Thread: The Beginning of Time and the Big Bang

I know this is controversial stuff but i was having an argument with my friend over this subject and came up with the following conundrum:

I am assuming that time started at the Big Bang, as is widely accepted (i think), and so when the universe expands to its fullest and starts to collapse due to gravity (i think), will it not collapse into an infinitesemally small space and start the big bang all over again?

If so then time could not have started at the Big Bang, because there could have been a big bang before it.

Or will the theory that time will run backwards when the universe collapses cancel this out?



(There is probably a very simple answer to this that i have missed which will make me look like a fool.)

(Oh well.)

Welcome to the forum!

Fool? No actually it's a perfectly valid question, one most of us have asked, so here is the answer: There is not thought to be enough mass in the universe to eventually cause a reversal of the big bang, if there were then and 'oscilliatory universe' would certainly be a valid possibility, google "Open Flat Closed Universe" to read about the possibilities

That is based on a "bladder universe", the theory being that gravity will slow universal expansion and bring everything into a big crunch. However this is not the accepted theory as observations have shown that the universe is not only still expanding, but expanding at an ever faster rate due to "dark energy".

I think you got the wrong idea of dark matter, that was proposed to explain an anomoly in the rotation of galaxies. :wink:

I said dark energy, not dark matter. :wink:

Sorry must have been my Dark screen... :wink:

Could someone explain to me the acceleration of the universe due to Dark Energy?

Is dark energy just something thought up to explain the accelerating expansion of the universe or has it been discovered?

Sorry for all the questions, i'm quite inquisitive.

Originally Posted by Hazz

Could someone explain to me the acceleration of the universe due to Dark Energy?

Is dark energy just something thought up to explain the accelerating expansion of the universe or has it been discovered?

Sorry for all the questions, i'm quite inquisitive.

Dark energy is the name of the thing that is driving the accelerated expansion of the universe. If you can explain what it is there is most probabily a fields medal (for the new maths) and a noble prize (for the new physics) with your name on on it

Its funny to think that we know about less then 4% of the total mass/energy content of the universe!

Originally Posted by Megabrain

Sorry must have been my Dark screen... :wink:

Or your eye-sight. !?

Please forgive my Dark-sense of humour.

Originally Posted by Hazz

I know this is controversial stuff but i was having an argument with my friend over this subject and came up with the following conundrum:

I am assuming that time started at the Big Bang, as is widely accepted (i think), and so when the universe expands to its fullest and starts to collapse due to gravity (i think), will it not collapse into an infinitesemally small space and start the big bang all over again?

If so then time could not have started at the Big Bang, because there could have been a big bang before it.

Or will the theory that time will run backwards when the universe collapses cancel this out?



(There is probably a very simple answer to this that i have missed which will make me look like a fool.)

(Oh well.)

Actually that is along the lines of current thinking on the 'infinite big bangs' theory, that the universe expands and contracts and the phase we are in is expansion after the most recent big bang. It will eventually be followed by a contraction phase when it begins to cool and eventually another big bang, energy release, expansion etc. The theory says there is no beginning to time or the universe and no end.