6 ms·

The truth about toilet swirl (2015) [video]

102 points by ValentineC 9y ago

degenerate 9y ago
OK that was pretty cool. Props to these guys for taking such simple thoughts/ideas and generating interesting content. Youtubers like this are the modern-day Bill Nye. The faster we all 'cut the cord' and ditch TV, the faster we can force the return of quality creative content like this. Either because TV dies outright, or networks are monetarily forced to put effort into quality programming again.
- criddell 9y ago
  Why would I want to cut the cord and ditch TV? Television is awesome. I wish I had time to watch more of it.
  - trapperkeeper74 9y ago
    Troll.
    - criddell 9y ago
      How is that a troll or even provocative? Last Sunday was the Game of Thrones finale and there was a lot of excitement over it. That's not because TV sucks and everybody should ditch it. Tonight I'll watch a baseball game on TV. Over the weekend I had it on more than usual because I was watching the Harvey news. Television is wonderful.
      - trapperkeeper74 9y ago
        Either you're hillariously sarcastic or not the sharpest instrument trying to rationalize their undying, partisan team promotion for glowing consumption. Assuming the former: GoT isn't "TV," it's multiplatform, third-party, ad-free, cable HBO. How is: - arranging your life around schedules of broadcasts - sitting through long, pointless ads wasting one's limited life - sitting in one place because a service isn't completely available except within an old, outdated, building subscription service framework - watching local lazy or "must carry" propaganda or in-bubble-centric, watered-down, biased national/cable news that doesn't address real issues (VICE and Democracy Now are good) "wonderful?" Is that anything like Trump "wonderful" or Apple "wonderful" when they charge $750 to "repair" a $0.25 part by throwing away a fixable board.
        criddell 9y ago
        You have a very narrow definition of what constitutes television. It isn't 1978 anymore.
- PhantomGremlin 9y ago
  The advantage of television channels and networks is they provide "curation". Someone needs to wade thru the crap and find the "quality programming" you desire. Take the average Nova or Frontline episode. It's not cheap to produce. Do you think people could afford to put the work into making shows like that if all they could count on was the crumbs that Google threw at them from page views on Youtube? And even if the funding could be solved, how would you discover this programming? There are very few HN submissions that ever get much notice. And the HN crowd is not nearly big enough to provide enough Youtube eyeballs to actually fund "real" programming.
rosstex 9y ago
Are there more examples of synced videos like these?
euske 9y ago
It has a better looking url: http://toiletswirl.com/ http://toiletswirl.com/ Actually, Veritasium merged the two videos into one because it is easier to watch on a smartphone. https://www.youtube.com/watch?v=mXaad0rsV38 https://www.youtube.com/watch?v=mXaad0rsV38
tomxor 9y ago
TLDW; They try toilets which dont work so they create a larger vortices in kiddy pools. just lol, they are so excited... I do hope they realise that there was never any debate about the Coriolis effect being real, cos ya know... math. Only debate was that the effect is not strong enough compared to other forces acting on small vortices in fluids, i.e toilets.
- latch 9y ago
  Derek Muller, the Veritasium guy, has a PhD in physics and a focus on the use of media for physics education. What you're seeing is his (and Destin's) successful take on how to make learning fun.
  - beefman 9y ago
    Muller's PhD is in physics education, not physics.
- function_seven 9y ago
  It’s clear they know that. Now a lot of people who didn’t have a great way to learn both how the Coriolis effect works, and also how weak it is on smaller scales.
- aaron695 9y ago
  > Only debate was that the effect is not strong enough compared to other forces acting on small vortices in fluids, i.e toilets. Pretty sure there's no debate here, it's not.
Jedd 9y ago
I really can't tell if this is an expensive and sophisticated troll, or they're genuinely bewildered. Using a graphic showing several thousand kilometre-wide pool with one edge touching a pole is disingenuous. At that scale, yes, you're going to observe Coriolis effect. Hurricanes don't form within five degrees of the equator -- that provides a useful data point for the lower end of the scale required to see the effect. Sydney's 34 degrees south, but the velocity delta at 1 metre distance would be dwarfed by various other environmental factors and starting conditions. (Temperature deltas and wind, especially for the outdoor pool, vortices produced by the elbow close to what looks like a 19mm outlet, texture on the PVC liner, etc.) Plus of course in any dual-pool-emptying experiment, there's a 25% probability of this result. I'm miffed that a single experiment gets described as 'this is science, dude!'.
