00:00:00
I have this propensity to
want to crush things.
00:00:03
So I want to show you what this
demonstration looks like.
00:00:05
[POPPING SOUNDS]
00:00:06
Let's do the same thing that we
just did, but this time the
00:00:09
can is a little bit bigger.
00:00:09
[EXPLODING SOUND]
00:00:12
So I bet you think this is the
part of the show where I'm
00:00:14
going to say, don't try these
experiments at home.
00:00:16
And you're right.
00:00:17
Except there is one experiment
we want you to try.
00:00:20
Just look for the graphic
that's right here
00:00:21
that says, Try It.
00:00:22
That's your signal that
you can try that
00:00:24
experiment at home.
00:00:25
Everything else, off limits.
00:00:27
Look, I've already given you
homework, and the show hasn't
00:00:33
Well, this is the answer to the
age-old question, what do
00:00:37
you do to crush that can?
00:00:38
Because of course, you
don't want to just
00:00:40
sit here and do this.
00:00:42
Expends so much energy.
00:00:43
Why wouldn't you want to have
this entire set up here just
00:00:47
to accomplish the same thing.
00:00:49
But there's nothing really
cool about that.
00:00:51
All right, so let's see if we
can do it a different way.
00:00:54
So here's what we have, is
we have three cans here.
00:00:57
In each of the cans, I have
a small amount of water.
00:01:00
Now, you could do this on a
burner if you wanted to.
00:01:02
In this particular case, because
we're portable, we
00:01:04
have this little camping
stove thing.
00:01:06
And so now, let's
turn this on.
00:01:10
So the object here is this, is
we want to boil that water.
00:01:14
So when you boil the water in
the can, water when it boils,
00:01:17
goes from a liquid into a gas.
00:01:19
And when it does that, those
little water molecules move
00:01:21
about 1,700 times farther
away from each other
00:01:24
than they were before.
00:01:25
In essence, we're turning
it into water vapor.
00:01:28
And you can see a little
of the water vapor
00:01:29
starting out here.
00:01:31
What we're really trying
to do is to push the
00:01:33
air out of the can.
00:01:34
This is a demonstration
in air pressure.
00:01:36
There's air pushing all
around the can.
00:01:38
If we're at sea level, it's 14.7
pounds per square inch.
00:01:42
It's pushing all over the can.
00:01:44
What we want, is we want to
evacuate the can from the air,
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