You always find the most random but interesting experiments

Your ability to find the most mind blowing things in the most mundane things in life is amazing.

that's pretty cool, I cant believe i never noticed that before!

Thanks. Now my friends think I'm weird. "Why do you keep staring at your hot chocolate? "

Looks like this is a great idea for the slow mo guys to film

I'm always impressed by how novel your videos are

It’s nice when people present things as “first described”, “first explained”, etc instead of first discovered for things like this.

This is just a guess , but may be the reason water droplet form on top and just doesn't mix with rest because , water droplet are pure water while rest is mixture (tea or cocoa). Which result in difference in composition, thus slower rate of diffusion.

1:05 Well the droplets are incredibly light, light enough to float around in wind. And the droplets have to touch the bulk liquid, but air is in the way. Regular water will also float around on regular water in some conditions

Your curiosity is infectious and your ability to relate complex scientific ideas to everyday life is unique.

I went through this *exact* thought process when observing this very effect on the surface of my morning coffee. Ended up concluding that the convection processes would dominate any movement compared to the relatively weak effects of any possible cosmic rays. I'd love to see you repeat this experiment with an alpha and beta ray source to be sure though!

Very cool experiment! I also suspected that the levitation is caused by a tiny electric charge :)

THIS is the content I love from you. Seriously please do more of this. You're taking something that is genuinely interesting and doing some actual science to figure out what the heck is going on. One of your best videos to date.

It would be neat to try this in a really shallow container. That should suppress convection and you could see if crack patterns still formed.

Highly recommend youtuber Posy who did a video on this called 'Hot water colors'!

1) levitation: caused by electrostatic + rotation-based magnetic charging during updraft vortex friction which is dependent on temperature. It is not non-coalescence of droplets due to air cushioning as there is a huge gap of levitation much higher than the cushion mechanism as volume-to-gap ratio. It is also not a hockey-like mechanism as evaporation strength can not be that homogenous as the variance of the levitation height is similar. 2) cascade: the droplets are clearly protected during an updraft. The updraft, as stated above, is an inductive mechanism of the levitation as it charges and also hurls the droplets on the surface, adding more droplets carried and vortexed with the updraft vacuum. It is during the lack of updraft when the crack cascade happens. the updraft vortex feeds itself by its flow speed causing extra vacuum. moreover the most important part is the perpendicular air hitting the surface created by the prior vertical vortex before it is moved due to turbulence. Turbulence causes the normally vertical vortices to be parallel or diagonal to the surface. Thus their updraft is not up but left or right for a finite amount of time. That horizontal pressure causes perpendicular droplets to crush on the surface. The creation of the droplets require vertical vortexes as it is caused by evaporation itself. Vertical vortexes causes horizontal spin on droplets and horizontal vortexes cause vertical spin. Thus differing magnetic axis. When two differing axis crushes, they are disturbed and lose their levitation. The disturbance caused by the perpendicular collision which disrupt the innate rotational axis of the droplet, during vertical vortexes. Vertical vortexes makes all the rotational axis of the droplets parallel and horizontal to each other. But when a turbulence changes the locations of the vortex-forming nucleation points, a non-veritcal, parallel to surface vortexes or drafts happen for a short amount of time containing vertical rotational droplets. When vertical rotational droplets collide with horizontal rotational droplets, electromagnetic disturbance is created. As you know negative charged turning droplet creates magnetic poles. The reason why the cascade can start at the same time parallel to each other is proving the idea of short-term parallel drafts or vortexes who touch the surface at the same time like a horizontal pipe. You can see the cascade velocity is very similar to the air updraft and air vortex velocity.

The power of observation

You have one of the best science channels. Always coming up with original and random topics that are both fascinating and educational. Keep up the great work!

Love how he's just calmly speaking while his geiger counter is losing it Edit: God yall have no sense of humour

I've been wondering about this for some time now. Thank you for covering it!

You always came with a unique idea. Thanks for teaching us. ❤

Posy has a fantastic video on this if you want to see good close-up footage of the levitating dots.

Tritium illumination sights also emit secondary gamma. It’s not much, but it’s detectable. I wouldn’t worry about Tritium illuminated watches, Gun sights, and keychains.

I feel the convection draws air down at certain points which the drag on the water particles overcomes their electrostatic repulsion to the point where they collapse in on each other like an electrostatic lightning bolt.

