Non-Coalescence-When Water Repels Itself 

I'd be interested to see the three water streams coloured red green and blue to be able to better observe the different states of repelling/mixing.

It would be interesting to see what would happen at higher pressure!

It's hilarious that, to this day, when I hear "surface tension" I automatically think of the James Blish sci-fi story that I read 45 years ago. Imagine all this scientific understanding mixed with tiny life forms, living out their lives in the process. Great video, thank you. I've noticed these effects with water, but never known how and why they work.

I'm reminded of lava lamps. The coil at the bottom is actually to break the surface tension so the blobs can rejoin each other.

4:45 That must explain why it always happens in my bathtub when I turn the shower on. The water in the tub basin mixes with soap residue, then that soapy water is hit with droplets of fresh water from the shower head causing it to repel for a couple of seconds. It’s so cool in the early morning because the sun comes in the shower window at just the right angle to illuminate just the droplets of water dancing around making them look like they’re glowing. Or, the repeated pelting from the drops of water coming from the shower head vibrates the water enough to maintain the spheres longer

Now increase the pressure. See if you can make it last longer.

I think I had always wished this would happen when I was a little kid and my cousins and I would “cross the streams” and have battles. Im not certain our moms loved that we played that game.

Thank you, I've been curious about this lately and you finally explained it!

I see this phenomenon when pouring oil in a funnel while changing oil in my car. Never knew it had a name though.

Wow this is really cool :) I've noticed this phenomenon a couple of times myself, but that vibration trick really blows my mind. Awesome!

Damn dude your videos just keep getting better and better over time. I've been thoroughly impressed by the last 6mo of videos

This sure seems fascinating. Couldn't even wrap around just how impactful this experiment is. Blew my head out of proportion.

Very interesting, especially the one with the vibration. Could you make this in a heavier atmosphere with e.g. SF6 Sulfur hexafluoride as well ?

I just used your link to send Historic Letters to a retired teacher that is going to love this. I just received a digital copy for myself. It was from the "Wright Cycle Company" to The Smithsonian Institution. It was dated May 20, 1899. This is so cool!

I accidentally made a weird mixture of liquids containing 5+ kinds of dyes and ink and some other stuff in middle school, and its droplets can stay on itself's surface for minutes when stable. I have absolute no idea how did I made such a weird liquid, and have never reproduced anything close to it again. 😶

Water that doesn't mix with water? Stop trying to break physics. You're going to crash the simulation we all live in.

I actually observed this by chance while urinating and got so intrigued by it that I ended up destroying the toilet. Needless to say my parents got very angry with me for that... For that matter, one paper I read suggests that a temperature difference between the droplets and the bulk liquid does help enhance the effect as the droplet evaporates, which is precisely what you get when pissing

EXCELENT VIDEO!!! THANK YOU! and MERRY CHRISTMAS!!! :)

I'VE ALWAYS WONDERED WHY THIS HAPPENS ONCE IN A WHILE. I always thought it had something to do with the leidenfrost effect because it was kinda similar but only temporary. I'm so glad I finally understand why this happens.

@6:20 If you would have slighty colored the water solutions with different colors (just as much as not to change the surface tension), perhaps one could discern the repulsion better. Here it seems, that it flows across.

The action lab always finds a way to get his vacuum chamber involved

Venkman: “You said crossing the streams… was BAD.”

Good explanation.. Always loves to watch

Great episode! You made surface tension seem far more fascinating than I ever thought it could be!

Makes me wonder what effect static electricity would have on this

I've seen this effect so many times, and was hoping to see an explanation and official name for it eventually, so this is exciting to see!

I think you have nailed it....From my fluid dynamics class you are descrbing classic boundary layer effects where the thickness of the layer is maximum under laminar flow. Just as you created in the in tube jets as tank head dropped.

This was very interesting, I learned a lot!

I just saw the slow mo guys short and commented I really wanted to see a physicist go into a super in-depth explanation of why this happens, then this video showed up in my recommended. Thanks youtube!

8:04 - It works better when you attach the tray to the vibrating surface..... It also looks cool looking over it w/ a nice back lighting.

Watched this happen at the beach in the ocean while it was raining. All the rain was bouncing from the fresh vs the salty ocean. Pretty cool to see.

Love the slow mo guys and smarter everyday shout-out!

8:30 I was about to complain that you didn't test in vacuum despite having one. God job man!

There's no Action Lab without vacuum chamber 😂

James have you ruled out electrostatic effects with the non - coalescing streams of water ? We know that fluids can acquire a charge when forced through a nozzle so maybe there is also some electrostatic repulsion ? Also , with the vacuum chamber how do we know the reduction in boiling point isn’t influencing the amount of vapour from the water itself which might change the forces between the droplets and the water ( or indeed the surface tension) and have an effect?

Me: GUYS WHAT IF THE CAKE IS A SPY!?!?!?!? cake:eat me

It looks so fascinating in slow mo! 💛💛💛

Thanks! You gave me an idea!

These beads of water skating across a water surface were called antibubbles in a Physics Girl video from a few years back. That video showed liquid in liquid as well as liquid in air bubbles.

0:34 What in the flying fudge... That literally looks like how a typical game glitch would look. When the center gets redefined and no external forces force it to be anywhere, it just has no parameters to decide to snap to one side and thus it just centers itself where it is. And that explains reality too, fascinating!

I would love to see the collaboration between Slow Mo Guys and The Action Lab on this experiment.

For that last test you did, it makes sense that removing the air will make it stop happening since air under the drop was what makes it work in the first place

Posy has great footage of this -- a hot drink can emit enough steam from the surface to provide a perpetual cushion, holding up condensed water droplets from the steam itself. Depending on the droplets' size, they can produce an iridescent effect.

