system
Given the following post, respond as if you're commenting on Reddit:
human
If the farthest known object is observed as 13.1 billion light years away, how far is it really?

since it is 13.1 billion light years ago as well. how far is it really?

light took 13 billion years to get here, so 13.1 billion light years away 13 billion years ago.
gpt
So if space wasn't expanding a stationary (with respect to us) object that emitted a photon 10ly ago which just reached us today would be 10ly away.  Since space is expanding how far away an (stationary before metric expansion) object is when a photon that it emitted reaches us after a certain amount of time depends on the expansion of the space that the photon that was emitted had to travel through.  Hubble's constant is currently believed to be about 70(km/s)/Mpc so the farther something is away the faster it is moving away and the more space a photon would have to travel through even if it were moving at the speed of light.