How Did Time Begin After the Big Bang?

[europium]

I have a question about the big bang

We theorise that all the matter came from a singularity and that this expanded at the big bang shedding matter and energy in vast expanses.

However, if this is the description of how matter came to be, then how did time ever come to be? The very first tiny fraction of a second (the Planck time?!)... how did this ever trigger.

Another aspect which is intriguing is that the universe at the very start of time was already *the Planck time* old (forgive me i have forgotten the age) before it was anything less. How does this happen? How could its very first instant be an age already. It's like saying that when a baby is born it is already 10 seconds old (not considering that it has been alive inside the womb) before it has been 1 second old Anyways, answers would be very appreciated... also if answers are not possible to give, i understand that also.

Regards K_

 

[hellfire]

I am surely not the right person to answer this question because the mathematics used in the models describing the origin of the universe is far behind my knowledge. But, anyway, I think it would be a pity if your interesting question remains without any comment.

In short: there are several models describing the origin of the universe, depending on what amount of new physics is assumed to be valid. The “classical” ones (as far as I know the ones remaining as close as possible to the established theories of general relativity and quantum field theory) are called Vilenkin-Linde and Hartle-Hawking models.

Both of them seam to give an explanation to the origin of time, although this may be unsatisfactory and may open new questions. The ultimate description must be done making use of a theory of quantum gravity, which is currently unknown.

You may read something about this topic here:
http://mercury.dfisica.ubi.pt/~pmoniz/Qc.html
or here:
http://web.uvic.ca/~jtwong/index.html

Regards.

 

[Layzie_Bone]

Its obvious we don't noe wat happen b4 that point!

 

[europium]

Thanks very much hellfire for the very useful answer i appreciate the links. Thankyou very much... as for Layzie Bone's somewhat less useful answer, i am not one too complain and all to their own, so thanks also for your err *insight*
These models were very intriguing hellfire and i am thankful you answered my question with consideration. Regards..

K_

 

[Deeviant]

I would suggest picking up Time's Arrow and Archimedes' Point. A good read and has much to say on the different scientific views on time.

 

[europium]

thanks very much

K_

 

[Chronos]

by definition, all predictive models break down at the moment of the big bang. intuitively, that makes sense. all we know is that a predictable form of reality emerged from that moment. god knows, we dont.

 

[Phobos]

Another aspect which is intriguing is that the universe at the very start of time was already *the Planck time* old (forgive me i have forgotten the age) before it was anything less. How does this happen?

It didn't. That's just the smallest time that modern physics can understand/deal with. Actual time can be shorter than that. It's still a mystery whether time is quantized or continuous.

 

[Mike2]

by definition, all predictive models break down at the moment of the big bang. intuitively, that makes sense. all we know is that a predictable form of reality emerged from that moment. god knows, we dont.

Perhaps it was the inconsistency of nothing at all that lead the singularity to expand.

Also, if it should be proven that causality requires space to produce more space so that the early universe expanded at an exponential rate, then zero space is acheived at negative infinity so the infinite energy density technically never really happened.

 

[europium]

quantized

It didn't. That's just the smallest time that modern physics can understand/deal with. Actual time can be shorter than that. It's still a mystery whether time is quantized or continuous.

How would you describe quantized and continuous time? i have never truly understood it and thought you may be able to enlighten me. Is quantized that the can be a 'smallest amount' of time so that we can say 1 second, 2 second (obviously not seconds - just an example), and continuous just a running of time without any real fundamentals?

K_ cheers

 

[Phobos]

How would you describe quantized and continuous time? i have never truly understood it and thought you may be able to enlighten me. Is quantized that the can be a 'smallest amount' of time so that we can say 1 second, 2 second (obviously not seconds - just an example), and continuous just a running of time without any real fundamentals?

For consideration...
Light can act as a wave (continuous) or a particle (discrete). Light energy is transmitted in quantized bundles (quanta).

If I may oversimplify...General Relativity models gravity as kind of a continuous 3D sheet/fabric of flexible spacetime. A quantum mechanical view may present the idea of a "graviton" which would be the smallest unit of gravity...another one of the fundamental particles (not made up of anything smaller) that make up the universe.

String theory (M-theory?) has a tiny string-like entity that is the smallest unit that makes up everything else in the universe.

Continuous vs. quantized time would be like the gravity situation I suppose. Either the timeline is unbroken (time flows and you can always measure a smaller unit of time) or it proceeds in small jumps that are undetectable at our scale. The unit of quantized time - the fundamental particle of time - is called a "chronon" (still a hypothesis like the graviton - - neither has been detected).