading the last few pages of Guth's book. "Should I actually believe this?" I bemusedly asked the two CERN physicists sitting on either side of me. "HELL NO!" said T, after glancing at the cover. "Inflation?? I HATE IT!!! It's why I gave up cosmology and went into nuclear physics! That's real science!" But A had a more positive opinion. "Well," she shrugged, "it's part of the standard Big Bang model. How else are you going to make sense of the observational data?" Then they both hastened to add that I shouldn't take seriously anything they'd said, they weren't experts, not their field. In fact, they didn't know. I wondered if they thought that would be a typical reaction, were I to ask other professional scientists. Would everyone say they didn't know, unless the question concerned the tiny area where they were an acknowledged world-class expert? A thought about it. "Probably," she said. So, ah, to summarise, no one except a handful of experts understands our current theories about the origins of the universe well enough to say whether they make sense, but Alan Guth, the guy who kicked it off, has written a book about how we got here. I personally found it very helpful and feel I grasp the idea of "inflation" far better than I did a week ago: the brief summaries I'd seen elsewhere had left me cold, but seeing how the ideas developed over time put them into perspective and made them less outlandish.
Though I still have real trouble believing this stuff; it seems impossibly speculative, even if it does "explain" important things, in particular the flatness and uniformity of the universe, and the slight unevenness in the Cosmic Microwave Background Radiation (CMBR) that later turned into galaxies. Guth describes his key insight from 1980 and the developments following on from it. You project the history of the universe backwards in time, and it gets hotter and denser the further back you go. At some point, about 10^-35 seconds after the beginning of time, things are so hot that the three non-gravitational forces - electromagnetism, and the strong and weak nuclear forces - all become the same force. But then, winding the clock forwards again, the universe cools down, and they split up into the three forces we see today. In the process of doing so, there could have been an intermediate state, a "false vacuum", where the universe was filled with the enormous energy released by the splitting up of the three forces. This energy would have caused it to expand exponentially, making it uniform and flat; quantum fluctuations would account for the minor unevennesses we have found in the CMBR.
This is indeed the standard story, but I am shocked to see how many assumptions you need in order to make it work. There is a bunch of "Grand Unified Theories" explaining how the three forces can be unified into one, but the energies needed to test them are over a billion times higher than anything we can create in our current accelerators. The potential curve which determines how the energy level falls during the splitting of the forces needs to have a very specific shape in order to get results that match the data. Originally, the idea was that the field mediating the energy was going to be the Higgs field, which we know something about; but in fact the Higgs field turns out not to have the right properties, so a new field was required. (By the way, this seems to be why the Higgs is often called "the God Particle"; people thought for a while that it had created the universe, but they later changed their minds). The universe has to be locally flat enough before inflation started, which involves some kind of theory of quantum gravity. All these theories are speculative.
I can't help being reminded of medieval cosmologies. Back then, astronomers tweaked systems of cycles and epicycles to make them fit the observed notions of the planets. Now, they tweak the potential curves of the inflaton field to make it fit the patterns found in the CMBR. No one had ever seen a crystal sphere, and no one has ever seen an inflaton; perhaps they are equally mythical. But careful analysis of the crystal spheres eventually produced better theories, and I'm guessing the same thing will happen here, given time. Why is there never a Newton around when you need one?
_________________________________
People who have read this book might want to look carefully at Appendix B and compare it with this paper by J.D. Norton. It certainly seems to me that the 1895 result from Seeliger quoted by Norton completely invalidates Guth's argument, and in fact leaves him looking rather silly. But see if you agree.
_________________________________
[Update: Aug 17 2014]
Check out Takahiro Terada's one-minute YouTube video Single Superfield Inflation: The Trailer, which I just saw on Sean Carroll's Preposterous Universe blog. It's amazing.
July 6, 2012
Almost everyone has heard Barenaked Ladies' lyrics on the popular TV show “The Big Bang Theory": “The whole universe was in a hot dense state, / Then nearly 14 billion years ago expansion started. / Wait!..."
Well, without Alan Guth’s seminal discovery of expansion, Bare Naked Ladies would have had to write a different set of lyrics....and we would still be trying to figure out how it all began.
What is “expansion”? In a nutshell, it is the time--billionths of a second in duration--when the first infinitesimal particle exploded and caused the entire universe to be created. Almost overnight, Guth himself, like the universe he postulated, exploded from an unknown grad student to one of the superstars of astrophysics.
The notion of the universe starting with a “big bang” had been around since the ‘thirties, actually a later term of derision of the physicist Fred Hoyle, who favored the Steady State theory of the origin of the universe. But Guth took the theory a step further. He postulated that not only did the universe begin in one incomprehensible fraction of a second--but the entire universe as it is now was created in that same time frame. In layman’s terms--it simply, suddenly “was.”
Guth later jokingly referred to this expansion as “the ultimate free lunch.”
All this is meant to be an introduction to his book THE INFLATIONARY UNIVERSE. First published in 1997, it is a look back at 1984 when Guth, a young researcher, “stumbled” on an extraordinary theory of the cosmic beginnings. He writes in an engaging, non-scientific style meant to reach out and grab readers such as I, people who have a hazy grasp of physics but who want a better notion of how our universe came to be.
Now a professor of physics at MIT, Guth’s name has become almost a household word. I would not be surprised if he were soon awarded a Nobel in Physics.
Read this book, and then sing along with Barenaked Ladies...with a new understanding of the hot dense state and the miraculous expansion that started it all.
Slán, Erin O'Quinn
Well, without Alan Guth’s seminal discovery of expansion, Bare Naked Ladies would have had to write a different set of lyrics....and we would still be trying to figure out how it all began.
What is “expansion”? In a nutshell, it is the time--billionths of a second in duration--when the first infinitesimal particle exploded and caused the entire universe to be created. Almost overnight, Guth himself, like the universe he postulated, exploded from an unknown grad student to one of the superstars of astrophysics.
The notion of the universe starting with a “big bang” had been around since the ‘thirties, actually a later term of derision of the physicist Fred Hoyle, who favored the Steady State theory of the origin of the universe. But Guth took the theory a step further. He postulated that not only did the universe begin in one incomprehensible fraction of a second--but the entire universe as it is now was created in that same time frame. In layman’s terms--it simply, suddenly “was.”
Guth later jokingly referred to this expansion as “the ultimate free lunch.”
All this is meant to be an introduction to his book THE INFLATIONARY UNIVERSE. First published in 1997, it is a look back at 1984 when Guth, a young researcher, “stumbled” on an extraordinary theory of the cosmic beginnings. He writes in an engaging, non-scientific style meant to reach out and grab readers such as I, people who have a hazy grasp of physics but who want a better notion of how our universe came to be.
Now a professor of physics at MIT, Guth’s name has become almost a household word. I would not be surprised if he were soon awarded a Nobel in Physics.
Read this book, and then sing along with Barenaked Ladies...with a new understanding of the hot dense state and the miraculous expansion that started it all.
Slán, Erin O'Quinn
March 18, 2014
I've been trying to call Alan all day to congratulate him, but his phone seems to be permanently busy. Oh well, this will have to do. Alan, I'm big enough to admit you were right and I was wrong, and just let me know when you want that dinner at the Fat Duck. Kisses, G.
August 20, 2017
Alan Guth is not a science popularizer like Carl Sagan or Neil DeGrasse Tyson, but the actual scientist who originated Inflation cosmology. This book is presented chronologically, following his and his colleagues' work through problems and dead ends, and occasionally even events from his personal life. Even though it is math-less, it conveys the conceptual trade-offs and reasoning, beyond a mere description of the resulting theory to be taken on pure faith. As an engineer with detailed knowledge of physics only in those certain spots relevant to my career, I found this both challenging and rewarding to read, in my drive to broaden.
Guth does not present all his work as a done deal in all particulars – although inflation certainly does seem necessary to address problems in the prior Big Bang model (compatibility with GUTs, horizon problem, flatness problem, etc.). The book was published 20 years ago, and the Epilogue describes “future” issues on which observational progress and theoretical progress have since been made. With the trade-off awareness gained, some brief summaries available online have a place to fit in. The reintroduction of cosmological constants to make timelines work out seems troubling to me. But as I have still not been through the math, and the math speculations precede observational data, I cannot claim to understand fully. It was especially gratifying to see theoretical physicists sometimes struggling just to understand each other’s work.
My notes per chapter are below.
1 The Ultimate Free Lunch - conservation of energy/matter.
2 The Cosmic Vista from Ithaca, New York - traditional Big Bang with homogeneous expansion. magnetic monopoles.
3 The Birth of Modern Cosmology – Einstein’s cosmological constant. Open/Flat/Closed Freidmann universe. Hubble redshift (1929); mistaken age of universe.
4 Echoes of a Scorching Past - detection of background radiation (1964). conformity to blackbody spectrum.
5 Condensation of the Primordial Soup - Big Bang Nucleosynthesis took place starting 0.1 sec after t=0. H-1, H-2 (Deuterium), H-3 (Tritium), He-3, He-4, Li-7. Heavier elements came from stars, later. 5-particle gap closed with only transitory nuclei. Blackbody radiation much later, from 300,000 years after t=0.
6 Matters of Matter and Anti-matter - Weinberg: baryon number conservation, 10^^-39 seconds of matter-antimatter annihilation. Baryogenesis.
7 The Particle Physics Revolution of the 1970s - development of the Standard Model. Gell-Mann and Zweig: Quarks (up/down, charmed/strange, top/bottom) and Leptons (electron/e-neutrino, muon, m-neutrino, tau, tau-neutrino). Yang and Mills: quantum chromodynamics.
