Fair food in the dish also say looks fairly innocuous now.

Very, very strong magnet.

All right, that hurt.

Get off.

Thes magnets are very strong.

Let's do the magic first way are talking about fair fluids.

This wonderful Well, it looks pretty innocuous.

It gets everywhere.

It stands everything.

This evil black sort of oil like fluid.

About this time last year, I went into my daughter's school.

Andi played around with this.

Andi, I've never seen a bunch of eight year olds get so excited about a piece of science.

So I really wanted T.

Dua 60 symbols video and let me cut to the cheers.

There we go.

Black oil evil.

In fact, they say that you should dispose of it.

Justice.

You dispose of oil.

It's pretty dirty.

It stands very body.

It's not toxic.

A told you don't need to stand back Pretty.

It's fine.

It's not quite level, right?

What we're gonna do now is captured the dynamics of how this fair of fluid response for a magnetic field would have been a magnet in up underneath it on Ben, take it away on.

We're gonna look with a high speed camera.

I'm absolutely surrounded by cameras here.

Lots of lights.

It's a very big sort of Hollywood production compared to the usual Brady carrying a camera on his shoulder.

Let's go.

So I'm gonna be Oh, why Howdy.

So what you bring the market up from from below.

Basically, the influence of the magnetic field is changing, and that's giving you different spikes as the favorite fluid fields of greater influence of the magnetic field.

Balanced against that is the surface tension, which is trying to hold the liquid together on so you about these two competing effects from the period is little spikes.

You can work out lots of fascinating things about the dynamics of the fluid and also the property.

That's the problem.

It's jumped out.

So I brought the magnet.

I stupidly brought the magnet to the top service and jumped out of my hand.

Without a body.

It's and I now have to wash my hands.

The fun bed is when you put the magnet on the top and watch it go up to that.

That's the phone bed.

That's a bit I'm looking forward to.

But then we will have to stop the video because I'll have to spend at least an hour cleaning myself.

Where does magnetism come from?

Or magnetism comes from the interactions off spins on what we basically do to represented what physicists do represent.

We take the electrons, and we think of them basically has either been spent up or spend on.

What happens is when you put the magnetic field on.

It'll spins a line right on there, lying right across the solid.

So with pharaoh magnets with the magnet you used to.

When you take the magnet away, their spins remained aligned, and you're left with what we call a permanent magnetic moment in things called power magnets.

What happens is that when you bring the magnetic field in, you can align them.

But when you bring it away, they no longer remain aligned.

That's exactly what's happening with these fair foods.

So we're gonna move away from considering the sort of individual atoms of the individual electrons and think about a nano particles comprises tens of thousands of up to 100,000 atoms on dhe, each one of those particles, the electrons in them.

Although spins interact.

What happens in the particle is that the particle ends up despite the fact that is comprising lots and lots of atoms ends up with one big nets.

Been we call it a single demand particle.

Now what's happening in the absence off the magnet in the fairy flutes.

So just as it stands just as it is like here, those particles are bouncing around, bumping off all the particles moving around like you would expect, you know, particles in a liquid to do, and so the spin get scrambled and they don't align when you bring the magnet in.

What's happening is you're getting the spins of those particles all to align, and you see in the collective response of all those particles responding to magnetic field, lining up on interacting with each other.

Take it away again on your back to the fluid.

When I bring you, why don't your atoms and a very good question really Certain things are magnetic?

All the things are not magnetic, and it depends on how the electrons are arranged in the solid.

That's the key thing.

Lots of organic material we see.

It's dia magnetic.

It's not fair.

A magnetic or not power genetic, and that's because busy the elections are not free to a line in the same way as they are in iron, for example, or the fire magnetic materials.

So the particles in this liquid are magnetized.

So in iron oxide on what they're coated with is something called a surfactant, which means that the particles are the surfaces of the particles are quite passive.

They come together, but then they don't chemically bond.

It's what we call a physical interaction.

It's a physical attraction, no chemical bonding on.

Then when you bring the magnet away that can release easily and then the bumping into each other in the solution.

But they're not forming chemical bonds, so you might think it's a fairly esoteric, you know, product.

You really haven't seen it before.

But where it crops up all the time isn't hard.

This technology, actually the spindles that are associated with tar discs where the hardest is spinning around that is lubricated, actually fairly fluid.

So you have to get a first time Brady because I'm gonna get covered in stuff.

I'm gonna bring it in both of the fair of fluid instead of putting the magnet from below was seen before.

When I bring it in from the top, let's see what happens.