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Once Before Time: A Whole Story of the Universe
In 2000, Martin Bojowald, then a twenty-seven-year-old post-doc at Pennsylvania State University, used a relatively new theory called loop quantum gravity—a cunning combination of Einstein’s theory of gravity with quantum mechanics—to create a simple model of the universe. Loop quantum cosmology was born, and with it, a theory that managed to do something even Einstein’s general theory of relativity had failed to do—illuminate the very birth of the universe.
Ever since, loop quantum cosmology, or LQC, has been tantalizing physicists with the idea that our universe could conceivably have emerged from the collapse of a previous one. Now the theory is poised to formulate hypotheses we can actually test. If they are verified, the big bang will give way to the big bounce. Instead of a universe that emerged from a point of infinite density, we will have one that recycles, possibly through an eternal series of expansions and contractions, with no beginning and no end.
Bojowald’s major realization was that unlike general relativity, the physics of LQC do not break down at the big bang. The greatest mystery surrounding the origin of the universe is what cosmologists call the big bang “singularity”—the point at the beginning of the universe, prior to the existence of space and time, when gravity, along with the temperature and density of the universe, becomes infinite. The equations of general relativity can’t cope with such infinities, and as a result big bang theory has never been able to give any explanation for the initial condition of our universe, succeeding only in describing and explaining the evolution of the universe from that instant onward. Bojowald’s theory takes us right up to the first moment of the universe—and then back, even before the big bang itself.
Ever since, loop quantum cosmology, or LQC, has been tantalizing physicists with the idea that our universe could conceivably have emerged from the collapse of a previous one. Now the theory is poised to formulate hypotheses we can actually test. If they are verified, the big bang will give way to the big bounce. Instead of a universe that emerged from a point of infinite density, we will have one that recycles, possibly through an eternal series of expansions and contractions, with no beginning and no end.
Bojowald’s major realization was that unlike general relativity, the physics of LQC do not break down at the big bang. The greatest mystery surrounding the origin of the universe is what cosmologists call the big bang “singularity”—the point at the beginning of the universe, prior to the existence of space and time, when gravity, along with the temperature and density of the universe, becomes infinite. The equations of general relativity can’t cope with such infinities, and as a result big bang theory has never been able to give any explanation for the initial condition of our universe, succeeding only in describing and explaining the evolution of the universe from that instant onward. Bojowald’s theory takes us right up to the first moment of the universe—and then back, even before the big bang itself.
309 pages, Hardcover
First published April 1, 2009
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Displaying 1 - 25 of 25 reviews
February 8, 2022
In relativitatea generala, spatiu-timpul are o structura continua care ii permite sa colapseze in singulatitati (volum zero, densitate infinita, timp zero), cum sunt cele din gaurile negre si Big Bang. In gravitatia cuantica cu bucle, pe de alta parte, spatiu-timpul are o structura discreta. E format din subunitati numite bucle. Cantitatea de energie care poate fi stocata in structura cu bucle este finita. Astfel se evita singularitatile. Universul colapseaza, apoi ricoseaza, dupa care intra in expansiune.
Intrebarea "ce a fost inainte de Big Bang?" are sens in gravitatia cuantica cu bucle. Teoretic ar trebui sa vedem dovezi indirecte, chiar data intervine un asa-numit principiu de "uitare".
Nu este o lectura usoara.
Intrebarea "ce a fost inainte de Big Bang?" are sens in gravitatia cuantica cu bucle. Teoretic ar trebui sa vedem dovezi indirecte, chiar data intervine un asa-numit principiu de "uitare".
Nu este o lectura usoara.
November 29, 2010
The first third of the book is a condensed and meager survey of physics up to the standard model. Sigh.
I'm not sure where the author is going with this, but he labels String Theory as "monotheistic" and Loop Quantum Gravity as "pantheistic"... yuck.
The random digressions into science fiction are jarring and confusing.
They butt against the scientific arguments in a way that can only be inferred as intentionally deceiving!
One chapter argues that entropy cannot be used to define the arrow of time.
You can see this is wrong by tasking a child with organizing still frames of a film showing a coffee mug shatter into pieces.
The child identifies the ordered state, called entropy, which is the only indication of the arrow of time.
This same chapter also contains an argument that the early universe need not have had low entropy.
So his argument goes, gravity is responsible for the low entropy of stars, galaxies, etc.
The problem with this argument is it supposes that it is just as likely to find a universe full of hot gas as to find a universe full of stars and galaxies.
It clearly is not!
Now, inexplicably, is a chapter on MYTHOLOGY, YUCK!