8 Grand Unified Theories - GUTs are unification of weak, e-m, strong interactions (gravity is much weaker). GUTs predict strengths of all known particle interactions. Experiments at 10^^2 GeV predict convergence at 10^^16 GeV. Spontaneous Symmetry Breaking are mechanisms for loss of high energy symmetry at lower energy. Minimum energy density on maps of multiple Higgs fields. Critical chapter; needs re-read!
8 Grand Unified Theories - GUT hierarchy problems; Higgs fields used in electroweak unification; 10^^16 GeV is just a step towards hierarchy of full unification. Spontaneous symmetry breaking is set at various Higgs values along the vacuum ring, arbitrarily during cooling after Big Bang. If changed, particle interactions would break out differently.
9 Combating the Magnetic Monopole Menace - standard GUTs led to overproduction of magnetic monopoles. Vacuum energy in three-Higgs-field model. Second phase transition? settled on Supercooling, but that has effect on expansion rate of early universe.
10 The Inflationary Universe - supercooling needs a Higgs energy map with dimple near origin, representing false vacuum (local minimum energy). Decay ultimately through quantum tunneling. False vacuum leads to temp reversal of certain properties, such as gravitation. EXPONENTIAL expansion. Inflationary period 10^^-35 seconds solves monopole, flatness and horizon problems. Universe is 10^^23 times observed universe.
11 The Aftermath of Discovery - 1st publication and new job at MIT. Graceful Exit Problem. No percolation of bubbles resolving to infinite connectivity. Guth found no solution.
12 The New Inflationary Universe - Guth 1st year at MIT with medical and legal problems. Linde's "New Inflation" single-bubble universe, using novel Higgs fields. Steinhardt used spinodal decomposition for phase transition without bubbles.
13 Wrinkles on a Smooth Background - Under the newer inflation, how to explain the nonuniformities of contemporary universe? Hawking wades in. Quantum perturbations, if the Higgs field energy density graph is further flattened. But then incompatible with best GUT. A newly defined field – Inflaton.
14 Observational Clues from Deep Below and Far Beyond - In 1992, COBE data confirmed nonuniformity of background radiation as per prediction of inflation.
15 The Eternally Existing, Self-Reproducing Inflationary Universe - Inflation is in a primordial soup of very hot uncombined elementary particles (quarks & leptons?), in which pocket universes form. Soup could be eternal. Evidence will not be found in space-time of our own pocket universe.
16 Wormholes and the Creation of Universes in the Lab - Nur ein gedankenexperiment. useful review of conditions necessary and events to cause creation of a pocket universe. Quantum tunneling in super high energy of inflation.
17 A Universe of Ex Nihilo - Tryon's vacuum fluctuation idea. With inflation, small size may not be an objection. pure speculation.
Epilogue - book released 1997. In past 20 years, Hubble constant measured to ~21, XMAP and Planck Spacecraft data have pointed to "Lambda-CDM" model (use of cosmological constant to address Age Problem)
Appendix A - Gravitational energy
Appendix B - Newton and the Infinite Static Universe
Appendix C - Blackbody Radiation
Appendix D - Units and Measures
Note that there are also useful bibliographical notes and a glossary.
Guth does not present all his work as a done deal in all particulars – although inflation certainly does seem necessary to address problems in the prior Big Bang model (compatibility with GUTs, horizon problem, flatness problem, etc.). The book was published 20 years ago, and the Epilogue describes “future” issues on which observational progress and theoretical progress have since been made. With the trade-off awareness gained, some brief summaries available online have a place to fit in. The reintroduction of cosmological constants to make timelines work out seems troubling to me. But as I have still not been through the math, and the math speculations precede observational data, I cannot claim to understand fully. It was especially gratifying to see theoretical physicists sometimes struggling just to understand each other’s work.
My notes per chapter are below.
1 The Ultimate Free Lunch - conservation of energy/matter.
2 The Cosmic Vista from Ithaca, New York - traditional Big Bang with homogeneous expansion. magnetic monopoles.
3 The Birth of Modern Cosmology – Einstein’s cosmological constant. Open/Flat/Closed Freidmann universe. Hubble redshift (1929); mistaken age of universe.
4 Echoes of a Scorching Past - detection of background radiation (1964). conformity to blackbody spectrum.
5 Condensation of the Primordial Soup - Big Bang Nucleosynthesis took place starting 0.1 sec after t=0. H-1, H-2 (Deuterium), H-3 (Tritium), He-3, He-4, Li-7. Heavier elements came from stars, later. 5-particle gap closed with only transitory nuclei. Blackbody radiation much later, from 300,000 years after t=0.
6 Matters of Matter and Anti-matter - Weinberg: baryon number conservation, 10^^-39 seconds of matter-antimatter annihilation. Baryogenesis.
7 The Particle Physics Revolution of the 1970s - development of the Standard Model. Gell-Mann and Zweig: Quarks (up/down, charmed/strange, top/bottom) and Leptons (electron/e-neutrino, muon, m-neutrino, tau, tau-neutrino). Yang and Mills: quantum chromodynamics.
8 Grand Unified Theories - GUTs are unification of weak, e-m, strong interactions (gravity is much weaker). GUTs predict strengths of all known particle interactions. Experiments at 10^^2 GeV predict convergence at 10^^16 GeV. Spontaneous Symmetry Breaking are mechanisms for loss of high energy symmetry at lower energy. Minimum energy density on maps of multiple Higgs fields. Critical chapter; needs re-read!
8 Grand Unified Theories - GUT hierarchy problems; Higgs fields used in electroweak unification; 10^^16 GeV is just a step towards hierarchy of full unification. Spontaneous symmetry breaking is set at various Higgs values along the vacuum ring, arbitrarily during cooling after Big Bang. If changed, particle interactions would break out differently.
9 Combating the Magnetic Monopole Menace - standard GUTs led to overproduction of magnetic monopoles. Vacuum energy in three-Higgs-field model. Second phase transition? settled on Supercooling, but that has effect on expansion rate of early universe.
10 The Inflationary Universe - supercooling needs a Higgs energy map with dimple near origin, representing false vacuum (local minimum energy). Decay ultimately through quantum tunneling. False vacuum leads to temp reversal of certain properties, such as gravitation. EXPONENTIAL expansion. Inflationary period 10^^-35 seconds solves monopole, flatness and horizon problems. Universe is 10^^23 times observed universe.
11 The Aftermath of Discovery - 1st publication and new job at MIT. Graceful Exit Problem. No percolation of bubbles resolving to infinite connectivity. Guth found no solution.
12 The New Inflationary Universe - Guth 1st year at MIT with medical and legal problems. Linde's "New Inflation" single-bubble universe, using novel Higgs fields. Steinhardt used spinodal decomposition for phase transition without bubbles.
13 Wrinkles on a Smooth Background - Under the newer inflation, how to explain the nonuniformities of contemporary universe? Hawking wades in. Quantum perturbations, if the Higgs field energy density graph is further flattened. But then incompatible with best GUT. A newly defined field – Inflaton.
14 Observational Clues from Deep Below and Far Beyond - In 1992, COBE data confirmed nonuniformity of background radiation as per prediction of inflation.
15 The Eternally Existing, Self-Reproducing Inflationary Universe - Inflation is in a primordial soup of very hot uncombined elementary particles (quarks & leptons?), in which pocket universes form. Soup could be eternal. Evidence will not be found in space-time of our own pocket universe.
16 Wormholes and the Creation of Universes in the Lab - Nur ein gedankenexperiment. useful review of conditions necessary and events to cause creation of a pocket universe. Quantum tunneling in super high energy of inflation.
17 A Universe of Ex Nihilo - Tryon's vacuum fluctuation idea. With inflation, small size may not be an objection. pure speculation.
Epilogue - book released 1997. In past 20 years, Hubble constant measured to ~21, XMAP and Planck Spacecraft data have pointed to "Lambda-CDM" model (use of cosmological constant to address Age Problem)
Appendix A - Gravitational energy
Appendix B - Newton and the Infinite Static Universe
Appendix C - Blackbody Radiation
Appendix D - Units and Measures
Note that there are also useful bibliographical notes and a glossary.
December 18, 2014
It this is the dumbed-down version of particle physics, I don't even want to try
November 27, 2022
The term Big Bang (BB) is coined for BBC radio audience by Fred Hoyle. BB is merely extrapolating backward in time the observation that the universe is expanding. It didn’t prescribe exactly how BB happens. Inflationary theories explain how this works. It’s not a precise formulation but the general ideas are somewhat of a consensus (that doesn’t mean it’s true).
First, some important ingredients.
1. false vacuum. This is a state where the energy density is of a local minimum. (Fig. 8.3 explains this well.) Note that this requires enormous energy to create (10^29° and then supper cooled)
2. False vacuum bubble: when a patch of space is in false vacuum surrounded by true vacuum (where energy density is in global minimum).
3. The Penrose theorem that says if matter collapses fast enough to satisfy some criterion, it will become a black hole. Nothing can stop it. (Any tool you bring in only accelerates the matter.)
Inside a false vacuum bubble, the field is such that there is gravitational repulsion, so the bubble want to grow. This is the space itself growing. But a false vacuum bubble will decay really quickly (their half life is measured in 10^-30s). So in a space full of false vacuum bubbles, many will disappear quickly because of decay. (Note that it’s not these false vacuum bubbles expand into true vacuum, it’s the internal “fabric of the space” inside the false vacuum bubble that’s growing. And if there’s high matter density inside such a false vacuum, Einstein tells us that mass bends the space. If you pack 1 oz of matter into a region of 10^-26cm across, the space will bend so much, that a baby universe is born (Fig. 16.4 shows this). And if this initial expansion is fast enough, it’ll be the Penrose theorem of black hole played backward in time (and hence called a while hole). Bingo, you have a new universe created at amazing speed.
