Hydrodynamic Levitation!
ฝัง
- เผยแพร่เมื่อ 27 ส.ค. 2024
- On a stream of water you can levitate light balls of all sizes and even disks and cylinders. The mechanism is not the Bernoulli effect...
Want to make this at home? • Video
My friend Blake from InnoVinci emailed me with a cool idea for a video and footage of levitating balls in water streams. Initially it was tough to explain the physics of what was going on. The standard Bernoulli effect relies on the object being completely immersed in the upward-flowing fluid. But in this case the water seems to form a single stream around the object and it's deflected away and down from the stream. By Newton's third law, the force on the water by the ball is equal and opposite to the force of the water back on the ball, pushing it up into the stream. There is a stable equilibrium position because if the ball moves into the stream, it "cuts off" the water going over the ball so it drifts out. If it drifts out too far, then lots of water passes over the ball, pushing it back into the stream.
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Slow motion by Hollywood Special Ops hollywoodspecia...
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FAQ:
1. This is similar to the Magnus effect in that the relative motion of a spinning ball through fluid creates a force that affects its motion. It's different in that here the fluid starts the ball spinning and there is an equilibrium point around which there are restoring forces. In the Magnus effect the ball must be spinning to begin with and since the fluid is everywhere it can continually change speed and direction.
2. It's not the Coanda effect. The Coanda effect relies on entraining fluid from the surrounding area creating a region of low pressure. Here there is no water surrounding the stream to entrain (since it is a narrow stream).
3. Adhesion between the water and the ball is important - this is what directs the water flow over the ball.
4. The sum of the forces I show should not be zero but equal and opposite to the weight of the ball. Hence the forces of up and out from the initial contact with the stream and up and in from the spray add to make an upward force equal to weight (the in part of the second force is much more important than the up part)
5. It would be interesting to try this with a hydrophobic coating and see if it still works. My hypothesis is it would be much harder.
6. Apparently there are other fountains and toys that use this principle that I was unaware of. This video uses the design created by my friend Blake.
You can do this with water in air going against gravity - what about doing it with air in water going against buoyancy?
Plus: The ball is hollow.
I am not sure the spray plays any significant role in this as most of it is actually happening at the top so is not providing any up force in aggregate.
I believe some or all these forces are helping maintain the equilibrium and keeping the disc up:
(1) water is not hitting the ball/disc exactly on the circumference. It's slightly inside. That force breaks down into two components: (a) rotate the ball/disc (b) apply upward force which helps counteract gravity.
(2) stickiness to water which applies an upward force as the water is shooting upwards, helping counteract gravity. This also provides an in force I think. Since the ball does not try to push out as it tends to adhere to the water stream.
(3) gyroscope effect for position stability esp for the disk
I thought static electricity between the styrofoam ball and the water would help keep it in place. Is it possible that it actually is true to any significant capacity?
What's up Derek?
His inner child came out when the ball levitated :)
Tell Me This Also he blew my ears.
Tell Me This His clap was so enthusiastic :D!
so did mine
Foo Ming, already ninth month?
Same honestly !
That ball is more stable than this media platform.
MCHappster oooooooooooooooooohhhhhhhhhhhhhhh
i don't get it
Then why are you on this channel
Keith Fuller does it matter?
i don't get that either.
What makes this guy so great at teaching physics stuff is that he is genuinely overjoyed to see how it works.
Legends say that If you say Laminar's Flow 3 times in a row in your TH-cam video Destin from SmarterEveryDay will appear.
Destin*
It's just Laminar, not Laminar's
@@AugustTheStag doesn't need a capital L either... :-)
Gotcha.....🤣🤣🤣✌🏻✌🏻
@@AAAyyyGGG Actually it does, because Destin "Laminar" Sandlin has trademarked all references to that type of flow ;)
*that ball is more stable than my grades*
Absolutely beautiful words. A+.
Punctuation. F.
Bucktooth1337 Captial letter at the start of a sentence. D-
It's more stable than my mental state.
...what??????
Best way to have fun and spray your lawn at the same time!
Exactly my thoughts. A fairly random sprinkler system that's massively entertaining to watch.
I wonder if you could put dimples or channels on the ball to alter the spray pattern?
"Watching the grass grow" has never been more fun.