The author actually seems to be proposing Buddhist mythology as evidence supporting his argument for a recurring universe.
I can sympathize, because he's got no other evidence...
His only argument against the big bang as the first event is that general relativity doesn't adequately describe the singularity.
As he would agree, hope to find a theory of quantum gravity which succeeds in describing the first plank.
But the fact of it's possible existence is no reason to believe this theory WILL or WON'T be cyclic!
I'm not sure where the author is going with this, but he labels String Theory as "monotheistic" and Loop Quantum Gravity as "pantheistic"... yuck.
The random digressions into science fiction are jarring and confusing.
They butt against the scientific arguments in a way that can only be inferred as intentionally deceiving!
One chapter argues that entropy cannot be used to define the arrow of time.
You can see this is wrong by tasking a child with organizing still frames of a film showing a coffee mug shatter into pieces.
The child identifies the ordered state, called entropy, which is the only indication of the arrow of time.
This same chapter also contains an argument that the early universe need not have had low entropy.
So his argument goes, gravity is responsible for the low entropy of stars, galaxies, etc.
The problem with this argument is it supposes that it is just as likely to find a universe full of hot gas as to find a universe full of stars and galaxies.
It clearly is not!
Now, inexplicably, is a chapter on MYTHOLOGY, YUCK!
The author actually seems to be proposing Buddhist mythology as evidence supporting his argument for a recurring universe.
I can sympathize, because he's got no other evidence...
His only argument against the big bang as the first event is that general relativity doesn't adequately describe the singularity.
As he would agree, hope to find a theory of quantum gravity which succeeds in describing the first plank.
But the fact of it's possible existence is no reason to believe this theory WILL or WON'T be cyclic!
July 28, 2011
Having finished the book I am surprised that it has a low rating. It is a good review of the state of current physics. To me it is one of the only books that gets to the bottom of the difference between String Theory and Loop Quantum Gravity without going into the mathematics. I don't think a book could go much further than this in reviewing physics without recourse to mathematics.
You have to be somewhat on his wavelength (no pun intended) to read this book with much joy or understanding. It is not the best book if you haven't got to the point of pondering the difficulties relating to a "true void" and the need to create space-time and not take it as a given.
Also, the use of relevant science fiction snippets makes absolute sense in what he is trying to achieve. Well worth reading at some point.
You have to be somewhat on his wavelength (no pun intended) to read this book with much joy or understanding. It is not the best book if you haven't got to the point of pondering the difficulties relating to a "true void" and the need to create space-time and not take it as a given.
Also, the use of relevant science fiction snippets makes absolute sense in what he is trying to achieve. Well worth reading at some point.
May 27, 2017
Exciting telling of interesting solution for reconciling very big with the very small, but the science of loop quantum gravity still needs flushing out before it can claim the crown, and since I've read this book I've seen very little growth in this area, but I can say the same for Suzy.
January 13, 2019
Well, it was about the time. Happy New Year :))
April 5, 2021
Fizica cuantica pe intelesul tuturor. Nu ai nevoie de cunostinte avansate pentru a intelege conceptele prezentate.
March 29, 2025
PRO: Martin’s got jokes
CON: Other than the jokes, I’m not sure I understood a single thing Martin was talking about
Additional CON: When this book was written, I was in 8th grade, Stephen Hawking was still alive, and we had no experimental verification of gravitational waves. So you could say it’s a little out of date.
CON: Other than the jokes, I’m not sure I understood a single thing Martin was talking about
Additional CON: When this book was written, I was in 8th grade, Stephen Hawking was still alive, and we had no experimental verification of gravitational waves. So you could say it’s a little out of date.
July 4, 2011
a physics prof describes the theory of loop quantum gravity, an alternative to string theory apparently, which proposes a contracting universe prior to the big bang and purportedly solves a problem faced by quantum mechanics + general relativity in explaining a "singularity".
As he acknowledges, there is currently no way of testing loop quantum gravity against observations, which lessened my enthusiasm for attempting to figure it out. Enthusiastic or no, my 10th grade physics from 35 years ago was most likely not up to the challenge. It's said to be a lay presentation of the theory, but not lay enough for me.
The two aspects of the writing that I could follow were uninteresting. He throws in frequent Nietzche quotes, science fiction excerpts, analogies with origin myths from various cultures, etc., I guess to make the material more relate-able, but at least in my reading this effect was not achieved. He also hints several times at political intrigue within the small community of loop quantum gravity theorists but never explains any aspect of it in enough detail that you can form an opinion about who did what to whom.
