The Truth About Toilet Swirl - Southern Hemisphere

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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:

Видео загрузил: Veritasium

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Добавлено: 1 год назад
Длительность: 8:3
Комментарии: 5889

Тэги для этого Видео:veritasium  science  physics  toilet  swirl  water  drain  northern hemisphere  southern hemisphere  coriolis effect  

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I Am CANADIANI Am CANADIAN (21 час назад)
Astronauts are not in space. They've never been to space.
Smarter every day? More like dumber by the minute. Pushing Nasa globe earth lies!

Lamar ShealeyLamar Shealey (4 дня назад)
you have to do this it is cool

John LarrabeeJohn Larrabee (13 дней назад)
super cool videos

Daniel GeorgeDaniel George (18 дней назад)
Wow that was just amazing :)

Tim EvanchickTim Evanchick (19 дней назад)
That was super awesome!

pecfreepecfree (21 день назад)
time to bed now flatards

William McCormickWilliam McCormick (21 день назад)
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 McCormickWilliam McCormick (21 день назад)
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 KennowChad Kennow (24 дня назад)
This was awesome Derek! :) Keep up the great work! :)

Rodrigo VelásquezRodrigo Velásquez (25 дней назад)
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 VelásquezRodrigo Velásquez (25 дней назад)
Simplemente espectacular... que ingeniosa idea la de los 2 videos, felicitaciones

Christopher SmallwoodChristopher Smallwood (25 дней назад)
you have my subscription. awesome videos you did with Destin. well done.

tinkmarshinotinkmarshino (25 дней назад)
you guys are crazy fun!

Melvin DuckenfieldMelvin Duckenfield (1 месяц назад)
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 DuckKel Duck (17 дней назад)
A demonstration of a scientific experiment, is just that, a demonstration.

Melvin DuckenfieldMelvin Duckenfield (17 дней назад)
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 DuckKel Duck (29 дней назад)
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 DeforestCody Deforest (1 месяц назад)
That was cool guys

Zephree Zen GoldZephree Zen Gold (1 месяц назад)
great team work see my comment on smarter everyday

mike nguyenmike nguyen (1 месяц назад)
the screen warp was pretty sick

DMatthewHenryDMatthewHenry (1 месяц назад)
This was really freaking cool.

ShadyNinjaGamingShadyNinjaGaming (1 месяц назад)
Brilliantly made
(other vid) - every day

jakub Krausjakub Kraus (1 месяц назад)
Too bad the Earth is obviously flat...


KoenshakuableKoenshakuable (1 месяц назад)
that was... (on the other channel)

what a load of nonsense

Z_E_DZ_E_D (1 месяц назад)
Awsome Double video experience! The timing can't have been easy! =)
Great job! and fun to learn

XeroXero (1 месяц назад)
cringy end

daniel hoaddaniel hoad (1 месяц назад)
this is to much effort to know which way a toilet flushes

Robert crowdiver BurnsRobert crowdiver Burns (1 месяц назад)
horseshit,, it does the same up north !

Ananthan S MenonAnanthan S Menon (1 месяц назад)
this comment is here.
find it

Ryo RyoRyo Ryo (1 месяц назад)
this video is creative...

Sam PetersonSam Peterson (1 месяц назад)
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 231lol 231 (1 месяц назад)
awesome video

Ya MiYa Mi (1 месяц назад)

Sean FreemanSean Freeman (1 месяц назад)
that was dope af

bubmah axrbubmah axr (1 месяц назад)
i watched both videos chronologically on a single screen, one video after the other, so the real drain happens on my brain.

Benjamin HersheyBenjamin Hershey (1 месяц назад)
Protip: put Destin on the left and Derek on the right for proper orientation.

Connieisland0Connieisland0 (1 месяц назад)
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??

sedawksedawk (1 месяц назад)
"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.

СергейСергей (2 месяца назад)
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.

ToastyRolandToastyRoland (2 месяца назад)
Sync these videos up.. it is extremely worth it. Cheers.

Cthulu MuramasaCthulu Muramasa (2 месяца назад)
Just learned this in science

Cthulu MuramasaCthulu Muramasa (2 месяца назад)

Cthulu MuramasaCthulu Muramasa (2 месяца назад)
It's the Coriolanus effect

bleuthootbleuthoot (2 месяца назад)
This is the ultimate way to collaborate

Everybody90Everybody90 (2 месяца назад)
hello from

Sirake WizenSirake Wizen (2 месяца назад)
Damn, I'm already subscribed to both :(

D-Schloss the boss H-town rowlin hardD-Schloss the boss H-town rowlin hard (2 месяца назад)
how did you know i put you on the right

RegularBradyRegularBrady (2 месяца назад)
Loved the syncing of the videos, super fun!!!

Rrroonald WeaslyRrroonald Weasly (2 месяца назад)
Perfect sync, first try. MVP.

Antony TheriaultAntony Theriault (2 месяца назад)
Really cool videos guys, but geez do you not realize how hard it can be to sync two videos on the same computer?

kopleriokoplerio (2 месяца назад)
time same the go both make to able not I'm If Sucks. (northern Hemisphere)

CRaSHeCLiPsCRaSHeCLiPs (2 месяца назад)

Mate RodićMate Rodić (2 месяца назад)
soo cool

DartnixDartnix (2 месяца назад)
One of the best ideas I've seen on youtube and very well put together!