All of this is simplification inside analogy wrapped by (my) potential misunderstanding. It didn’t help that Guth likes to go on tangent on irrelevant details of his postdoc life and so on. Nevertheless, as Tyson pointed out “the universe is under no obligation to make sense to you”. A corollary of that is that Alan Guth is under no obligation to make the part in which I’m interested super easy to understand.
First, some important ingredients.
1. false vacuum. This is a state where the energy density is of a local minimum. (Fig. 8.3 explains this well.) Note that this requires enormous energy to create (10^29° and then supper cooled)
2. False vacuum bubble: when a patch of space is in false vacuum surrounded by true vacuum (where energy density is in global minimum).
3. The Penrose theorem that says if matter collapses fast enough to satisfy some criterion, it will become a black hole. Nothing can stop it. (Any tool you bring in only accelerates the matter.)
Inside a false vacuum bubble, the field is such that there is gravitational repulsion, so the bubble want to grow. This is the space itself growing. But a false vacuum bubble will decay really quickly (their half life is measured in 10^-30s). So in a space full of false vacuum bubbles, many will disappear quickly because of decay. (Note that it’s not these false vacuum bubbles expand into true vacuum, it’s the internal “fabric of the space” inside the false vacuum bubble that’s growing. And if there’s high matter density inside such a false vacuum, Einstein tells us that mass bends the space. If you pack 1 oz of matter into a region of 10^-26cm across, the space will bend so much, that a baby universe is born (Fig. 16.4 shows this). And if this initial expansion is fast enough, it’ll be the Penrose theorem of black hole played backward in time (and hence called a while hole). Bingo, you have a new universe created at amazing speed.
All of this is simplification inside analogy wrapped by (my) potential misunderstanding. It didn’t help that Guth likes to go on tangent on irrelevant details of his postdoc life and so on. Nevertheless, as Tyson pointed out “the universe is under no obligation to make sense to you”. A corollary of that is that Alan Guth is under no obligation to make the part in which I’m interested super easy to understand.
August 5, 2017
This is more anecdotal than a rigorous scientific review ...
Fun and instructional read ...
I occasionally would see saw Dr. Guth at MIT in Grad school (at the time I was till an undergrad).
I however knew relatively well his colleague Dr. Henry Tye who went on to become a String Theorist at Cornell (I wound up swithcing to Nuclear Engineering altogether :-))
I read this book a while ago .. I am a lot more interested in QFT ( checkout Huang's book!).
Dr. Guth relates in his book how he first had collaborated with Dr. Tye on a Particle Physics/Cosmology piece of research during a post-doc (at MIT?).
This research led him on to come up with his inflationary theory ...
I (as many others) am uncomfortable with (monetary and :-)) cosmic hyper-inflation.
Space expands (but it is a void expansion????) at a speed much higher than the speed of light.
So what exactly is expanding ? Could it be dark energy and/or matter ?
You heard it here first folks !
But yes, inflation is extremely useful (and necessary) to explains the near "isotropy" of the Universe ....
Fun and instructional read ...
I occasionally would see saw Dr. Guth at MIT in Grad school (at the time I was till an undergrad).
I however knew relatively well his colleague Dr. Henry Tye who went on to become a String Theorist at Cornell (I wound up swithcing to Nuclear Engineering altogether :-))
I read this book a while ago .. I am a lot more interested in QFT ( checkout Huang's book!).
Dr. Guth relates in his book how he first had collaborated with Dr. Tye on a Particle Physics/Cosmology piece of research during a post-doc (at MIT?).
This research led him on to come up with his inflationary theory ...
I (as many others) am uncomfortable with (monetary and :-)) cosmic hyper-inflation.
Space expands (but it is a void expansion????) at a speed much higher than the speed of light.
So what exactly is expanding ? Could it be dark energy and/or matter ?
You heard it here first folks !
But yes, inflation is extremely useful (and necessary) to explains the near "isotropy" of the Universe ....
February 20, 2014
The triumphs of discovering the Comic Inflationary Theory
Alan Guth is one of the outstanding physicists of our times, and it feels great to read this book written about his own discovery. The author reveals one of the deepest secrets about our universe called cosmic inflation. The book documents the drama in his life as a physicist, and his struggle to make a decision about working in the area of monopoles, when he has doubts about his own strength in the field. Being cautious about his calculations and conclusions, feeling low when discouraged, and sometimes ridiculed by his superiors, yet at the same time feeling triumphant when his peers find his work outstanding. The author describes his experience beautifully.
A brief summary of this book is as follows: A natural consequence of the properties of Grand Unified Theories (GUT) is that the universe at a very young age may have gone through a very rapid expansion in a very short time and then returned to a more leisurely rate of growth dictated by the standard big bang theory. Hubble's constant illustrate that the universe is undergoing homogeneous expansion. The first turning event for the author is when physicist Bob Dicke proposed that the value of omega (the ratio of actual mass density to critical mass density) at one second after the big bang was between 0.999999999999999 and 1.000000000000001. If the value was less than this then the universe would have expanded forever and galaxies would never had time to form; on the other hand if the value was slightly more than this, then the universe would have collapsed sooner before it had any chance to grow to this big. This ratio was expected to be very close to one, this is called flatness problem: The big bang theory has no explanation for this ratio. According to general relativity, the mass density of the universe not only slows the cosmic expansion, but it also causes the universe to curve. If the mass density is higher than the critical density; then space curves back on itself forming a spatially closed universe. In such a universe, the sum of the angles a triangle is more than 180°. If the mass density is less than the critical density, then the space is curved in the opposite sense, and the sum of the angles of a triangle would be less than 180°. If the mass density is equal to the critical density, the space is known to be flat, which means that an ordinary Euclidean geometry is valid (the sum of the angles in a triangle is 180°.) The observed universe is remarkably balanced to stay flat!
The second turning point for the author is when physicist Steven Weinberg accounted for the large asymmetry between the baryons (matter) and anti-baryons (antimatter). Since in the early universe protons and neutrons did not exist, but only quarks existed. His calculations showed that for every 300 million quarks there was equal number of anti-quarks less one. At 10exp(-6) seconds after big bang, all matter was annihilated by anti-matter, and the residual matter resulted in the present abundance of matter, but he did not offer an explanation what caused this matter-antimatter inequality. The third problem that needed an explanation is that the big bang theory of Friedman, Lemaitre, Hubble, and others describes the universe as a giant refrigerator cooling and expanding forever, and the remnants of this bang still exists today as an afterglow of 2.7K background microwave radiation. The large scale uniformity of the observed universe is clearly reflected in this, which is known to have been released after 300,000 years of the big bang (before this time the universe was too foggy (dense) for the glow to appear). It has the same temperature in all directions with a remarkable accuracy. Simple calculations show that at this time of the universe, the opposite side of the universe would be separated by a distance 100 horizon distances (90 billion light years), and since light can not travel more than one horizon distance due to specail relativity, it needed an explanation. This is referred to as the horizon problem.
Prior to 10exp(-37) seconds after the big bang, the radius of the universe was only 10exp(-52) meters. At this time GUT predicts that the super-hot matter would have undergone phase transition (sudden change in the behavior of the matter) and the universe went through a tremendous exponential expansion called inflation to spectacular size of 10exp(23) times the size of visible universe. The inflation is driven by the physics of GUT, a patch of false vacuum, volume 10exp(-26) cubic centimeters and a mass of 10exp(-32) solar masses (about 25 grams); this corresponds to a density of (10exp(80) per cubic centimeter; lead to inflation and thus the universe evolves out of nothing at all. The author calls this an ultimate free lunch.
The mechanism of inflation involves false vacuum, which is a peculiar form of matter that existed in the form of fields. This is meta-stable and has negative pressure which creates repulsive gravitational fields that can drive the universe into a period of exponential expansion. After more than 100 doubling time, the inflation stops by forming bubbles. The later theories propose that inflation continues as the fields roll gently towards a minimum energy value, and a single bubble becomes large enough to encompass the entire observed universe. This is called graceful exit problem because end inflation preserves the uniformity. This also solves the horizon problem, the flatness problem and also generates density perturbations that would later become the seeds for galaxy formation. As long as the exponential expansion continues long enough; the value of omega reaches one with great accuracy. As inflation proceeds, the matter that was present at the beginning would be diluted to irrelevance, while space becomes filled with the exquisitely uniform mass density of the false vacuum.
Alan Guth is one of the outstanding physicists of our times, and it feels great to read this book written about his own discovery. The author reveals one of the deepest secrets about our universe called cosmic inflation. The book documents the drama in his life as a physicist, and his struggle to make a decision about working in the area of monopoles, when he has doubts about his own strength in the field. Being cautious about his calculations and conclusions, feeling low when discouraged, and sometimes ridiculed by his superiors, yet at the same time feeling triumphant when his peers find his work outstanding. The author describes his experience beautifully.
A brief summary of this book is as follows: A natural consequence of the properties of Grand Unified Theories (GUT) is that the universe at a very young age may have gone through a very rapid expansion in a very short time and then returned to a more leisurely rate of growth dictated by the standard big bang theory. Hubble's constant illustrate that the universe is undergoing homogeneous expansion. The first turning event for the author is when physicist Bob Dicke proposed that the value of omega (the ratio of actual mass density to critical mass density) at one second after the big bang was between 0.999999999999999 and 1.000000000000001. If the value was less than this then the universe would have expanded forever and galaxies would never had time to form; on the other hand if the value was slightly more than this, then the universe would have collapsed sooner before it had any chance to grow to this big. This ratio was expected to be very close to one, this is called flatness problem: The big bang theory has no explanation for this ratio. According to general relativity, the mass density of the universe not only slows the cosmic expansion, but it also causes the universe to curve. If the mass density is higher than the critical density; then space curves back on itself forming a spatially closed universe. In such a universe, the sum of the angles a triangle is more than 180°. If the mass density is less than the critical density, then the space is curved in the opposite sense, and the sum of the angles of a triangle would be less than 180°. If the mass density is equal to the critical density, the space is known to be flat, which means that an ordinary Euclidean geometry is valid (the sum of the angles in a triangle is 180°.) The observed universe is remarkably balanced to stay flat!