This makes me want to watch Posy's video on this effect. He does a great job capturing the droplets with a macro lens. It'd be cool to see y'all do a collab on something.

"These are blocked by the platsic...." The Geiger counter starts screaming. XD

In the Aussie desert, the dust bowls are, or used to be before they sealed the road HUGE. If on a dead still VERY hot summer day , back in 1958 I noticed this! Get down really close to the dust, there is a mist of the finest dust partials over the surface, as I remember it was about a centimeter thick, thin enough to see through it but you could actually see the partials dancing in the sunlight!

The drops are where the water is vaporizing and condensing pretty much instantaneously. Water heats up, vaporizes, then loses heat to either air particles or other vapor particles even, but it causes condensation under the wall of steam (count the steam as a ceiling and the air gap beneath as a cooler system). The faster particles brush by and slow their momentum enough that they lose thermal energy and cool down just below the temperature, but, they cool so close to the surface temperature that the heat difference is extremely small, so heat transfers slower. This keeps it as approximate condensing temperature, but bouncing just above and below this temperature for a time. But, once the convection currents reach a cooler state, more particles can fit into that cooled state, absorb heat and fluctuate also. I suspect it is the heat that gets trapped in that space (the difference between the lower interaction and the upper interaction being minimal), so that, when enough particles get there, their activity becomes excited, pushing more vapor around and allowing for cooler air to be exposed, which allows more water to evaporate. The electric charge accelerates the water molecules as a diamagnetic substance and the added motion equals added heat (so more steam, as it takes longer to fill the "heat vacuum" left behind so more particles can evaporate due to the added energy to the system). But that's just how I see it.

Do the bubbles actually levitate, or is it just surface tension? Could it be a kind of reverse Leidenfrost effect?

Suddenly a magical world appears!

Found this a couple of years ago while looking at my tea and couldn't find anything online (was hard to search properly). So cool to see an explanation!!

Man, you come up with the most awesome videos and examples. So often so simple, but so incredible and insightful. Thanks for so many years of intrigue!

7 minutes in and I realise I'm not watching a short.

Hot chocolate made with water....how gross

I saw this phenomenon once while enjoying some coffee and always wondered what caused it! Thanks for the awesome and informative video!

answer at 7:49

4:23 “but these are blocked by the plastic” Proceeds to beep crazily

Thank you for this excellent example of good experimentation and analysis! One hypothesis that crossed my mind for the rapid formation of narrow linear clearings is some kind of slow electrical discharge. You mentioned that the small drops appear to be charged. If so, they may behave a bit like two-dimensional clouds that build up electrical charge due to the convection going on beneath them. After the charge builds up to a certain level, these “clouds” may discharge their electrical buildup back into the fluid. If that hypothesis is correct, it would make your lines an extremely slow-motion form of lightning. Fun! That hypothesis should be testable. Incidentally, a university professor and I once spent a couple of hours experimenting with the small flashes of light that occur in a glass beaker of mercury if you (carefully!) swirl the Mercury around in a dark room. Papers from decades before speculated that these flashes might be a form of cavitation sonoluminescence. What we discovered, though, was that the flashes were due to a buildup of induced static charge on the inner wall of the beaker. Swirling would induce the charge, which eventually built up until an entire section of the beaker wall would discharge instantly back into the Mercury, focusing all of the discharge onto a single tiny point. It was the lightning like flash at this point of charge re-entry that people had seen for decades looked as a small point of light. We uncovered what it really was by doing nothing more than staying in the dark room until our eyes fully adjusted to the dark. Once we did that, we could see a beautiful web of lightning like flashes converging on the point where the brightness was greatest. Earlier experimenters had not noticed the surrounding flash network because it's too dim to see until your eyes are fully dark adapted. Once you can see it, however, it's quite beautiful. Some mysterious phenomena have straightforward explanations that are very different from the ones postulated. The structure of the mercury discharge flashes is still fascinating, but in a different way from cavitation. How, for example, can charge build up on a glass surface that is an intimate contact with highly conductive metallic mercury? Clearly there are still mysteries in this phenomenon. Unless the professor did it, we never published these results. We probably should have!

This man made an entire interesting video on the steam above a cup. Give this man his award, please.

Wait... did you just create ball lightning? (A small spark/ember from a strike, floating around, but under charge and thus causing a mist "ball" around it?)