As he acknowledges, there is currently no way of testing loop quantum gravity against observations, which lessened my enthusiasm for attempting to figure it out. Enthusiastic or no, my 10th grade physics from 35 years ago was most likely not up to the challenge. It's said to be a lay presentation of the theory, but not lay enough for me.
The two aspects of the writing that I could follow were uninteresting. He throws in frequent Nietzche quotes, science fiction excerpts, analogies with origin myths from various cultures, etc., I guess to make the material more relate-able, but at least in my reading this effect was not achieved. He also hints several times at political intrigue within the small community of loop quantum gravity theorists but never explains any aspect of it in enough detail that you can form an opinion about who did what to whom.
September 16, 2012
wow!
Somewhere i read about that the whole mathematik get changed by
him and his work...???
Hmm
So i inscribied 2009 to the Astronomie Institut at the
University in Vienna and read the book :d
The stuff at University was nearly the same, so i
got the answer to my question
about the ... the integral from Bojowald :d
It is verry good written. Also all stuff is clearly
understandable and you can figer it out, what the
book is about and :d how to manage to live with
such tiny things.
August 20, 2012
Theoretical Physics intrigues everyone but nobody really knows anything about it. In the same vein as "The Elegant Universe" by Greene, Bojowald does a good job of introducing the laymen to a very new, and very advanced topic. You like String Theory? You like being the center of attention at cocktail parties? Learn about Loop Quantum Gravity and impress the guests.
August 13, 2011
I think it was a little above my head all in all. My favorite parts were when he went on little tangents about something in pop culture (or really nerd culture) that tied into his basic topic, such as explaining scientific issues with star trek technology.
April 30, 2016
This might be an interesting book, but you have to have a more thorough knowledge of physics. So, by rating as I did, I am not dismissing the book, but rather badly my lack of insight for missing out so much of what could possibly be a really great book.
December 16, 2016
When does the universe continue?
When is at the end of the universe?
When is at the beginning of the universe?
Where is at the end of the universe?
What is any black holes? What is dark matter and dark energy?
The book answers these questions.
When is at the end of the universe?
When is at the beginning of the universe?
Where is at the end of the universe?
What is any black holes? What is dark matter and dark energy?
The book answers these questions.
September 14, 2011
The intro to this book indicates it's written for the common man. I would submit, not so. Complex read and at times brutal.
October 22, 2020
Fantastic work! No math, ok, one wave-function, everything explained in plain english.
October 5, 2022
The book's primary focus is on the author's pet theory "loop quantum gravity" which is an alternative to the more popular string theories. The main goal is to bridge the gap between general relativity and quantum mechanics, both of which are spectacularly successful, yet inherently incompatible. One of the advantages of the author's approach is that it largely eliminates the pesky singularities that pop up, such as the one at the heart of the Big Bang theory. The details of the theory itself are ultimately not critical, and despite some early promise hasn't progressed that much in the past 2 decades.
But the book is still highly interesting, peppered throughout with quotes from [mostly German] philosophers and long asides into science fiction, mythology, and philosophy, supplemented with the author's sharp wit (often delivered in the form of acerbic commentary in footnotes). As the author cautions in the conclusion, it is dangerous to become too enamored with established ideas, and we ought to seek out alternate paths [such as his] in order to better understand the universe and our place in it.
Not the best introductory text to the subject, I would read a few more popular introductions to the topics before tackling this one. But if you are comfortable with the basics of relativity, quantum stuff, and cosmology, it's a worthwhile read.
But the book is still highly interesting, peppered throughout with quotes from [mostly German] philosophers and long asides into science fiction, mythology, and philosophy, supplemented with the author's sharp wit (often delivered in the form of acerbic commentary in footnotes). As the author cautions in the conclusion, it is dangerous to become too enamored with established ideas, and we ought to seek out alternate paths [such as his] in order to better understand the universe and our place in it.
Not the best introductory text to the subject, I would read a few more popular introductions to the topics before tackling this one. But if you are comfortable with the basics of relativity, quantum stuff, and cosmology, it's a worthwhile read.
December 22, 2022
Estamos ante un libro de referencia para comprender como a través de la historia se ha entendido las fases iniciales del universo, con todas las complicaciones que esto conlleva. Además de explicar con relativa claridad una opción de interpretación de la estructura cuántica del mundo la "teoría de gravitación cuántica de bucles".
En su recorrido nos lleva por la explicación de teorías como la gravitación de Newton, la relatividad general, la relatividad especial, la teoría de cuerdas, la teoría inflacionaria, y algunas más, acompañado de la exposición de los límites de cada una de ellas y una visión filosófica y cosmogonía del asunto.