The second turning point for the author is when physicist Steven Weinberg accounted for the large asymmetry between the baryons (matter) and anti-baryons (antimatter). Since in the early universe protons and neutrons did not exist, but only quarks existed. His calculations showed that for every 300 million quarks there was equal number of anti-quarks less one. At 10exp(-6) seconds after big bang, all matter was annihilated by anti-matter, and the residual matter resulted in the present abundance of matter, but he did not offer an explanation what caused this matter-antimatter inequality. The third problem that needed an explanation is that the big bang theory of Friedman, Lemaitre, Hubble, and others describes the universe as a giant refrigerator cooling and expanding forever, and the remnants of this bang still exists today as an afterglow of 2.7K background microwave radiation. The large scale uniformity of the observed universe is clearly reflected in this, which is known to have been released after 300,000 years of the big bang (before this time the universe was too foggy (dense) for the glow to appear). It has the same temperature in all directions with a remarkable accuracy. Simple calculations show that at this time of the universe, the opposite side of the universe would be separated by a distance 100 horizon distances (90 billion light years), and since light can not travel more than one horizon distance due to specail relativity, it needed an explanation. This is referred to as the horizon problem.
Prior to 10exp(-37) seconds after the big bang, the radius of the universe was only 10exp(-52) meters. At this time GUT predicts that the super-hot matter would have undergone phase transition (sudden change in the behavior of the matter) and the universe went through a tremendous exponential expansion called inflation to spectacular size of 10exp(23) times the size of visible universe. The inflation is driven by the physics of GUT, a patch of false vacuum, volume 10exp(-26) cubic centimeters and a mass of 10exp(-32) solar masses (about 25 grams); this corresponds to a density of (10exp(80) per cubic centimeter; lead to inflation and thus the universe evolves out of nothing at all. The author calls this an ultimate free lunch.
The mechanism of inflation involves false vacuum, which is a peculiar form of matter that existed in the form of fields. This is meta-stable and has negative pressure which creates repulsive gravitational fields that can drive the universe into a period of exponential expansion. After more than 100 doubling time, the inflation stops by forming bubbles. The later theories propose that inflation continues as the fields roll gently towards a minimum energy value, and a single bubble becomes large enough to encompass the entire observed universe. This is called graceful exit problem because end inflation preserves the uniformity. This also solves the horizon problem, the flatness problem and also generates density perturbations that would later become the seeds for galaxy formation. As long as the exponential expansion continues long enough; the value of omega reaches one with great accuracy. As inflation proceeds, the matter that was present at the beginning would be diluted to irrelevance, while space becomes filled with the exquisitely uniform mass density of the false vacuum.
December 3, 2022
4.5 stars
July 5, 2020
An interesting book that gives the explanation of the origins of the universe from scratch. This book is a joint description of the story of the universe and Alan Guth's life story and his journey through the realms of physics and cosmology. This combined description makes it easy to retain temporal arrangement of different events during the development of the theory of inflation.
Alan Guth has given a background of the big bang cosmology and an introduction of the standard model, Higg's field and the grand unified theories. He explains how grand unified theories led him to the idea of inflation ie at high energies where the three basic forces (Electromagnetic, Weak nuclear and Strong nuclear forces) were expected to coalesce, there would be super-cooling that would create a false vacuum state which would drive inflation. This false vacuum would decay at various points forming what we can consider "bubbles". These bubbles should then join together forming our universe. He realised how inflation would solve two major problems in the world of cosmology ie the flatness problem and the horizon problem. But later he and others realized that the bubbles formed during the decay of false vacuums wouldn't be able to join and create a universe. This led to the development of the new theory of inflation which suggested that our universe was a pocket universe existing in only one of those bubbles that form during decay of a part of false vacuum. And the heterogeneous bubble front would be enough to create the small scale variations existing in the universe. (Pockets of matter)
This new theory therefore also suggests that our universe would be just one among the many: rather unlimited: universes that would be branching off from the original false vacuum. Hence a multiverse would be an inevitable consequence of inflation.
Also the new theory of inflation had to be modified and was independent of the grand unified theories.
He explains how the theory was corroborated by the results of the COBE satellite but still it was not a proven theory. The beauty of the theory lies in its ability to explain the universe that we live in and to solve the flatness and horizon problems. Still we don't know for sure what exactly caused inflation and it is a matter of speculation. We just know that it is possible to create mathematical models that fit well with inflation. One contender is eternal inflation where a false vacuum has existed forever and pocket universes are branching off from it.
At various places the explanations and calculations were a bit too difficult for me to follow. And sometimes I felt that the explanation could have been simpler. However I did learn a lot from this book. I basically read this book in order to understand how inflation resulted in a multiverse and I feel I have understood it reasonably. Some of the information ofcourse is outdated but still worth a read.
In short, time well spent.
Alan Guth has given a background of the big bang cosmology and an introduction of the standard model, Higg's field and the grand unified theories. He explains how grand unified theories led him to the idea of inflation ie at high energies where the three basic forces (Electromagnetic, Weak nuclear and Strong nuclear forces) were expected to coalesce, there would be super-cooling that would create a false vacuum state which would drive inflation. This false vacuum would decay at various points forming what we can consider "bubbles". These bubbles should then join together forming our universe. He realised how inflation would solve two major problems in the world of cosmology ie the flatness problem and the horizon problem. But later he and others realized that the bubbles formed during the decay of false vacuums wouldn't be able to join and create a universe. This led to the development of the new theory of inflation which suggested that our universe was a pocket universe existing in only one of those bubbles that form during decay of a part of false vacuum. And the heterogeneous bubble front would be enough to create the small scale variations existing in the universe. (Pockets of matter)
This new theory therefore also suggests that our universe would be just one among the many: rather unlimited: universes that would be branching off from the original false vacuum. Hence a multiverse would be an inevitable consequence of inflation.
Also the new theory of inflation had to be modified and was independent of the grand unified theories.
He explains how the theory was corroborated by the results of the COBE satellite but still it was not a proven theory. The beauty of the theory lies in its ability to explain the universe that we live in and to solve the flatness and horizon problems. Still we don't know for sure what exactly caused inflation and it is a matter of speculation. We just know that it is possible to create mathematical models that fit well with inflation. One contender is eternal inflation where a false vacuum has existed forever and pocket universes are branching off from it.
At various places the explanations and calculations were a bit too difficult for me to follow. And sometimes I felt that the explanation could have been simpler. However I did learn a lot from this book. I basically read this book in order to understand how inflation resulted in a multiverse and I feel I have understood it reasonably. Some of the information ofcourse is outdated but still worth a read.
In short, time well spent.
February 2, 2013
Prof. Alan Guth's book about his scientific investigation and subsequent discovery (while a postdoc) of the exponential inflationtary expansion of the universe is consistently brilliant, and one of the best books I've read in a long while. I'm very sure he's going to win a Nobel Prize in the near future for his discovery.
Prof. Guth's intutive physical explanations of complex mathematical ideas (such as the idea of a false vaccum, 'negative' pressure, the higgs field, the analogy between thermodynamic phase transitions in materials and the manifestation of the four fundamental forces by spontaneous symmetry breaking) is very clear and easy to follow.
He also goes to great lengths to talk about the experimental evidence for inflation; a remarkable agreement between the predicted microwave background radiation spectrum and the experimental measurments from the WMAP mission, as well as pointing out how the theory resolves the flatness problem, the horion problem and the magnetic monopole problem.
The 'human' aspect of the various people involved, and the sequence of events that led to the discovery is also refreshing to follow. It's like reading a well-written detective story on the grandest of scales.
When you're awake at 4 in the morning and wondering about life, the universe and everything else, a book like this makes you realize how amazing and mind-boggling reality actually is. As Feynman put it:
I can't recommend this book highly enough.
Prof. Guth's intutive physical explanations of complex mathematical ideas (such as the idea of a false vaccum, 'negative' pressure, the higgs field, the analogy between thermodynamic phase transitions in materials and the manifestation of the four fundamental forces by spontaneous symmetry breaking) is very clear and easy to follow.
He also goes to great lengths to talk about the experimental evidence for inflation; a remarkable agreement between the predicted microwave background radiation spectrum and the experimental measurments from the WMAP mission, as well as pointing out how the theory resolves the flatness problem, the horion problem and the magnetic monopole problem.
The 'human' aspect of the various people involved, and the sequence of events that led to the discovery is also refreshing to follow. It's like reading a well-written detective story on the grandest of scales.
When you're awake at 4 in the morning and wondering about life, the universe and everything else, a book like this makes you realize how amazing and mind-boggling reality actually is. As Feynman put it:
That is a much more exciting story to many people than the tales that other people used to make up about the universe – that we were living on the back of a turtle or something like that. They were wonderful stories, but the truth is so much more remarkable.
I can't recommend this book highly enough.
November 10, 2019
The universe went through a seemingly illegal brief expansion near the 10^-35 second where it went from size=almost nothing, to size=beach ball. But it did this faster than the speed of light as we know it. But this quick spreading out of matter at the very beginning now allows us to look at stars to our left that are 10+ billion light years away, and stars to our right at 10+ billion light years away, and they look the same! Inflation explain the homogeneity of our universe, and other things too. One of the greatest physicists to not (yet) win a Nobel Prize.