@@Varksterable Omg... You just gave me an awesome idea... What about 10 or 30 of those at the same time? Muahahah
@@8koi139 If you really want a challenge, try collecting and redirecting the spray off one ball to somehow drive another. So only one source to drive multiple balls.
Definitely would be very hard, but I cant see how it's impossible.
Would need more pressure and a much bigger garden than mine, though!
That is real magic!
@@arindamsarkar2208 No one really cares
No it's physics
@@mikhilkumar4806 physic is real magic
@@Noname-67 why did you reply back to your own statement
Indeed so.
So early! Awesome demonstration
Grant Thompson - "The King of Random" hi grant dude your here, cool
Grant Thompson - "The King of Random"
Grant cmon you know you've gotta build one and play with it now
Grant Thompson - "The King of Random" would really love if you still did diy
Suh dude
U guys shud collab
Use an extremely hydrophobic coating on the ball and see how the lack of adhesion changes it.
PterodactylDanceParty this couldn’t lead to any explanations
@@twitchEmailOkay could lead to some weird magic tricks with friends, give em the not working balls, use the working balls urself, ta da, "magic"
I'm not sure, but maybe the magnus effect will still work, because the ball still (might) spin. But idk
Hydrophobic Aerogel?
Mitchell Vaughan Veritasium’s next viral video is this video but with an aerogel ball.
Wonderful video! Inspired me to make a question on it!
Sir, Your problems are gr8 . Keep making more problem videos. I have been watching this channel for a long time now. This channel is ocean of potential JEE problems. You can consider making video on a very good problem discussed on this channel under the name : ' Risking my life to settle a physics debate'.
The system of dynamic shown in this video have high potential to become question in exams like JEE. It combines flotation, kinematics , rotational dynamic and many more concepts.
your question was really amazing sir
@@srsanderson4932 thanks, ill check it out!
@@sakshampaliwal8170 thanks!
dont forget us when your famous sir
Vinay uppal squad where you at 🥶
yo yo yo!!
🤘
Lmao that cringy teacher who thinks saying yo yo yo is cool?
yo yo yoyo Physics Vinay
lol 😂
@@godson200 It seems cringe at first but after going through the content, it starts feeling good.
Drink every time he says 'balls'
Drink typically implies alcohol so I guess you're too young to understand
Brian Sierzega OK I'll take out my 12 pack of Capri-sun... not sponsored by capri sun :(
69th like :D
Thanks for your input, Bevis.
you mean drink water from dripping dirty balls ?
Derek, it would be awesome to try this with a ball covered in *hydrophobic coating* - if the water cannot stick to the ball, much less of it will be deflected at an angle, probably making the configuration unstable, right?
Petee and a hydrophillic coating.
Yes, this is an excellent idea.
DO THIS!
i was honestly thinking about this righjt before i saw your comment, would b an awesome experiment
Petee it won’t work. You’ve essentially reduced friction. Friction is required to put the sphere or disk in rotational motion.
metwono
thats the point, to see the case in which this phenomenon breaks down
I'm imagining a multicolour disco ball that is light enough to use as a water feature for a pool party.
OMG YEAS
Yeah! Integrate a light pointing up at it and set it going at night, and you have an awesome effect! 😎
Yes and also uses the water as an energy source.
imagine the water bill
Seeing him laugh and get excited makes me happy!! anyone else?
4:52 a wild veritasium appears
Veritasium AKA Derek
brilliant Ryan
It is because of the Magnus force. He made a video on.
A wild veritasium in his habitat
Now catch that Pokémon
Alternative titel: Two grown men playing with water and their balls
How about "Two grown men getting their balls wet"?
New toy allows men to wet their own balls. Fun spray action! Get lifted in no time!
Alternative *Clickbait* title*
Two grown men playing with wet balls.
Two grown men get their balls and cylinders wet with squirts of water
(technically those disks are cylinders ( ͡° ͜ʖ ͡°) )
5:07 my grandparents after I fix their tv by switching it off and back on
I love how excited you get for science, that genuine love of the mundane is the main reason I love your channel so much. Can't wait to build my own water spout!
Who said this is mundane
It’s not science, it’s nature, science is just the study of it, not it’s demonstration…
I love the child like smile of wonder and curiosity on your face.
I had never seen this before. It's really counterintuitive, but also somehow makes sense.
4:58
He's like an excited child!😃
2:18 PEOPLE ARE SLEEPING IM MY HOUSE AND I WAS NOT PREPARED FOR THIS
Yup same here dude😁
Same here, except I was next to my mother and my volume was high.
