The Truth About Toilet Swirl - Southern Hemisphere

  • Added:  2 years ago
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    Some notes:
    We each repeated the experiment 3 times, and got the same results every time. For those of you who might be skeptical, great! A right circular prismatic kiddie pool is only $10 and you can do the experiment for yourself at your latitude. There's really no reason you shouldn't 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 Vanessa for filming in Sydney:


    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:
  • Video CategoriesEducation
  • Runtime: 8:3
  • Tags for this video:  veritasium  science  physics  toilet  swirl  water  drain  northern hemisphere  southern hemisphere  coriolis effect  

Comments: 5 918

  • Jacob Brink
    Jacob Brink 3 hours ago

    So what happens when you drain a pool on the equator? Nothing?

  • H2TA
    H2TA 2 days ago

    looks good with dual monitors

  • shutemdwn
    shutemdwn 2 days ago

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

  • justin hyland
    justin hyland 3 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.

  • Joseen Garcia
    Joseen Garcia 3 days ago

    It was way too much for my mind to process.

  • Achmad Syauqi
    Achmad Syauqi 5 days ago

    never been this so damn serious watching my toilet water swirling

  • Sarah Treadwell
    Sarah Treadwell 5 days ago

    that was soooo good!

  • xXE4GLEyEXx
    xXE4GLEyEXx 5 days ago

    This is...

  • roslan mat ali
    roslan mat ali 6 days ago

    this right

  • B Rice
    B Rice 7 days ago

    Cool idea, guys!

  • Dr.Evil/// Shadow hunter

    what was with the faces

  • ZEM pro.
    ZEM pro. 10 days ago

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

  • Tiphanie Morgan
    Tiphanie Morgan 11 days ago

    The rotation of the water is based upon the direction from which you drained the pool. Since you were to right of the pool this caused the spin to have a clockwise rotation to the right. Just as the guy in the northern hemisphere in Alabama drained the pool from the left side of the pool causing a counter-clockwise rotation. The Coriolis Effect is as real as Gravity.

  • Jeff Forsythe
    Jeff Forsythe 12 days ago

    Awesome videos thanks

  • Eldar Djedovic
    Eldar Djedovic 13 days ago

    What if you do it on the equator

  • Charlie Flor
    Charlie Flor 14 days ago

  • Ilay Morlevi
    Ilay Morlevi 15 days ago

    Damn! how did you manage to do that?!

  • lou crecc
    lou crecc 15 days ago

    Shill Nye shill

  • lou crecc
    lou crecc 15 days ago

    33 degrees of south latitude Freemasonry..

  • Reid Jameson potts
    Reid Jameson potts 15 days ago

    Would the spin or drain be faster according to disctance from each pole???

  • Zain Abdeen
    Zain Abdeen 16 days ago

    How about at the equator??

  • Richard Waskiewicz
    Richard Waskiewicz 19 days ago

    That was awesome! :D :D

  • 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 21 day ago

    So then what happens directly on the equator?

  • The Big Pickles
    The Big Pickles 21 day ago

    Awesome vids. well done

  • Nithar Shana
    Nithar Shana 29 days ago


  • KitKatinBama
    KitKatinBama 29 days ago

    That was amazing!!

  • Noel Ruppenthal
    Noel Ruppenthal 1 month ago

    This format not exactly compatible with a veritasium marathon late at night with an iPad

  • Can Attal
    Can Attal 1 month ago

    You were dropping dye in it and you claim the water to be still. You people are desperate.

  • Chris Modisette
    Chris Modisette 1 month ago

    Fantastic work!

  • Aryamaan Singh
    Aryamaan Singh 1 month ago

    ...and put this video on right. You are welcome :)

  • Armin Hierstetter
    Armin Hierstetter 1 month ago

    Awesome job, guys!

    PS: This comment is synced.

  • 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

    Try it in Saudi Arabia in Mecca please...

  • 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.

