The Truth About Toilet Swirl - Northern Hemisphere

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    Some notes about this.
    We each repeated the experiment 3 times, and got the same results every time. For those of you who might be skeptical, great! The good news is that right circularly prismatic kiddie pools are only $10 and you can do the experiment for yourself at your latitude. There's really no reason you shouldn't do this on your own, so before you criticize how we've done it, I'd strongly encourage you to do it for yourself.

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    Gordon McGladdery did all of the sound design for the video. We used two songs from other artists (licensed of course). Derek split the first one up so it fades from video to video, and Gordon split the instruments up on the second one. There are violins on one video and percussion on the other for example. It's really neat.

    The neat earth animation at the beginning and the synchronizing timer was made by He also made still images of the earth from the top and the bottom.

    Thanks to Jacob Vehrs for helping make the plywood pool platform.


    There was a study performed at MIT years ago ( that explained the physics involved. We repeated some of these demonstrations, but on opposite sides of the globe…and in a way that can be easily understood.
    This site is a great resource on the Coriolis effect and ways people have gotten it wrong:

    The Coriolis Effect influences the flight of a bullet.

    We would love for someone to replicate this demonstration. Please tweet your results to us @SmarterEveryDay and @Veritasium.
    Here's the link to puchase the exact same pool:

    Tweet ideas to me @SmarterEveryDay

    The thought is it will help educate the world as a whole, and one day generate enough revenue to pay for the kids' education. Until then if you appreciate what you've learned in this video and the effort that went in to it, please SHARE THE VIDEO!

    If you REALLY liked it, feel free to pitch a few dollars towards their college fund by clicking here:

    Warm Regards,

  • Video CategoriesScience & Technology
  • Runtime: 8:2
  • Tags for this video:  Smarter  Every  Day  Science  Physics  youtube edu  Education  Math  Smarter Every Day  experiment  nature  demonstration  slow  motion  slow motion  education  math  science  science education  be smart  edu science  what is science  Physics of  projects  experiments  science projects  coriolis effect  toilet swirl  australia  Coriolis  Fluid Dynamics  

Comments: 5 758

  • Matthew Britton
    Matthew Britton 4 hours ago

    Hi Destin - does the direction and/or rate of flow depend on the relative position of the Earth's wobble? This affects atmospheric things that ultimately affect macro-geographical things like the Sahara Desert, but does it affect local things like toilet bowls?

  • venomjuker
    venomjuker 11 hours ago

    Who actually have it in sync? This is awesome! The parts where they keep quiet are the parts where the other video starts talking!!!

  • antonio garibay
    antonio garibay 15 hours ago

    what If your on the equator??

  • Ian Richardson
    Ian Richardson 1 day ago

    Physics! My favorite spectrum of science!

    • Ian Richardson
      Ian Richardson 1 day ago

      Mainly because all other sciences rely on it. ^v^

  • anthony halstead
    anthony halstead 1 day ago

    Bring this expiriment to the equator and make 2 and put one on both sides and see if they swirl different

  • millertas
    millertas 2 days ago

    Prof. Brian Cox said it was a myth BUT Michael Palin in his TV series 'Pole to Pole' showed a man on the equator in Kenya demonstrating the affect.

  • Xptechmike nosehairextractorguy

    Their test was inconclusive. They didn't have enough variables. If they had Five kiddie pools one of him may have inadvertently began turning in the opposite direction. Where one direction may be a default, it wouldn't have taken much to get it going in the other direction from a stopped starting position.

  • zhibro gamebro
    zhibro gamebro 6 days ago

    WOW now i convince its true,before i see this vid my belives and disbelive is 50/50

  • H2TA
    H2TA 6 days ago

    looks good with dual monitors

  • shutemdwn
    shutemdwn 6 days ago

    Ok that was cool how you synced the two videos. Do some more of that!

  • justin hyland
    justin hyland 7 days ago

    This is an amazing video! good idea on the synchronous videos as well.
    Ive knew about the Coriolis effect, but this experiment is an awesome illustration.

  • Max Ducke
    Max Ducke 7 days ago

    It was way too much for my mind to process.

  • xXE4GLEyEXx
    xXE4GLEyEXx 9 days ago

    ... an amazing idea!

  • Haikal Gaming
    Haikal Gaming 10 days ago

    this left

  • B Rice
    B Rice 11 days ago

    Cool idea, guys!

  • Felix s
    Felix s 12 days ago

    pair of frickin pole vaulters.

  • Brandon Lewis
    Brandon Lewis 14 days ago

    If the earth is spinning it's going faster than the speed of sound at the equator. So if there is momentum, which should cause an immense force. Not just affect water draining lol that causes Coriolis there must be centrifugal force as well. And we should be flinging off the earth. But I guess there's this mythical force called gravity. the earth is so BIG is bends nothingness creating a force that adjusts to everything independently on earth lmfao insane.

