Alex McColgan

And yes, it's time for me to explain with another diagram.

I'm Alex McColgan and you're watching Astrum.

And to understand everything, it's time to scrutinize time, space and relativity.

We don't tend to think of relativity in the way I'm about to show you, but it's vital that we improve our intuitive understanding of this topic, or no attempt to explain why special relativity really happens will make sense.

Besides, who doesn't like having their mind blown by cosmic weirdness from time to time?

When it comes to special relativity, you might have felt like you understood the gist of it,

When an object travels at high enough speeds, time slows down for it.

At least, it does from the perspective of an outside observer at rest.

For the object itself, time seems to go the same speed, in a principle known as time dilation.

And, curiously, if you travel at light speed, from your perspective, you'd be ticking along as normal, but everything else would suddenly be slowing down, not you.

feels the universe shouldn't work this way, with both sides thinking the other is moving slower.

But this does appear to be the fundamental rule of our universe.

An object's rate of travel through time seems to be down to the relative position of your perspective.

There is no true rate at which things travel through time.

Weird already, but I wonder if you are aware of just how far this principle goes.

The implications get pretty mind-bending.

Let's talk about a second element of special relativity, length contraction.

This is a bit of a weird one.

From the point of view of an outside observer at rest, if an object were to travel at a large enough percentage of the speed of light, the observer would start to see the object flatten.

A ball would become a giant pancake.