So I heard that, possibly, two super massive black holes could be merging by the end of this or next year. My question is this, and essentially trying to get my head around, if it takes x amount of time for light to reach us, has this event already happened? And we are just seeing it in its past?
In: 1
Many people have experienced this. A very similar thing is happening when you hear echoes. If you shout and hear your echo a few seconds later, that is ‘your voice’ from ‘the past’.
Well, the same thing, not the echo part, but the delay part happens with light. Light travels at a very fast speed but not an infinite speed. So light from any event takes time to reach your eyes. NOTHING you see with your eyes is happening at the time that you see it. Everything is delayed, it is just that for most human stuff, we cannot notice the delay.
Since stars are really far away, the delay is measurable.
Latest Answers