  • ZEM pro.
    ZEM pro. 14 days ago

    this was a really cool idea! itss awesome how you guys managed to synchronize the videos perfectly!

  • Robert Graff
    Robert Graff 14 days ago

    First off: cool synchronization! Second, my friends wanted me to film a toilet flush when I visited Australia, but it was hard to tell if there was any change (probably none though) - wish I had thought of food coloring...genius.

  • Mr. Crumb
    Mr. Crumb 16 days ago

    how many times did you do the pool experiment? you show in the beginning how to stagnant sinks can be randomly drained differently. therefore I hope you guys didn't just do one try if it's a 50-50 chance like you suggest in the beginning

  • Jeff Forsythe
    Jeff Forsythe 16 days ago

    awesome videos thanks

  • Querez854
    Querez854 17 days ago

    Can't syncronize on phone :/

  • Eden Youtuber
    Eden Youtuber 17 days ago

    mine does not even swirl lol
    by the way i dont live on the equator i live in the usa

  • Charlie Flor
    Charlie Flor 18 days ago

    This was so...

  • Sasha galkina
    Sasha galkina 19 days ago

    Sow if you throw coin in the air ones that will be evidence of what
    exactly? what if 10 times? it takes thousands of times to see chance
    50/50. What if there is other explanation of
    Swirl water? Do you aware that people can find cables, water stream underground with bend metal sticks holding in their hands? Aha that means there is activity under ground that effect 90 degree bend stick that you hold in your hands. Can it affect water to swirl at certain direction?
    Can water and air swirls be affected by flying in circle over flat earth son? Right under son is hottest spot and son fly around always at the same direction. Can that moving spot of heat influence movement of air? hot air goes up cold goes down closer to centre swirls at one side and in other side closer Antarctic ring swirl too other side.
    Are you still lathing about how easy you can be convinced about stuff? Because I did not finished to mention all variables that have impact on swirl I leave it to you :O)
    Hey dummy have you anything in your head? No? Nobody home? Good, because intelligence is ability to observe with empty head with out judgements see the truth as it is

    So how many variables we can not observe and there for don't see whole picture?

    How about line of equator? It fits perfectly on flat earth circle line under the son, but it does not fits ball because according NASA globe is tilted on one side ...

    I like that flat vs globe fight did you noticed that we learn something every day ?

  • Kenny Arias
    Kenny Arias 21 day ago

    2.4 M views here
    2.2 M views on veritasium
    200k people didn't get it v:

  • River Styx Armory
    River Styx Armory 22 days ago

    extremely long range shooting can really show off the Coriolis effect.

  • Richard Waskiewicz
    Richard Waskiewicz 22 days ago

    That was awesome! :D :D

  • aliseraj 28
    aliseraj 28 23 days ago

    but my toilet doesn't swirl it goes back wards

  • Trigon Playz
    Trigon Playz 23 days ago

    3:30 google chrome

  • jason of the disbury family

    Dont listen its fake the conditions are not the same the Container has to be the same and the plug hole has to be the same the water has to be put in the same the conditions were not the same FAKE FAKE

  • Amber Ridgdill
    Amber Ridgdill 24 days ago

    So then what happens directly on the equator?

  • The Big Pickles
    The Big Pickles 24 days ago

    Awesome. well done guys.

  • Sharon Hunter
    Sharon Hunter 27 days ago

    42.448.. it swirls clockwise! Southern Oregon!!

  • Zyga Sokól
    Zyga Sokól 29 days ago

    This test is not showing anything.

    It should be repeated many times and with the same pool with similar conditions, not two different pools.

    I'm not saying the test is wrong because it's very interesting but we only can watch cutted clip, not the whole uncuted and unedited video so...

  • mvcorse1
    mvcorse1 29 days ago

    once u said the earth is spinning this became science fiction

  • Exner's Range
    Exner's Range 1 month ago

    awww that was very cool!!!!!!!!!!!

  • Nithar Shana
    Nithar Shana 1 month ago

    that was....

  • KitKatinBama
    KitKatinBama 1 month ago


  • ᚲᚨᚢᛚᛞᚱᛟᚾ ᛃᛟᛏᛁ

    Robert Fico

  • Grant Keller
    Grant Keller 1 month ago

    that was interesting but the Coriolis force is a atmospheric effect of freely moving air deflected by earth's rotation how does it apply to your pool drainage ?

  • Can Attal
    Can Attal 1 month ago

    You were dropping dye in it and you claim the water to be still. And you didn't show the courtesy let us watch the experiment without a cutscene.

    What a bunch of bullshit.

  • Guja Natroshvili
    Guja Natroshvili 1 month ago

    wow that's great even Michelson Morley could not prove earth's rotation, but you did it...

  • Chris Modisette
    Chris Modisette 1 month ago

    Fantastic work, guys! Thank you for clearing up that issue.

  • Rafael Valle
    Rafael Valle 1 month ago

    I put the videos on the wrong side v.v They should have warned us

  • Aryamaan Singh
    Aryamaan Singh 1 month ago +1

    Put this video on left...

  • Abhinav the Human
    Abhinav the Human 1 month ago

    anyone notice the difference in views between the two channels?

  • Armin Hierstetter
    Armin Hierstetter 1 month ago

    Awesome job, guys!

    PS: This comment is synced.

  • Tiphanie Morgan
    Tiphanie Morgan 1 month ago

    In this controlled experiment doesn't it matter which side of the pool you're on when you drain out the water? When the water was spinning clockwise, he was on the right hand side of the pool. The other guy in Australia who did the same experiment was on the left side when he drained out the water, causing the water to drain out counterclockwise.... Has nothing to do with the poles or hemispheres..

  • Angela Gonzalez
    Angela Gonzalez 1 month ago

    what happens on the equator

  • Fahad Hossain
    Fahad Hossain 1 month ago

    Guys, I love you both and both of you clearly describes complicated things

  • Geert Vis
    Geert Vis 1 month ago

    What will the water do on the exact middle of the earth, the Equator?
    The middle of north and south?

  • OG Afghan
    OG Afghan 1 month ago




    And its funny because Muslims claim Prophet Abraham built the "KABAA" 🕋 where Muslims submit towards it from all over the world and the Muslims who make pilgrimage there also go around the Kaaba in the same direction. And if we look at the orbit rotation & the expired stars with black holes we can see how they rotate in same old direction. Much SIGNS of science in Quran.


    ~ Albert Einstein

  • TieXiongJi
    TieXiongJi 1 month ago

    Great pair of videos. This helped me win an internet debate, but it was already obvious thanks to the hurricanes I have seen on the Weather channel.

  • Mahesh M
    Mahesh M 1 month ago

    Antipodean Myth

  • Amet Moussi
    Amet Moussi 1 month ago

    You recycled that water ?

  • random human
    random human 1 month ago

    i read it as Taylor swift 😅

  • NasToy
    NasToy 1 month ago

    I placed the videos on the wrong side of eachother, so the end where you go to the other guys camera, it just looked weird.

  • lee guankiat
    lee guankiat 2 months ago

    I am going against everyone in the world. The earth is concaved.

  • The TomFoolery Of The International Space Stage

    I recreated your experiment and failed to get a anti clockwise rotation.

    Do you really think you can detect the spin of he earth with a kiddy pool in your shed lulz?

    The "Truth" About Toilet Swirls - Destin Sandlin and Veritasium Coriolis Experiment #1

  • Brad Lamont
    Brad Lamont 2 months ago

    that was sick

  • Xanthopteryx
    Xanthopteryx 2 months ago

    Your explanation of the the coriolis effect is not quite right, unfortunately.

  • Lamar Shealey
    Lamar Shealey 2 months ago

    you have to do this it is cool

  • teo_B_boy
    teo_B_boy 2 months ago

    So if the earth wasn't rotating the water won't be spinning at all

  • Joey Finton
    Joey Finton 2 months ago

    What if you did this on the equator?

  • Ben Kissell
    Ben Kissell 2 months ago

    This is the best vid ever

  • John Larrabee
    John Larrabee 2 months ago

    this was genius

  • Daniel George
    Daniel George 2 months ago

    Wow that was just amazing :)

  • Tim Evanchick
    Tim Evanchick 2 months ago

    That was super awesome!

  • Bdr Jde
    Bdr Jde 2 months ago

    I wonder how the Coriolis effect applies to "toilet swirl" if you were to centralize the drain over one of the poles. I think it would be cool to see visualized instead of assumed or accepted in theory.

  • Harold Westrich
    Harold Westrich 2 months ago

    I like the way you describe it but I think you should add that in any system, like a pool or toilet, the Coriolis effect works based on THAT small system and the much larger system, of the earth, is not as effective on the tiny condensed water system. In other words; small water systems are far more effected by local motions such as momentum added through filling of the container or pulling of the plug or deflection of drain guards etc. etc, etc. My way of thinking about it is the same as you would see an ice skater spinning with arms extended, then when they pull their arms into their bodies their rotation increases greatly. It's the same way a Tesla turbine increases speed as fluid from slow outer diameter approaches the center exhaust port.

    • Harold Westrich
      Harold Westrich 2 months ago

      Examples of things that take advantage of Coriolis effect: Tesla Turbine, Spinning Dancers, Swimmers on inner tubes who pull arms and legs in to spin faster! Tether ball when string wraps around pole.

