Kind: captions
Language: en
today we're trying something that's
never been done before I have made this
video and Destin has made a video on
smarter every day and we want you to
play them both at the same time so
there's a link to his video down in the
description find a way to load both of
these videos and then synchronize them
on my mark in five 4 3 2
1 in Australia we are at 34° south
latitude which is the opposite side of
the world from Huntsville Alabama so
which way did the toilets flush that is
the
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question The Simpsons did a whole
episode based on toilets flushing the
opposite direction in Australia plus
other shows have supposedly demonstrated
this
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effect so is this a real effect or not
the application of this principle to
draining water in Earth's two
hemispheres is just
bunk if if you try it yourself you'll
find inconsistent
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results this sink sometimes drains one
way and sometimes the other
way in any container of water there's
always going to be some rotation the
water is not perfectly still and it is
this rather than the hemisphere that
determines which way the water will
swirl down the drain
but what if we could eliminate all
motion from the
water I have here a 5ft wide Kitty
pool I actually filled the pool in the
anticlockwise direction to be sure that
any clockwise motion we see is not due
to the way I fill the
pool and I've left this water sitting
here for 24 hours so it seems like I've
damped all of the Motions from The
Filling I really hope this works Destin
wish me
luck I'm about to pull the
plug three two
one and the pool is draining but you
can't see any motion of the water just
yet to help us see where the water is
Flowing I'm going to put some food
coloring in on the four cardinal
directions around the pool
you can clearly see that the water is
Flowing clockwise in this direction and
that makes sense because that's how it
should flow in the southern hemisphere
due to the Earth's rotation
but you can see what a tiny little
effect it is and what extraordinary
lengths I had to go to to see this
effect so really you're not going to see
it in a bathtub and you're not going to
see it in a sink or in a toilet because
there are other sources of angular
momentum that totally wash out this
effect the coris effect there you have
it it
works to understand how it works imagine
a pool with one Edge touching the South
Pole
the pool is stationary relative to Earth
but every day it's actually completing
one full
Revolution now you can see the side of
the pool furthest from the pole travels
much farther every day than the side
right next to the
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pole so the outer side of the pool is
moving fastest towards the east and as
you get closer to the pull the velocity
decreases down to
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zero now imagine we drain the
pool water From The Far Side is moving
too fast relative to the drain and so it
gets out ahead whereas water from near
the pole is going too slow and so it
lags behind
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so when the water approaches the drain
it swirls
clockwise and this is the reason
Cyclones swirl clockwise in the southern
hemisphere the higher pressure air
rushes into the eye of the storm and
just like in our pool swirls in the
direction dictated by the hemisphere and
that's the truth about toilet
swirl I definitely learned something and
if you did too then you should share
these videos with your
friends so you should subscribe to this
guy subscribe to Destin run every
day okay go yep yep you're here
that's what we're going to do we're
going to subscribe to veritasium and
mass because it's an awesome
channel oh oh look where's the Subscribe
button but seriously have you subscribed
to smarter every day yet Destin has made
some of the best videos on the internet
like the backwards bicycle Prince
Rupert's drop and what it looks like to
get a tattoo in slow motion now I've
been friends with d for about 3 years
and I'm pretty much convinced that the
man is superum not only does he run a
remarkably successful YouTube channel he
also has a wife and four kids and he has
a full-time job the man is literally a
rocket scientist and he's friends with
astronauts and when he asks them
questions they answer him from space and
you are getting smarter every day this
man deserves your subscription if you're
not subscribed to him already I don't
know what you've been doing with your
life but go over to his Channel right
now and subscribe to smarter everyday
and trust me you will thank me later and
I want to thank you for watching you
know we have been working on this
collaboration for about 3 years and it
feels so good to have it finally out
there in the world I hope you enjoyed it
as much as we enjoyed making it all
right I'll see you next time