The Action Lab - 2025-07-18
Why is there no splash in a vacuum? I try the experiment for myself to see if splashing disappears in a vacuum chamber. Published paper on this effect: effect:https://arxiv.org/pdf/physics/0501149 Where I found the video of the splashing drops by Sidney Nagel: https://www.quantamagazine.org/finding-beauty-and-truth-in-mundane-occurrences-20250509/
Thank you for solving a long time issue! I’m now going to start giving my kids a bath in a vacuum chamber. No more splashing and no more wet floors!! You’re the man!
If you keep the vacuum pump running once they're finished, they'll be desiccated. This will save the need for you to towel them down afterwards.
Another tip. When the police arrive say nothing until your solicitor is present. Just tell them you don't know what happened.
one final bath indeed.
😂 crazy
@@KenFullman When the police arrive, just turn on the bathroom shaped vacuum chamber again.. problem solved.
@@KenFullmanOr just dry them off with an IR laser.
could you then do this test in a pressure vessel and expect a larger splashing effect?
Yes, that would be a good one!
yes like over 5 atm or in different density gases like co2
yes, i would watch that too
Exactly what I came here to say!
Beat me to the same comment by an hour!
Wait a minute; the video is only an hour old! You commented as soon as he posted the video!
I spent a few decades in high-vacuum, designing chambers, valves and feedthroughs. Your solutions to the problems of getting power and materials into the chamber are ingenious! On the other hand, I cringed at the flat-sided chamber. That looks to be a couple of square feet on a side, which would mean over two tons of force on each face! It obviously works, but I don't know the longevity of plexi when cycling at those forces.
Oh, to get drops into the chamber, use a micro-pipette with the nozzle placed in your access port. Also, be sure not to run your turntable motor for more than a few seconds at a time since it will overheat very quickly. The only cooling available is radiative and a little bit of conduction through the structure. If we ever had to put a motor inside a chamber, we needed to "can" it with a cooling jacket with cooling liquid circulated through it. Finally, I would guess that the transition from splash to no-splash happened during Knudsen flow, a regime that is the transition between viscous flow (like we are all sitting in now) and molecular flow, where you can treat gas molecules as ping-pong balls.
Very good video!
You are amazing being able to keep clear headed enough to do design work even after decades in high vacuum. The hypoxia alone would kill us mere mortals.🙂
@@karlharvymarx2650 🤣🤣🤣😂😂😂
Yeah, I'm really good at holding my breath...
I wouldn't have thought about the cooling issue. Makes sense, I just don't think of myself as being surrounded by high pressure coolant all the time.
Fascinating. Thanks for sharing.
@@karlharvymarx2650yeah, that must have been depressing....
I’m 74 and always loved science and that’s why I reckon your up there with the best, in finding and demonstrating nature at work. Those who don’t appreciate your work simply lack imagination and the thinking process. Take care from an avid follower in Australia 🇦🇺
how were the dinosaurs back then
I can imagine moviemakers using this effect in a movie. It is often fascinating to guess or figure out how certain physical movie special effects are done.
You are outstanding when it comes to,
selecting interesting physics,
telling how you intend to illustrate it,
visualizing it and finally explaining.
Your channel is definitely one of my favorites.
Greetings from Sweden
Exactly!
When I have watched that guy first time few years ago I thought he was weird... and I was right.
He is weird but in the right direction. Great mind!
Wow, your comment is almost like a haiku.
@@maskedmarvyl4774GET OUT OF MY HEAD 😂
@@maskedmarvyl4774 I thought the exact same thing!
@balboa9439 his early content was very homebrew-style. Really gave the vibe of a guy in his garage with a phone camera lol. But he's one of the best science channels on here now in my opinion.
Also, at 5:41 you can see the top drop is flattened horizontally from the air resistance, but the bottom drop is perfectly spherical at low pressure. So neat!!
Oh yeah, great observation!
When ignoring air resistance, one can assume a perfectly spherical droplet.
