David Kirtley

And so you can have one very, very high energy particle and very cold energy particle, and they may not even touch each other.

But maybe occasionally they bang into each other, they collide, and then they transfer energy.

And that's where we call rarefied.

And then you can go even hotter than that.

And that's where now the actual atomic states, which has the nucleus, which is a proton and a neutron, and an electron gets so hot, that electron gets energized and then escapes.

leaves the system.

And now they're charged.

You have a positive nucleus and a negative electron floating out.

And that happens on the order of 10,000 degrees.

So way hotter than what we're used to.

But now we're going to go hotter.

We're going to take this plasma and go even hotter.

And what does that mean?

At that point, a lot of the way we think about temperature doesn't really apply.

The idea that you have these random motion of particles, because now they're all individual particles moving at very high velocity.

So what it's really is a measurement of is velocity.

It's really a measurement of how fast is that particle moving.

And that's how I really think about temperature when you get to that 100 million degrees.

And so it does some more complex things.

If you have this high energy particle, that's why we like fusion, is moving at high velocity, and there's another one moving at high velocity, they will come together, they will collide, and they will fuse.