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moonsoundsonsnow t1_ix70bsg wrote

Reply to comment by redphoenix932 in Someone tell me how the Big Bang began 13 billion years ago, yet the *observable* universe is 83 billion light years apart? by novacks0001

but what is the reference point for which the velocity of the expansion of space is measured?

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triffid_hunter t1_ix70n30 wrote

Doesn't matter.

Cosmic expansion behaves like new empty space is being injected everywhere all at once, not like some sort of border moving away from a specific point - ie more like bread rising in the oven than a spreading puddle.

Thus, the expansion of space looks pretty much the same from all locations.

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This_Username_42 t1_ix74byy wrote

I went to undergrad for physics and took some (not many) Astronomy courses and I do not think I knew this. Thanks

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