That is so cool
Yeah I never would've guessed honestly that's why it splashed.
Love it.
Beat me to it!
I've been a mechanical engineer for over 25 years, having careers in process piping and food processing equipment, and I am today years old since I knew about the science behind splashes.
thank you for the wonderful science videos.
0:15 MINECRAFT SLIME BLOCK PLACE SOUND
How many hours of Minecraft would you need to recognize that sound from one sample?
@@MikkoRantalainenat least 5
@@MikkoRantalainen LMAO
And?
@@MikkoRantalainenNot very many
What amazes me is not that liquids don't splash in a vacuum but that the fact has only just been discovered...
It has been discovered several years ago. I am not sure of the exact date but its at least 20 years ago, when this specific group discovered it. I believe there is another paper/group who discovered it even earlier.
Seriously, astronauts have been going into space for decades and movement of liquid in vacum has been well documented. This just seems like a grade school level science fair experiment at this point.
@@eddiemason4316 you seem to confuse vaccum and zero-gravity
I mean, usually you don't want liquids in your vacuum.
What amazes me is how counterintuitive it seems to even very smart people. It feels like a lack of critical thinking being applied here- after all, what even would make the drop splatter? It is assumed, and that is the part where an open but critical mind shines.
All the momentum is at the floor, if momentum was allowed to play out it would just cover the surface according to it's surface tension. So clearly something else plays a part, and obviously anything moving through the air is going to interact with it. It would have been(and was) natural to me to hypothesize that the air is what was causing the splatter, so in a vacuum, there is no droplets.
I love how you don't just describe the scientific concept, and other folk's video of the experiment, but you actually replicate it, in true scientific method fashion. Most of us couldn't do the replication ourselves, and you help us out by doing it for us!! Thanks!!!
1:10 for a moment I really thought you were going to see if it was really true that it causes you to fall to the floor laughing
Spoiler, he did not.
🤣 I love when it’s kinda ambiguous based on context. I mean if you only hear the sentence before it does seem like that
👁
Science nerds have a completely different sense of humor. I, myself, love some good old science jokes.
Sry for the dealyed response. I was on the floor laughing.
That was quite the surprise! So counter intuitive to one's thinking. Thank you for the demo.
5:02 for those who needs simple answers
I love scientific discoveries about basic fundamental interactions! It isn't always the high-cost, complicated discoveries. There's still really basic things to be found
Splashtonishing!
Indeed
One of your most surprising and amazing videos, yet so simple. Beautiful.
Holy, didn't watch your channel for a while, the new vacuum chamber you've got now is GIGANTIC compared to the previous one!
Thank you for showing what it looks like in the first 20 seconds! I was always going to watch the entire video regardless, but I appreciate having "the best part" of the video right at the beginning.
🤘🏼😎🤘🏼
How about at a higher atmospheric pressure?
EXACTLY what I was thinking...
I was wondering if you could get the pressure high enough that the water drop would stay a drop. Like, if it couldn't over power the air and the air just forces it to act more like a bouncing ball.
ngl we share the same idea
@@lostlion7796 the surface tension of water is enough to do just that without an increase of atmospheric pressure
slow mo guys actually captured this perfectly in one of their older videos
I have a PhD in Chemistry and a degree in science which included Math and Physics at Uni. I watch a lot of science videos on YouTube, and often can guess or understand a phenomenon. However, when I saw the title of this video, I just thought what? Surely liquids would splash in a vacuum? (Though ultimately liquids cannot exist in a vacuum). Just had to watch. Thank you for selecting and posting.
Yea, it not to often I see a science yputuber do a demo where I haven't know about the effect. But I've been working with high vacuum systems for 20 years and have never heard of this. Granted most of my experience with liquid in vacuum is when something is going horribly wrong so not really paying attention to invidual droplets.