@@Killbayne F
I hope you've got your phone back
@@prateekpanwar646
tbh why should she? I'm watching an educational video and guy accidentally yells a bit too loud, just a mistake one shouldn't get punished for.
it's so great that there are people like you that demonstrate that physics is more than educational, it is fun!!
Oh come on!!! again! I do a video and when I go to upload it someone beat me to it. :(
😂😂😂
It's ok I'll still watch your video. Do one with ball balancing on mercury stream. Use air compressor to pump the mercury. You can probably even use a basketball.
How come this comment has so few likes?!
I'm a big fan Cody!!!
I like yours better Cody!!
I love it when Derek shows his "OMG this is so cool!!!" face! It reminds me of little children exploring the world and being excited about everything.
0:38 I love how his friend was about to say something and he completely cut him out.
he also cut out the link to his friend's video lol
Would the ball behave the same way if you coated it with a hydrophobic layer?
Probably not because the water wouldn't bond cohesively to the ball, it would be reflected off the ball, pushing the ball out of the way of the stream
Fishface 88 i think you meant to say adhesively not cohesively.
inademv that would be a really cool experiment to try to verify his explanation!!
Sad not to have an example of this in the video. It was certainly the first thing I was curious about.
inademv the boundary layer will still be a layer of water, even if there is a hydrophobic coating.. it might work the same, but an example would have been good. top notch observation.
This is the content I subbed for not vids with the king of ad revenue
Cheeki Breeki Comrade u mean the king of random?
Cheeki Breeki Comrade don't click'em and shut up unless you're a patreon.
Cheeki Breeki Comrade
You need a hobby.
lol he's right here in the comments too
just use ad blocker if that makes you feel better...
I love how passionate this channel and its participants are. It makes it so fun to WATCH, as well as gives inspiration to learn more about each phenomenon and the science behind our universe and its various properties. This channel is everything you could ask for: informative, educational, energetic, positive, and interactive. Thank you, for feeding my love for science for 5 years now.
In this video, the excitement & joy you show for science and discovery is infectious. You encourage us to be just as interested as you are in this kind of knowledge & investigation. That is a great thing. Thanks !
Ye, i love the enthusiasm shown in his videos, makes them fun to watch too
I didn't think the ball was that cool, but the disc... That was bloody awesome!
I didn't see any blood, just water...
Dude if you keep glitching the matrix they're gonna unplug you!
NEPAAlchey
🔌
Dear 'Derek Muller" your REACTION IS REALLY INCREADIBLE after disc levitation!!!!
I LIKE IT
This is a perfect example of how depressingly important thumbnails are... I have seen almost all your videos (and love them all) but ignored this one for a while... I now feel like a fool because this is one of the coolest phenomena you've shared. Thank you!
Exactly, thumbnail doesn't look too attractive but this video is so great. Thumbnails and titles are important, can't deny that.
this is how we'll reach the sun
LMAO
omg...lol
You can go first and let us know how it is, k?
But, don't forget to go at night, otherwise it will be rather hot.
This is also how we can send fidget spinners into the sun.
The Veritasium formula:
1. Find counter-intuitive physics
2. Draw some arrows representing forces
3. Profit! Cool slow-mo shots and people feel like they're learning science
at least it brings out the fun of science, because pure science mostly isn't
Don't hate the player, hate the game
I prefer the Vsauce formula:
1. Find a random fact
2. Go on a tangent
3. Go on another tangent
4. Go on yet another tangent
5. Make a link between the first and last tangent to make viewers question their existence
VSauce makes me think harder than Veritasium. Sorry, Veritasium, it's not you, it's me.
Hey, Veratasium, Derek here, but where are your floating wet balls?
I know this video is 4 years old but I would love to see this on a massive scale
The force of the spray down cannot equal the force of the water out, the system momentum has to be equal and the sprays in all directions put pay to this theory. In addition this would have no affect on the initial suction of the ball prior to the spin being induced. The actual explanation comes from a common misconception about the lift from airflow being from bernoulli's principle alone. In actual fact a large force comes from the coanda effect, which is the suction caused by the boundary layer on the surface in the flow. If you dangle a spoon from a string and bring the curve under a stream of water under a tap you can see this effect yourself, noting how its not the pressure differential of the two sides of the spoon causing the spoons displacement. This demonstration of the ball in water is much the same. Its the suction of the boundary layer caused by the coanda effect, not the countering momentum of the water droplets, which itself would be minimal. This also helps to explain the natural balancing to bring the ball back into the stream as the effect is exasperated by increased deflection of the boundary until the point boundary separates from the surface and the ball falls from the stream.
