Kind: captions
Language: en
So, a while back I did an imploding drum
experiment, but at the time I didn't
have a very good high-speed camera. And
so, I use something called optical flow
to interpolate between the frames. And
basically, it just tries to add in what
must have happened. But since it doesn't
actually capture what happened, you can
see that it actually warps the frame and
looks really weird and unrealistic. So,
I've come down to the Questicon Science
Center in CRA and I'm going to shoot
this again with their amazing high-speed
12200 frames per second. Okay, we've got
steam billowing out of the drum. So,
it's totally full of water vapor at the
moment. Now, I'm going to take it off
the heating element.
Now, we're going to cool down all that
water in there, which is going to cause
it to condense. As it condenses, it's
going to create a vacuum in there, which
hopefully will get it to implode.
Whoa.
Oh,
[laughter]
yeah.
[music]
A lot of people think this experiment is
just about showing [music] the power of
the atmosphere. here. But I think
there's a more important consequence. It
explains why at a a power station, for
example, you need to cool the steam as
it comes out of the exit. To turn over a
turbine, you have to get very hot steam.
And everyone appreciates the steam needs
to be incredibly hot, as hot as you can
make it. But on the other side of the
turbine, you need to use a condenser to
cool down that steam. And this is why,
because that creates this big suction.
So, not only do you heat up the steam so
it pushes over the turbine, you also
need to cool it down when it's gone
through the turbine. So, you have a big
change in energy, and that is what turns
the turbine over. [music] Now, of
course, suction is just the word we use
when a fluid flows from an area of
higher pressure into an area of lower
pressure, which you'd know if you've
seen Vsauce's video on the space straw.
The lowest pressure you can get in a gas
is [music] zero, a perfect vacuum. But
you can actually get negative pressures
[music] if the fluid is a liquid and
it's inside a tree. Now that's real
suction. So click on the link in the
description if you want to learn more.
So that 20 L drum was good, but perhaps
this 200 L drum will be better. But the
question is, will it implode? I want you
to place your bets now. Uh we have two
gas heaters, you can see heating up this
drum. It's uh pretty hot. We have a bit
of steam coming out the top as you can
see there. In a moment, we're going to
pull it off these gas burners, seal it
up, and start cooling it down with
water. The water vapor inside will
condense, and we will see if the
atmosphere can crush it. I'm cautiously
optimistic.
[music]
Round objects are incredibly strong
under compression, as Destin showed us
with Prince Rupert's drop. But if you
create just a little ding in a round
object, it should significantly weaken
the structure. And that's what the
hammer is for.
All right, let's whack it.
[laughter]
Well, that's how it should work in
theory anyway.
Underwhelming science.
There we go.
[music]
The implosion happens so fast in just
25,000 of a [music] second that the
water on the left hand side of the drum
can't keep up. Have a [music] look.
[music]
A human blink takes about 100
milliseconds. That's [music] four times
the time it took for the drum to
implode. So, it's literally blink and
[music] you'll miss it. So, there we go.
We showed that the atmosphere is
powerful enough to crumple even this
very thick,
very big drum. When we later measured,
we found that the drum had crumpled into
[music] a perfect equilateral prism.
Which might not surprise you if unlike
Viheart, you prefer your maths potatoes
with a minimum amount of gravy. You see,
for a given perimeter, the equilateral
triangle encloses the minimum amount of
area of any regular polygon. So, the
drum was optimizing to make the minimum
volume in its interior, which is what
you'd expect cuz there's a vacuum in
there. Isn't that awesome? That is
awesome.
[sighs] That feels good.
Now you may have noticed that the big
drum crumpled into an equilateral prism
whereas the smaller drum crumpled into
something resembling a hexagon. So the
question is why were they crumpled in
different ways? I mean one thing I was
thinking was that perhaps they were
created in different ways. So maybe they
were welded in different points and that
explains the structure that we saw. But
I'd like to hear your thoughts. Why do
you think we saw these different
crumpling patterns? I mean, obviously
things with three corners are generally
quite stable. So that may explain also
why it crumpled just to a a triangular
prism. But I'd like to hear what you
have to say. So, let me know in the
comments.