How would time flow for each parallel universe?

[Brennick908]

TL;DR

question using the parralel universe thoery if true, how would time work in other universes.

do parralel timelines have to run concurrently to our time? what I mean by this is basically if there is a version of me or you out there in a parralel universe right now in 1963 for example just living like normal or do all parralel timelines have to be in the same timeframe as us?

 

[phinds]

Summary: question using the parralel universe theory if true, how would time work in other universes.

do parralel timelines have to run concurrently to our time? what I mean by this is basically if there is a version of me or you out there in a parralel universe right now in 1963 for example just living like normal or do all parralel timelines have to be in the same timeframe as us?

I see no reason why it should but in any case it's irrelevant because since they (assuming they exist, which I don't) are not in causal contact with us we could never tell anyway.

 

[Aidyan]

I think the question is not clearly formulated, since it is not clear how one could define, even in principle, 'timelines that run concurrently between different parallel universes' (provided they exists in the first place). However, intuitively I might understand what you mean and suggest the following reasoning. If all the fundamental physical constants, such as the speed of light, the Planck constant, the fine structure constant, etc., are the same in all universes, then one can imagine (I mean 'imagine' because we don't know how to measure that anyway) the time flow indicated by the same type of clocks (say Caesium atomic clocks) running 'concurrently'. If however the physical constants are different then they do not. One second in one universe might be a million years in another.

 

[hilbert2]

You can even have a situation where a second in one Lorentz frame is a million years in another inertial coordinate system, both of them in our universe. Just accelerate something to almost the speed of light.

From an intelligent observer's viewpoint, it also matters how their own cognition senses the flow of time. You could think of some strange alien lifeform that is almost immobile like a tree or a coral and is so slow that its subjective "day" is a week for us. Like an extreme version of our folivora mammals on Earth.

 

[PeterDonis]

Summary: question using the parralel universe theory if true, how would time work in other universes.

do parralel timelines have to run concurrently to our time?

What "parallel universe theory" are you talking about? Please give a reference.