ChevronTango now thats a much better explanation. I was thinking the same thing about how the water tossed out cannot balance the force of gravity. seems like dumb people levitate towards the simple explanations jesus christ
This isn't exactly the kind of videos that used to be uploaded, like when I first subscribed, but I suppose this is still content! I can't hate free, science-filled content!
Andrew Kovnat what's your favorite video?
Derek, your content is always greatly appreciated. BTW - 'Magnets: How do they work' for the win!
I really enjoyed the video on Svalbard's seed vault, and also the most radioactive places on Earth. Those videos about phenomenon and interesting stories of culture and Human innovation really intrigue me.
I like how most of your videos, above all, always invoke thinking about the subject in the video. They propose certain ideas I'm compelled to think about, even after I've finished watching.
I like those ones too - I'll keep this in mind. The programming on this channel is not really organized, it's whatever I'm into at the time.
I didn't like episode #237 of The Simpsons, so I wrote an angry letter to their production company.
U celebrate Science....man.... I can see the child like enthusiasm in your eyes....very good... Keep it up
flat earthers: impossible
What happened to sciencium?
Red Pinch Thinking the same thing 🤔
it decayed just like Francium.
+Saunterblugget Hampterfuppinshire
So does Sciencium decay into Veritasium?
+Saunterblugget Hampterfuppinshire So, that happened a whole 'decayed' ago?
Had a half life of 4 months
+veritasium , I'm not sure if the explanation in the video is properly adressing the physics behind the effect, what do you think of the following following?
I think the system works like this:
- The water hits the ball (putting forces of momentum on the ball as described by Derek), but also overruling the vanderwaal’s forces of the waterdrops on micro-level, making the water ‘sticking’ to the ball.
- We see water leaving the ball as it rotates.
- So the mass attached to the ball by surface-tension (vanderwaals forces), decreases as a function of the angle (theta) and the rotational velocity (omega). (Differential equilibrium).
{Vanderwaalsforces < m*r*omega^2 --> m_dot (massflow)}
- The distribution of the water over the ball is significant in respect to the low mass ball.
- Radially the mass moment of inertia of the ball is distributed eccentrically in respect to the center of mass of the ball (the rotation point of the ball), by the mass leaving the ball (imagine the leaving droplets 'pulling' the ball, (local/micro level))
Visualize the ball’s wall is always thicker on the side of the beam (system level).
- The sum of the centripetal forces on the side of the beam(collocated-side) > (non-collocated side). The separation of the contribution is located at the center of the ball, which is its turning point.
- The equilibrium exists as follows:
{ Forces of momentum of waterbeam (as function of eccentricity) } + { non-collocated centripetal forces of the water established by vanderwaals forces } = { Collocated centripetal forces of the water established by vanderwaals forces }
OK... Your videos about the cosmos seem like they're mostly trying to fit the most recent observations to some old, highly warped and contingent models. But these videos make it evident that you're actually looking into what's happening and seeing it. Excellent work and presentation.
Just look at the pure joy on his face at 4:55. That enthusiasm is so contagious, I love it!
I had some confusion about his explanation after watching, so i will explain what causes this effect.
The effect is due two an equilibrium of these two phases:
A) The ball adheres to the water, and uses its torque to force the adhered water downward and away from the stream. This causes the ball to go the opposite direction of expelled water; upward and into the stream.
B) As it enters the stream or expels the water, the torque decreases, and the ball stops moving up and into the stream. The ball then is touching the water at the most outer point on the ball that is perpendicular to the ground, on the side of the stream.
The end of phase B actually increases torque and adhesion, which makes the ball move into the stream as the expulsion of water increases. (edit) This is where phase A begins.
I absolutely love your videos!
Halo_ me too
“A hydro what?”- Squidward
I think it has a lot to do with how the water sticks to things. The droplets are going up with considerable force. As they hit the ball they tend to bounce on the other direction (as do things that hit each other), but they are stuck to the ball now and that momentum pulls the ball and the droplets back together. Since the droplets had motion before touching the ball, that keeps the ball and droplets system in place.
there's a celebration of corpus Christi in Barcelona where they make an egg "dance" in fountains with this very same effect hahaha
it's called L'ou com balla if you want to check it out
Finally a Vsauce video!
