It's a paperclip compass.

Compass.

Distance also plays a role. Think back to playing with a magnet.

JH Now is this electromagnetic here, or are these static?

We have to generate an electromagnetic field...

I need a compass.

Compass needles point to the north.

This is a large pulley made by sandwiching rubber between two old CDs.

No compass?

A magnet attracts iron.

This is a horseshoe magnet.

JH I agree.

In other words, the field of the magnet is near the pigeon's head.

The magnets, of course, have a magnetic field around them.

Circuit

And the closer they are, the stronger the attraction.

Whenever current flows through the coil, this becomes an electromagnet.

You can see, this is the generator. It's a crank generator.

Skids down. Mag lock secure.

Charles Walcot investigated the magnetic compass bearing sense in pigeons.

This is a picture about a year ago.

I have here a superconductor, which I wrapped up so it'd stay cold long enough.

It includes 330 compasses.

Circuit

Short Circuit

Circuit

Therefore it has a smaller gravitational pull on the astronaut.

Now this is important for two reasons.

I've got some pieces of notebook paper folded up into a rough Z shape.

It's a remarkable effect. It's very strong.

If I spin this pulley, the small one's going to spin much faster.

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If you float a one yen coin on water and move a magnet slowly towards it then the coin will approach the magnet.

Keeton put magnets on the heads of his pigeons.

The magnets on their heads were responsible for that.

Maybe one more thing might help. Have you ever played with two magnets?

You know, the magnets with the north and the south poles?

This is a permanent magnet.

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Circuit NPN Transistor