  • winko567
    winko567 1 month ago

    i wonder how it would flow if u were right on the equator

  • miamicanez16
    miamicanez16 1 month ago

    You skewed the results adding the drops and bumping the table as you did it.

  • miamicanez16
    miamicanez16 1 month ago

    I clearly seen you bump the table a few times and cause ripples. If you were a real scientist you would do this multiple times and see if it is REPEATABLE. Im not convinced the wind or something else couldn't play a factor.

  • HackiH
    HackiH 1 month ago

    So which of the 2 videos is actually more successful? Veritasium has (today) about 8.9% less views but its like to dislike ratio is 80.6 compared to 76.4 and it even has 2.25% more likes :D I guess the most important question is why the heck did i calculate that?

  • Lamar Shealey
    Lamar Shealey 2 months ago

    you have to do this it is cool

  • John Larrabee
    John Larrabee 2 months ago

    super cool videos

  • Daniel George
    Daniel George 2 months ago

    Wow that was just amazing :)

  • Tim Evanchick
    Tim Evanchick 2 months ago

    That was super awesome!

  • pecfree
    pecfree 2 months ago

    time to bed now flatards

  • William McCormick
    William McCormick 2 months ago

    There is another possible explanation. The axis of the planet is charged from the North Pole to the South Pole, by the movement of the planet in the atmosphere and the atmosphere and its contact with the light gases of space.

    This actual electrical effect might be the actual effect that causes the water to spin in one direction as opposed to the other. It at least posses variables that must be answered before you call this done or explained.

    At the North Pole the Aurora Borealis is not electricity created by the earths spinning, rather it is a reactionary electricity created to and against the electricity that is drawn into the North Pole by the earths spinning. Much like lightning is the reaction to electricity from the earth, striking the cloud face of a storm cloud that cannot pass that quantity of electricity through the cloud and into the vastness of space.

    If your hypothesis about the pool spinning because one side of the pool is moving faster than the other is correct, then you would have to prove that without interaction of any kind that the pool constantly swirls without draining of any kind. In the direction you predict it will spin. This may be true or not, I do not know. However it would be so if your theory is correct.

    I believe that when the water starts moving, vertically, it creates a magnetic field in order to do so. I believe it is this magnetic field that causes the direction of the swirl, along with the different electrical fields of the earth in the North and South hemisphere.

    The actual magnetic interaction of the North and South hemisphere seems rather a complex situation to explain. I am sure it could be explained. But I think it would take a few years and a lot of serious research to do so, before it did not seem like blatant conjecture even if totally accurate.


    William McCormick

    • William McCormick
      William McCormick 2 months ago

      I think a magnet kind of demonstrates a little bit of the principle I am trying to put across.

      Basically the way a magnet can attract steel at both the North and South Pole of the magnet, yet repel similar poles of another magnet.

      The center of the magnet between the North and South pole of the magnet becomes neutral while both ends have a similar effect on steel.

      It could be that both the North and South pole create a similar effect on water and the equator another. That could explain why a vertical flow could cause the two different effects on the North and South Hemisphere respectfully.


      William McCormick

  • Chad Kennow
    Chad Kennow 2 months ago

    This was awesome Derek! :) Keep up the great work! :)

  • 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

    you have my subscription. awesome videos you did with Destin. well done.

  • tinkmarshino
    tinkmarshino 2 months ago

    you guys are crazy fun!

  • Melvin Duckenfield
    Melvin Duckenfield 3 months ago

    At 4:08 he states, "So really you're not gonna see it in a bathtub and you're not gonna see it in a sink or in a toilet because there are other sources of angular momentum that totally wash out this effect." What are those sources? It appears to me that there are multiple variables to be considered before one can definitively "prove" the desired conclusion. Additionally, only one experiment was done. Can we draw a definitive conclusion based on one experiment? Could the direction of the air current above the pool, since it was outside, have affected the direction in which the water drained? Were both platforms identical and completely level? I would be more inclined to consider his conclusions if he and his partner had repeated their experiments multiple times under various conditions and in various locations in the respective hemispheres to prove their hypotheses. Isn't that what the scientific method is all about?

