Time and Space

I always find it fascinating to think that the light we see in the sky from the stars has actually left those stars millions of years ago and has only now reached us. To think that some of those stars we see today might not even exist anymore. Some might have been swallowed up by a black hole, while others might have collided with bigger stars that slowly consumed them.

Astronomers just witnessed a supernova explosion for the first time (supernovae occur when huge, mature stars effectively run out of fuel and collapse in on themselves).

I was reading the article and than I saw this picture:


which was accompanied by this caption: "The stellar explosion occurred 400 million-light years away." And that's when I realized the implication: that star was 400 million light-years away from us when it exploded... 400 million years ago.

That's awe inspiring to me. That explosion occurred 400 million years ago, but just now we are able to see it, because obviously we're 400 million light-years away.

Amazing.

I remember once realizing that if the sun suddenly stopped emitting light, as if it just turned itself off, we wouldn't know it for 8.3 minutes, because we're so far away from it that it takes that long for its light to reach us. Isn't that incredible?