The universe is a really bizarre place. To us, it doesn't appear that way in day to day life because the scale of reality we deal in is really small. Like, really, really, small.

Consider this: the light from the Sun takes 8 minutes and 20 seconds to reach us. So, if the Sun were to suddenly disappear, we wouldn't even know for 8 minutes and 20 seconds!

This might be a bit hard to wrap your head around at first, but it totally makes sense once you get it. As far as we know, the speed of light is the speed limit of the universe. Also, whatever we see is because of light.

In day to day life, we don't notice any delay. That's because the distances involved are too small. Light travels at just under 300,000,000 meters per second. And assuming airplanes fly at 13000 meters above the ground, it means that light from an airplane reaches us almost instantaneously. But light from the moon would reach us after about 1.3 seconds. The further you go, the longer this time gets.

Dinosaurs Still Alive?

So, with that knowledge, let's do a thought experiment. Let's say there is an alien race that is 65 million light-years away from us (a light-year is the distance that light travels in a year).

So light from our planet would reach them only after 65 million years. That means, if they point their powerful telescopes at our planet, they would be seeing 65 million years in our past.

And what happened during that time? Well, the dinosaurs were alive... almost about to die. So, if the aliens timed it right, they could witness the annihilation of the dinosaurs. How cool is that?

If you think about it, our universe is like a time machine. It sort of combines distances and time together. Difficult to grasp but it's the reality!