cmb_timeline.  Image credit:  WMAP website

Cosmology

Thinking About Time Before the Big Bang

13 Jun , 2008 by

What happened before the Big Bang? The conventional answer to that question is usually, “There is no such thing as ‘before the Big Bang.'” That’s the event that started it all. But the right answer, says physicist Sean Carroll, is, “We just don’t know.” Carroll, as well as many other physicists and cosmologists have begun to consider the possibility of time before the Big Bang, as well as alternative theories of how our universe came to be. Carroll discussed this type of “speculative research” during a talk at the American Astronomical Society Meeting last week in St. Louis, Missouri.

“This is an interesting time to be a cosmologist,” Carroll said. “We are both blessed and cursed. It’s a golden age, but the problem is that the model we have of the universe makes no sense.”

First, there’s an inventory problem, where 95% of the universe is unaccounted for. Cosmologists seemingly have solved that problem by concocting dark matter and dark energy. But because we have “created” matter to fit the data doesn’t mean we understand the nature of the universe.

Another big surprise about our universe comes from actual data from the WMAP (Wilkinson Microwave Anisotropy Probe) spacecraft which has been studying the Cosmic Microwave Background (CMB) the “echo” of the Big Bang.

“The WMAP snapshot of how the early universe looked shows it to be hot, dense and smooth [low entropy] over a wide region of space,” said Carroll. “We don’t understand why that is the case. That’s an even bigger surprise than the inventory problem. Our universe just doesn’t look natural.” Carroll said states of low-entropy are rare, plus of all the possible initial conditions that could have evolved into a universe like ours, the overwhelming majority have much higher entropy, not lower.

But the single most surprising phenomenon about the universe, said Carroll, is that things change. And it all happens in a consistent direction from past to future, throughout the universe.

“It’s called the arrow of time,” said Carroll. This arrow of time comes from the second law of thermodynamics, which invokes entropy. The law states that invariably, closed systems move from order to disorder over time. This law is fundamental to physics and astronomy.

One of the big questions about the initial conditions of the universe is why did entropy start out so low? “And low entropy near the Big Bang is responsible for everything about the arrow of time” said Carroll. “Life and death, memory, the flow of time.” Events happen in order and can’t be reversed.

“Every time you break an egg or spill a glass of water you’re doing observational cosmology,” Carroll said.

Therefore, in order to answer our questions about the universe and the arrow of time, we might need to consider what happened before the Big Bang.

Carroll insisted these are important issues to think about. “This is not just recreational theology,” he said. “We want a story of the universe that makes sense. When we have things that seem surprising, we look for an underlying mechanism that makes what was a puzzle understandable. The low entropy universe is clue to something and we should work to find it.”

Right now we don’t have a good model of the universe, and current theories don’t answer the questions. Classical general relativity predicts the universe began with a singularity, but it can’t prove anything until after the Big Bang.

Inflation theory, which proposes a period of extremely rapid (exponential) expansion of the universe during its first few moments, is no help, Carroll said. “It just makes the entropy problem worse. Inflation requires a theory of initial conditions.”

There are other models out there, too, but Carroll proposed, and seemed to favor the idea of multi-universes that keep creating “baby” universes. “Our observable universe might not be the whole story,” he said. “If we are part of a bigger multiverse, there is no maximal-entropy equilibrium state and entropy is produced via creation of universes like our own.”

Carroll also discussed new research he and a team of physicists have done, looking at, again, results from WMAP. Carroll and his team say the data shows the universe is “lopsided.”

Measurements from WMAP show that the fluctuations in the microwave background are about 10% stronger on one side of the sky than on the other.

An explanation for this “heavy-on-one-side universe” would be if these fluctuations represented a structure left over from the universe that produced our universe.

Carroll said all of this would be helped by a better understanding of quantum gravity. “Quantum fluctuations can produce new universes. If thermal fluctuation in a quiet space can lead to baby universes, they would have their own entropy and could go on creating universes.”