Screaming MatchScreaming Match (2 месяца назад)
Ya'll did great!

Dj2xPDj2xP (2 месяца назад)
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. (2 месяца назад)
What about equator?

qwchrbichnqwchrbichn (2 месяца назад)
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 JonesBarnabyFilibuster Jones (2 месяца назад)
This is one of the best uses I have ever had for my second monitor :)

Liza Marie RiosLiza Marie Rios (2 месяца назад)
omg you guys are awesome.

Bron CinzahBron Cinzah (2 месяца назад)
're amazing ...if you follow this you're Genius...

FuckYouGooglePlusFuckYouGooglePlus (2 месяца назад)
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.

silikonmanufaktursilikonmanufaktur (2 месяца назад)
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 SinghTej Pal Singh (2 месяца назад)
all my favourite people in one video.

jon poundersjon pounders (2 месяца назад)
why didn't you guys do the same test in the northern hemisphere to make this study complete?

Seán MercierSeán Mercier (2 месяца назад)
Hey guys, wanted to say I've been watching both of your channels for a while now and just stumbled across this. Being from a Video making background, I found this synchronised fusion really exciting on top of your usual high quality content. Thanks for doing what you do!

DR. NEODR. NEO (2 месяца назад)
the sync was amazing

Vincent PaulVincent Paul (2 месяца назад)
I synchronized the video and it was very interesting.

Brian KilloughBrian Killough (2 месяца назад)
could we place something low that would hardly if not at all be affected by wind to flow to a specific spot in the ocean? Is the pool and the hole in perfect symmetry and perfectly level?

Death_KennyDeath_Kenny (2 месяца назад)
Got it timed perfectly first try... Really amazing Idea of you both! Loved it!

Maven SonyMaven Sony (2 месяца назад)
Now do this experiment in exactly midpoint of equator .Lets see what happens..

znatimznatim (2 месяца назад)
You could mention Foucault experiment

sharan kaursharan kaur (3 месяца назад)
Happiness when u r subscriber of both channels 😆

kuoniratkuonirat (3 месяца назад)
Now I can impress my female colleague, who claimed otherwise.

Southern HemisphereSouthern Hemisphere (3 месяца назад)
Name stealer :(

Strike EagleStrike Eagle (3 месяца назад)
Im subbed to him but i still dont know what i am doing with my life

Strike EagleStrike Eagle (3 месяца назад)
That... Was... AWSOME! The 2 vid idea was crazy cool!

MrGMrG (3 месяца назад)
what a great idea! You both are awsome guys. I allways said the internet is a huge dunghill where here and there thrives a flower. You are these flowers I was seeking. Stay smart and above all, stay curious.

zazke girotronzazke girotron (3 месяца назад)
hey this is cheating: 2 views at the same time per person... well played

oceanceaseroceanceaser (3 месяца назад)

Dean StewartDean Stewart (3 месяца назад)
Champion effort guys

mrcleanisinmrcleanisin (3 месяца назад)
I haven't read all the comments, but surely someone asked them why they didn't repeat the expirments more than one time?

Kel DuckKel Duck (29 дней назад)
Perhaps read the description instead

Roan WilkinsRoan Wilkins (3 месяца назад)

Mohamad ZaidMohamad Zaid (3 месяца назад)
nice..i did sync both video with two monitor. haha burnn


Al-mujahedeen SalahadeenAl-mujahedeen Salahadeen (3 месяца назад)
SmarterEveryDay brought me here!

MWB GamingMWB Gaming (3 месяца назад)
1:32 you are not here in AU
our power outlets look like an arrow not like the face of someone getting probed

dan hewittdan hewitt (3 месяца назад)
Who else subbed from smarter every day? Great channel btw? I like ur vids alot. 😊 peace from the UK

farooq shaikfarooq shaik (3 месяца назад)
Open Two tabs and cascade

Abodimax AlrashdiAbodimax Alrashdi (3 месяца назад)
what will hAppen if you. we're on the. equator

Gabri Janse van RensburgGabri Janse van Rensburg (3 месяца назад)
This was so cool. I got it to sync up exactly on my first try. You guys are awesome.

Dj OtsiraveDj Otsirave (3 месяца назад)

Agusta MotorAgusta Motor (3 месяца назад)
That is also the reason why australians drive clockwise on roundabout, and Americans drive anti clockwise

EmeraldGamingEmeraldGaming (3 месяца назад)
Too bad this doesn't work on mobile

gmeastgmeast (3 месяца назад)
yeah ... I figured this out on my own in my 1965 high school physics class. What's the big deal?

MinerQuickMinerQuick (3 месяца назад)
Wow that was Impressive 2 vid in 1

Michael ScofieldMichael Scofield (3 месяца назад)
Awesome project guys, loved the synced videos

Abishai SinghAbishai Singh (3 месяца назад)
Really creative way of collaborating and I was fun watching both the videos simultaneously in 2 different tabs. Hope to see more vidoes....

pietersrvpietersrv (3 месяца назад)
So there IS an effect!

Sasami R ConwaySasami R Conway (3 месяца назад)
so cool

Kristjan NiibergKristjan Niiberg (3 месяца назад)
awesome guys!!!

ThePiGuy24 GamingThePiGuy24 Gaming (4 месяца назад)
This is an awesome half video.

Benjamin JohnsonBenjamin Johnson (4 месяца назад)
read my comment on the other vid

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