February 17, 2022
Excellent book about cosmological inflation, as you might expect, from the man who first proposed it. Nicely written for the non-physicist, entirely comprehensible and fascinating. The theory is widely accepted, has astonishing implications, and it's hard to believe Guth hasn't received the Nobel for it yet. One of the implications is that for our Big Bang, there are two regions on "each side" that will breed their own Big Bangs, with each Big Bang having their own adjacent regions to breed more Big Bang/adjacent regions, ad infinitum. Much more in the book.
October 14, 2020
When I read this book I was wondering whether this is the Alan Guth's autobiography or a work about the theory of inflationary universe. There are many personal issues, so difficult to say. The reasoning could be simpler without it. The very concept of inflationary universe is also presented vaguely and barely understood.
May 19, 2021
An interesting book that accomplished exactly what it sets out to do. Guth does a great job of making the science behind inflationary theory simple enough for the average reader to understand, and yet still complex enough to be mysterious and intriguing.
May 12, 2015
This book is definitely written for the non-scientist. Clear and concise without all that confusing scientific jargon. I'm nerdy, I like space and I loved this book!
January 15, 2024
This is an account of the Inflation model of the universe by none other than his originator Alan Guth. The book contains both the historical account of the development of the inflation model as well as a semi-biographical account of Guth's beginning career in physics written in lucid and direct style like the way Guth's lectures. Even though the book intends to bring an historical account of the inflation model, Guth offers very clear technical detailed discussions in all topics, more technical than most books that are supposed to reach a popular audience.
If you just want to read Guth on inflation, you can probably start reading from chapter 9 "Combatting the Magnetic Monopole Menace". As it is well known that it was working on the magnetic monopole problem that led Guth into the inflation model. However his earlier chapters 3 to 5 on the Big Bang model also provides good insights in his early understanding of cosmology. The theoretical content is somewhat like his "Early Universe" class at MIT. Chapter 5 "Condensation of Primordial Soup" features a good discussion of the 5th particle gap in Big Bang nucleosynthesis pursued by cosmologist which is a topic not often seen in popular cosmology book. The 5th particle gap is the search for a 5th stable nucleus after Helium 4 for nucleosynthesis before arriving at stars interior forming higher elements. Chapter 6 "Matter on Matter/Antimatter offers a good discussion of Steven Weinberg view that Baryon number is not conserved reflecting an asymmetry between matter and antimatter in the early universe.
In terms of the magnetic monopole problem, Guth was looking for an account to explain the small quantity of magnetic monopole. According to the Grand Unified Theory, the early universe should have as many of them as protons and neutrons. Magnetic monopole is 10 to the 16th time heavier than the two baryons. The presence of that many heavy magnetic monopoles would cause the universe expansion rate to plummet making the universe to be 1200 years old! The monopole number has to be 10 to the 24th times lower. Guth came up with a super cooling solution causing a delay of phase transition which would reduce magnetic monopole production. Such delay of phase transition leads to an inflation of the early universe. The initial inflationary model features an exponential expansion in the early universe within the first second caused by a false vacuum to move down to a true vacuum at zero energy density level by quantum tunneling over an energy barrier. The advantage of inflation is not just explaining the Bang of the Big Bang, but it also explains the flatness, homogeneity, horizon problem and offers a solution to magnetic monopole.
Guth is very helpful in the book to highlight some of the technical issues he encountered in the theory. One of which is the bubble collision problem. During the exponential expansion, bubbles can be too far apart that suppress the number of collisions, which may not result in sufficient collision to spread the matter uniformly throughout the universe. Later Guth met Andrei Linde who sidestepped this worry by confining the observable universe to within one bubble thereby avoiding the homogeneity problem of bubbles collision. Guth initially found the approach misguided but Linde's approach eventually result in the new inflationary model. In the new model, the energy density lowers more gradually from a gentler energy slope allowing time for bubbles to expand closer for collision. The graph does not feature quantum tunneling.
Also presented in the book is measurements from COBE satellites of the nonuniformities that are from the gravitational clumping for the structure of the universe expected from the inflationary model. The measurements matched the density perturbation of a scale invariant graph.
This book is no doubt a go to book for anyone to understand how the inflationary model of the universe from both a historical and conceptual point of view. Guth's clear and direct prose makes the journey easy to follow.
If you just want to read Guth on inflation, you can probably start reading from chapter 9 "Combatting the Magnetic Monopole Menace". As it is well known that it was working on the magnetic monopole problem that led Guth into the inflation model. However his earlier chapters 3 to 5 on the Big Bang model also provides good insights in his early understanding of cosmology. The theoretical content is somewhat like his "Early Universe" class at MIT. Chapter 5 "Condensation of Primordial Soup" features a good discussion of the 5th particle gap in Big Bang nucleosynthesis pursued by cosmologist which is a topic not often seen in popular cosmology book. The 5th particle gap is the search for a 5th stable nucleus after Helium 4 for nucleosynthesis before arriving at stars interior forming higher elements. Chapter 6 "Matter on Matter/Antimatter offers a good discussion of Steven Weinberg view that Baryon number is not conserved reflecting an asymmetry between matter and antimatter in the early universe.
In terms of the magnetic monopole problem, Guth was looking for an account to explain the small quantity of magnetic monopole. According to the Grand Unified Theory, the early universe should have as many of them as protons and neutrons. Magnetic monopole is 10 to the 16th time heavier than the two baryons. The presence of that many heavy magnetic monopoles would cause the universe expansion rate to plummet making the universe to be 1200 years old! The monopole number has to be 10 to the 24th times lower. Guth came up with a super cooling solution causing a delay of phase transition which would reduce magnetic monopole production. Such delay of phase transition leads to an inflation of the early universe. The initial inflationary model features an exponential expansion in the early universe within the first second caused by a false vacuum to move down to a true vacuum at zero energy density level by quantum tunneling over an energy barrier. The advantage of inflation is not just explaining the Bang of the Big Bang, but it also explains the flatness, homogeneity, horizon problem and offers a solution to magnetic monopole.
Guth is very helpful in the book to highlight some of the technical issues he encountered in the theory. One of which is the bubble collision problem. During the exponential expansion, bubbles can be too far apart that suppress the number of collisions, which may not result in sufficient collision to spread the matter uniformly throughout the universe. Later Guth met Andrei Linde who sidestepped this worry by confining the observable universe to within one bubble thereby avoiding the homogeneity problem of bubbles collision. Guth initially found the approach misguided but Linde's approach eventually result in the new inflationary model. In the new model, the energy density lowers more gradually from a gentler energy slope allowing time for bubbles to expand closer for collision. The graph does not feature quantum tunneling.
Also presented in the book is measurements from COBE satellites of the nonuniformities that are from the gravitational clumping for the structure of the universe expected from the inflationary model. The measurements matched the density perturbation of a scale invariant graph.
This book is no doubt a go to book for anyone to understand how the inflationary model of the universe from both a historical and conceptual point of view. Guth's clear and direct prose makes the journey easy to follow.
October 23, 2018
Cosmic Inflation has always been a concept I struggle with. I finally bit the bullet and read this autobiographical account from Guth himself of how it came to be. Although the book is a bit dated (it is from a pre Dark Energy era), it is a pretty comprehensive treatment of the evolution of the theory from crackpot idea to widely accepted as the best model we have of the early universe. Along the way, Guth gives some of the most cogent explainers of the Ultraviolet Catastrophe, Quantum Field Theory, Pocket Universes, White holes, child universes, gravitational energy as negative energy, and many other 20th century esoteric physics concepts.
In short, Inflation arose in his quest to explain the non-survival/possible existence (? still not clear on that one) of magnetic monopoles in some (?) Grand Unification Theories (requiring that he think a lot about the physics of the ultra high temperatures of the early Universe). Cosmologically, Inflation solved both the flatness problem and the homogeneity problem (namely why the universe is so uniformly flat (when it is so statistically unlikely) and that it had the same temperature 400,000 years after the Big Bang everywhere when it was too big to come to equilibrium in that amount of time). Along the way, Inflation also (probably) provides a key piece of puzzle of the slight inhomogeneity of matter due to quantum fluctuations in the early universe which gave rise to the structures we find today in the universe.
If all that isn't enough, inflation also plays a key role in the idea that something (the Universe) came come from nothing: Sure all the conserved quantities in the universe are zero, but how did a vacuum fluctuation (or some other concept of nothing) get so big without inflation? Also the scientific idea of the multiverse comes from inflation theory - I never knew that! (Basically, since the ending of the unstable condition of the false vacuum (which causes Inflation) has a half-life, various portions of the larger universe break out into pocket universes at various times. Since the Inflationary and regular expansion rates are so vastly different, this creates various pocket universes that are effectively cut off from each other; we live in one such pocket universe). The beginning of time is (kind of) resolved in that our pocket universe begins with the ending of our inflationary period and we will never be able to pinpoint an earlier 'time' that the greater universe 'began.'
Wow, it's been a while since my mind was so stretched...
In short, Inflation arose in his quest to explain the non-survival/possible existence (? still not clear on that one) of magnetic monopoles in some (?) Grand Unification Theories (requiring that he think a lot about the physics of the ultra high temperatures of the early Universe). Cosmologically, Inflation solved both the flatness problem and the homogeneity problem (namely why the universe is so uniformly flat (when it is so statistically unlikely) and that it had the same temperature 400,000 years after the Big Bang everywhere when it was too big to come to equilibrium in that amount of time). Along the way, Inflation also (probably) provides a key piece of puzzle of the slight inhomogeneity of matter due to quantum fluctuations in the early universe which gave rise to the structures we find today in the universe.