Granted, — and Carroll stressed this point — any research on these topics is generally considered speculation at this time. “None of this is firmly established stuff,” he said. “I would bet even money that this is wrong. But hopefully I’ll be able to come back in 10 years and tell you that we’ve figured it all out.”

Admittedly, as writer, trying to encapsulate Carroll’s talk and ideas into a short article surely doesn’t do them justice. Check out Carroll’s take on these notions and more at his blog, Cosmic Variance. Also, read a great summary of Carroll’s talk, written by Chris Lintott for the BBC. I’ve been mulling over Carroll’s talk for more than a week now, and contemplating the beginnings of time — and even that there might be time before time — has made for an interesting and captivating week. Whether that time has brought me forward or backward in my understanding remains to be seen!

By  -        
Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.


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MrBill
Guest
MrBill
June 13, 2008 3:26 PM

The universe is expanding because when it was created a huge amount of anti-matter and regular matter annihilated each-other, producing incredibly rapid expansion and hurling the remaining matter away from the center of the universe at relativistic speeds.

Entropy increases because our universe only experiences time unidirectionally.

MegaChrist
Guest
MegaChrist
June 13, 2008 2:14 PM

so basically the article is about a bunch of ‘scientists’ whining that the model of the universe they have invented doesn’t make sense. Of course it isn’t going to make sense when you abandon the natural and true idea of God. They struggle and struggle when the answer is right there.

Astrofreak
Guest
Astrofreak
June 13, 2008 1:56 PM

So, what’s with the funny emails?

Hard to believe, an article in here that actually begins with the word “speculative.” You all must have turned over a new leaf!

Kendall
Guest
Kendall
June 13, 2008 2:16 PM

This is what I love about Astronomy! Just wondering and investigating, then wondering even more!

Joe Shmoe
Guest
Joe Shmoe
June 13, 2008 2:17 PM
“Events happen in order and can’t be reversed.” Doesn’t that directly contradict the quantum mechanical principle of unitarity? I think this goes to show that the contradictions between our “theory of large stuff” and our “theory of small stuff” are not confined to extreme cases, but instead produce many irreconcilable inconsistencies in the interpretation of fairly simple observations. There’s a difference between forming a scientific hypothesis which simply lacks support as yet, and forming a philosophical speculation that’s incapable of being established even circumstantially. There’s nothing wrong with philosophy, but it’s not consubstantial with science and shouldn’t be treated as such. I’m not saying that this crosses the line, it’s just something to be aware of and cautious… Read more »
Al Hall
Member
Al Hall
June 13, 2008 3:42 PM
I have no data, nor have I attempted to try any experiments… But I have been drunk a few times, and I think it is possible that the Big Bang was created from the “other side” of a super massive black hole that ‘ate’ -it is my understanding that they break everything down to at least the atomic level- for billions (if not more) years, then finally reached a critical mass and exploded (out the other side) to create the universe as we know it. And I will go a step further and say this is probably commonplace with countless other “universes” out there. Although I believe there can be only one universe and all of the other… Read more »
Al Hall
Member
Al Hall
June 13, 2008 3:46 PM

OOPS.. Sub-atomic…

MegaChrist – Are you here just to piss people off, or trying to convert them… Or perhaps just to stimulate debate? smile

Ry
Guest
Ry
June 13, 2008 4:13 PM
MegaChrist, what an awesome name, Im going to say that whenever something shocks me from now on. I dont see why anyone would logically choose to believe in god. It seems so self-indulgent to think that because that which cannot be explained, however, seems like it can by a method that feels like it makes sense. Aside from that being sloppy science, personally how can that ever be fulfilling? To believe in anything as if that belief somehow stood for a truth beyond the desire to think it so? I would not be able to live inside myself and impose my imagination on a universe that was beyond that size, at least not willingly. This isnt an attack… Read more »
Polaris93
Member
June 13, 2008 11:27 PM

MegaChrist seems to be comfortable with a very small God — most of us aren’t. That said, “I don’t know” and “we don’t know” can often be more productive, scientifically speaking, than any version of “We have all the answers.” It’s good to see cosmologists beginning to explore and publicly report on aspects of their field of study that we really don’t know much about, however strange and vexing these may be. This is how we grow up, culturally and scientifically, and come to fit a much larger universe than the one we knew as children. No God worth His salt would dislike that. smile

Sili
Member
Sili
June 13, 2008 4:43 PM

So why, pray tell, did God make the universe lopsided, mr Megachrist?