- mchahn 9y ago
  "I'm miffed that a single experiment gets described as 'this is science, dude!'". A single data point is still a data point and this is still science.
  - Jedd 9y ago
    > A single data point is still a data point and this is still science. Both presenters are enthusiastic and engaging, undeniably. And yes, this is a data point. But this isn't science. Partly because they claim they've 'proved it because we eliminated variables' (3'57"), when they clearly haven't. Partly because one of the basic tenets of science is repeatability. As I noted above, there's a 1 in 4 chance of getting this result if you assume equal probabilities of clockwise / counter-clockwise. That assumption should be the starting point of any experiment around this effect. Food colouring should have been put in - for some of the repeated experiments at least - before the valve was open, to confirm the water was in fact still motionless. (Or to show that it wasn't.) Similarly that little match-stick cross on one of the pools - those should have been present on both pools, probably several of them, spread around the surface (though surface motion is not necessarily indicative of sub-surface movements). I could go on.
    - 9y ago
grecy 9y ago
I am from Australia, have been living in North America for 10 years. I have also driven across the Equator twice - once in Ecuador[1] and recently in Gabon, West Africa[2]. It's funny to watch the guys standing on the Equator tricking tourists with a swirl of their wrist to supposedly demonstrate this effect. I thoroughly enjoy watching the stars change as I progress from the Northern Hemisphere to the Southern, and the water direction slowly change. [1] http://theroadchoseme.com/the-equator http://theroadchoseme.com/the-equator [2] http://theroadchoseme.com/the-equator-gabon http://theroadchoseme.com/the-equator-gabon
tgarma1234 9y ago
It's clickbait to generate youtube views. Seriously how many times have we seen this trick?
- foobarbecue 9y ago
  How many times have you seen the baking soda / vinegar volcano demonstration? The more the better, in my opinion, and I'm a volcanologist.
imron 9y ago
The real truth about toilet swirl is that toilets in Australia don't swirl, they flush: https://www.youtube.com/watch?v=X11zXXEgIes https://www.youtube.com/watch?v=X11zXXEgIes
- Taniwha 9y ago
  and non-toilets have the hot tap on the other side potentially biasing things when they are filled
- djsumdog 9y ago
  When I lived in AU and later NZ, I'd get this question and I'd respond the same way. AU and NZ toilets are almost always dual-flush (dual flush toilets were invented in AU) and they push water quickly front to back, not in a swirl like US toilets. I've also never clogged an AU or NZ toilet. Not to say you can't, just that it's much more difficult with their design.
  - sosborn 9y ago
    Does this mean I should be proud about my incident at an Auckland hotel 6 years ago?
    - djsumdog 9y ago
      I'm not sure if "proud" is the right word.
- Double_a_92 9y ago
  Neither do they in Europe... It's probably just a 'murican thing.
- stephen_g 9y ago
  Yeah, American toilets are weird. First time I saw one (at LAX after flying in from Australia) I thought it was broken - firstly given the huge amount of water in it at the start, and then the way it fills up when you flush it! I really thought it was going to overflow.
emmelaich 9y ago
All mention of Coriolis should refer to this 1965 Letter in Nature magazine titled "The Bath-Tub Vortex in the Southern Hemisphere" http://www.nature.com/nature/journal/v207/n5001/abs/2071084a0.html http://www.nature.com/nature/journal/v207/n5001/abs/2071084a... As you can read below, even with extreme care the Coriolis effect can be overwhelmed by very small perturbations such as how the lid is lifted. http://web.aeromech.usyd.edu.au/history-chapters/C3%20ThermoFluids.pdf http://web.aeromech.usyd.edu.au/history-chapters/C3%20Thermo... ... > At Tom Fink’s invitation, Professor Lloyd M. Trefethen of Tufts University, USA, spent a short sabbatical in Mechanical Engineering in 1964/65. Already famous for his work on surface tension phenomena, he led us into a repeat of the experiments on the bathtub vortex that had recently been conducted by Ascher Shapiro at MIT. After much careful design, a circular tank of some 2.4m in diameter and 0.4m depth was constructed and installed in one of the subterranean dungeons of the old Peter Nicol Russell building. Carefully designed procedures and their diligent execution resulted in absolutely conclusive results that were published in Nature [Trefethen, et al, 1965). A re-enactment for the local media was a disaster: Bilger and Tanner muffed the removal of the covering baffles creating a great vortex in the water that then went out the wrong way. ‘Scientists baffled’ cried the media. We even made Time magazine!