If all that isn't enough, inflation also plays a key role in the idea that something (the Universe) came come from nothing: Sure all the conserved quantities in the universe are zero, but how did a vacuum fluctuation (or some other concept of nothing) get so big without inflation? Also the scientific idea of the multiverse comes from inflation theory - I never knew that! (Basically, since the ending of the unstable condition of the false vacuum (which causes Inflation) has a half-life, various portions of the larger universe break out into pocket universes at various times. Since the Inflationary and regular expansion rates are so vastly different, this creates various pocket universes that are effectively cut off from each other; we live in one such pocket universe). The beginning of time is (kind of) resolved in that our pocket universe begins with the ending of our inflationary period and we will never be able to pinpoint an earlier 'time' that the greater universe 'began.'
Wow, it's been a while since my mind was so stretched...
November 5, 2022
Big Bang then Inflation.
POSTED BY ME AT AMAZON 2002
Big bang, inflation and slower paced expansion seem to properly describe developing stages of our visible Universe today.
This book has been completed just before science accepted "dark energy" as a main ingredient of the Universe and discovery of its current accelerating expansion.
Concept that our Universe grew very early out of rapid inflation is very successful in explaining the flatness, the large scale uniformity of space and origin of visible matter in it, but lacks direct evidence and requires huge extrapolation of laws of physics.
But, never mind: Alan Guth, internationally recognized theoretical physicist and leading actor of the Inflationary Universe theory, writes with passion about his career, mathematical intricacies leading to his proposal in 1979 and further modifications.
You will learn about life, work and personalities of many top cosmologists including father of the big bang George Gamow, master of the black holes Steven Hawking and finally Paul Stainhardt and Andrei Linde - both contributors to advanced forms of inflationary postulate. They all try to shed some light on the events taking place when Universe lasted only the tiniest fraction of a second.
Could it start from nothingness devoid of matter and space?
How about eternally existing multiverses, false vacuum and gravity having negative energy? Are we living in a very tiny corner of the much, much larger cosmos than anyone ever suspected?
Alan Guth's masterpiece represents everything in one volume: classic physics refreshing course, update on particle physics, introduction to modern theoretical cosmology, summary of knowledge derived from observing stars, galaxies and cosmic background radiation, and plans for future projects involving new satellite missions. These satellites will deliver new data and most likely confirm predictions of Inflation theory.
Overall, what I liked the most was a successful attempt to explain role of Higgs particles and very helpful 3D drawings of their energy fields. Higgs fields suppose result in certain kind of particles important for complete understanding of Standard Model of particle physics.
Do not hesitate; even now after three years since being published, "The Inflationary Universe" is still a marvelous, definitely not outdated popular science book full of surprises and mind twisting speculations.
POSTED BY ME AT AMAZON 2002
Big bang, inflation and slower paced expansion seem to properly describe developing stages of our visible Universe today.
This book has been completed just before science accepted "dark energy" as a main ingredient of the Universe and discovery of its current accelerating expansion.
Concept that our Universe grew very early out of rapid inflation is very successful in explaining the flatness, the large scale uniformity of space and origin of visible matter in it, but lacks direct evidence and requires huge extrapolation of laws of physics.
But, never mind: Alan Guth, internationally recognized theoretical physicist and leading actor of the Inflationary Universe theory, writes with passion about his career, mathematical intricacies leading to his proposal in 1979 and further modifications.
You will learn about life, work and personalities of many top cosmologists including father of the big bang George Gamow, master of the black holes Steven Hawking and finally Paul Stainhardt and Andrei Linde - both contributors to advanced forms of inflationary postulate. They all try to shed some light on the events taking place when Universe lasted only the tiniest fraction of a second.
Could it start from nothingness devoid of matter and space?
How about eternally existing multiverses, false vacuum and gravity having negative energy? Are we living in a very tiny corner of the much, much larger cosmos than anyone ever suspected?
Alan Guth's masterpiece represents everything in one volume: classic physics refreshing course, update on particle physics, introduction to modern theoretical cosmology, summary of knowledge derived from observing stars, galaxies and cosmic background radiation, and plans for future projects involving new satellite missions. These satellites will deliver new data and most likely confirm predictions of Inflation theory.
Overall, what I liked the most was a successful attempt to explain role of Higgs particles and very helpful 3D drawings of their energy fields. Higgs fields suppose result in certain kind of particles important for complete understanding of Standard Model of particle physics.
Do not hesitate; even now after three years since being published, "The Inflationary Universe" is still a marvelous, definitely not outdated popular science book full of surprises and mind twisting speculations.
July 22, 2019
کتاب The Inflationary Universe نوشته خودِ آلن گوث است و به داستان شکلگیری ایده تورم توسط خودش میپردازد که با توجه به نقش محوری گوث در این ماجرا، شامل اطلاعات دست اول و بسیار جذابی از داستانِ پیچیده و پر فراز و فرودِ شکلگیری تا همهپذیر و فراگیر شدنِ یک ایده علمی بین دانشمندان است و این باعث میشود علیرغم دستهبندی کتاب در رده کتابهای علمی برای عموم، حتی برای خواننده دانشگاهی نیز اطلاعات ارزشمندی داشته باشد. گوث در ضمنِ این داستان، دو داستان به نظرِ من مهم را هم تعریف میکند،یکی داستان کیهانشناسی نوین و دیگری داستانِ زندگی دانشگاهی خودش؛ که به نظرم هر دوی این داستانها مهم هستند، داستان کیهان شناسی مهم است چون از زبانِ یک کیهانشناسِ برجسته میگوید که کیهانشناسی چگونه با توسل به مشاهده، به حوزهای پویا و مهم تبدیل میشود و اهمیت و موقعیت تورم را در این شاخه توضیح میدهد، داستان زندگی خودش هم مهم است نه به خاطرِ این که او آلن گوث است، بلکه به خاطرِ این که جزئیات زندگی یک محقق تراز اول را شرح میدهد (که بی شباهت به جزئیات باقی انسانها نیست)؛ از نگرانیهای مالی و شغلی گوث گرفته ��ا مشکلاتی مثل بیماری فرزندش و دردسرهای جابهجایی و ....
گوث هنگام نقل کردن داستان کیهانشناسی و انگیزههای نظری خودش، سعی میکند خواننده غیر متخصص را با اصلِ مباحثی که درگیر آن بوده آشنا کند و تلاش بر این بوده که این کار را به زبان غیر فنی و ساده انجام دهد اما به نظرم لذت این کتاب را کسانی بیشتر میچشند که تا حدی مستقلا با داستانِ کیهانشناسی و تورم آشنا باشند. به نظرِ من گوث در سادهسازی مفاهیم -یا بهتر بگویم، عامهسازی مفاهیم- چندان موفق نبوده ( دست کم به اندازه هاکینگ موفق نبوده، شاید اصلا مباحث را نمیتوان بیشتر از این ساده کرد، در واقع به نظرم گوث سعی کرده دقت را فدای سادگی نکند) با این همه، کتاب برای خواننده آشنا به فیزیک میتواند بیاندازه جذاب باشد، چنانچه دست کم برای من بود.
ترجمه این کتاب از انتشارات مازیار به همت جمیل آریایی با عنوان «جهان تورمی، کاوشی برای نظریه منشا کیهانی» در دسترس است که من نیز از همین ترجمه خواندهام. ترجمه کتاب نسبتا خوب و روان است و حتی معادلسازی واژههای تخصصی به فارسی نیز به خوبی انجام شده. تا جایی که در خاطر دارم تنها در معادلسازی چند واژه بیشتر تخصصی میتوان اشکال دید که به نظرم قابل چشم پوشی است.
گوث هنگام نقل کردن داستان کیهانشناسی و انگیزههای نظری خودش، سعی میکند خواننده غیر متخصص را با اصلِ مباحثی که درگیر آن بوده آشنا کند و تلاش بر این بوده که این کار را به زبان غیر فنی و ساده انجام دهد اما به نظرم لذت این کتاب را کسانی بیشتر میچشند که تا حدی مستقلا با داستانِ کیهانشناسی و تورم آشنا باشند. به نظرِ من گوث در سادهسازی مفاهیم -یا بهتر بگویم، عامهسازی مفاهیم- چندان موفق نبوده ( دست کم به اندازه هاکینگ موفق نبوده، شاید اصلا مباحث را نمیتوان بیشتر از این ساده کرد، در واقع به نظرم گوث سعی کرده دقت را فدای سادگی نکند) با این همه، کتاب برای خواننده آشنا به فیزیک میتواند بیاندازه جذاب باشد، چنانچه دست کم برای من بود.
ترجمه این کتاب از انتشارات مازیار به همت جمیل آریایی با عنوان «جهان تورمی، کاوشی برای نظریه منشا کیهانی» در دسترس است که من نیز از همین ترجمه خواندهام. ترجمه کتاب نسبتا خوب و روان است و حتی معادلسازی واژههای تخصصی به فارسی نیز به خوبی انجام شده. تا جایی که در خاطر دارم تنها در معادلسازی چند واژه بیشتر تخصصی میتوان اشکال دید که به نظرم قابل چشم پوشی است.
December 21, 2023
It took me five weeks, but I finally crawled my way through this. Even without use of mathematical formulas this is still dense with scientific theory. It certainly gave me plenty to chew on; enough to satisfy my hard science quota for the year. If you are looking for something beyond the gee-whiz popularization of Michio Kaku or Neil DeGrasse Tyson, but want something a little less dryly didactic than Sir Roger Penrose, this could be for you.
Firstly, this was published in 1997, so a lot has happened in science in the intervening years. I found parts of this book inspired, at a five-star level, but other parts, focusing on the backstory of lectures and conversations and conferences, to be more at a three-star level. Hence my overall rating of four stars. Secondly, the backstory may be interesting one time around, but that’s enough. Chapters One, Ten, and Sixteen, and the beautifully written foreword by Alan Lightman, are what made this book worthwhile for me. There’s plenty here that is still thought-provoking even today.