This is so well done!, Thanks for the quality production! it feels in another level

Fascinating subject ! Can't wait for my next cup of coffee to look at the effect myself

I was just wondering what this was the other day

Lost interest at the sponsored section. Please don't promote such an extremely unethical company who have been found guilty of selling their customers' data even after saying they wouldn't do that.

I noticed this before, and failed utterly at looking up how it works. I haven't come up with a good experiment for testing it. So I really appreciate your video. Thank you!

Years ago i did work experience in a factory. There was machine that moulded plastic lids for syringes. If you turned off the anti static device these plastic lids would begin assembling into a structure , like these droplets, along the wall of their container. When they reached the top they would start exiting the container.

Action lab never disappoints 👍

Wonderful explanation but please stop making hot chocolate this way 😭

I've tried this experiment several times with my coffee, but I keep getting an odd result. I brew the coffee, set it down, then when I prepare the tests, the coffee is gone. I also notice the more I try, the more wired and awake I feel

Really well done video, great observation & solid science TAL! I would be interested in hearing more about this for sure

I think the pattern that the drops makes is like a lightning 🌩 effect 🤔

A KZfaqr called "Posy" made a beautiful video (Hot Water Colors is the title) about this. Don't think he went into the science part, but he made amazing footage with this!

To see it BY EYE, aim your light at the hot surface, then glance around the edge of the light. (You want to see retroreflection, where the light hits the suspended droplets, then reflects and returns to the light source ...but some of it spreads, so it just misses your flashlight. With a small flashlight, hold it between your eyes, aimed at the dark hot liquid.) With a heat-bath, with ink-dyed water, I found it worked best at a bit above 80C. Some of the "tracks" are actually the centers of little tornadoes, where hot rising air will swirl. But those tracks are slow, and only give single dark lines, not branches or wide regions.

Possibly, the oils in Cocca are non polar so they create long chains such as Hydrocarbons, and oils will float on top of water also giving that scattered light rainbow effect? The cracks one sees could be due to convection current bringing sections of oils together coming to the surface then resurfacing?

The thumbnail is rather misleading, saying “cosmic rays” with no question mark. Very interesting video otherwise.

Posy will be proud of you

Holy thing.. Im almost 50 and I wondered what are these lines from being child. And yes I know of bubble chamber.

I made a reddit post in r/sciences a month ago where I asked about this phenomenon, I'm happy to see a video that goes through all the theories and questions we had on this subject. Thanks a lot !

It's kinda like reading the cocoa 😂

6:00 Experimenting with charged nails in a chamber filled with an air/alcohol vapor mix sounds like a marvelous idea! More of that, please!

The hot fluid is evaporating from the surface as a saturated vapour. Once it leaves the air/fluid interface, it cools sufficiently to condense, forming a droplet mist, supported by further evaporation. (Its all about the vapour-pressure phase boundary). An equilibrium is reached where the condensation in the fine water droplets is balanced by the further evaporation from their surface, hence they appear to 'float' above the surface. When the droplets are disturbed by fractional air convection-currents, local forces induced by electrostatically charged nails, etc, they come into contact with each other, breaking the equilibrium and falling back into the fluid. The disappearing droplet causes the others to rush into the space created; some collide, causing the domino effect and the tracks observed. (or something like that)

I noticed the "surface mist" in my teacup many years ago, but never could find an explanation as to why it was happening. It appears no one else could, either! Fascinating!

The drops are cause by the electromotive force generated by the Ether acting on the fFlat eEarth.

*IN 2018 I WAS IN MY SOUTH FACING APARTMENT* sat on the sofa opposite the big window when I got a REALLY bright flash in my right eye. About 2 hours later it happened again. This happened maybe 6 times over 3 days and in both eyes - but ONLY sat opposite the window at about 5pm. I mentioned it online and a few people from other countries said they TOO had been seeing these strange bright flashes. I can only assume they were some high energy particle from some event in space - never happened again. ---> It was very noticeable at the back of the eye - it was not a flash you were seeing in front of you - it was inside your eye at the back.

this is so much more fascinating than expected

What causes them to levitate is surface tension. The water vaporizers and falls back down, but not with enough momentum to break the surface tension. I'm curious if the density difference also has anything to do with the microscopic water droplets not immediately recombining, since the water droplets should be relatively pure vs the infused cocoa/coffee/tea.

