Looking Back In Time

It is possible. All you have to do is just look at the stars above you in the night sky. Or the sun.

What's the science behind this?

We are only able to see an object when light is reflected or emitted from the object into our eyes. Now, let's say a star is 5 light years away from Earth. This means that it takes 5 years for the light from the star to travel to our Earth.

So when we are looking at a star that is 5 light years away from us, we are actually looking at the star as it is 5 years ago. The star may have suddenly disappeared 3 years ago, but we wouldn't know until 2 years later, when the last of the light from the star reaches our eyes.

So everytime we look at the heavens, we are actually taking a look back into the past.

In case you were wondering, it takes 8 minutes and 18 seconds for the light from the sun to reach our planet. That means that if the sun were to suddenly cease existing for whatever reason, we would only notice the absence of sunlight 8 minutes later.

This isn't actually rocket science and anyone who knows about how we can only perceive things when light from the object enters our eyes should know all that I've stated above, but I still find it interesting regardless.