102 points by ValentineC 9y ago

OK that was pretty cool. Props to these guys for taking such simple thoughts/ideas and generating interesting content. Youtubers like this are the modern-day Bill Nye. The faster we all 'cut the cord' and ditch TV, the faster we can force the return of quality creative content like this. Either because TV dies outright, or networks are monetarily forced to put effort into quality programming again.

criddell 9y ago
Why would I want to cut the cord and ditch TV? Television is awesome. I wish I had time to watch more of it.
- trapperkeeper74 9y ago
  Troll.
  - criddell 9y ago
    How is that a troll or even provocative? Last Sunday was the Game of Thrones finale and there was a lot of excitement over it. That's not because TV sucks and everybody should ditch it. Tonight I'll watch a baseball game on TV. Over the weekend I had it on more than usual because I was watching the Harvey news. Television is wonderful.
    - trapperkeeper74 9y ago
      Either you're hillariously sarcastic or not the sharpest instrument trying to rationalize their undying, partisan team promotion for glowing consumption. Assuming the former: GoT isn't "TV," it's multiplatform, third-party, ad-free, cable HBO. How is: - arranging your life around schedules of broadcasts - sitting through long, pointless ads wasting one's limited life - sitting in one place because a service isn't completely available except within an old, outdated, building subscription service framework - watching local lazy or "must carry" propaganda or in-bubble-centric, watered-down, biased national/cable news that doesn't address real issues (VICE and Democracy Now are good) "wonderful?" Is that anything like Trump "wonderful" or Apple "wonderful" when they charge $750 to "repair" a $0.25 part by throwing away a fixable board.
      - criddell 9y ago
        You have a very narrow definition of what constitutes television. It isn't 1978 anymore.
PhantomGremlin 9y ago
The advantage of television channels and networks is they provide "curation". Someone needs to wade thru the crap and find the "quality programming" you desire. Take the average Nova or Frontline episode. It's not cheap to produce. Do you think people could afford to put the work into making shows like that if all they could count on was the crumbs that Google threw at them from page views on Youtube? And even if the funding could be solved, how would you discover this programming? There are very few HN submissions that ever get much notice. And the HN crowd is not nearly big enough to provide enough Youtube eyeballs to actually fund "real" programming.

rosstex 9y ago

Are there more examples of synced videos like these?

euske 9y ago

It has a better looking url: http://toiletswirl.com/ http://toiletswirl.com/ Actually, Veritasium merged the two videos into one because it is easier to watch on a smartphone. https://www.youtube.com/watch?v=mXaad0rsV38 https://www.youtube.com/watch?v=mXaad0rsV38

tomxor 9y ago

TLDW; They try toilets which dont work so they create a larger vortices in kiddy pools. just lol, they are so excited... I do hope they realise that there was never any debate about the Coriolis effect being real, cos ya know... math. Only debate was that the effect is not strong enough compared to other forces acting on small vortices in fluids, i.e toilets.

latch 9y ago
Derek Muller, the Veritasium guy, has a PhD in physics and a focus on the use of media for physics education. What you're seeing is his (and Destin's) successful take on how to make learning fun.
- beefman 9y ago
  Muller's PhD is in physics education, not physics.
function_seven 9y ago
It’s clear they know that. Now a lot of people who didn’t have a great way to learn both how the Coriolis effect works, and also how weak it is on smaller scales.
aaron695 9y ago
> Only debate was that the effect is not strong enough compared to other forces acting on small vortices in fluids, i.e toilets. Pretty sure there's no debate here, it's not.

Jedd 9y ago

I really can't tell if this is an expensive and sophisticated troll, or they're genuinely bewildered. Using a graphic showing several thousand kilometre-wide pool with one edge touching a pole is disingenuous. At that scale, yes, you're going to observe Coriolis effect. Hurricanes don't form within five degrees of the equator -- that provides a useful data point for the lower end of the scale required to see the effect. Sydney's 34 degrees south, but the velocity delta at 1 metre distance would be dwarfed by various other environmental factors and starting conditions. (Temperature deltas and wind, especially for the outdoor pool, vortices produced by the elbow close to what looks like a 19mm outlet, texture on the PVC liner, etc.) Plus of course in any dual-pool-emptying experiment, there's a 25% probability of this result. I'm miffed that a single experiment gets described as 'this is science, dude!'.