  • Jusonn99
    Jusonn99 2 months ago +1

    which way does it spin directly on the equator?

  • pecfree
    pecfree 2 months ago


  • Chad Kennow
    Chad Kennow 2 months ago

    This was awesome Destin! :) I can't believe I just saw this now! Thanks for all you do! God Bless!

  • Huthuswami
    Huthuswami 2 months ago

    have you question this MEXICO IS CLOCK WISE so IS Supposedly clock wise!
    and supposedly equator is below mexico
    so supposedly mexico shoul be the northen and anti clock wise something is really wrong, and by logic maybe north america is as well clockwise so its southern hemisphere so that MEANS EQUATOR IS ABOVE NORTH AMERicA! And Eurpoe Is Anti clock Wise So that Means Is Above! North america! wtf!!!!!!! like The falt earth map of the onu is the true one! or wtf!!!

    see the videos live of thequator
    your welcome world lol!!

  • Sp0oks00
    Sp0oks00 2 months ago

    Another cool effect that you can see is that in Derek's video, he's having a little more trouble with the food coloring, as its sinking straight through to the bottom. This is a clear indicator that the water in Derek's video is warmer than the water in Destin's video.

  • Rodrigo Velásquez
    Rodrigo Velásquez 2 months ago

    You guys should both travel to Ecuador and set two pools , one just north of the equator and the other just south, and make the same experiment. And you could add a third pool, in the very equator. And see what happens too. It should be awesome to see them at the same time spinning in diferente directions. Regards....

  • Rodrigo Velásquez
    Rodrigo Velásquez 2 months ago

    Simplemente espectacular... que ingeniosa idea la de los 2 videos, felicitaciones

  • Christopher Smallwood
    Christopher Smallwood 2 months ago

    i cant tell you how cool these videos were. well done. I loved it

  • Enes Jashari
    Enes Jashari 2 months ago

    what happens when the pool is in the equator

  • Brian Smith
    Brian Smith 3 months ago

    what happens with the swirl on the equator or poles?

  • Zephree Zen Gold
    Zephree Zen Gold 3 months ago

    my comment is on veritassium

  • Farinhir
    Farinhir 3 months ago

    Was already subscribed to you. Vertitasium got my subscription today. Like his name. Guessing it indicates something to do with truth.

    Ah, I see in the video. An element of truth. Glad i figured out at least some of it.

  • Ethan Patane
    Ethan Patane 3 months ago

    I experienced the change in flow rotation direction in real life. I went to the galapagos, but first stopped in Ecuador, where I went to the equator. The tour had a portable sink with him that had a removable plug in the bottom of it. He put the plug in, filled it up with water, and moved it perhaps a yard to the left of the equator. As the water drained, it spun clockwise. After it drained, he filled it back up and moved it one yard to the RIGHT of the equator. Sure enough, the water spun counterclockwise. But that's not the best part. He then filled it back up and drained it right on top of the equator. This time, when the water drained, it didn't spin AT ALL. It was really incredible!

  • ShadyNinjaGaming
    ShadyNinjaGaming 3 months ago

    brilliantly made
    Getting Smarter -(other vid)

  • Dafuq
    Dafuq 3 months ago

    i thougth the earth was flat

  • Hunter McFarland
    Hunter McFarland 3 months ago

    i live there

  • bernardakoito
    bernardakoito 3 months ago

    snipers knew about this for a long time

  • Koenshakuable
    Koenshakuable 3 months ago

    (cont'd from the other channel).. feeqin awesome!!!

  • Kwong Lung Ching
    Kwong Lung Ching 3 months ago

    Will you do the same experiment at the equator?

  • Emma
    Emma 3 months ago +1

    That was so cool!

    HOPEFOR TRUTH 3 months ago

    absolute nonsense the world is flat there is zero measurable curvature. vast bodies of water cannot conform to the outside of a shape in reality. water always finds level

  • Z_E_D
    Z_E_D 3 months ago

    Awsome Double video experience! The timing can't have been easy! =)
    Great job! and fun to learn

  • shaheen eagle
    shaheen eagle 3 months ago

    Well after watching like 20 videos you now have earned my subscription. congrats.👌👌👌👍👍👍

  • Max Davis
    Max Davis 3 months ago

    I kept watching both videos at the same time when the synchronization ended...

  • Muhammad Zaidan
    Muhammad Zaidan 3 months ago

    squatting toilet> sitting toilet

  • Jørund Eldøy
    Jørund Eldøy 3 months ago

    This explains stuff, not the swirling effect, but why the video was weird when i saw it two years ago.

  • Ananthan S Menon
    Ananthan S Menon 3 months ago

    the second half of

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