# Thread: Antigravity and the Big bang

1. ## Antigravity and the Big bang

If you did a time reversal of the expansion of the universe would the model show anti-gravity?

It would almost seem like to opposite of a black hole where things are continuously decellerating the further back in time we go.

2. Originally Posted by tommac
If you did a time reversal of the expansion of the universe would the model show anti-gravity?

no

3. Originally Posted by tommac
If you did a time reversal of the expansion of the universe would the model show anti-gravity?

It would almost seem like to opposite of a black hole where things are continuously decellerating the further back in time we go.
No, deceleration due to gravity happens as the universe expands. Run that backwards in time, and acceleration due to gravity happens as the universe contracts.

4. Originally Posted by tommac
If you did a time reversal of the expansion of the universe would the model show anti-gravity?

It would almost seem like to opposite of a black hole where things are continuously decellerating the further back in time we go.
How is this different from your other post that was closed?

The expansion of the universe is not anti-gravity. It isn't following an inverse square law, it is a linear amount.

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No. I think we have a quorum.

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The big bang still isnt a black hole, Tommac.

7. ## Impossible fantacy...

Originally Posted by tommac
If you did a time reversal of the expansion of the universe would the model show anti-gravity?

It would almost seem like to opposite of a black hole where things are continuously decelerating the further back in time we go.
BUT ! Time can not be made to reverse. It only has one direction. Any deviation from that is just fantasy.
As you want to know what if the universe were to collapse would time be effected ? No.
Your perception of the rate of time can be manipulated by your velocity or proximity to a gravity well. Perception is entirely reliant on your point of observation. I am tolerant of your 'what if ?' question and can find that if the expansion of the universe were to slow and reached a velocity less than the accelerating rate then yes headlong into oblivion. Some 14.7 billion years later. Making all sorts of assumptions regarding the collapse rate...and gravity force... but, not time. and then you ask anti-gravity ? No the opposite would be the case. Without expansion gravity would become the predominant force.
Then you suggest decelerating as we go back... No. accelerating as we collapse more likely. Forget about the time reversal...that would break with logic... but you are there already...
Last edited by astromark; 2009-Nov-23 at 09:01 AM. Reason: added ?

8. This thread is exactly the same as part of the closed thread.
Tommac this does not belong to Q&A (although it is a question) because it will invariably turn into your ATM that the universe is a black hole or everything is a black hole or whatever.

If you have something to discuss do it in ATM, you should no much much better by now.