I never bought into the cyclic universe theory of Penrose, nor the spontaneous generated multi-verse of the string theory advocates, but Guth presents an interesting idea for the spawning of a separate universe from the false vacuum state. He provides a background for calculating the mass density of false vacuums in the Higgs field, and there is also much discussion of the omega density and the geometric flatness problem. Not light reading by any means, but worth the effort if you have the brain bandwidth!
Firstly, this was published in 1997, so a lot has happened in science in the intervening years. I found parts of this book inspired, at a five-star level, but other parts, focusing on the backstory of lectures and conversations and conferences, to be more at a three-star level. Hence my overall rating of four stars. Secondly, the backstory may be interesting one time around, but that’s enough. Chapters One, Ten, and Sixteen, and the beautifully written foreword by Alan Lightman, are what made this book worthwhile for me. There’s plenty here that is still thought-provoking even today.
I never bought into the cyclic universe theory of Penrose, nor the spontaneous generated multi-verse of the string theory advocates, but Guth presents an interesting idea for the spawning of a separate universe from the false vacuum state. He provides a background for calculating the mass density of false vacuums in the Higgs field, and there is also much discussion of the omega density and the geometric flatness problem. Not light reading by any means, but worth the effort if you have the brain bandwidth!
May 24, 2023
This book is a personal narrative of the years surrounding Guth’s discovery of the inflationary paradigm. According to inflation, the universe underwent exponential expansion a small fraction of a second after the Big Bang. Guth delves into the nooks and crannies of this model, keeping the discussion qualitative and mostly understandable to the general reader. He begins by providing background science that was developing in the 1970s, in particular the Grand Unified Theories of particle physics. He moves on to how he arrived at the insight of inflation and the success he achieved with this discovery. Guth then describes subsequent modifications to the initial theory, noting that today, there are a plethora of inflationary theories on the market.
All the while, he intentionally keeps the story a personal one by describing his emotions, his family situation, and his job relocations to remind the reader that even the most revolutionary discoveries are made by ordinary people (who work hard). Having some amount of prior knowledge about cosmology will definitely make this book an easier read, as there are quite a few concepts that are tricky to grasp even for experienced readers. Nevertheless, I would certainly recommend this popular cosmology book for those interested in learning about how our universe may have unfolded right near its beginning.
All the while, he intentionally keeps the story a personal one by describing his emotions, his family situation, and his job relocations to remind the reader that even the most revolutionary discoveries are made by ordinary people (who work hard). Having some amount of prior knowledge about cosmology will definitely make this book an easier read, as there are quite a few concepts that are tricky to grasp even for experienced readers. Nevertheless, I would certainly recommend this popular cosmology book for those interested in learning about how our universe may have unfolded right near its beginning.
November 9, 2024
From the physicist that discovered Inflation, setting straight the mathematics for all of physics following the big bang, this book is immensely readable and a vigorous challenge. Guth sets the scene for future Grand Unified Theories (GUTs or, as he argues should be abbreviated, GUTHs). I highly recommend the chapter about possible fractal universes.
October 25, 2023
greatest discovery?
or this is multiverse....
or this is multiverse....
February 24, 2012
NOTHIN' FROM NOTHIN'
LEAVES SOMETHIN'?
The same mystery that Greek philosophers such as Eudoxus,Aristotle,and Aristarchus,and Ptolemy grabbled with is the same mystery in the sixteenth century,that Copernicus,Kepler,Galileo and Isaac Newton wrestled with.
In 1923 Edwin Hubble shattered the mystery that our galaxy is not alone in the cosmic void. Einstein's theory of a static universe was wrong. When he looked into the sky,he believed the stars were fixed and that the universe was motionless.It was a mystery to him that the universe is expanding.
Alan H. Guth's book "The inflationary Universe" is based on his "Inflation theory" which he states is not a finished story and the details of how inflation works is still a mystery. One of the most pressing unsolved problems in cosmology is the " age-cris". How old is the universe? Guth's inflation theory is a open-ended question if the universe is older than scientists think it is.When Guth says age-crisis he defines it as the expansion rate of the universe{big bang nucleosynthesis:the process which took place between one second and 3-4 minutes after the begining}.Guth is confused but hopeful that he is on the threshold of settling this question. Without the question answered his inflation theory remains unproven.
Alan Guth is brilliant yet it was bothersome for me, a non-scientist, for him to say " the calculations are very simple, and among my fellow scientists I have heard no real skeptism about their validity."
His inflationary theory seems to me an extroidinary 'leap' into extrapolation-----to state that it is relatively easy to calculate the universe backward to one second after the initial big bang? Does he actually think the critical mass calculus for density for the early universe is possible? Guth actually believes his inflation theory allows him to calculate,to 15 decimal places,the mass density of the Milky Way galaxy one second after the big bang?
Throughout his book the question of "why" the universe began in a state of such esquisite uniformity is not addressed. He mentions the Higgs field, false vacuums, quantum fluctuations.He states ,"Blackbody radiation shows us,among other things ,that the universe at 300,000 years was incredibly uniform". Again I ask "why" Guth answer is " Although we do not necessarily understand 'why' the early universe was so uniform,the cosmic background radiation provides direct evidence that it was " he also states " after two thousand years of scientific research, Lucretius was wrong.Conceivably 'everything' can be created from nothing". Sounds like bs to me. Even the singer Billy Preston would not agree as he sang his hit tune "Nothin' from nothin' leaves nothin'.You gotta' have somethin'".
Maybe Alan Guth should read how the Dogon tribe in Africa every 60 years have a celebration called ' sigui' during which the shamans put on mask and perform James Brown like dances based on a cosmic ceremony on the motion of the "Dog Star",Sirius. The Dog Star is the brightest star in the Milky way galaxy and it is in the constellation Canis Major near Orion.
The Dogon tribe have knowledge of Sirius and its ghostly or invisible partner the "White Dwarf"---Sirius B. The first photograph of Sirius B was not taken until 1970. How could a so called primitive tribe know about "Sirius B " in the 1950s? The great American scientists,Carl Sagan in his book "Dragons of Eden" essentially said that it was a joke to think that primitives without any notion of a scientific methodology could be capable of such a feat. He is talking about the information stored in Dogon caves in the form of masks that have hieroglyphic records on them relating to the Dog Star that is more than 5,000 years old and handed down to them from ancient Egyptians astronomers before 3200 B.C.
The difference between the Dogon tribe and Alan H. Guth's "Inflationary Universe" is that there is 5,000 year old empirical evidence---there is no age-crisis.
I believe like the singer Billy Preston "You gotta' have Somethin'". Is that somethin' possibly GOD ?
FINIS
September 23, 2014
A friend asked me how credible the "multiverse" theories are that imagine our universe as just one of a potentially infinite number of eternally generating bubble-universes, and I realized that I lacked even the basic scientific background concerning the Big Bang or the laws of matter and energy to provide an informed answer (or an intelligent guess). So I started looking around for a book that would give me the foundation I need, and I settled on this one, because even though it was written over fifteen years ago, it is by Alan Guth, the co-inventor of the "inflationary universe" model that is the starting point for much of the multiverse talk we hear today — besides which, his ideas on the exponential expansion of the universe in the first microsecond after the Big Bang are now pretty much canon, and will likely win him the Nobel Prize within a few years. So this is not a book of rank speculation and sensationalism, but solid science by a widely respected theorist writing for a popular audience.
Guth's style throughout is remarkably lucid even when dealing with difficult material, and he is also clearly interested in "humanizing" the world of theoretical physics by painting portraits of the major players, their quirks and individual contributions. As one of the major players himself, he knows everyone personally, and he blends the story of his own entry into the field with the excitement of wrestling with new, complex concepts and testing them against the observed world. But while this, and his often whimsical style, are pleasing, what really matters is that this book provides an overview, for those who need one (like me) of the entire history of 20th century cosmology and particle physics, from Einstein's theory of relativity to the discovery by Hubble that the universe is expanding, to the confirmation of the Big Bang theory in the early 1960s with the discovery of the cosmic background radiation, to the development of the standard model of particle physics in the 1970s (quarks, etc.), which led to Guth's own investigations and breakthrough around 1980, when he realized that if our universe had expanded exponentially in the first instants after the Big Bang, this would provide a simple, elegant explanation for a whole series of previously vexing consmological questions (while raising a number of new issues). As someone trained in particle physics but relatively ignorant of early universe theory, a new field for him at the time, Guth is refreshingly humble about the contributions of others that he built upon for his own breakthroughs. His own process of discovery serves as a proxy for us, the readers, as he builds his theoretical foundation step by step.
In summary, I found this book to be an extremely lucid and effective introduction to 20th century theories of cosmic origins, particle physics, and the rich area of overlap between them — because understanding the physics of the Big Bang helps to explain how we have the physical properties we do at the particle level, and vice versa. Guth comes across as a real mensch, lucky enough (if luck is the word) to be at the heart of all this while it was coming together, and his enthusiasm shines through. He makes a convincing case for his core idea of exponential inflation, while admitting that he didn't get everything right and the work of several other researchers was needed to refine the model. Some people may not like that he barely mentions string theory and the more cutting-edge ideas of the last couple of decades, but this isn't the last book I'm likely to read on the subject — rather, it was the first. What I was looking for was a book that would provide a solid conceptual foundation in quantum physics and Big Bang cosmology, written for non-specialists but not dumbed down, while clearly distinguishing what we know almost with certainty from what remains pure speculation. On this last point in particular, Guth does an admirable job. He is, as he says once or twice in the text, someone who wants to make sure he's got the math right before making a claim, and I appreciate that sense of caution. Now, as I venture into the land of more speculative and perhaps sensational theories, I'll have a reliable touchstone to return to as a point of comparison.
