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!

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

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

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.

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 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.

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

@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.

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

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

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

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.

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

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

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. 😶

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

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

Good explanation.. Always loves to watch