# Cannot stand the eternity in cyclic models

1. Dec 31, 2012

### xponential

I have had this question for a long time and thought this forum might be the best place to answer..

If there is an infinite number of bangs happened before the big bang, our universe's bang should never have happened because it would require an endless number of bangs that -by definition- would never get covered all for ours to occur!

2. Dec 31, 2012

### Charmar

Maybe someone can explain it better but here is my take on it.

If you divide infinity in half it is still infinity. If this is a cyclic event that keeps happening over and over as it always has and will continue to do so, it is infinite. Think of it as there was no first big bang, they just always have happened. You can think about a million big bangs ago and still go a million more, you can do this until you go loony making up any large number you like, and there will still be just as many previous to the last one because they have always happened.

3. Dec 31, 2012

### xponential

Are you implying there is no causation between a cycle and another? Are the future events already happened?

Do you know of a source that illustrates this idea? I searched for cyclic models but didn't find a clear explanation about eternity.

4. Dec 31, 2012

### Naty1

you question is not clear. If an infinite number of cosmological cycles have already occurred, that does not preclude them from continuing.

Cyclic models do not explain eternity. Eternity is a philosophical question not in the realm of science. Cyclic models don't explain a 'first' bang nor a 'last' one.

There ARE causal connections between cycles in the Turok-Steinhardt model.

http://en.wikipedia.org/wiki/Cyclic_model

5. Dec 31, 2012

### xponential

Cyclic models don't explain eternity but they imply it. I don't see how eternity is even naturally possible. If there is infinite cycles of the universe before the current one in which we live in, our current cycle should never have happened since an INFINITE number of cycles before it should have passed first.

6. Dec 31, 2012

### Naty1

just not so.

That's a misconception.

So if you like one,single, unique, bang in all of 'history'...why should THAT have ever happened?? nobody knows.

there is much in nature that is difficult to understand.
see my signature....don't blame the physics....nor math...

7. Dec 31, 2012

### phinds

Look up Hilbert's Hotel ... it has an infinite number of rooms and they're all full, but you can always get in one more guest.

8. Dec 31, 2012

### Drakkith

Staff Emeritus
Do you think he has vacancy tonight? I might need a place to stay.

Anyways, I believe it is a misconception to think that there cannot be individual bangs in an infinite cyclic model. In order for there to be an infinite cyclic model, you MUST have individual bangs occurring. Otherwise there would be no cycle.

9. Jan 1, 2013

### Chalnoth

An infinite past is no more a problem than an infinite future. It only becomes a problem when you try to impose colloquial notions of cause and effect that exist nowhere in the fundamental physics.

10. Jan 1, 2013

### phinds

Wife kicked you out again, huh?

11. Jan 1, 2013

### mitchell porter

They had an infinite amount of time to happen in. You are still reasoning as if time had a beginning, after which infinitely many cycles occurred. In an eternal cyclic universe, there was no beginning to time. There are cycles before cycles before cycles, but there is no first cycle.

12. Jan 1, 2013

### ImaLooser

Where does a Universe-sized gorilla sleep? Wherever it wants to.

13. Jan 1, 2013

### Chronos

Perhaps reviewing Cantor's theory of infinite sets would be instructive.

14. Jan 2, 2013

### Drakkith

Staff Emeritus
Nonsense, I am not married. It was the cat this time. But wait, I don't own a cat...