Fun with Vortex Rings in the Pool

recently on one of the simplest but most mesmerizing phenomena
I’ve ever discovered. You drag a plate
through the water, creating two dips
on the surface. And sunlight shining
through the dips will create two
crisp black spots on the bottom of the
pool that can persist across the length of the pool. But the dips in the water are
just the tip of the iceberg, as they say. Underneath the surface is
an entire half-ring vortex, a.k.a., a toroidal vortex. I had never seen
these before, so there is so much more to explore. And I know not everyone
else has a pool, so I took some of your
awesome suggestions and I’m going to try them out. For this one I have
to get in the pool. Ooh! I know I look ridiculous,
but this is not warm. You can see here,
as the food coloring has dropped into the dips. The best part, I think,
are the reflections you get off of the surface. [MUSIC PLAYING] I couldn’t see
what I was filming, but this just looked way better
than I could have imagined. So we tried two in sequence. [MUSIC PLAYING] The red one cut the
green one in half. The red one didn’t die,
but the green one kind of disintegrated. It was cool. And, of course, it runs
into my camera and dies. The vortex hit on this
end of the camera, and then you could see the
death of the vortex just moving along the rest of the vortex. It almost looked like
it was unraveling, which I’m hoping won’t happen here. We’re going to put
the pole in the pool and let the vortex pass
by so that the pole cuts it right in the middle. And I’m hoping that it’ll
meet back on the other side or it’ll split
into two vortices. Aw, it just kills it. I think there’s
too much turbulence when there’s an asymmetric
collision of the vortex with an object in the water. Unlike when you hit a
wall with the vortex, it’s a lot more symmetric and it
can keep that nice laminar flow in the spin of the vortex. I’ve been told that yellow is
not the best color for a pool. So we’re going to try blue and
red to see how the fluid mixes. Nice. That looks awesome. It almost looks like the
red is engulfing the blue. It’s surprising that the
colors don’t mix together. It’s almost like they stay in
their own layers of the vortex. We tried a smaller
plate just for fun. [MUSIC PLAYING] Check that out. [MUSIC PLAYING] I was a bit surprised
by this one. I thought the ping
pong ball would disturb the flow of the vortex. But it dropped right
in and shows us how fast it’s spinning, at
least close to the center. [MUSIC PLAYING] The motion of these vortices
is really unpredictable. Like, sometimes they just
seem to die for no reason. Sometimes they turn. Sometimes they hit the wall. Sometimes they spread out. Sometimes they go faster. When it’s spinning too fast,
there’s a lot more turbulence, and that breaks up the vortex. And if there are
disturbances on the surface, that actually causes
sort of that unraveling death of the vortex
to move across it. But I guess the
unpredictability is what makes fluid dynamics
so fun and beautiful. Thanks for all of the great
ideas, and thanks for watching. [MUSIC PLAYING] If you’ve enjoyed these videos
and would like to see them continue, head over to [MUSIC PLAYING]

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  1. If you think of the surface of the pool as the fabric of space-time, and the ping pong ball (2:55) as being a planet; then the vortex that it falls into could be the gravity well of a black hole.
    Black holes spin, so maybe the distortion they make in the fabric of space-time is a vortex? As opposed to an endless depression as they are usually depicted.
    As Physics Girl said, a vortex can't begin or end in a fluid, So, for the pool the vortex has to either hit the bottom, or loop up to the surface. A black hole's vortex would carry on to infinity, as there's no barrier to hit. But perhaps it could loop back up to the surface too? Meeting the vortex of a second, sister black hole.
    Then consider the molecules of dye moving between the two vortexes (2:19). perhaps in this way, teleportation between galaxies is possible?
    One molecule at a time. With no way to reassemble them in the correct order at the other end.
    And I think you answered you own question about why the blue and red dye are in different layers, when you talked about laminar flow at 4:10. I don't understand laminar flow, I just like this video

  2. on the one vortex eating the other I am guessing that is from slight differences in speed caused by uneven pushing of the plate through the water. as for what rimstarorg was mentioning about pulling, I am sure the smaller item wont be if they are filled with air and light like the pingpong balls, the foodcoloring, works because its nearly the same weight as the water so it is easy for it to mix into downward as well as upward in the water with little effort energetically.

  3. LOL… The Electric Universe Theory. Now picture the pool vortex as a Galaxy floating in space and the plasma electromagnetic connection between them through interstellar particle beams. i.e. The Galactic Web. Try making 8 vortex with four plates simultaneously from each side of the pool and see how they all interact with different color dye?
    IMO… Gases, Liquids & Magnetic energy flow are all one and the same. They all follow the same path. Vortex Mathematics.

    Love this video! Great Job. Cool discovery.

  4. This is how I stir my coffee, but obviously with a spoon.  Mind blown, super cool (yes, I'm a physicist…).  Thanks!

  5. Do you all Think about the shadows on swimmig floor explained like lens could be exactly the same as Black holes in Space, separating two or more different densities dimensions acting like mirrors?
    Someone say something, please.

  6. You say the dips create the shadows but I bet if you did it completely at the bottom of the pool without disturbing the surface there would be some kinds of shadows too.  Try pumping water into water at the bottom.  I'm not asking you to go to the bottom and hold your breath.

  7. Hey, also, this seems to add some evidentiary validation to the possibility of worm holes in space.
    I read about the how Einstein proposed the possibility of said phenomenon, but concluded that
    He'd been lickin toads again. Just no way I could make that one work. But Wow, look what you did.

  8. Looks like one always stays inside the other, when they connect. Conservation of momentum I suspect. Coolest improvised experiment in a looong time.

  9. Could you get an air hose, which ejects a rotating stream of air, and then pump the air into one of the vortexes to try to create a stable underwater river/tunnel full of air please?

