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
You’ve got it, pretty much. If, today at this moment, an alien on a planet 65 million light-years away had a really good telescope and pointed it at Earth, they would see Tyrannosaurus Rex walking around North America. Because it would have taken 65 million years for the light that bounced off that T-Rex to reach that alien.
If he then kept watching us for 65 million more years, eventually he might see me, today, typing this reddit comment, 65 million years after I’ve died and been buried. Compared to the overall scale of the universe, light travels pretty slowly.
Granted, 65 million light-years is still an ungodly distance. That’s over 650 times the length of our entire galaxy. It’s over 25 times further away than Andromeda, the nearest major galaxy to us. In other words, that alien has to be really, really far away if he wants to see dinosaurs.
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