If stars we see are billions of years dead, what is really out there now?

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They say that when we look up to see stars, we’re actually seeing the light from dead stars. So technically, we can’t see what’s out there in the present? What do you think is out there now? is it just new, modern stars or we don’t get to see anything at all? (since by now, everything has expanded billions of miles apart from each other that light is far from anything to reach)

In: Planetary Science

20 Answers

Anonymous 0 Comments

The universe is highly homogeneous which means that on the largest scales we see the same thing everywhere. Galaxies are not too dissimilar from one another. (Even though there is plenty of variety there are also lots of galaxies to sample.) So looking at very distant galaxies and ones closer is like looking at one sort of average galaxy at different points in time.

So we don’t know exactly what is going on “right now” but we roughly know. Maybe very massive stars we see in a galaxy 2-3 billion light years away are long gone, we have a good idea how that galaxy looks now by looking at galaxies a bit closer. Or rather we can only see a specific galaxy at a specific point in time but given a large number of similar galaxies we can easily piece together possible “screenplays” for galaxy formation and development.

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