Alex McColgan

This flattening occurs in the direction the objects travel, and it has been shown to occur both mathematically and experimentally.

We fired protons in the Large Hadron Collider, and their collision patterns only make sense if this pancaking is occurring.

It's very weird, but it does seem to be real.

Multiple experiments seem to confirm length contraction, including the Kennedy-Thorndike experiment and experiments with muon decay, where muon particles falling through our atmosphere don't decay as fast as they should thanks to this effect.

It's worth noting, however, that just like with time dilation, length contraction is a matter of perspective.

If you were the thing that had been accelerated to near the speed of light, you would not see yourself contract.

Instead, just like with time, you would start to see everything else contract in the direction of your acceleration.

There's some good maths that talks about why this is, but I won't get into that today.

as it's the consequences of length contraction I want to talk about, not so much its causes.

After all, we want to get to the part where we start seeing the future.

And for that, we are going to need a thought experiment.

This thought experiment is known as the Barn Pole Paradox, and it goes like this.

What happens if you try to fit a 40 meter pole inside a 20 meter barn?

Let's imagine the barn has a door on each side, which you can slide the pole through.

Now, obviously, normally this task would be difficult to do without bending or breaking the pole.

However, if we take advantage of special relativity, it is possible to do this.

All you have to do is fire the pole into one open door of the barn at near light speed, let's pretend for a moment that you can do that, and

Hey presto, as long as it's going fast enough, length contraction would occur, causing the length of the pole to diminish to our necessary 20m.

The pole would fit in the barn, for a tiny fraction of a second at least, before blasting out the other end.

Mission success.