The formation of our Universe as we know it

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There are many ideas on how the universe came into being. Please put ideas on how into the replies/comments, as I would love to hear, and debate them. Thanks!
 

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  • #2
DaveC426913
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There are many ideas on how the universe came into being. Please put ideas on how into the replies/comments, as I would love to hear, and debate them. Thanks!
Uh. Usually, the OP (you) has something they'd like to share or ask, not just a general, broad request for information. You can search PF, or you can Google it.
 
  • #3
PhilKravitz
There are many ideas on how the universe came into being. Please put ideas on how into the replies/comments, as I would love to hear, and debate them. Thanks!
No body knows but that does not stop them from speculating.

The two major schools are
1) it was always that way (static universe, Einstein)
2) BANG!

The big bang folks breakdown into several group depending on what they think will happen next.

1) open universe expand forever, heat death of the universe, die with a wimper
2) closed universe bang-expand-contract-bang-expand-contract... etc a dynamic version of it was always that way
3) open universe with space itself exerting a repulsive force causing and increase in the rate of expansion and total energy of the universe (not clear to me what happened to conservation of energy) leading to BANG! leading to ??? not clear what these folks would say Roger Penrose seems to be in this group. I guess if it leads to just one new universe with a "big bang" then this would also be another dynamic version of it was always that way.

So I guess we have heat death or some repeating pattern (it was always that way).

In the heat death version (and only in) you could ask what came before. Darned if I know. Some would offer "one really big quantum fluctuation".
 
  • #4
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I've never really been that much of a fan of the neverending cycle theory, it seems like a bit of jiggery-pokery to avoid asking the question, what came before?
 
  • #5
bapowell
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I've never really been that much of a fan of the neverending cycle theory, it seems like a bit of jiggery-pokery to avoid asking the question, what came before?
If it is truly cyclic then the nothing came before.
 
  • #6
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If it is truly cyclic then the nothing came before.
and thats the jiggery-pokery.
 
  • #7
marcus
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There are many ideas on how the universe came into being. Please put ideas on how into the replies/comments, as I would love to hear, and debate them. Thanks!
Try,

cosmology is the topic here, not philosophy. Just to be clear. There is a philosophy subforum down in the "General Discussion" department. You can find it on the menu.

We try to focus on understanding mainstream professionally researched cosmology. That means fitting math models to the data.

Some math models go back indefinitiely into the past, some go back just so far and then break down, blow up, or for some reason will not go back further.

They don't address the question "Why does existence exist?" or
"What brought existence into being?" (a kind of funny question, not sure it makes sense :biggrin:)

If you want to ask that kind of question, or hear people talk about that kind of thing, you have to go somewhere else.

On the other hand if you want to learn about the general features of the math models of the cosmos that are currently being studied—this is a pretty good place to ask questions.
 
  • #8
marcus
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and thats the jiggery-pokery.
As far as I know, a mathematical model can go back indefinitely into the past without being cyclic.

And I see no reason a model (cyclic or not) that goes back indefinitely into the past would automatically for that reason be "jiggery". Got to look at models without prejudice.

The question should always be how well does it fit the data---there is a huge river of data coming in and the instruments keep improving and recording more detail.

And there's also the question how well does the model conform to what we know about spacetime geometry (essentially Gen.Rel.) IOW how well does it conform to the known physics of gravity.
 
  • #9
PhilKravitz
And there's also the question how well does the model conform to what we know about spacetime geometry (essentially Gen.Rel.) IOW how well does it conform to the known physics of gravity.
It is like Fourier analysis if you have a function of time defined on an interval say 0 seconds to 10 seconds you can fit it with a Fourier series and that series will reproduce that function on every n*10 to (n+1)*10 interval. This does not mean that the function exists there, it only means this is how the math works.

Likewise I know of no experimental data that says how many repeats of the universe existed before this one (if any). Do you? There are models and the model repeats, that is far different from physical experimental measurements/data.

Cyclic models are unappealing because humans seek to understand the context and cause of things. A cyclic model has no context of course maybe this is the one thing that indeed has no context (the whole universe, the whole of everything). But what is the experimental data that shows there is no context? Likewise it offers no cause and even though it is the whole universe we still want to understand the cause. It is like a bouncing ball (with no friction and no energy loss) we can say the ball came from a previous position and we can trace that position indefinitely far back in time but we still want to know where did the ball come from and what made it move to start with?

If we take the formal approach that we must have data we can say physics has zero data on before the big bang, physics has nothing to say about time, space or cause before the big bang. This is exclusively the domain of religion and philosophy.
 
  • #10
PhilKravitz
Of course if we need data first then we should stop talking about string theory, M theory, and quantum gravity. Those theorist are naughty they talk about stuff without data. In fact they may have gone so far that what they do is no longer physics, it may be pure math instead. Maybe we need a new name for a branch of math that deals with theoretical universes and send these folks to the math department.
 

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