And no, “he works in mysterious ways” is not an acceptable answer.

trux
Guest
June 13, 2008 5:46 PM

I wonder why MegaChrist is visiting this blog (other than provocation). When he really believes that God is the answer for everything, and that there is no need for searching how things work, because it is God is the answer for everything, then there is no need for astronomy, physics, mathematics, biology, medicine, … or any other science. We all should better turn into theologists, and only study the Bible instead. With this attitude we would be still in the Stone Age, or better told on the trees – arrgh I forgot that Evolution is the wrong theory too! We all came from the apple sin in fact. Or was it the snake who fertilized Eve?

Mars
Guest
Mars
June 13, 2008 6:43 PM

MegaChrist knows what he is talking about and the rest of you punks don’t. 2012 is coming 53 representing!!!

Mars
Guest
Mars
June 13, 2008 6:46 PM

53 you heard me he is right and the rest of you are high school dropouts!

Mars
Guest
Mars
June 13, 2008 6:50 PM

If you got a problem with MegaChrist you got a problem with me! And if you don’t believe in God well then how do you suppose the universe came to be? And don’t say “we’re working on it.”

c-lab
Member
c-lab
June 13, 2008 7:58 PM
OK Mr Mars, and Mr MegaChrist, I sincerely hope at least one of you is kidding around. God is the only answer! “I have a cold” – “God!” “Gas is over $4 a gallon” – “God” “I’m bored on a Friday night” – “God!” So, the end is neigh! Really ?!? REALLY?!? And it’s all Gods will, huh? There are so many good arguments logically tackling that – but its a futility of effort, some people just do not want to talk. Look, how many apocalypse predictions have there ever been – for thousands of years people have started cults, religions, hell, wars over jsut that. Haven’t panned out though – we’re still here writing comments on Universe… Read more »
Al Hall
Member
Al Hall
June 13, 2008 8:44 PM

I could be wrong, but didn’t some guy say we were going to be in a nuclear war yesterday?…. I can only imagine what his followers are thinking today… Or what his sermon will sound like tomorrow..

c-lab
Member
c-lab
June 13, 2008 9:01 PM

Exactly!

My only fear is that someday some nut is going to predict the end of the world – and have the means to effect it!

Such is the tenuous nature of life… c’est la vie!

Steffen
Guest
Steffen
June 13, 2008 9:30 PM

Dear Mega Christ and others please take your discussion to your Christian science fair where all questions are taken care of to your liking. It is great that you have the answers to everything but some people like the one that enjoy reading this blog might prefer things to be a bit more complex. And before you write anything else please tell us that you at least know what “entropy” means.

Otherwise I do like the black hole idea – even though it’s rather science fiction (for now).

SkepticTim
Member
SkepticTim
June 13, 2008 9:41 PM
I find question concerning times arrow, entropy and the association between entropy and information very interesting. I speculate as follows: Viewing the universe as the ultimate information processor and invoking Landauer’s Principle, if entropy is at a minimum at the instant of the “big bang”, information is a maximum at that instant. If the universe then evolves towards a point where eventually entropy reaches a maximum value (near infinite) then the universes information content evolves towards zero. If I make the assumption that “information” may be equated in some way with “existence”. I.e. For an entity to exist, that entity must be associated with information: otherwise we have no way of knowing that it exists. An entity that… Read more »
Al Hall
Member
Al Hall
June 13, 2008 9:57 PM

ScepticTim –
Sorry… I probably can’t enlighten you or provide an enlightening comment………. What???
So….. If possible…. In one or two paragraphs, … What happened before the Big Bang?

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