...sorry wrong channel
Gurpreet Singh MAtharoo we knew the drill dude...
Everybody has to become a sellout at some point...*sigh*...
*vsauce music porn video plays at the background*
What happened to vsauce?
JonnyRobbie vsauce is making videos for youtube red :) and sometimes videos
The sheer happiness in this video has made my day. Thank you Veritasium!
engineers never grow up. We just play with bigger and more dangerous toys
This reminds me so much of "l'ou com balla" in Barcelona, it's a very famous tradition here! You should definetly check it out!
I actually think this is a mixture of rotation, surface tension, a force upwards, and the counter force Veritasium mentions. Water hits the ball, starts to push it up, causing the water to cling to the Styrofoam surface, spinning it away from the water source. The rotation of the ball starts to give it stability and so the water clinging to the surface does indeed get thrown off the other side causing it to not stray from the water source, so does the surface tension and ration though. Anytime the ball gets close and hits more of the stream the rotation is slowed down thus just getting pushed by the water it moves outward. Anytime the ball strays too far its rotation speeds up throwing more water and basically wanting to climb the water like a treadmill. Nothing more I can say.
I think you nailed it.
Back in the 80's I had a toy like this but instead of a ball it was a conical shaped thing, wide base narrow top. I think it had small holes in the sides to spray water outwards over the kids, but the top was a closed cap. Because of that, it was easier to accept the water kept it semi-stable, not like the ball off kilter. But I always felt it was MORE stable than it should be. Like I felt if I didn't hold it perfectly flat when placing it on the water stream, it should topple off sideways before it had a chance to balance - but actually you could be quite casual and it would still take. As I remember it rose and fell and oscillated too, maybe because of the water holes on the sides? It's main colour was yellow I think, with red decorations. Who remembers it?
Just as exciting as it was in the 50's. We used a water hose and a beachball. With the right stream we could get the beachball 20 to 25 feet up in the air.
Chuck Norris can do it by peeing. With a bowling ball.
Pfahaahha, one of the better Chuck Norris references in a good while!
Thank you, sir! :D
György Mohl well Chuck Norris would get covered in his own piss
And it would attract women
Aaron Smith No because his skin is hydrophobic.
Amazing, Derek. Keep doing stuff like this, and keep your enthusiasm. I'm glad to be your patreon :-)
really interesting. I love how happy Derek gets over this phenomenon :D
This gets a like if only for the sake of the amount of excitement Derek displays.
At 2:14 rip headphones XD 😂
Why did i look at that again .. :D
Yep. Very good sound editing there. A physicist that isn't bothered by audio clipping.
Any kid with a hose found this out, It wasn't invented by him.
frognik79 what if he was the first kid to do this
frognik79 He invented that toy though, that specific toy with that specific design.
Omg that is the most fun backyard sprinkler toy ever.
the miracle here is the physics scientist who can actually hit a ball with his foot at the first try!
Haha, Derek's like a kid in a candy store.
Great you just created a doctor strange portal effect
His friend should produce that commercially! I think kids would have a lot of fun with it and potentially learn something as well.
You can really see the compression dying with these crazy water droplets flying everywhere. This is actually amazing.
the tutorial for making it a t home is now a private video and can't by watched anymore :( .
4:54
One day I will know happiness at this level.
Its a mission
What's more remarkable here is that for any particular weight of the ball / disc, and depending on the pressure of water stream, it maintains a particular height of the ball/disc to which it is being levitated. Noticed the video, where Derek started the ball and disc on some level ..but based on its weight and water pressure, it goes to its particular height ...
So not only that the ball and disc is levitating .. it's also maintaining a particular height ...
i have done it at home as a child, some 50 years ago. I used to use a fountainpen ink filler of glass to make a small jet, and make a TT ball float on it.
Love the Video, but where is the video about redefining the kg?
