Things in space being “xxxx lightyears away”, therefore light from the object would take “xxxx years to reach us on earth”

Question

I don’t really understand it, could someone explain in basic terms?

Are we saying if a star is 120 million lightyears away, light from the star would take 120 million years to reach us? Meaning from the pov of time on earth, the light left the star when the earth was still in its Cretaceous period?

In: 292

Answer 1

>Are we saying if a star is 120 million lightyears away, light from the star would take 120 million years to reach us?

Yes, that’s exactly what it means. The day-to-day equivalent would be talking about distances in hours. The colloquial expression just drops some of the details of the assumptions about speed.

Sacramento to LA is about 6 hours driving at 65mph. So Sacramento is six (65mph-hours) from LA.