David Kirtley

And so that means we have to do it on the order of a millionth of a second.

We have to do it in a millionth of a second.

And so in practice, this is hard.

And we can only do it now because of semiconductor switching.

Because we can move things, we can switch things, like the transistor in every CPU in a computer switches at a gigahertz.

That means in a nanosecond, it's switching in a billionth of a second.

And so now, which we didn't in the 1950s when these theta pinches were invented, but now we have the semiconductors to be able to do that.

So what I like to do is use an analogy here of once you've made it,

it's actually somewhat straightforward to understand.

Getting to it is tricky.

And how they discovered it the first time is absolutely amazing.

But once you've made it, it's a lot more straightforward to understand.

And a magnetic coil, when you have a round electrical coil, you have electrical current flowing in that coil.

And if you have a conductor, if you have a metal inside that coil, and this is called Lenz's Law in one of the Maxwell equations, is that as you have electrons and you have current flowing in that coil, an equal and opposite electrical current is induced in a piece of metal nearby.

This is the same thing that happens in a transformer.

where you have a primary on a transformer and you have electricity flowing it, and you have a secondary where electricity flows exactly the opposite direction.

We use this every day in our lives.

And so in this condition, you have a conductor, an electrical conductor, where current can flow, and you have an electrical current flowing on the outside, electrical current flows on the inside.

And in that case, now I've described two pieces of metal.

Now let's go one step further.