  10. fascinating, I have a question about your vortex rings. If you change the temperature of the water does it effect the vortex in any way?

  11. Great video! Years ago I caught a natural double vortex from a dock…

  12. Um… this blew my mind. It got me thinking. Could this mean that twin black holes, or twin galaxies produce some kind of gravity/magnetic/dark energy "vortex" shaped as a ring? Man , can't stop thinking about this!

  13. how to derive this phenomenon from physics equations like we can when we derive the behaviour of gyroscopic procession or damped/forced harmonic motion?

  14. I know you did these two different dyes colors already but do it again and this time change the temperatures of each dye so one is cold and the other is hot, and see what happens

  15. I think we better knew the reasons why some of the vortexes die and some hit the wall if we have magnetic compass besides the pool. Suppose the Coriolis effect may be responsible with that…

    Good video…

  16. Anyone else hypothesizing about dark matter and worm holes with this? Humour me:: If we are linked to a sister world of an unseen nature and we know turbulent flow scales up, I would think these observations should be pretty useful once someone with a mind for it really takes a closer look.

  17. It's is the variation of the vibration in the water that causes it to act predictable. Try to pour color salt water at both hot and cold to see what happens. I am sure the vortex will try to to get larger or smaller.

  18. Seeing this experiment makes me wonder what would be happen if instead a rounded plate, the plate was squared? something sugesting me that those vortex where created in this shape because the rounded plate, but I'm not shure, just wondering 🙂
    Thanks for your amazing videos!

  19. I remember doing this in the bathtub as a kid. without food coloring of course. I had no idea what i was doing but i knew it looked cool. turns out i was making a vortex. pretty cool.

  20. I bet fish see these vertical rings regularly since they perceive light polarization and stuff better.

  21. 2:20 it seems to be like, two Blackhole are connected with each other and forming a WORMHOLE. In which we can travel through a futuristic ship. Would it be correct to relate it with WORMHOLES?🐶

  22. immediately made me think of wormholes in space 🙂 Last year a group of researchers modelled a black hole using a plug hole so who knows, you might have stumbled onto something… It would be really cool to see this scaled up to a really BIG vortex 🙂 got to try this one when summer comes. In the southern hemisphere the winter solstice happened today 🙂

  23. 2:11 i think if you had sort of an airodynamic object but vertical to cut the vortices it would help

  24. Could there be a space-related version of this? Seems like it could easily translate to how gravity works with blackholes, but I'm just a layman.

  25. you should have the half vortex ring collide into the pool wall and see what happens under the water using food coloring

  26. Hi Physics Girl, As you pointed out that breaking the vortex destroys it, would this work in the case of a big vertical vortex like a tornado. Detonate an explosive device at a given point in the chimney of the twister to see if it can stop it in its tracks before it causes to much damage. Kevin U.K.

  27. I would be curious to see what would happen if the ring was formed between two mediums that are liquid, but of different densities. So instead of the two mediums being water and air, have the two mediums be oil and water, and somehow run the plate between the two mediums?

  28. The fact that i love science and love colors at the same time(though i love them better in light) this vid is perfect for my likings 😍😍

  29. Try a Mega Plate and see if you can use both hands holding 2 plates like normal or mini plate and see if it creates 2 pairs.

  30. I just realized, Potentially the color red itself has a stronger frequency. I've recently learned, through Infrared Light, the conscious mind can collapse a wave (allegedly) which explains why observing the double slit experiment alters the randomized results.

  31. I LOVE this! Such as simple way to show this phenomenon. Have you ever seen the vortices created by dolphins? There are a few videos of captive dolphins creating complex air vortices with their tails where they pull down air from the surface and create an air filled vortex that stretches from the surface of the air/water interface down several meters into the water of their tank. Some of these tubule vortices are smaller than the width of a pencil. Dolphins also create torroidal rings with their sonar/echolocation abilities, then they blow air into the ring and an amazing silver spinning torroidal ring is created. The dolphins can then "blast" this spinning ring with sonic frequencies and move the ring around the water. Some dolphins can even change the shape and size of the air filled vortices. It is truly amazing to watch. The physics behind what they are doing for play is incredible. Thanks for posting.

  32. Rainbow has white center and ring in color. This one is black. Nice! Every morning I create C ring of bubbles that freeing water from minerals. Like ring of fire. It would be nice connect all to stRING theory. In optics parabolic CC's like basketball Gordian knot reminds a lot on pictures from this video experiment. All best physicsgirl! Stay super as cosmic superstrings. Chromosoms X.

  33. i realised that if she has a smaller plate, the vortexes will be small as well. so my question is can you create 2 vortexes big enough and with enough pull to let objects pass through it.

  34. Wonderful experiment 💚
    I'm a huge fan of you….perhaps your biggest fan…💗
    Would you like to make an experiment of rotational infinite magnetic motor?
    Is it possible?? which called free energy…

  35. I have suggestions for two experiments:
    Experiment #1. Try two at once, using an assistant. You move your plate, for example, from one end of the pool south, while your assistant is at the side of the pool moving a plate west. In other words, hopefully the two vortices would move independently, orthogonally through each other. In support of this theory, think about throwing two pebbles in a pond and the concentric ripples move through each other with no apparent interaction.
    Experiment #2: Since the vortices terminate at the surface of the water, how do you know the air above the pool wasn’t going through the same phenomenon, but we just couldn’t see it? You might try the experiment in a tank, with water on the bottom, and oil (vegetable oil, etc.) floating on top. You’d need your plate (or simple rectangular plate mounted to a horizontal piston) at the level of the interface. I have no idea how you’d introduce the colored dyes.

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