A bowl full of glass beads, tiny glass beads that represents sand set up her on.

Operators hold a steel ball bearing at a height of a meter above the surface.

You flicked a switch.

The ball drop down, went into the sand and made a crater the advantage of using glasses that it's more nearly spherical around so it doesn't have any sharp, jagged edges.

We have two bags of these downstairs.

One is the diameter of a typical bead is about 1/10 of a millimeter.

The other one is 10.64 millimeters, which you can imagine because you see it on a ruler.

So that's actually quite a course screen, so there's a substantial difference between these two.

This is the find powder, the 20.1 millimeter beads.

You could see it falling down as if it were water fall into the tiny bowl on.

We do this slowly so that the bowl underneath gets ah, uh, layer, which is a CZ gently created as possible.

It turns out that air has a big effect.

We want to trap the air as much as possible.

If you don't do it this way.

If you stamp it down, the whole effect disappears, Right?

This is the bed of the And here comes the little ball bashing into it and you get a lice crown appearing as you might expect.

And then after this crown dies away, a plume appears in the center of the screen, rising up fire and higher and higher.

And then that plume seems to break into little bits and fall down.

So you get a secondary effect of a jet, a plume coming out of this cloud, which appears as you look in sideways.

Now we repeat the experiment, using the bigger beads 0.6, the millimeters and the stoop ball comes in.

You get a Corona coming out, but wait for it.

There is no plume.

Nothing rises up from the center.

You just get a normal crater appearing in the glass beads.

Now we're using the final grain particles on the sphere comes down on bashes in, and you can see it more or less from a top view.

It digs a hole, blows arctic ring shaped thing on the plume rises from the center, goes up, goes up, goes up.

So you've got a crater circular crater formed, And now, as the plume falls down, you get a little dimple or pimple or whatever you would like to call it.

Now we're looking at the same experiment for the larger glass spheres.

Down comes a sphere creates a crater, a hole in the middle, and now you can see that there is a slight dimple pimple in in the middle.

But nothing came up a za plume, so it's almost the same, creating a very nice crater.

But the plume has almost disappeared.

The bed of sand is full of air.

As the sea comes down, it compresses the bed of sand.

When it hits, hits, it pushes down, creates a hole at all.

The air in the region that it's just compressed wants to get out.

So the further down this, this fear goes, you've got a little tube coming up on that.

The air, trying to escape wants to go out about tube so you get after a little while a blast of air coming up through this tube sad can fall into this tube from the sides on.

It gets carried away with the wind that's blowing upwards.

So if these particles are tiny.

They get swept up by this gust of wind.

If the particles of heavy they don't get swept along so easily, and that's the reason why they don't really blow up.

You can see a little bit because they might have been blown up tiny amount, but they don't go way up into the air.

So the fine of the particles are, the more they get carried up by this blast of air.

Where did that come from?

Was that the air that was between the part, like under the ball?

Now?

Yes, directly under the ball.

Because it comes down, it pushes and pushes these particles together and compresses them on that air.

Wants to escape somehow.

The only place you can go is up and go sideways, but you do get this jet.

What's causing this is the air.

On the proof of that is the experiment was set up by a group led by Jaeger in Chicago, a rip, very respected group, and they decide to do it in a completely sealed container so the bowl is in the container.

The ball is in the container and is cut off from the rest of the world and they could pump out the air.

When the air is there, the effect is present.

By reducing the pressure of the air sufficiently, they could make the effect go away.

If you'd like to see more on this subject, including Worthington jets when objects hit a water surface, I'd really recommend Destin's video over.

It's smarter every day.

Be warned.

There's a little bit of toilet humor, but he's from Alabama.

Also.

I recently made a video about what I think when people write first in the comments section on YouTube.

You can have a look at that if you like.

And if you just want more slow motion, where we're doing a lot of periodic videos with chemistry videos at the moment, I'll also include a link to that on the screen, I imagine I don't know yet, but I imagine it'll be below me and to the side in a box down there.

I don't know.

I sort of do this afterwards, but you get the idea.

And of course, all these links will also obey in the description.