mchahn 9y ago
"I'm miffed that a single experiment gets described as 'this is science, dude!'". A single data point is still a data point and this is still science.
- Jedd 9y ago
  > A single data point is still a data point and this is still science. Both presenters are enthusiastic and engaging, undeniably. And yes, this is a data point. But this isn't science. Partly because they claim they've 'proved it because we eliminated variables' (3'57"), when they clearly haven't. Partly because one of the basic tenets of science is repeatability. As I noted above, there's a 1 in 4 chance of getting this result if you assume equal probabilities of clockwise / counter-clockwise. That assumption should be the starting point of any experiment around this effect. Food colouring should have been put in - for some of the repeated experiments at least - before the valve was open, to confirm the water was in fact still motionless. (Or to show that it wasn't.) Similarly that little match-stick cross on one of the pools - those should have been present on both pools, probably several of them, spread around the surface (though surface motion is not necessarily indicative of sub-surface movements). I could go on.
  - 9y ago

grecy 9y ago

I am from Australia, have been living in North America for 10 years. I have also driven across the Equator twice - once in Ecuador[1] and recently in Gabon, West Africa[2]. It's funny to watch the guys standing on the Equator tricking tourists with a swirl of their wrist to supposedly demonstrate this effect. I thoroughly enjoy watching the stars change as I progress from the Northern Hemisphere to the Southern, and the water direction slowly change. [1] http://theroadchoseme.com/the-equator http://theroadchoseme.com/the-equator [2] http://theroadchoseme.com/the-equator-gabon http://theroadchoseme.com/the-equator-gabon

tgarma1234 9y ago

It's clickbait to generate youtube views. Seriously how many times have we seen this trick?

foobarbecue 9y ago
How many times have you seen the baking soda / vinegar volcano demonstration? The more the better, in my opinion, and I'm a volcanologist.

imron 9y ago

The real truth about toilet swirl is that toilets in Australia don't swirl, they flush: https://www.youtube.com/watch?v=X11zXXEgIes https://www.youtube.com/watch?v=X11zXXEgIes

Taniwha 9y ago
and non-toilets have the hot tap on the other side potentially biasing things when they are filled
djsumdog 9y ago
When I lived in AU and later NZ, I'd get this question and I'd respond the same way. AU and NZ toilets are almost always dual-flush (dual flush toilets were invented in AU) and they push water quickly front to back, not in a swirl like US toilets. I've also never clogged an AU or NZ toilet. Not to say you can't, just that it's much more difficult with their design.
- sosborn 9y ago
  Does this mean I should be proud about my incident at an Auckland hotel 6 years ago?
  - djsumdog 9y ago
    I'm not sure if "proud" is the right word.
Double_a_92 9y ago
Neither do they in Europe... It's probably just a 'murican thing.
stephen_g 9y ago
Yeah, American toilets are weird. First time I saw one (at LAX after flying in from Australia) I thought it was broken - firstly given the huge amount of water in it at the start, and then the way it fills up when you flush it! I really thought it was going to overflow.

emmelaich 9y ago

All mention of Coriolis should refer to this 1965 Letter in Nature magazine titled "The Bath-Tub Vortex in the Southern Hemisphere" http://www.nature.com/nature/journal/v207/n5001/abs/2071084a0.html http://www.nature.com/nature/journal/v207/n5001/abs/2071084a... As you can read below, even with extreme care the Coriolis effect can be overwhelmed by very small perturbations such as how the lid is lifted. http://web.aeromech.usyd.edu.au/history-chapters/C3%20ThermoFluids.pdf http://web.aeromech.usyd.edu.au/history-chapters/C3%20Thermo... ... > At Tom Fink’s invitation, Professor Lloyd M. Trefethen of Tufts University, USA, spent a short sabbatical in Mechanical Engineering in 1964/65. Already famous for his work on surface tension phenomena, he led us into a repeat of the experiments on the bathtub vortex that had recently been conducted by Ascher Shapiro at MIT. After much careful design, a circular tank of some 2.4m in diameter and 0.4m depth was constructed and installed in one of the subterranean dungeons of the old Peter Nicol Russell building. Carefully designed procedures and their diligent execution resulted in absolutely conclusive results that were published in Nature [Trefethen, et al, 1965). A re-enactment for the local media was a disaster: Bilger and Tanner muffed the removal of the covering baffles creating a great vortex in the water that then went out the wrong way. ‘Scientists baffled’ cried the media. We even made Time magazine!