On really cold rainy days I see water non coalescing on top of the lake or river. Sometimes on my windshield too.

My first thought was to retry the experiment in higher atmospheric pressure, but then someone suggested a heavier gas. Both might give different results and I'm not sure how the heavier gas would behave... I mean, the two experiments in the video were with a Nitrogen/Oxygen atmosphere and a vacuum. Maybe a different atmosphere would cause the water to behave differently.

Thanks

If The Matrix/Simulation ever is going to start glitching out. Or if that theory ever is going to be proven, this channel is where we are going to see it first. The man is effectively breaking reality by dismantling it to its most basic functions and putting it back together again. On a platform where its easy to get overwhelmed by intense and dedicated stupidity, channels like this are VERY important. 🧠

Those historic letters are brilliant. You just pay $70 and they mail you a paper printout from google images each month! What a deal!

I love how almost everything on this channel ends up being in a vacuum chamber.

Really cool!. Be interesting to know if raising the pressure would allow the effect to start happening in water without the added soap.

I always wondered what these were when I was a kid, and I did notice that it happened when the water was soapy. Wasn't sure if it was a weird type of bubble or something.

I observed a similar effect with oil draining from an ATV. The final stream broke into droplets before hitting the oil in the drain pan and then danced across the top for about 4 inches before snapping into the surface. Perhaps the Texas humidity had some influence?

Ah Yes Nice To See This Guy Again!

Ive always wondered why that happened in my shower sometimes!

That vacuum chamber has earned its price a hundred times over on this channel.

9:16 It would be really interesting to see with a more dense gas how the non-coalescence increase, or just augmenting the air pressure instead of degassing

Thank you for blinding me at 0:45

Really cool experiment! Thank you! I have a big fascination with water! I took some Laws of Water and experimented in my pool, one summer! LOL Had a blast!

1:05 When you’re sword fighting with the homies.

Might be interesting to see if you could demonstrate the strengthening of the effect in water by increasing the pressure in a chamber🤔🤔

3:35 love that Dr. Pepper shirt, now I want one.

4:11 it's a good information

Time to get a pressure globe! 😊

This is a perfect opportunity to play with INCREASING pressure, instead of always using the vacuum chamber. Try experimenting with a high pressure chamber. Great content as always.

I was waiting for the vacuum chamber to make an appearance. The Action Lab didn't disappoint!

Physics Girl did a video called "What are Antibubbles?" seven years ago about this. 😻

My brother, and I observed something similar on regular occasions when we were kids.

Loving the Fallout 3 -like sound track in the beginning 👌

This would make for a nice segue into cold welding

i love your content! I do have a question, Is there a practical application for this effect?

If he showed this to a peasant in the 1600's his head would just explode.

@TheActionLab great video as always. What type of microphone do you use? If you've addressed it before I apologize. Thank you for your time.

I don't think pressure has anything to do with it. The main issue is that air gets in between the drop and the surface of the water. All you did was remove the air from the vacuum chamber so there's no more air to get in between the drop and the surface so then there's nothing to bounce against. As someone else suggested, it might be interesting to see what happens when you increase the pressure. Does it add enough air that there's more "cushion" between the drops and surface or does maybe the air pressure can push "harder" against the drop and push it into the surface more?

It's always a resonant frequency created on the surface of the water that creates them. If you notice, it happens mostly near the edge of your container, and the size of your drop, the nearness to the edge of the container effects that resonant frequency. I bet the larger the container is the less likely you can create this with just water.

These kind of channels must be like real nightmares to fact resistant people.

put a piece of double sided styky tape under the basin to fix it to the plate

just watch this and now I wanna recreate it somehow

Those few droplets that were bouncing on the surface were so cute

9:22 - I think its more accurate to say that its air dependent, not pressure dependent

never fails to use the vacuum chamber

It wouldn’t be an actionlab video without a vacuum chamber test

you should also test it with the frequency machine in the chamber, to see if it's only pressure dependant or not, it seemed to me that vacuum chamer not only pull the pressure but also the air and i think it only reducing the chance it happening, and i think i could still see it at max vacuum in this vid

I had a panic attach that you added so much teflon to the water. People might think that’s a good thing. 😂

Finally, waterproof water

Hey Action Lab, could you perhaps make a video on Stoichiometry? I've been trying to get a better idea of how it works and i think it would make for great content on this channel

instruction unclear. me and my brother ended up peeing on each other's legs.

This is so cool

Neat, I wonder if you could also increase the duration by increasing the atmospheric pressure, or by trying another gas.

Very cool man

It would be interesting to see if increasing the atmosphere pressure could make it last longer. Don't know if you have a pressure pot with a clear lid

YAY I LOVE UR VIDS

The pressure may just be shaping the drop on the way down. Or it is affecting the speed achieved, so the fall distance should be reduced to actually compare extremes.

Awesome

9:15 It is a neat demonstration but it doesn't take away all of the possibilities. There Is a possibility that it is dependent on the closeness to the boiling point and not the pressure. While the pressure drops so does the boiling point.

I have a suggestion for a future video. In soundproofing it is impossible to stop very low frequencies. Even noise cancellation doesn't really work. High frequency sound proofing is no problem. It would seem that having a vacuum chamber around the room to be soundproofed would stop any frequency. This would solve the issue, but you would need a solution for the door. Fun project?

Me seeing the moving drops in the shower: MoOoOm ThErS BuGs iN mY sHoWeR

That's interesting the way the drops bounce on the water like that. 🤔

at the end can you increase pressure to make it more time?

I see this all the time in my shower and I had no clue what was happening

Maybe it's a similar/same effect in the shower when you pour a stream of liquid soap.....like shampoo in your hand, at an ANGLE. It deflects instead of streaming down into your hand.