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View Full Version : The singluarity, infinity, and the beginning of the universe



iknowiknownothing
2007-Sep-27, 07:11 PM
My question is based on the reconciliation of two concepts of the beginning of the universe. First is the idea of the all of the matter of the universe being crammed down into the size of the plank length at the start. Where this becomes interesting to me and where my struggle to understand begins, is the idea of the space itself is considered to be infinitely flat.

How do space and matter interact? Who is right Newton or Mach?

I recently read Brian Greene's The Fabric of the Cosmos and he made an comment that I wish had been explored further. I do not have the exact quote but to paraphrase he said, "It is as if the Big Bang occurred everywhere." (I'll find the page)

My current conception of these ideas is that at the beginning, big and small mean nothing and the plank length was infinite.

Neverfly
2007-Sep-27, 07:26 PM
I've been reading here (http://www.talkorigins.org/faqs/astronomy/bigbang.html) for quite a while.

Especially the section discussing misconceptions about the Big Bang and where they came from;)

Someone else posted this link in another thread but I don't remember who they are or what thread...:shifty:

It's a thankless job...

Neverfly
2007-Sep-27, 08:28 PM
Found it.

Neried posted that link I referenced above here: http://www.bautforum.com/1077657-post2.html

Cougar
2007-Sep-27, 09:26 PM
My question is based on the reconciliation of two concepts of the beginning of the universe. First is the idea of the all of the matter of the universe being crammed down into the size of the plank length at the start.
Several books that I've read recently state that we are fairly certain about the state of the universe when it was one second old, and this is due to our findings from particle accelerator experiments and detailed observations of the cosmic microwave background. But before that, we do not have any data to go on, and therefore cannot say anything about it. We can speculate, but without evidentiary support, one leaves the realm of science.


Where this becomes interesting to me and where my struggle to understand begins, is the idea of the space itself is considered to be infinitely flat.
Ummm... I don't know that you can separate "space itself" in this context. The curvature of the universe can be determined by measuring the average density of matter within it... that is if you ignore the possibility of dark energy or "vacuum energy," which has some fairly good observational support. Check our Wiki's Shape of the Universe" (http://en.wikipedia.org/wiki/Shape_of_the_Universe).


How do space and matter interact?

"While walking with Heisenberg, the physicist Felix Bloch, who had just read Weyl's Space, Time and Matter, felt moved to declare that space is simply the field of linear equations. Heisenberg replied, 'Nonsense. Space is blue and birds fly through it.'"



Who is right Newton or Mach?
You'll have to phrase your question with a little more specificity. :o



I recently read Brian Greene's The Fabric of the Cosmos and he made an comment that I wish had been explored further. I do not have the exact quote but to paraphrase he said, "It is as if the Big Bang occurred everywhere."
Yes, I agree with that. What's the question?


My current conception of these ideas is that at the beginning, big and small mean nothing and the plank length was infinite.When scientists turn up an infinity in their equations or workings, this is usually an indication that something is terribly wrong. As Tony Rothman (http://www.physics.princeton.edu/~trothman/sci_pub.htm) has said....


"We mentioned that the FLRW cosmology begins with a singularity. This is a much more serious breakdown than a flat tire or a cracked engine block. It is, in fact, a physical impossibility -- a region where the laws of physics break down altogether and even spacetime comes to an end."

Jerry
2007-Sep-28, 05:54 PM
Several books that I've read recently state that we are fairly certain about the state of the universe when it was one second old, and this is due to our findings from particle accelerator experiments and detailed observations of the cosmic microwave background. But before that, we do not have any data to go on, and therefore cannot say anything about it. We can speculate, but without evidentiary support, one leaves the realm of science.

Before or after. Inflation, whatever that is, has never been rationally modeled with any success. I leave it to the reader to decide whether we can say we understand one moment in the past rather well, but not the next.

KaiYeves
2007-Sep-29, 12:50 AM
Great name and welcome to the board, iknowiknownothing.

curry
2007-Sep-29, 01:31 AM
Originally Posted by iknowiknownothing
I recently read Brian Greene's The Fabric of the Cosmos and he made an comment that I wish had been explored further. I do not have the exact quote but to paraphrase he said, "It is as if the Big Bang occurred everywhere."
As we look out into the universe all is expanding away from us. It looks like we are at the center of the universe. There is not a single center because everywhere in the universe would also look like it was the center. Everyplace is the center and is where the big bang started. The universe does not have a single center with an edge away from that point. There was and is no outside existing space to expand into. Space itself expanded.

Cougar
2007-Sep-29, 03:02 AM
Several books that I've read recently state that we are fairly certain about the state of the universe when it was one second old....
Before or after. Inflation, whatever that is, has never been rationally modeled with any success.
Inflation, which has some pretty good support, is still not on the firmest of foundations, it's true. But inflation is hypothesized to have occurred in the briefest of instants back when the universe was only 10-33 seconds old, which is well before the universe was a second old and had expanded and cooled considerably. It is at this later, cooler point that scientists are reasonably certain that our concept of the state of things is quite accurate. I suppose you'll have to read those books* to understand the empirical and theoretical support for that reasonable certainty.


I leave it to the reader to decide whether we can say we understand one moment in the past rather well, but not the next.



"...cosmologists are claiming that they can extrapolate backward in time to learn the conditions in the universe just one second after the beginning! If cosmologists are so smart, you might ask, why can't they predict the weather? The answer, I would argue, is not that cosmologists are so smart, but that the early universe is much simpler than the weather!" -- Alan Guth

* The Life of the Cosmos [1999] -- Lee Smolin; The Cosmic Landscape [2006] -- Leonard Susskind; Many Worlds in One [2006] -- Alex Vilenkin; Endless Universe, Beyond the Big Bang [2007] -- Paul Steinhardt and Neil Turok