    • Kel Duck
      Kel Duck 2 months ago

      A demonstration of a scientific experiment, is just that, a demonstration.

    • Melvin Duckenfield
      Melvin Duckenfield 2 months ago

      My understanding of the scientific method is that more than two or three experiments under extremely controlled conditions do not provide sufficient, empirical evidence for a theory to be considered a fact. In the age of "consensus science" I suppose conducting an experiment a statistically irrelevant amount of times will just have to suffice.

    • Kel Duck
      Kel Duck 2 months ago

      If you read the description, it does tell you how many times it was completed. (3)

      You probably should also realise this is a scientific demonstration, they don't need to do it a statistically relevant amount of times.

      This experiment has been done many times in many different parts of the world, the hypothesis has already been proven in more exacting circumstances.

  • Cody Deforest
    Cody Deforest 3 months ago

    That was cool guys

  • Zephree Zen Gold
    Zephree Zen Gold 3 months ago

    great team work see my comment on smarter everyday

  • mike nguyen
    mike nguyen 3 months ago

    the screen warp was pretty sick

  • DMatthewHenry
    DMatthewHenry 3 months ago

    This was really freaking cool.

  • ShadyNinjaGaming
    ShadyNinjaGaming 3 months ago

    Brilliantly made
    (other vid) - every day

  • jakub Kraus
    jakub Kraus 3 months ago

    Too bad the Earth is obviously flat...


  • Koenshakuable
    Koenshakuable 3 months ago

    that was... (on the other channel)

    HOPEFOR TRUTH 3 months ago

    what a load of nonsense

  • 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

  • Xero
    Xero 3 months ago

    cringy end

  • daniel hoad
    daniel hoad 3 months ago

    this is to much effort to know which way a toilet flushes

  • Robert crowdiver Burns

    horseshit,, it does the same up north !

  • Ananthan S Menon
    Ananthan S Menon 3 months ago

    this comment is here.
    find it

  • Ryo Ryo
    Ryo Ryo 3 months ago

    this video is creative...

  • Sam Peterson
    Sam Peterson 3 months ago

    I love what you guy's did with this video!!!! So smart and awesome! I've been subscribed to both of your channels for some time now... glad to see two of my most entertaining choices working together.😁 thanks guys!

  • lol 231
    lol 231 3 months ago

    awesome video

  • Ya Mi
    Ya Mi 3 months ago


  • Sean Freeman
    Sean Freeman 3 months ago

    that was dope af

  • bubmah axr
    bubmah axr 3 months ago

    i watched both videos chronologically on a single screen, one video after the other, so the real drain happens on my brain.

  • Benjamin Hershey
    Benjamin Hershey 3 months ago

    Protip: put Destin on the left and Derek on the right for proper orientation.

  • Connieisland0
    Connieisland0 3 months ago

    This is video is so misleading and untrue. It throws the scientific method out the window.
    Water spins according to the shape of the drain, its immediate surrounding. Sadly the masses will be believe a video like this more than making the experiment themselves.
    If people think that earth rotation is detectable by no other instruments but a simple water flow going down a drain, then they should really do a check up with the reality around them.
    There are no instruments that ever detected the rotation of the earth, however you're telling us that water going in a drain gets affected by this so called rotation??

    • sedawk
      sedawk 3 months ago

      "There are no instruments that ever detected the rotation of the earth" - Wow. Just Wow. Perhaps you should take your foot out of your mouth and google Foucault's Pendulum.

      Their experiment is valid. You can completely predict and calculate the force that caused the rotation. The predicted force is small - hence the caution in the experiment. True - you don't see this everyday because most other forces overcome the forces imparted on the water due to the Earth's spin - but this was clearly stated and demonstrated in the video as well.

