Does the 1 Second after the Big Bang = 1 second now?

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Discussion Overview

The discussion revolves around the concept of time measurement in the context of the Big Bang, specifically questioning whether a second measured shortly after the Big Bang is equivalent to a second measured now. Participants explore the implications of time dilation, reference frames, and the nature of time in extreme conditions such as black holes.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants propose that the duration of time, such as 1/2 second, is the same now as it was shortly after the Big Bang.
  • Others question the validity of comparing clocks from different epochs, suggesting that there is no meaningful way to synchronize or compare them.
  • A participant mentions that cosmic rays may decay at different rates, raising questions about the implications of this on time measurement.
  • There is a discussion about time dilation near black holes, with some participants suggesting that this concept may not apply in the same way to the universe as a whole.
  • One participant emphasizes that time in cosmological coordinates is measured in relation to "comoving" observers, who perceive the universe as homogeneous and isotropic.

Areas of Agreement / Disagreement

Participants express differing views on the nature of time and its measurement in relation to the Big Bang. There is no consensus on how to approach the comparison of time across different epochs, and the discussion remains unresolved.

Contextual Notes

Limitations include the challenge of defining a meaningful comparison between time measurements from different periods and the dependence on specific cosmological models and reference frames.

Pjpic
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When I read that conditions were such and such 1 to .05 seconds after the big bang, is that duration somehow longer than 1/2 second is now (maybe because of the difference in density or like the twin paradox?)?
 
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Do you mean one second after the Big Bang? There is no before the Big Bang.
 
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Khashishi said:
Do you mean one second after the Big Bang? There is no before the Big Bang.
sorry S/H/B "After"
 
Pjpic said:
sorry S/H/B "After"
I fixed your thread title for you. :smile:
 
The duration of 1/2 second right after the big bang is the same as the duration of 1/2 second now.
 
Khashishi said:
The duration of 1/2 second right after the big bang is the same as the duration of 1/2 second now.
Cosmic rays decay at a different rate ( I think) but, from your answer, that is a different type of situation?
 
I'm not sure your question is well posed.

It is true that two clocks that are synchronised, moved apart, and brought together again may no longer be synchronised. But how would you bring a clock from one second after the Big Bang together with one now in order to compare them? There's no meaningful way to do that, so I'm afraid that there's no physical way to ask your question, let alone answer it.
 
Ibix said:
I'm not sure your question is well posed.

It is true that two clocks that are synchronised, moved apart, and brought together again may no longer be synchronised. But how would you bring a clock from one second after the Big Bang together with one now in order to compare them? There's no meaningful way to do that, so I'm afraid that there's no physical way to ask your question, let alone answer it.
I think I read time seems to almost stop in a black hole. So I was wondering if the same was true for the big bang and if when it is said something happens from .5 seconds to 1 second after the big bang what frame of reference that is in.
 
Pjpic said:
I think I read time seems to almost stop in a black hole.
Either you misunderstood what you read or it's wrong. Unless you tell us what you read where, we have no way of knowing which it is.
 
  • #10
Pjpic said:
Cosmic rays decay at a different rate ( I think)

What makes you think that?

Pjpic said:
when it is said something happens from .5 seconds to 1 second after the big bang what frame of reference that is in.

It is in the standard coordinates used in cosmology. Time in these coordinates is the same as time elapsed on the clocks of "comoving" observers, i.e., observers who see the universe as homogeneous and isotropic.
 
  • #11
Nugatory said:
Either you misunderstood what you read or it's wrong. Unless you tell us what you read where, we have no way of knowing which it is.
Pretty sure he's referring to time dilation from general relativity.

The fault in logic here is that from the perspective out an outside observer, time moves way slower close to a black hole. From the frame of reference of something already in the hole, time moves normally. You can't use the same logic when applying to the universe as a whole because we're in the same reference frame.
 

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