*WHERE ARE YOUR FINGERS?*
coming. They're not actually going to redefine the kg until 2018 so I've got time. But I'll get it done much sooner than that
I'm not as smart as you nor do I have the physics background so take this with a grain of salt... but... just looking at it, I would think it has more to do with the rotational center of mass being changed by the water. That is, due to the fact that the water clings most in the quadrant of the ball immediately after where the stream hits, the ball is heavier in that quadrant. That brings the ball's center of mass inward toward the water stream which make the ball rotate around a center that is slightly toward the stream of water. If you think about it, that will cause the ball to rotate around an axis that pushes it in toward the stream of water. This naturally balances in a feedback loop. If you look at the slo-mo, you can see the ball "wobbling" from the off-center center of mass.
I agree there seems to be something 'off' with his explanation. There isn't enough water thrown off on the far side to cause a greater force toward the stream. Most of the water is thrown off on the same side as the stream.
His explanation sucks. And yours may be more correct. There is no evidence the water is "thrown" down. Perhaps to the side. Now granted, a styrofoam ball has very small mass.
Unfortunately, this Derek's technical explanations, accuracy, and self-fact-checking has really gone down the drain recently.
Mikey C I think the reason it levitates is the water which passes the ball and goes further upwards. Through the adhesion water transfers it's (vertical) kinetic energy onto the ball, creating a force high enough to withstand the gravity force
He said "what I think it happening" he didn't say "this is what is happening, for sure, I fact checked it". No need for complete accuracy, or fact checking when making an opinionated statement.
You got it more right than Derek at least :D. The reason is not exactly the mass (it has also some influence on that) but mostly it is because of the leaving water in the direction that you pointed out. As most of the water moves out in that direction, it drags also the object with itself (and that is because of the surface tension of the water not "wanting" do get separated). This result in a force at the opposite direction that the center of mass is.
had a game like this back in 50's so Blake reinvented it , maybe.
That was a pretty good kick at the end. Good base for tricking.
BOING BOING
Dont think your friend invented this. Remember seing this as a kid in a shopping mall. At least 25 years ago. But really cool effect and nice with an explanation of it
Hi Derek. I'm a bit late to the party, but I only just saw this video. Your explanation makes sense (conservation of momentum as the water leaves the ball) but I'm not so sure that the Coanda effect doesn't play a part... I think it's possible that the levitation happens because you have flow over the surface of the ball, which entrains surrounding air, generating a low pressure region where the water stays attached to the ball. Some water separates as it travels with the ball. The separation of water disrupts the entrainment of the surrounding air so the local pressure reduces compared to the start. When you integrate the pressure over the whole surface, you end up with a net force up and towards the stream. Similarly, you can take a piece of paper, hold it vertically and move it towards a running tap. As soon as it touches the water, the paper bends more towards the water. When the tap is running without the paper, air is still entrained but from all sides so the water runs straight down as it's in equilibrium. When the paper is placed with one side towards the stream and touching the stream, the dry side has no entrained air by the stream, only the wet side resulting in a low pressure and a net horizontal force further towards the stream. Try this out :) (maybe with a laminated paper, cause the paper gets soaked very quickly otherwise and stops working).
Vertasium: "I will put a link to his video on this right here"
I see: "why oppenheimer deserves his own movie"
Magnus effect?
+Andika Raditya kinda like that just instead of moving ball, stationary fluid it's moving fluid, stationary ball
Exactly what I was thinking.
Exactly what I thought...
That depends on your frame of reference!
Magnus effect is a consequence of the bernoulli effect. So what's in the video is ultimately too, even if it may not look like it.
4:57 this would curiosity and discovery looked like...
After watching 'Why TH-cam Used to Prefer Quality', I have realised I have indeed been slacking as a loyal subscriber of yours, but Veritasium Marathon, here I come :)
a beautiful example of Bernoulli principle and newtons third laws of motion of rotating bodies
This doesn't feel like a very fundamental explanation.
Why is the force from the water rolled over the ball to the other side that pushes it back in the stream bigger than the force from the water that pushes it out?
I suppose bernouillu's law makes up for this difference.
Will it levitate if it can't spin?
I agree.
I suspect as the ball moves out, the steam can apply more torque than closer to the center, transferring more energy to the water stuck to the ball, and that causes more acceleration which gets the adhered water to fling of earlier, so more horizontally than straight down, resulting in the ball being pushed back into the steam.
I agree that the explanation didn't seem complete. I understood it better after trying it for myself - you can replicate it with just a spoon at your kitchen sink. With the tap water flowing over the back surface of the spoon, you can feel how strong the force is (it works best with nicely rounded curves like measuring spoons). The ejected water to the side strongly pulls the spoons back into stream of water.
