Check this out Hahaha, isn't that awesome? That is hydrodynamic levitation Check it out! This styrofoam ball is levitating on this stream of water And it's doing so in a very stable way. The set up it's so stable you can play Frisbee through it Which is weird to me because the water is off to one side of the ball And that doesn't seem to make any sense, cause you can block the water for a second and the ball will still levitate, have a look Isn't that cool? How can it be stable like this? How can this be a stable configuration? That is what we're gonna explain This is my friend Blake He is a toy inventor, and he actually came up with this and he brought it to me And I was like "That is awesome, there's some really cool physics going on here." Juggling with water. I can't believe it will just allow you to switch balls like that. They can even hit each other as they go down It doesn't take the other one off the stream. So how does this effect work? Well a lot of people might think of the hairdryer ping-pong ball effect. Which works basically based on Bernoulli's principle That's actually what we're showing here We've brought this stream down so it's going at a very low velocity So it's pretty much laminar flow, and what you can see, if you look at the ball, is it's entirely enclosed in water, so that water stream comes up, goes around the ball and just as with the ping-pong ball If it moves to one side of the stream it slows down the flow of fluid, and according to Bernoulli's principle This increases the pressure relative to the faster flowing fluid on the other side So it pushes the ball back into the middle. That is what provides the stability for this ball. But I think what we're seeing with the bigger balls is something different. This is the largest styrofoam ball I could find, so I don't expect it to work, but hey we're gonna give it a shot Should I go higher? Oh! It's happening! That is incredible! Look at it dance on there man! It's like got this instability, but it corrects. It's incredible! You should see the way the water is spiraling off there That is awesome! So I've been thinking a lot about the physics that makes this possible What I think is happening is as the stream contacts the ball It pushes it up, but it also pushes the ball out, away from the stream so what I think is remarkable is that the ball actually will stay there. It is in a stable configuration and From looking at the high-speed footage what I really think is going on is this water is getting thrown over and down by the ball and since the ball is putting a force over and down on the water that water is putting a force up and in on the ball which keeps it right in that stream It's because there's a bit of adhesion between the water here and the styrofoam. Starts to go a little slower That pulls all that water over the ball And that's the start of how you get the ball to spin And how you get that sprayed down on the right-hand side which provides more lift and keeps forcing the ball back into the stream Come on once the ball is levitating it remains stable because if it drifts too far into the stream that decreases the flow of water around the Ball reducing the force pushing it into the stream And if it drifts too far out that increases the water flow over the ball increasing the force pushing it back into the stream That's what makes the equilibrium position so stable. Any slight perturbation creates a restoring force that moves the ball back to equilibrium The rotation I think is also nice because that gives it that angular momentum Providing a little bit of stability side by side, that's not so important for these balls But it certainly is important for the disc. If you try to levitate a disc you need to keep it in the right orientation Oh, yes! Getting the discs to levitate is significantly harder than the balls because they have to maintain their vertical orientation In order for this to work. Even a slight breeze makes this very difficult HEY! Check that out! Can you come in and get it? Oh my goodness This is a clear demonstration that that is not just about the Bernoulli effect, right? It's due to the rotation of the disc that actually carries the water over and sprays it down which pushes that back into the stream. That's amazing Not only is this an awesome experiment it's also pretty fun to play around with in the summer, and it was invented by my friend Blake So come over my channel Innovinci and I'll show you how, with a simple Home Depot run, you can build this in your own backyard I'll put a link to that video right here. So if you want to make this, go check it out
This is pretty cool, but as a toy? 5 minutes and done.
Is that Dirk from Varintium? Duke from the Vatican? Desk from Varitanium?
I think your all wrong and oversimplifying it in my opinion this is an example of surface tension and the coanda effect.
Hers a link to a video showing a similar example https://youtu.be/AvLwqRCbGKY
Did anyone need to see that slomo to understand how this works?
It's not the water going "over and back down" which keep it there, but rather the water going "over and up at an angle", forcing the ball back down into the water stream.
You can do this with a leaf blower too. Minutes of fun. Minutes, I tell you. Unless you have a toddler, then it'll be minutes of fun several times a day.
/r/SummerReddit
So this is the post that made you, @tincanstan?