Time - How Long was the first second?

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The discussion centers on the concept of time measurement in relation to the Big Bang and singularities. It clarifies that the first second after the Big Bang is defined as one second, despite differing perceptions of time near singularities. Observers near a black hole experience time differently than those far away, but this does not apply to the initial singularity of the Big Bang, which is a moment in time rather than a spatial location. The idea of gravitational time dilation is also deemed inapplicable to the universe as a whole, as it requires a stationary spacetime. Ultimately, a second remains a second by definition, regardless of the context.
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If a singularity slows time. How long was the first second after big bang?
 
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The first second, was by definition, one second long.
 
A second by my watch is different from a second next to a singularity. Are you saying it would be the time it took light (if it had existed) to travel 186000 miles (in which case it would have been a really long second)? Just trying to get this concept right in my head before I launch into more study.
 
TonyLondon said:
A second by my watch is different from a second next to a singularity.
No, it is not. It looks different to a remote observer but that's a different story.

Are you saying it would be the time it took light (if it had existed) to travel 186000 miles (in which case it would have been a really long second)? Just trying to get this concept right in my head before I launch into more study.
Yes, It would have been the time it took light to travel 186000 miles along a spacetime geodesic, assuming there was nothing to get in its way.
 
How do you measure that "first second"?

;)Aleksandr Solzhenitsyn: "Who could act rationally on the first morning of Creation?" (Cancer Ward)o_O

Garth
 
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TonyLondon said:
A second by my watch is different from a second next to a singularity.

If you're thinking of a black hole, this applies to an observer "hovering" near the horizon, not the singularity (you can't "hover" near the singularity since you'd be inside the horizon and everything inside the horizon has to fall inward), and, as phinds says, it refers to a second by that observer's clock as seen by a remote observer.

None of this applies to the initial singularity in the Big Bang model. First, that singularity is a past singularity, not a future singularity (like a black hole's); second, you can't "hover" near the Big Bang, since it's really a moment of time, not a place in space (it would be like trying to "hover" near last Tuesday); and third, the concept of "gravitational time dilation" such as occurs near a black hole's horizon is not applicable to the universe as a whole, since it only works in a stationary spacetime and the universe is not stationary.

So the only real answer to your question is Matterwave's: a second is a second by definition.
 
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Abstract The Event Horizon Telescope (EHT) has significantly advanced our ability to study black holes, achieving unprecedented spatial resolution and revealing horizon-scale structures. Notably, these observations feature a distinctive dark shadow—primarily arising from faint jet emissions—surrounded by a bright photon ring. Anticipated upgrades of the EHT promise substantial improvements in dynamic range, enabling deeper exploration of low-background regions, particularly the inner shadow...
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
Title: Can something exist without a cause? If the universe has a cause, what caused that cause? Post Content: Many theories suggest that everything must have a cause, but if that's true, then what caused the first cause? Does something need a cause to exist, or is it possible for existence to be uncaused? I’m exploring this from both a scientific and philosophical perspective and would love to hear insights from physics, cosmology, and philosophy. Are there any theories that explain this?

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