Post Big Bang Time

[Deepwater6]

In the seconds after the universe was created say, it was only the size of a orange, what was time doing at that moment? What would my perception of a clock be at that time when the universe is expanding at such an incredible rate? Space/time would obviously be distorted and expanding on a much greater scale than today. Since space would be expanding faster than the speed of light, what would that do to my perception of time? If the answer is that time was speeding by at incredible speed would time seem to slow down as the universe continues to cool and exspansion slows? I have heard that scientists have know reason why time runs forward. If that's so and if this exsansion were to stop and start contracting would that be a reason for time to go backwards?

[CraigD]

In the seconds after the universe was created say, it was only the size of a orange, what was time doing at that moment? What would my perception of a clock be at that time when the universe is expanding at such an incredible rate?

First, no matter where and when you are, your perception of a “nearby” clock nearly at rest relative to you is the usual one: about 1 sec/sec (or, generally, 1 any time unit/1 the same time unit). It’s only when you’re observing a clock that’s moving relative to you, or is much closer of further than you from a large mass, that you’ll see that clock disagree with a nearby stationary one. What “perception of a clock” really means here is “comparison of the reading of a clock to that of a nearby, stationary clock.”

 

What I think you’re asking here, Deepwater, is what would a clock inside the young, rapidly expanding universe, look like to an observer outside of that universe. Though hard to imagine, and fraught with difficulties such as how the light/sight of the clock would get to the observer, how a clock could exist in the early universe where even the fundamental particles, let alone the matter needed for a clock, didn’t yet exist in a usable state, and whether the space the observer is in should be considered to be expanding like that of within the orange-size universe, the answer would be, I think, that the clock would appear to be nearly unchanging. The reason for this answer breaks down into 3 parts:

• velocity time dilation – not much effect due to this, as despite the clock “moving” along with the expanding universe, it wouldn’t be moving relative to the space it and the observer are in. This is a profoundly weird idea: points in the inflating universe aren’t moving away from one another, the space in which they’re contained is getting bigger.
  
• gravitational time dilation – assuming gravity exists at this point – by no means a given – the clock in the small universe would be very “low” compared to the observer, so would exhibit a lot of this kind of time dilation.
  
• redshift due to the expansion of space – light showing the first (and only – the orange-size universe exists only for a very brief instant) “ticks” of the clock are stretched/redshifted by a gigantic factor. So the tick – which must be much shorter than any real clock can produce, less than 10^-32 s – would appear to us to be as long as the time it takes to cross the post-expansion universe, about 100,000,000 years.
  

(For more, see the wikipedia articles time dilation, metric expansion of space and redshift)

 

If the answer is that time was speeding by at incredible speed would time seem to slow down as the universe continues to cool and exspansion slows?

As I outlined above, the answer is exactly the opposite: time would seem to speed up as cosmic inflation stops – though inflation doesn’t appear to be stopping, but after slowing by a gigantic factor about 10^-32 after starting, to be increasing at an ever-increasing rate. The “drinking cup” graphic at its above linked wikipedia article diagrams this nicely.

 

I have heard that scientists have know reason why time runs forward. If that's so and if this exsansion were to stop and start contracting would that be a reason for time to go backwards?

First, best-accepted theory and data contradict the assertion that the expansion of space will ever stop and reverse – head toward what’s traditionally termed “the Big Crunch”.

 

That said, we need to think a bit about what “time running forward” or “backwards” means, and why we could say we “know the reason” it runs forward. Condensing a lot of thinking into a few words, “time running forward” means, and we “know the reason” why it does because things get more disorganized – a cup dropped on the floor become disorderly fragments of broken cup more often than fragments dropped on the floor reassemble into an unbroken cup. The terms “disorganized” and “disorderly” in this context are part of the physics concept of entropy, but that word has so much non-scientific baggage, I prefer to stick with these ordinary language terms.

 

So time running backwards would be a state where things gets more organized – cups form from broken pieces, stars suck up light and heat, split helium into hydrogen, then balloon into protostellar nebulae, etc.

 

Physics doesn’t predict this happening. Even if it did, it’s hard to conceive of how any human could experience it, as how we experience things. Our senses, perception, consciousness, reason, and memory, are due to stuff happening in our brain and other organs analogous to breaking cups and shining stars. Though intuition leads us to think disorder is bad, and life and thought decreases it, in physically exactly the opposite is true – life increases the total disorder of the universe, and information equates to disorder.

[seemagarg]

I have heard that scientists have know reason why time runs forward. If that's so and if this exsansion were to stop and start contracting would that be a reason for time to go backwards?

 

Hours back, I went through 4 videos on 'Laws of Creation of Cosmos' and 1 video on 'gravitation- does g increase inside earth' uploaded by one 'chakrabortyashitk' on Youtube. I have found them soothing and exceptional in the context that present day researchers have made astrophysics very much complicated by writing large equations based on assumptions. You may search your answers in these videos. This person's theory is based on expansion & contraction of universe.

[Southtown]

Honestly dunno. Haha! But wow, ty Craig. Serious food-for-thought.