The video Posy did on this is much more well shot than this is, in his video, he has a macro lens on a slow motion camera that's capable of literally seeing what's happening, you can see droplets floating above their own reflections.

“Hershey” sucks man! 😂 0:44

I have noticed this many times on my morning tea and it looks like the traces in the surface layer are formed by the edges of the uprising steam "flames", they seem to get the same form as the steam flames.

I had always thought it was surface tension and the oil content of the beverage. Pretty interesting stuff! Glad to see many people observing their beverage.

Lovely video! 👍 If you think this effect is mesmerizing to watch, I HIGHLY encourage you to look up the video “hot water colors” by Posy (one of the best under the radar creators on YT). The macro shots he got of this effect are truly mind blowing. Great work and can’t wait for the next video!

Every like represents a century that humanity will thrive.

The levitation could be caused by the droplets finding a point of equilibrium where they are warm enough to become steam but too cool to escape without the heat coming from the hot water. Water is polar in its charge so introducing a charge disrupts the equilibrium as well as creating a current of air flow that causes increased cooling, shown by the increase in steam when a charged surface is present.

I've noticed on 2 liters of soda there tends to be one or more large (in comparison to these) sphere of liquid floating on top when I open them. I've had one sit on the top of the liquid for over a minute before it dropped back into the rest. I think it's a weird interaction with the surface tension of the liquid, but I don't have any clue beyond that. It's neat to see

I am both amazed and happy. About two months ago, I encountered a similar phenomenon in a cup of hot chai where the foam pulsated with a distinct hissing sound as a result. I filmed it and immediately shared my discovery with my friends, also drawing parallels to your videos about radiation in cloud chambers. You have always been a great inspiration to me, so seeing you address this made my entire day. Back then, I conducted the same test as you did with the smoke alarm with the same result, which led me to believe it had something to do with electrical charge rather than radiation. It may not have confirmed all the theories we discussed, but it certainly made me feel a little less alone with my fixation over a cup of hot drink. Keep doing what you're doing, because you do it best!

The droplets float because they have the same charge as the liquid. They fall when they lose that charge. Is a charge formed when they condense? Is a charge formed when water evaporates? What is the charge like in the upwelling areas and in the downflowing area?

How would you recommend to heat up my cocoa powder? Should I wet the water before I mix it?

so if you were to prop a charged rod above a reducing pot of soup or something like that, would it reduce any faster since you're preventing the water particle barrier or whatever that is from forming on top? Or i guess is there any particular practical application this could be applied to in that vein?

You truly have become my most favorite "Science" youtuber. Showing illustrations and math is fine but few do the hands on, and sometimes dirty, experiments you should deserve more success.

My God - i have seen this! but didn't stop to understand why thank you - i have students that i prepare cloud chambers for - but its so hard to repeat good results (quick enough for those youth that need fast examples before they drift away to their phones sadly) this is a perfect fast experiment to capture them, so they, a standard Wilson cloud chamber can be observed! Thank you!

The borders in the convection currents also might have varying amounts of oils from the cocoa mixed in, as it is really hard to get hot cocoa anywhere near fully homogenous. Classic method of making it that I know is to slowly heat it while stirring as much as possible. Failing to do this or leaving hot cocoa long enough or let it cool, a lot of the oils will come out and sit on the surface. I would guess that immediately after heating, with so many convection currents, those oily layers/bubbles of varying concentration are mixing folding and having layers combine and burst, there may be a charge interaction that is disrupting whatever equilibrium is on the surface, right along those convection boundaries you can see lining up with the sudden collapses. I don't know the physics of how oil and water separation actually works at the molecular or electron level. I would assume that there are some sort of charge "shells" between layers of varying concentration chaotically seething. Solar flares would be the closest analogy I can think of.

We love you and your great content bro! ❤️❤️❤️ THANK YOU

My theory on why they levitate has to do with the orientation with the water molecules on the surface layer, they create a potential jump of about 0.2V which could be repelling the water droplets depending on their charge. It could explain why they coalesce when an external electrical field is introduced too.

Funny enough I had a moment wondering about this at work. My first guess was cosmic rays (cloud chamber style) but my senior collegue rheologist's wisdom pointed more towards convection cells. Brilliant video!

Looks like there seems to be a temperature at which the surface tension breaks and a droplet forms on the surface which quickly gains its surface tension since droplet has a higher surface area and hence the temperature of the droplet quickly falls. It is possible that temperature and surface tension are inversely related/proportional.