Si bien el libro en algunas partes se hace algo denso, la manera de explicar del autor hace menos difícil su comprensión, es recomendable para personas que ya tengan un acercamiento con la física, aunque no es necesario ser un experto.
En su recorrido nos lleva por la explicación de teorías como la gravitación de Newton, la relatividad general, la relatividad especial, la teoría de cuerdas, la teoría inflacionaria, y algunas más, acompañado de la exposición de los límites de cada una de ellas y una visión filosófica y cosmogonía del asunto.
Si bien el libro en algunas partes se hace algo denso, la manera de explicar del autor hace menos difícil su comprensión, es recomendable para personas que ya tengan un acercamiento con la física, aunque no es necesario ser un experto.
June 29, 2022
I like this book explains and talks about the subject matter. I give this an overall score of 3.78 (my rule is to always round down). Definitely worth to read if you find theoretical physics and its application in the real world interesting. Stay away if you get existential crises easily from understanding your own relative size to that of the universe lol!. Nihilists welcome (please note this book is not a philosophy book though it does make a few philosophy references this is merely just my own humor) !
All in all I would say that Thad Roberts's "Einstein's intuition" is more accessible and to some extent more entertaining. this is a good follow-up to that and goes more in depth into quantum gravity which ties in nicely with my understanding of Bohmian mechanics.
All in all I would say that Thad Roberts's "Einstein's intuition" is more accessible and to some extent more entertaining. this is a good follow-up to that and goes more in depth into quantum gravity which ties in nicely with my understanding of Bohmian mechanics.
August 20, 2024
.... no logra desarrollar algo nuevo, o al menos diferente
February 22, 2015
Es una gran obra que nos actualiza de una manera amena la situación actual dentro de las teorías en física en camino hacia una teoría del todo o unificada. El autor muestra su gran cosecha en el campo de la física pero también nos muestra una capacidad de exposición apta para un público no muy inmerso en estos temas, además de los elementos de filosofía, teoría del conocimineto, epistemología y religión que han enriquecido la visión cr´ticia que tiene sobre el trabajo teórico realizado.
Debo admitir que no pude digerir del todo algunas cuestiones de teoría física y supongo que no seremos pocos los que nos sentimos así (quienes no hemos estudiado ciencias) pero sí se nota que el autor nos ha querido mostrar de una manera más comprensible todo aquello.
Debo admitir que no pude digerir del todo algunas cuestiones de teoría física y supongo que no seremos pocos los que nos sentimos así (quienes no hemos estudiado ciencias) pero sí se nota que el autor nos ha querido mostrar de una manera más comprensible todo aquello.
December 31, 2011
Difficult book to get through. The two pieces I found important were the explanations regarding why electrons don't fall into the nucleii. (Hula hoop effect of electron wave function which due to repulsion does not allow it.) And also the reason for discrete electron shells, relating to wave length and interference which only allows for increases by quanta.
This entire review has been hidden because of spoilers.
August 21, 2013
Todo parece muy poco convincente
February 26, 2015
[Audiobook] Couldn't follow this book anymore. This guy's voice kept putting me to sleep!
Read
December 18, 2015I quit after chapter 5.
Read
April 23, 2018Una revolucionaria teoría sobre el origen del universo y qué pasó antes del Big Bang. En su conocida obra Historia del tiempo, Stephen Hawking afirmaba que preguntar qué había antes del origen del universo es tan absurdo como preguntar qué hay al norte del polo Norte. Desde Einstein, el Big Bang era la última frontera que ningún físico se atrevía a cruzar. Incluso para la teoría general de la relatividad ese punto ha sido considerado una singularidad que no se puede calcular y cuyas reglas físicas no están definidas. Es el punto en que comienza para nosotros el universo. Pese a todo ello, seguimos haciéndonos las mismas preguntas: ¿Qué había antes del Big Bang? ¿Cómo nació el universo? El joven físico Martin Bojowald da respuesta gráficamente y sin fórmulas. Sus asombrosos descubrimientos sobre un mundo desconocido y emocionante, con tiempo negativo, inversión de la orientación espacial y un cosmos que se contrae para expandirse después del Big Bang actualizan viejos modelos cosmológicos sobre los ciclos de expansión y colapso del universo. Reseña:«Bojowald consigue lo que Einstein y sus sucesores no consiguieron: llegar al punto temporal cero.»Wissenschaft im Brennpunkt
Displaying 1 - 25 of 25 reviews