“The furthest lights are 13+ billion light years away, so they assume the galaxy is 13+ billion years old. To get that, you have to assume:
1. that galaxies travels at or near the speed of light. They don’t, so it may have taken them long to get to where they are, or were when the light we see started.
2 You have assume we are at the center of the universe, since we can see galaxies at that distance in all directions.”
Your ignorance of astronomy and the age of the universe is astounding.
So, Tex, Tell me again the one-way speed of light? Einstein couldn’t nor wouldn’t try. He understood that we can only derive a round trip SOL, so knowing just how light acts in reality, is, well, beyond us. A convention agreed upon because knowing, not just assuming, is not possible given both technology and constraint. All of the facets of physics simply tell us, “whoa, there fella, my secrets are mine”.
“In the Beginning (of time)... God said, “let there be light, and light was””. Ought to make us think about light in a different, well, light.
And, to those who will say it has to be uniform, the correct answer is no, it only has to be seen as consistent from application to application, and observation to observation.
Most of astronomy has passed from observation to supposition and assumption; and, heaven help us, consensus.
But I defer to those who spend much more time on the subject, as to breadth of training and assumption, not truth, necessarily.