Guth's style throughout is remarkably lucid even when dealing with difficult material, and he is also clearly interested in "humanizing" the world of theoretical physics by painting portraits of the major players, their quirks and individual contributions. As one of the major players himself, he knows everyone personally, and he blends the story of his own entry into the field with the excitement of wrestling with new, complex concepts and testing them against the observed world. But while this, and his often whimsical style, are pleasing, what really matters is that this book provides an overview, for those who need one (like me) of the entire history of 20th century cosmology and particle physics, from Einstein's theory of relativity to the discovery by Hubble that the universe is expanding, to the confirmation of the Big Bang theory in the early 1960s with the discovery of the cosmic background radiation, to the development of the standard model of particle physics in the 1970s (quarks, etc.), which led to Guth's own investigations and breakthrough around 1980, when he realized that if our universe had expanded exponentially in the first instants after the Big Bang, this would provide a simple, elegant explanation for a whole series of previously vexing consmological questions (while raising a number of new issues). As someone trained in particle physics but relatively ignorant of early universe theory, a new field for him at the time, Guth is refreshingly humble about the contributions of others that he built upon for his own breakthroughs. His own process of discovery serves as a proxy for us, the readers, as he builds his theoretical foundation step by step.
In summary, I found this book to be an extremely lucid and effective introduction to 20th century theories of cosmic origins, particle physics, and the rich area of overlap between them — because understanding the physics of the Big Bang helps to explain how we have the physical properties we do at the particle level, and vice versa. Guth comes across as a real mensch, lucky enough (if luck is the word) to be at the heart of all this while it was coming together, and his enthusiasm shines through. He makes a convincing case for his core idea of exponential inflation, while admitting that he didn't get everything right and the work of several other researchers was needed to refine the model. Some people may not like that he barely mentions string theory and the more cutting-edge ideas of the last couple of decades, but this isn't the last book I'm likely to read on the subject — rather, it was the first. What I was looking for was a book that would provide a solid conceptual foundation in quantum physics and Big Bang cosmology, written for non-specialists but not dumbed down, while clearly distinguishing what we know almost with certainty from what remains pure speculation. On this last point in particular, Guth does an admirable job. He is, as he says once or twice in the text, someone who wants to make sure he's got the math right before making a claim, and I appreciate that sense of caution. Now, as I venture into the land of more speculative and perhaps sensational theories, I'll have a reliable touchstone to return to as a point of comparison.
July 7, 2014
There are moments where the process of scientific discovery looks a lot like a fumble recovery play in football. The solution is right there in front of you, bouncing in crazy directions, if you could only get your hands on it. In that light, the most revealing anecdote in Alan Guth's intellectual history of cosmic inflation is Steven Weinberg's reaction after learning of Guth's discovery: he allegedly cursed out loud and said he wished he had though of it himself.
Inflation is one of those ideas that is so elegant and useful that most working astronomers assume it (or something like it) must be true even without any direct observational evidence. (The recent BICEP2 discovery of a gravity wave signature in the CMB, if they survive the simmering controversy, would be the first direct evidence for inflation.) As Guth shows, inflation is a logical (or at least likely) consequence of the particle physics revolution of the late 1960s/early 1970s. As an added bonus, it elegantly solves several major conceptual problems with the standard Big Bang theory (the flatness, horizon and monopole problems). All of these ideas were floating around in the mid-70s, but it was Guth who put them all together in a seminal 1980 paper. (In the Soviet Union, the same ideas were advanced independently by Andre Linde and Alexei Starobinsky -- the 3 of whom shared the recent Kavli Prize for the discovery.)
To coherently explain inflation to a lay audience there is a large amount of introductory material that has to be addressed first -- general relativity and the standard Big Bang theory, along with quantum mechanics and the Standard Model of particle physics. Plus some advanced topics like the Higgs mechanism and topological defects. Thankfully Guth is a lucid writer and handles the material efficiently and cleanly. If the experimental discovery holds up, Guth and Co. will probably be heading to Stockholm in a few years and this will be the book every journalist is skimming to get up to speed.
Inflation is one of those ideas that is so elegant and useful that most working astronomers assume it (or something like it) must be true even without any direct observational evidence. (The recent BICEP2 discovery of a gravity wave signature in the CMB, if they survive the simmering controversy, would be the first direct evidence for inflation.) As Guth shows, inflation is a logical (or at least likely) consequence of the particle physics revolution of the late 1960s/early 1970s. As an added bonus, it elegantly solves several major conceptual problems with the standard Big Bang theory (the flatness, horizon and monopole problems). All of these ideas were floating around in the mid-70s, but it was Guth who put them all together in a seminal 1980 paper. (In the Soviet Union, the same ideas were advanced independently by Andre Linde and Alexei Starobinsky -- the 3 of whom shared the recent Kavli Prize for the discovery.)
To coherently explain inflation to a lay audience there is a large amount of introductory material that has to be addressed first -- general relativity and the standard Big Bang theory, along with quantum mechanics and the Standard Model of particle physics. Plus some advanced topics like the Higgs mechanism and topological defects. Thankfully Guth is a lucid writer and handles the material efficiently and cleanly. If the experimental discovery holds up, Guth and Co. will probably be heading to Stockholm in a few years and this will be the book every journalist is skimming to get up to speed.
September 1, 2013
I found the book interesting and a provocative read. No one may ever know what "came before" the Universe. Unless this simulation crashes and the Prime Programmer reveals the mysterious workings and divine code. However, there appears to be little doubt at this point the universe is expanding. The question is now about why, not if. Most people probably don't give much thought to the idea that a) the universe can also refer to the "universe of universes," meaning our universe is but one among a collection, a "bubble among bubbles" and b) we cannot see the entirety of even our own universe, so we have the known universe, or the visible universe, and the parts beyond what we are able to view with current instruments.
This book is a decade old, at least, as I write this. Most of the sensors described at the end have already been put into service, or put into service and decommisioned already. I know there is some excitement among cosmologists that the temperature variation found in the CBE, the thermal axis and the cold spot, may point to a collision with a neighboring universe, or at least indicate interaction with a nearby universe.
I also appreciated the autobiographical accounts of Guth's efforts. People seem to think that all scientists know everything about everything. Guth admits when he runs up against a wall, science outside of his experience. He then turns to people more knowledgeable. Especially in this age of Climate Science, and climate change deniers, people are willing to listen to physicists and chemists and whoever, who may be very good at what they do in their field, but atmospheric science is not their field. Its like getting a second opinion from a pediatrician about kidney disease or a brain tumor. Doctors defer to other doctors who have more experience in a specialty. It's nice to see even particle physicists have problems with math :)
This book is a decade old, at least, as I write this. Most of the sensors described at the end have already been put into service, or put into service and decommisioned already. I know there is some excitement among cosmologists that the temperature variation found in the CBE, the thermal axis and the cold spot, may point to a collision with a neighboring universe, or at least indicate interaction with a nearby universe.
I also appreciated the autobiographical accounts of Guth's efforts. People seem to think that all scientists know everything about everything. Guth admits when he runs up against a wall, science outside of his experience. He then turns to people more knowledgeable. Especially in this age of Climate Science, and climate change deniers, people are willing to listen to physicists and chemists and whoever, who may be very good at what they do in their field, but atmospheric science is not their field. Its like getting a second opinion from a pediatrician about kidney disease or a brain tumor. Doctors defer to other doctors who have more experience in a specialty. It's nice to see even particle physicists have problems with math :)
March 16, 2014
According to the preface, this book was written for the nonscientist. It is designed to explain not only the traditional Big Bang models but also a handful of the many that use author Alan Guth's (b. 1947) idea of inflation, that is, a brief time of exponential expansion of the early universe. Remarkably free of mathematics, it relies instead on graphs, pictures (I like pictures!) and analogies to get the points across. The writing is clear, even lighthearted at times, despite the esoteric topics under discussion. The author uses footnotes frequently, not only to explain in further detail some technical point but also to give biographical background information on a scientist or even to make a joke.
The forward was written by M.I.T professor Alan Lightman who also wrote “Einstein’s Dreams.” In it, he states that the explanatory power of Guth’s theory of the inflationary universe is such that “it has become an underlying assumption of many working cosmologists today.” (p. xi)
Guth starts with a history of physics which covers much of the same ground as beginning textbooks tend to, but somehow make it a whole lot more entertaining. In the first short chapter, he explains the idea of conservation of energy as it developed in the works Parmenides ("Being is ungenerable and imperishable") and Lucretius ("Nothing can be created from nothing") through Lavoisier, Newton, Einstein and others to conclude, in the last sentence, that the universe is the ultimate free lunch. A few footnotes explain things such as the use of scientific notation and vector additions.
Please read the rest of the review here.
The forward was written by M.I.T professor Alan Lightman who also wrote “Einstein’s Dreams.” In it, he states that the explanatory power of Guth’s theory of the inflationary universe is such that “it has become an underlying assumption of many working cosmologists today.” (p. xi)
Guth starts with a history of physics which covers much of the same ground as beginning textbooks tend to, but somehow make it a whole lot more entertaining. In the first short chapter, he explains the idea of conservation of energy as it developed in the works Parmenides ("Being is ungenerable and imperishable") and Lucretius ("Nothing can be created from nothing") through Lavoisier, Newton, Einstein and others to conclude, in the last sentence, that the universe is the ultimate free lunch. A few footnotes explain things such as the use of scientific notation and vector additions.
Please read the rest of the review here.
Displaying 1 - 30 of 44 reviews