The Truth About Toilet Swirl – Southern Hemisphere

June 3, 2015 by 22 Comments

Both videos on one page (for desktop):
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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:…


22 Replies to “The Truth About Toilet Swirl – Southern Hemisphere”

  1. Chris Sche says:

    When you have two phones, but an unreliable connection on both of them 🤷🏻‍♂️

  2. Gammareign says:

    I kind of figured the design of the inside of the toilet determined which way the swirl goes.

  3. Lol I’m using both my current and old phone

  4. Dillon says:

    this was so cool! Especially because I have two monitors!

  5. Already subscribed to both for a very long time, but I remember finding Destin first. Anyways I got a bit frustrated trying to sync it perfectly so I gave up. I did watch it at the same time with a few millisecond difference. At some points where you both speak the same line at the same time, it got doubled but oh well, worked close enough. Didn't help that the first few times, one video buffered so I had to resync everything and rewatch. Cool video project though. I knew of the Coriolis effect and remember reading about the storms thing but didn't think about that in relation to draining water.

  6. I'm not sure how I missed this episode. I've been following you for a long time and I've also been following smarter everyday for a long time. I finally just came across this video today! Although, I did see the video first on smarter everyday's channel, LOL

  7. Clint B says:

    this was really cool guys

  8. Roman K says:

    It is the same toilet on both videos 😡

  9. Alex Potvin says:

    if you don't watch them simultaneously the sync end is the most socially awkward thing

  10. 1:46 I see you live at the equator. ;p

  11. Rapid Atoms says:

    That's was a cool dual video thing. And the subject matter was cool.

  12. emilstnt says:

    yeah not bad man

  13. when synchronising you see Earth spinning in different directions…. the Earth is not split in half, it spins around it's axis in a direction as a whole planet… so it can't spin clockwise in one hemisphere and anti clockwise in the other…

  14. Skully says:

    "The man is literally a rocket scientist"

    No mark rober

  15. CreativeGuy says:

    Unintentionally debunking the ridiculous "flat earth" junk.

  16. did anyone get this video from there teacher…

    no just me

    okay 👁👄👁

  17. I love what you did with the measurements of the pool. You used imperial units (in Australia) while the other chap used metric (in the US). Lol. Very clever.

  18. blown away with the work done by both channels. Do more of these, awesome job educating my kids and me!

  19. Tim S says:

    Apparently I was subbed to both channels in the first place.

  20. code 913 says:

    Why arent you guys upside down in Australia

  21. MariusTV says: