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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
used 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 Questacon science
Center in Canberra and I'm gonna shoot
this again with their amazing high speed
1200 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 gonna 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 yeah
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a lot of people think this experiment is
just about showing the power of the
atmosphere but I think there's a more
important consequence it explains why at
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 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 know if you've seen
Vsauce this video on the space straw the
lowest pressure you can get in a gas is
zero a perfect vacuum but you can
actually get negative pressures 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 liter drum was
good but perhaps this 200 liter drum
will be better but the question is will
it implode I want you to place your bets
now we have two gas heaters you can see
heating up this drum it's pretty hot we
have a bit of steam coming out the top
as you can see there in a moment we're
gonna 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
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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 well that's how it should work in
theory anyway
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the implosion happened so fast in just
twenty five thousandths of a second that
the water on the left-hand side of the
drum can't keep up have a look a human
blink
takes about a hundred milliseconds
that's four times the time it took for
the drum to implode so it's literally
blink and 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
crumbled into a perfect equilateral
Prizm
which might not surprise you if unlike
vihart 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 drone
was optimizing to make the minimum
volume in its interior which is what
you'd expect because there's a vacuum in
there isn't that awesome that is awesome
that feels good wash
you
now you may have noticed that the big
drum crumpled into an equilateral Prizm
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 triangular
prism but I'd like to hear what you have
to say so let me know in the comments