Of all of the chemical compounds-- and
there are many millions--
I think water has to be one of the most amazing.
And it's one of my favourite.
What we're going to do today is see how just a tiny amount
of water can cause an enormous fire ball.
This is a giant safety screen.
A giant cylindrical safety screen, as it will be, to
protect Peter from the effects of pouring a small amount of
water into some burning, boiling oil, which hopefully
will produce a giant fire ball.
Thanks to the screen it will go up, rather than out.
We're going to take you up to the roof because no ordinary
room could contain the fire ball that we
are hoping to produce.
As you may know, oil and water just don't mix.
And I can show this.
So we'll put some water in here and put some oil in here.
The oil molecules are really actually quite large.
They contain a lot of hydrogen, a lot of carbon
atoms, a bit of oxygen, and maybe a few other elements.
But this is really quite a large molecule.
The water?
Just three atoms--
which one's going to come out on top?
The amazing thing is the water is actually more
dense than the oil.
And this again is because of the interactions between the
water molecules really holding them in closely together.
The oil molecules are not polarised in the same way.
They don't have that same separation of charge that the
water does, and that's why we've got
these separate layers.
But what would happen if the oil was really hot?
Here we've got around 100 millilitres of oil.
We're going to heat this up, and eventually
it will catch fire.
Then we're going to add some water to the burning oil.
Now we've seen that the water sinks underneath the oil, and
at this high temperature it's going to
instantly turn into steam.
And then we'll see what happens.
One millilitre of water will produce enough steam to fill
this entire flask, which takes up around 2000 times the
volume that the water did.
OK, I think we've got ignition here.
If we can have the gas off.
Gas off?
Gas off.
OK?
Ready?
[EXPLOSION SOUNDS]
Well, now you can see why you should never add water to
burning oil.
How did it look?
It was awesome.
Did it come out the top, or--
Really good.
Yes it did, for several feet, a foot and a half--
I'm sorry, I have no idea.
Absolutely none.
But I did feel this.
It was good.