Time travel

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I think everyone is fascinated with time travel. It might be due to popular Sci-fi movies which show different kinds of time machines with clocks sticking out of them or too many lights that attract our inner child. Or maybe because we make so many mistakes in our lives that we really want to go back in time and fix all of them. No matter what the reason for this attraction is this will always be a fascinating as well as controversial debate, at least until it is proven to be possible or impossible definitively. 

But for now we might not be able to go in the past but due to the speed of light we sure can see in the past. Because when we start looking farther and farther away the speed of light, as fast as it is, does not seem to be fast enough. Even in the case of our own solar system which is not that large when we consider things on a cosmic scale. We know that we can only see something when light from that thing reaches us. Whether that thing is the source of the light or light from another source is reflected from it, whether the light is in the visible range, ultraviolet or infrared we have to wait for the information in that light to get to us in order to see it.

For example, it takes light 8 minutes and 20 seconds to reach from the sun to us so the sun is just a little less than 8 and a half light minutes away from us. What that translates to is that when we look at the sun we are actually seeing it in the position it was 8 minutes and 20 seconds ago and not in its current position. So in essence we are seeing the sun in the past even though it is just a few minutes it is still the past. If the sun vanishes right now we will keep seeing it for 8 minutes and 20 seconds. The effects of the sun's gravity will also be felt for that amount of time. This is not a trick or an illusion it is just how things are due to causality that is the speed of light in space. 

If we start looking farther away, we can see things days, weeks, years, even billions of years in the past. Because the farther we look the more time it takes for the light to reach us. Theoretically speaking, if we go to a distance of exactly 100 light years from earth right now and look back with a powerful telescope we will see the earth as it was in the year 1920 so that is a form of time travel.

We don't know what the future will bring maybe someone will invent a time machine or discover wormholes that take us in the past or the future and maybe he or she will read this post and make fun of me in the comments. 

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