I think what he didn't mention was that the force pushing the ball out of the stream greatly reduces (to almost nothing) when the ball has almost fallen out of the stream. Think about it - the water is hitting the ball's surface at an almost vertical angle, so it can't transfer much sideways momentum.
This explains why the ball is actually stable at an off-centre position. The force pushing outwards has reduced to a point which perfectly matches the total force from water being ejected.
*TLDR:* The force pushing the ball outwards reduces to almost nothing when the ball has almost fallen out of the stream + more water ejected sideways = ball moves back into stream.
I'm pretty sure the force is equal, otherwise it wouldn't be stable
I'm pretty sure he did not say that it was stable at the center.
This vid makes me smile at the thought of doing this with my 5 year old daughter Phoenix!!
Religion is the answer
Lovely dad
I remember seeing this video and literally saying, "Man, this isn't the Derek I remember..." and after seeing your Veritasium2 channel, this all makes sense. You are among the best, Derek. Take care.
I can't tell for sure but, I believe the ball is getting a significant pull to the center and upwards by the water that still has momentum upward. The water rotates around the ball slightly until it starts to overcome the waters surface tension which pulls back on the water, in turn pulling on the ball sideways and upward. I believe the water is pulling on the ball even more than the remaining water is pushing the ball.
I just realized how old this video is. Hopefully you still see this somehow 🤞
Last time I came this early it levitated a ball
Lol
So Awesome! going try this at home :)
The linked video isn't working, though
This is why physics is more fun to learn.
For me.
Angular momentum. The inertia of the balls rotation will keep is spinning towards the water stream. It applies an opposing force that is greater than that of the push away from the stream due to this speed inertia, keeping it in the stream, and it stays in the air due to the lift (the pushing water) as oppose to the mass and gravitational pull.
children in california couldve drunk that water
Nah, their parents would just re-route it to water the lawn.
no way, the water wasn't vegan/organic/fair trade
Not bling water, they definitely wouldn't touch it.
Children in africa could have eaten that water
children's parents in california shouldve not voted for trump.
3:33
You claim there is a return force. I disagree.
The fact that the water is carried over and falls off the other side of the ball is not an indication that the water is forcing the ball back to where it was. That is what you thought. That isn't the case.
I am pretty sure what is going on has to do with water bonding with the ball and the suction effect it creates upon bonding. You know this bonding from the popping noise when a ball sits in your pool and you yank it out, for example.
So what is actually happening is, the water shoots by and some of the water creates a contact point where the water and the ball are now bound. Much like a vacuum.
The water, still having momentum, tries to carry the ball up with it. But the ball is too heavy and the bond isn't strong enough so the bond breaks and so ends the vacuum. That leaves the ball behind. Some of the water shoots up and some of the water rolls with the ball. The ball would fall at this point but because more water is hitting the ball, the process restarts.
In conclusion, there is no other force beyond water pushing into the ball and then water pulling on the ball as it tries to carry it with it. There is no other force pushing the ball back to the center again. The cause for reset is 100% the vacuum.
I really hope you're joking
This guy needs to patent this ASAP. Best lawn sprinkler ever.
When I was 9-10 years old in 2013-14, I used to take a hollow plastic ball with me whenever I used to go to bath and a water pipe with me, and holding that pipe at an angle I could easily levitate that ball on that water coming out of the pipe, Its a old thing for me…..but yet I got happy seeing a thing I used to do as a child.
So wait... he's claiming to have been the inventor of that kids toy where you place a small plastic ball on a small 'tower', you put your foot down on a peddle, and the ball shoots up and stays there via water? I'm sorry but I dont believe that for a second... that toy has been out for years and years and years now...... i'm 26, and that was around when i was like, 12......
came to the comment section for this, saw this in a place with all sorts of experiments/phenomena about 14 years ago, so i don't understand where this claim of 'invented this' came from
Lol i can't determine if you're referring to my comment, or just reinforcing my comment XD
definitely reinforcing! to clarify, i don't know where the claim made in the video of "inventing" came from and looking at the comments i'm happy a lot of people brought it up
Yea lol. I mean, I can understand if he's claiming to have invented the thingy used in the video, but he did not invent the concept, idea, nor the method..
exactly , but the first time talking about his friend he says "he came up with this" , so that's definitely not the same as "invented this particular toy" that's why it bothered me (and clearly other as well)