Well that makes me feel smart 🤓🤓
I worked with piezoelectric dispensers for a few years while making immunoassays, and I thought it was pretty interesting that the picoliter droplets didn't splash - they made (near) perfectly round circles when depositing the proteins. If they splashed, we would have picked up a bunch of static around the drops upon analysis. So from the explanation given here, there might be a size limit when trapped air becomes a factor in creating splash, and we were operating under that limit. I always kind of thought the splash droplets were so small that they effectively became water vapor, or at least misty enough to get caught in air currents and not deposited.
And now I want that experiment.
The element Mercury is a liquid that would survive a vacuum. Change My Mind
@@LawernceSimmonswouldnt it slowly vaporize?
1:50 you could've sandwiched a bit of cloth under the magnet to wipe away the previous drop. But I think the turntable solution is way cooler.
As soon as I saw how it landed I knew exactly what the explanation would be. Pretty intuitive when you see it but not when just doing a thought experiment. A good example of how physical experimentation is so important.
This is so cool. So splashing is not just a gentle thing, it's a battle between the air pressure and the surface tension.
Forget about the splashing phenomena (not really, it’s awesome) but for me, this video is about engineering and creativity to solve “problems” or issues that need to be dealt with to get results. You rock James!
Ok. Now we need to test a pressure washer in a vacuum.
And a vacuum cleaner in a decompression chamber
Wow Science really is amazing thing ! every experiment is eye opener !
Seriously counterintuitive as you said, fascinating.
Idk what's more mind blowing: the lack of splashing or the fact that we only discovered this phenomenon 20 years ago.
20 years ago? Dude, that's a 2025 article, basically super recent. Can't be right, 20 years have gone by, WTF...
A 2005 article*
@@CaliChemist_ITA We are living in the future 😎
I love how your solution to drying the surface off was a spinning mirror instead of sticking a rag or paper towel to the magnet you literally just used for the previous attempted solution.
Also, running mains voltage over exposed copper tape instead of just using a 12/24DC motor.
The JWT design on Tshirt is genius. Love it.
I admire the amount of creativity you have to this channel theme.
Thank for answering question! I always wondered why the rain wouldn’t splash on the ground when there was no atmosphere!
It's amazing that the mechanisms behind something this mundane, have only been discovered 20 years ago. There's SOOOOOOOO much we have yet to learn. Thank you.
No, it's not been discovered 20 years ago. Most people who knew about it before then thought it was too basic to even call it a discovery. It's something so obvious when you're literally compressing a gas between two thing, there's bound to be more of a push up.
i wonder what would happen if you dropped it onto a hydrophobic surface. and also a spherical surface
Once it got close enough to detect the hydrophobic surface, the drop would stop and reverse direction
the hydrophobic surface would cancel the drop on twitter
AND changing the gas from air to other vapor state of different types of liquids vs different types of liquid drops. Polar vs non-polar liquids / gases (with different viscosities). The experiments with bouncing oil drops on oil baths explicitly REQUIRE an atmosphere!
@@Ancient_Yuletide_Carol wrong
Dropping liquids on hydrophobic surface in vacuum (and near vacuum to find transition point) would make an interesting video. And if the water stays flat on hydrophobic surface in vacuum, what would happen when you slowly increase the pressure again?
Could you do dropping a drop onto a liquid surface? That normally splashes, it would be interesting to see what effect low pressure has on that too!
Or a small pebble
At 4:12 (and at 4:48) comes a second drop in the liquid surface of the first one. It doesn't splash.
@@martinwest2538 If you go frame-by-frame around 4:12 (pause + comma or pediod on desktop browser on YouTube) you'll see that there's a small splash-like form. I would assume we would see some kind of splash if the drop was high enough. The depth of the target liquid might also affect the results.
Omg. This is the first time in months I've seen this channel on my feed.
Random topics like this, is why I love this channel.
I find it so weird that nobody has noticed a splash in a vacuum until now.
Edit: ok it was 2005,but still seems a bit late.
