Is the Big Bang Theory Really Wrong?

[pmb_phy]

I took a look at the wrong claims thread today to find out that its closed. There is something I'd like to mention at this point. An example used in the link http://math.ucr.edu/home/baez/RelWWW/wrong.html has an example that is not quite logically correct. The topic is "The Big Bang Theory Is Wrong." The author states

This one gets the most space, perhaps since the idea of a beginning (particularly a violent beginning) to the Universe seems to trouble many nonscientists (and even some scientists).

The Big Bang theory does not say that the universe has a beginning. What it states is that at a particular time there was a rapid explosion/expansion. Theorists can't explain what happened at this time. They can only come very close to t = 0, never mind discussing what happened before t = 0. "Pure" Big Bang theorists even consider the later to be an invalid question. There is a new theory which goes beyond the current picture of the Big Bang and addresses what came before it. This new theory is aptly named Pre-Big Bang Cosmology.

Two major players in this game are G. Veneziano and M. Gasperini. I found the website of the later.

http://www.ba.infn.it/~gasperin/

Pete
Tw

 

[Garth]

Thank you Pete, is their theory falsifiable?

Garth

 

[pmb_phy]

Thank you Pete, is their theory falsifiable?

Garth

I believe so since in that link they discuss tests for the theory.

Pete

 

[Garth]

Ah yes, I found that as well: Are pre-big-bang models falsifiable by gravitational wave experiments? The test is the "presence of a stochastic background of relic gravitational waves in the frequency band accessible to Earth-based detectors." Hoping of course that we can detect gravitational waves in the first place!

Garth

 

[SHtRO]

First let me say I don't BELIEVE the commonly stated Big Bang theory, but I'm not saying it's wrong. I'm just saying I'm not CONVINCED. There are holes in my knowledge, but also weaknesses in the theories. For instance, up until this past year or so there was much talk of "open" and "closed" Universe, but recent (WMAP) observations seem to demonstrate the Universe is flat. Another example is the repeated amazement at unpredicted observations (# of galaxies in our field of view for example).

Much of the data on the (very excellent) document mentioned here is dated and needs to be updated to match current cosmological observations.

I don't feel bad for not "getting it" if I don't. We all have enormous holes in our knowledge (i.e. TIME, GRAVITY). We don't even know WHY c is a constant, just THAT it is. I "get" RELATIVITY and that is satisfying. I "get" QM and that is satisfying.

Unfortunately for me, everytime I almost "buy in" to Big Bang, something comes along to shake my confidence in it. I think the whole idea of BIG BANG is a cultural phenomenon related to the times of Hubble and Einstein. If the redshift was originally misinterpreted as a doppler effect, then all that follows is equally misinterpreted. Our adherence to BIG BANG may very well be preventing such scientific advances as unification of magnetism and gravity.

Note, I'm not saying that BIG BANG is wrong. I'm not saying that BIG BANG is preventing scientific advance (it is actually propelling it!). I'm saying that BIG BANG is often justified by BIG BANG. I'm saying that everytime I hear the words "proof of the Big Bang" or "what the Universe was like at the beginning" I cringe. That is not science, that is religion. Many other scientists and non-scientists have great confidence in the theory and I laud them. I'm just not one of them.

I have numerous issues which I hope to resolve for myself in these fora so I ask that I not be treated as a crackpot if I seem so wrong.

I also promise to be nice (or at least polite).

 

[yogi]

Expansion may or may not require a finite beginning - if expansion is exponential or logrithmic, time might simply be a diminishing standard where the increments perpetually shrink to an infinitely small length. The Big Bang may not be a beginning but a moment where things rapidly get altered - an era where the gravitational force changes from something previous to its present strength.

 

[JesseM]

The Big Bang theory originally came out of general relativity, and if you assume that general relativity exactly describes gravity in our universe, then as I understand it, it's possible to prove that this expanding hot dense state must have began in a singularity, in which case it doesn't make sense to talk about what happened before it, so the singularity really is "the beginning". But of course, most physicists nowadays don't believe general relativity is exactly accurate, and hope to find a theory of quantum gravity which will eliminate the singularities in GR. The "pre-big bang cosmology" you mention is based on ideas about quantum gravity. So I don't think the statement on Baez's page is really wrong, you just have to understand that they're talking about the big bang theory in the context of general relativity.

 

[Phobos]

I took a look at the wrong claims thread today to find out that its closed.

It's been closed for over a year. It's a good general resource we keep on-hand to help introduce this forum.

There is a new theory which goes beyond the current picture of the Big Bang and addresses what came before it. This new theory is aptly named Pre-Big Bang Cosmology.

Appears to be a String Theory/M-Theory website. Better discussed in our String Theory forum? (https://www.physicsforums.com/forumdisplay.php?f=66) Unless you want to discuss it with a slant more toward Relativity?

 

[pmb_phy]

Howdy Phobos

Actually I was hitting on it from the perspective of how one can't jumpt to conclusions regarding certain things in physics which may first seem obvious. I explained what I meant on this in my first post. Perhaps this thread then belongs in Cosmology?

Thanks

Pete

 

[pmb_phy]

The Big Bang theory originally came out of general relativity, and if you assume that general relativity exactly describes gravity in our universe, then as I understand it, it's possible to prove that this expanding hot dense state must have began in a singularity, in which case it doesn't make sense to talk about what happened before it, so the singularity really is "the beginning".

I believe that to be an inaccurate notion. We're talking about a quantum singularity and not a singulary in spacetime. It seems reasonable to me to speak of a quantum singularity as being describable by a time parameter since such an object may be able to have structure which evolves with time. This part is not touchable by GR. It gets into QM/string theory

But of course, most physicists nowadays don't believe general relativity is exactly accurate, and hope to find a theory of quantum gravity which will eliminate the singularities in GR. The "pre-big bang cosmology" you mention is based on ideas about quantum gravity. So I don't think the statement on Baez's page is really wrong, you just have to understand that they're talking about the big bang theory in the context of general relativity.

Hence people who might argue that BB is not as it seems is not speaking pure GR and that's the objection that a person may make against BB.

Pete

 

[JesseM]

I believe that to be an inaccurate notion. We're talking about a quantum singularity and not a singulary in spacetime.

As I said, I think the implicit context of the quote you gave is how GR models the Big Bang, not how a future theory of quantum gravity would model it. Also, what's a "quantum singularity"? As I understand it, most theories of quantum gravity simply say there are no singularities.

 

[Phobos]

Perhaps this thread then belongs in Cosmology?

agree...
thanks Pete