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What is the age of the Universe from the big-bang light perspective?

We all agree that the universe is around 14 billion years, from the perspective of a hypothetical observer moving in a galaxy, e.g. ourselves.

But what would be the age of the universe from the perspective of the first light that emerged from the big bang, given that it has been traveling at the absolute $c$ speed of light?

Qmechanic
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eharo2
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  • Maybe 380000 years younger? See http://en.wikipedia.org/wiki/Cosmic_microwave_background – Qianyi Guo Apr 22 '14 at 03:24
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    At lightspeed, time is not a meaningful concept. – hdhondt Apr 22 '14 at 03:25
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    Or if you prefer, the answer is zero, since proper time approaches zero as the observer's speed approaches $c$. Though, since those photons weren't emitted right at the big bang itself, you could also say the answer is 380,000 years, which is the age of the universe at the time of photon decoupling. (See http://en.wikipedia.org/wiki/Cosmic_microwave_background.) – N. Virgo Apr 22 '14 at 06:22
  • Possible duplicates: http://physics.stackexchange.com/q/29082/2451 and links therein. – Qmechanic Apr 22 '14 at 06:31

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Lengths of time are not well-defined for objects moving at $c$ in Einstein's theories of relativity. That is to say, light cannot attribute age to anything.

Logan J. Fisher
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