Dennis Whyte

is get essentially a rocket going out like this.

And then what happens is that the sphere like, and this is happening in a billionth of a second or less actually, this rapidly, that force like so rapidly compresses the fuel that what happens is that you're squeezing down on it.

And it's like, what was the, see BB, that's bad actually.

I should have started with a basketball.

Goes from like a basketball down to something like this.

Mm-hmm.

and a billionth of a second.

And when that happens, I mean, scale that in your mind.

So when that happens, and this comes from almost from classical physics, so there's some quantum in it as well too, but basically if you can do this like very uniformly and so-called adiabatically, like you're not actually heating the fuel, what happens is you get adiabatic compression such that the very center of this thing all of a sudden just spikes up in temperature and

Because it's actually done so fast.

So why is it called inertial fusion?

It's because you're doing this on such fast timescales that the inertia of the hot fuel basically is still finite, so it can't push itself apart before the fusion happens.

This is why you use lasers, because you're applying this energy in very, very short periods of time, like under a fraction of a billionth of a second.

And so basically that, and then the force which is coming from this comes from the energy of the lasers, which is basically the rocket action, which does the compression.

No.

You want to keep the fuel cold and just literally just ideally compress it.

And then in something which is at the very center of that compressed sphere, because you've compressed it so rapidly, the laws of physics basically require...

for it to increase in temperature.

The effect is like, if you know the thing, so adiabatic cooling, we're actually fairly familiar with.

If you take a spray can, right, and you push the button, when it rapidly expands, it cools.