  • Сергей
    Сергей 4 months ago

    In my bath it always swirls in one direction. Even if i try to change the swirling direction with a stick or smth like that, water changes the direction again to the initial one after a minute or so.

  • ToastyRoland
    ToastyRoland 4 months ago

    Sync these videos up.. it is extremely worth it. Cheers.

  • Cthulu Muramasa
    Cthulu Muramasa 4 months ago

    Just learned this in science

  • Cthulu Muramasa
    Cthulu Muramasa 4 months ago


  • Cthulu Muramasa
    Cthulu Muramasa 4 months ago

    It's the Coriolanus effect

  • bleuthoot
    bleuthoot 4 months ago

    This is the ultimate way to collaborate

  • Everybody90
    Everybody90 4 months ago

    hello from

  • Sirake
    Sirake 4 months ago

    Damn, I'm already subscribed to both :(

  • D-Schloss the boss H-town rowlin hard

    how did you know i put you on the right

  • RegularBrady
    RegularBrady 4 months ago

    Loved the syncing of the videos, super fun!!!

  • Rrroonald Weasly
    Rrroonald Weasly 4 months ago

    Perfect sync, first try. MVP.

  • Antony Theriault
    Antony Theriault 4 months ago

    Really cool videos guys, but geez do you not realize how hard it can be to sync two videos on the same computer?

  • koplerio
    koplerio 4 months ago

    time same the go both make to able not I'm If Sucks. (northern Hemisphere)

  • CRaSHeCLiPs
    CRaSHeCLiPs 4 months ago


  • Mate Rodić
    Mate Rodić 4 months ago

    soo cool

  • Dartnix
    Dartnix 4 months ago

    One of the best ideas I've seen on youtube and very well put together!

  • Screaming Match
    Screaming Match 4 months ago

    Ya'll did great!

  • Dj2xP
    Dj2xP 4 months ago

    Hahaha, I have a dual screen setup so synching these was not hard, but I chose to put Veritasium's video on my left screen, which broke the immersion at the end :D

  • Ali Tahrei Sh.
    Ali Tahrei Sh. 4 months ago

    What about equator?

  • qwchrbichn
    qwchrbichn 4 months ago

    The truth about toilet swirl is that toilets force the water in one direction or another. The side-by-side sink comparison is hardly surprising. A better side-by-side comparison would be ones with drains in the center of each compartment.

  • BarnabyFilibuster Jones

    This is one of the best uses I have ever had for my second monitor :)

  • Liza Marie Rios
    Liza Marie Rios 4 months ago

    omg you guys are awesome.

  • Bron Cinzah
    Bron Cinzah 4 months ago

    're amazing ...if you follow this you're Genius...

  • FuckYouGooglePlus
    FuckYouGooglePlus 4 months ago

    This is jus silly. A 12 foot pool is NOT showing off the Coriolis effect. The effect on something that small would be way more than canceled out by imperfections in the pool itself. Like not being level, or any deviations from roundness, etc. Even imperceptible wind.

  • silikonmanufaktur
    silikonmanufaktur 4 months ago

    Wow, didn't think it would really work ! Amazing. Did you try several times to make sure it wasn't just a lucky coincidence ? Best way to do it would be using several pools at the same time, to make sure no tiny asymmetry in the outlet, the valve, the plug etc determines the direction of the rotation. Because that might easily be the case, considering the incredible tiny difference in angular momentum we are talking about. And air has a lot less friction compared to water, while the distances covered by those storms are hundreds of miles ! I must confess i would have bet money on you guys failing to show the coriolis effect in a kiddie pool ! Congrats and well done ! :-)

  • Tej Pal Singh
    Tej Pal Singh 4 months ago

    all my favourite people in one video.

  • jon pounders
    jon pounders 4 months ago

    why didn't you guys do the same test in the northern hemisphere to make this study complete?

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