In Neil deGrasse Tyson's Astrophysics for People in a Hurry, he writes:
By now, one second of time has passed.
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The universe has grown to a few light-years across...
If nothing can move faster than the speed of light, then it seems to follow that it should take a year after the big bang to reach a radius of one light-year.
This line of thinking brought me to another apparent paradox: the age of the universe is 13.8 billion years but it's radius is 46.6 billion light-years.
How is this possible?
