Alex McColgan

This is what would happen from the pole's point of view.

The pole enters the barn just like we would expect, and then, there.

Did you see it?

Perhaps, but what did you just see?

You just saw an example of the myth of simultaneity.

And remember, this is really what happens according to special relativity.

Events that are simultaneous from one point of view are not simultaneous from another.

To be clear, this is not just a weird consequence of light taking its time to reach us.

If we were just dealing with an optical illusion caused by light taking its time to move to our eyes, then we'd see the closer event happen first, and the more distant event happen second.

but this is happening the opposite way around.

In this case, and from the point of view of the pole, the more distant event spatially happens first, and the closer event happens second.

In other words, this is not just a trick of the light, but the suggestion that something more fundamental is going on.

And what is going on?

When I first learned about this, it boggled my mind.

It seemed wrong as a matter of principle.

But the more I thought about it, the more it started to make sense, based on my understanding of the universe.

And the more startling implications started to arise.

Don't worry, I've not forgotten about that seeing the future thing.

I'll get to it.

Let's take another look at what's happening here.