I've always wanted to know the explanation of this phenomenon. Great video as always!

perhaps they are slowly evaporating, creating water vapor all around them, that prevents them from touching the actual surface of the drink. If they were charged, you should be able to either attract them or repel them using an external charge. Also that charge should quickly disappear when for example burning a match nearby (ionizing the air).

Exactly this kind of curiosity is what got me into science and I love it!!!

It happens on the top of a transparent plastic dome that goes over a Rotissory Chichken. When it is just separated from the stack of domes and just placed over the chicken the steam builds up and the moment you nearly touch it anywhere on the surface these lightning patters appear and start to spread leaving the area clear of seam build up on the inside.

I think you nailed it with the speculion that new steam from the surface is keeping the droplets aloft. Similar to the Leidenfrost effect. I'm not too sure your experiments with static electricity here show the droplets are charged. They would react even if they were originally neutral.

Nice analytic example, formulation and testing of hypotheses

Fascinating!! The convection lines remind me of the surface of Jupiter. Makes the most sense to me that the particles float on the surface because the liquid is in the process of evaporating. The liquid is too hot for the particles to cool and collapse into, but since they are cooled by the air above the surface of the liquid, they are in a state of equilibrium where they cannot become gaseous and get stuck. Could also be that theyre too small to overcome the surface tension of the liquid so they just chill on top. As to why the cracking patterns form, definitely a cool problem! Never noticed this phenomenon, thanks for showing us!

Could it be the pattern of swirling water vapor being mirrored on the surface of the liquid? As the liquid is evaporating off of the cooling surface the water vapor appears to have a similar pattern to the perceived "cracks" on the surface.

My guess is that the levitation of those droplets is actually a Leidenfrost effect on a very small scale. Yes, that one where you pour water over a hot metal and the droplets just roll around. The surface of the cacao produces water vapour constantly, it's very hot. The water vapour in the air above interacts with the centers of nucleation (dust, etc.), producing small droplets of water. Those droplets fall down, and those are cooling rapidly, since they have a lot of surface over a very small volume (square-cube law). We now have a big amount of the cooled water droplets over a very hot surface with a layer of hot gas in between - a Leidenfrost effect in its finest. The charge of the droplets could be not enough to actually cause levitation, the size is too big (and I guess it should be actually force the droplets to fall, since if we assume the vapourization removes some charge from the neutral volume, then it acquires the opposite charge, and opposites should attract), but it's enough to cause equal distribution of droplets over the surface, as there is almost no friction. And when you are bringing a charged object near the surface , it causes more vapour to appear, since individual water molecules are highly polarized, and when those are leaving the surface, they are acceletaring upwards, being attracted to the source of the electring field, which breaks the layer of gas over the surface and effectively stops levitation. I can't say anything about the "traces", though, since it's definitely a very complex process, but I doubt that this is caused by cosmic rays or something else. Probably it's just a spontaneus "crack" in the structure of droplets, since they interact with each other in pretty much the same way as ions in the crystal. And what happens when you suddenly remove some "ions" from the structure, disrupting an equilibrium? Yep, a crack appears. I can guess you can even compute the speed of the "crack" propagation using this model if you'd measure the charge of the individual droplet somehow, and thus check this theory.

Hey James, can you switch the functions of mint and peppers? Like making capsaicin of peppers choose the cooling sensation in our tongue, and turn the menthol in mint choose the hot sensations in our tongues?

The Brownian motion sorta gives it away and leaves not really a need for high energy rays to happen but would be fun to narrow down all the variables to explain the changes over time as far as boundary patterns. It may be it can party be droplets of water vapor condensing back, or something a bit more spicy than that.

Fascinating! So can we control evaporation using electric charges, and would this have an application in something like desalination?

I just noticed this when I put cling film over my bowl of noodles. The droplets were bigger than the surface ones here, but they randomly coalesced, and I could significantly slow the rate at which the larger droplets coalesced by placing my hand over the bowl.

I have another one for you, why when I boil water on my Glas and stainless steel kettle if forms bobble that move on organic patterns at the button?

I think the super saturated mist above the surface reacts to the convection lines of the liquid chocolate milk. The slight temperature difference made by the convecting liquid may make minute temperature variation right above the liquid surface and affecting the mist.