Similarly, a man invented a new kind of screw around the same time
ts is so tuff
I thought the same thing, however I think it's simply because high-speed cameras have been INCREDIBLY expensive only until the last decade or so. Even in 2005 a high-speed camera was about $100,000.
The biggest reason, imo, is that generally if you're going through the trouble of creating a vacuum you want a vacuum, liquids evaporate and poison the vacuum so are avoided at all costs. But that's high vacuum for physics based systems, chemists use rough vacuums all the time with liquid agents, but I suppose they aren't interested in the splash mechanics since they're doing chemistry not physics.
@@SylviaRustyFae Details? Sources? Names? I'm curious!
I would have never guessed that - Thanks for showing
While you have everything already set up, you should try not just a single drop but more....or make a little container with liquid and drop small metal ball (with be easy with magnets)
So awesome, thanks for sharing!
Okay...start of video...I've thought of a LOT of esoteric scenarios in my life, but never once have I thought of this. Thanks for the enlightenment as well as changing how I see the world.
Ngl, thats some real basic physics, it impressed me that people got shocked by that. I mean... thats not something you need more than 5 minutes thinking to figure out. Great video btw!
Wait, so air resistance is not negligible??
Never has been 👨🚀🔫👨🚀
😢 i thought my physics teacher was always correct
I always wanted to see the sperical cow in an infinte plain...
only for spherical cows!
Résistance is only négligible in high school 😂
Lets not tell the engineers
I think stuff like this illustrates that our views and assumptions about how the world works are so strongly shaped by the conditions we live in that we don't even question certain phenomena. In this case, we haven't even questioned why or if simple momentum is strong enough to break the surface tension of a falling water droplet. It seems we just assumed it was because that's our every day experience
true
like the fact that it is the same affect that let a older car with a carburettor can drive and the force that make a big earoplane flies . Venturi , in the carb exactly Bernouli affect
before watching the full video, i am at 0:45 my hypothesis is that due to the water needing to push away air some of the air takes some of the water with it while being pushed away
Whatever his name-Helmholtz instabilities need another fluid that’s my hypothesis.
I think it’s surface tension
Ahh You were wrong. It was the droplets ability to spread out because no air was in the way. Spoiler warning.
Thank you so much for serving treats to curious minds !
You always have great answers to questions i didn't know i had.
The fact that we found this out just now is amazing.
@TheActionLab - 2025-07-18
Answering a few of your questions:
1. Why didn’t the alcohol boil in the vacuum? —because I was still above the vapor pressure of the alcohol at room temperature. Boiling point of IPA is around 6kPa. It did evaporate faster than at atmospheric pressure but the liquid hung around longer than you’d expect. That’s why I needed to have a mechanism to wipe off the drops.
2. Why not use water?—the original experiment was alcohol. So I wanted to match it. I used 99% isopropyl alcohol. I actually tried it with water but even in atmospheric pressure there is very little splashing that occurred. The surface tension of water is much higher so this suppresses the splash. The alcohol gives an explosive splash but the water barely splashes.
3. So increased pressure should give more splashing? —yes! Although I would assume there is a “saturation” point where it splashes as much as it can. But it’d be cool to do this in a pressure chamber and see.
@YoReid - 2025-07-18
That still counts as a vacuum? I would assume it being above vapor pressure would mean the amount of air is not negligible and so it wouldn't really fit the definition of a vacuum anymore
@gregkocher5352 - 2025-07-18
I suspect a drop in a pressurized box would not only splash more but travel a shorter distance. A bit more air would provide more resistance to liquid moving.
@Commenter-5519 - 2025-07-18
@@YoReid I wonder if you could use some liquid like gallistan with a negligible vapour pressure. (Like a few atoms/cubic kilometer, I think I read somewhere.)
@Quardanter - 2025-07-18
Fqct: this is generated by AI, specifocally, ChatGPT
@KenFullman - 2025-07-18
I notice you used alcohol. Alcohol has very little surface tension. I don't understand why you didn't try the same experiment with water. It would have been interesting to see how much difference that made.