For those who didn't like the shaking, I motion stabilized the entire video and posted it on my second channel. Here you go! ruclips.net/video/acFkZiELN2g/видео.html. Sorry for shaking it so much! I thought one of the most interesting things is watching how the liquid waves change. And also when the meniscus is almost gone, you can’t really see anything unless it’s moving. But point taken if I ever do this again, I will do less shakes, lol.
it was a little bit annoying to watch, but reading your explanation makes it less annoying. so maybe being more descriptive with your actions would help next time. thanks for doing what you do.
The problem is the whole table appears to shake at a low enough intensity that everything on screen moves a LOT but there inst much affect on the actual container relative to the movement. Which is very disorientating.
@@Qermaqwhat joke. him shaking it is not going to raise the pressure. he just wants to make the layers combine faster and to show the liquid surface disappearing.
I just had a job interview for a company that uses supercritical CO2 as a solvent in industrial processes, I wish I had seen this video before my interview, very cool to actually *see* the phase transitions! Note that both liquid and supercritical CO2 are compressible, so those density figures are pressure and temperature dependent.
Was it super-critical CO2 or just liquid CO2? It's pretty easy to have industrial quantities of liquid CO2 but a real PITA to have even relatively small amounts of super critical CO2.
If they use knowledge of supercritical phenomenon as a hiring filter, they are fucking idiots. That's about as job-specific as it gets and it's THEIR job to teach you any pertaining knowledge.
@@GilmerJohninsightful question! The company currently has commercial processes that use supercritical CO2, but the owner just got a patent for a new process that will use liquid CO2, for precisely the advantages you cite, much lower costs for pumps, pipes, and containers.
he was shaking it to show the effect, otherwise youd just be watching a line slowly disappear which wouldve been far more boring, the number of people complaining about this is insane
A missing observation here is that the styrofoam got absolutely crushed. While it's in there you can tell the surface that was mostly smooth at the beginning is dimpled inward significantly. But then at the end 7:51 when he's handling it, you can see that the former half sphere is now a bowl. Styrofoam is normally less than 100 g/L density, so for it to sink in a 400 g/L fluid means that it must be squished to less than a quarter of its original volume.
You could basically get the same result here with regular water and compressed air, I remember a children's science experiment where you can make a toy submarine dive and surface just by squeezing the bottle it's in... Foam gets a lot of its buoyancy from the air trapped in it, increasing the pressure around it and compressing the trapped air in it reduces it's buoyancy
This needs to be done with something that isn't a foam. And then the question is easy, and just depends on how dense the object you choose is - is it more of less dense than the mass of the CO₂ you use divided by the volume of your chamber.
Super cool idea, but I need to criticise some things: - you covered the thing with your hand at the beginning when releasing the pressure; - stop shaking it please; - the word you're looking for is "interface"; the meniscus is the bending or "climbing" of the liquid along the walls of the container.
Well he was shaking it to make the line visible. I guess most people don't want to see that part of transition? Interesting thing on Google: meniscus seems to be the bending of the liquid on the surface directly. In the middle not the walls.
@@caydennormanton9682 The word comes from the Greek for "crescent" and refers to the curved part of the surface of the liquid where it meets the container, not the centre of the surface. Unless there is very little surface and it is all curved, as in a capillary tube. The OED has: "The convex or concave upper surface of a body of liquid resulting from the effects of surface tension and capillarity where the surface meets the walls of a container."
@@pattheplanter I looked into this further, and the definition you provided is the most accurate, and my simplified definition is incorrect: "A meniscus is the curved surface of a liquid in a container, influenced by the interplay of cohesive forces within the liquid and adhesive forces between the liquid and the container. The meniscus forms at the interface where the liquid contacts the container walls. If the adhesive forces between the liquid and the container are stronger than the cohesive forces within the liquid (as with water in glass), the meniscus is concave, curving upwards at the edges. Conversely, if the cohesive forces are stronger (as with mercury in glass), the meniscus is convex, curving downwards at the edges. This phenomenon is a result of surface tension and capillarity, and it is particularly pronounced in narrow containers like capillary tubes."
Why? Do you think a little shake will cause it to explode or something? Or is it just annoying to see? As he points out in his pinned comment, that's the best way to see it.
@@kindlinnk, that's just annoying, you can still clearly see it wave because of the right side becoming supercritical and Moving around the whole "liquid"
@@KDYinRUclips It wouldn't be a bad experience if he didn't shake it. Besides he could have shaked it way less. It's clearly visible without shaking so it wouldn't have ruined the experience and would have also be way less annoying
the shaking wouldnt be as bad if you either stabilized the footage to the tank, or mounted the camera directly on it, so we just see the liquid moving, and not the whole tank. BUT i didnt mind it that much and it was a very interesting demonstration!
I think it would be interesting to find a material which has lower density than supercritical CO2 but greater density than gaseous CO2. This means it should rise up to the top when it becomes supercritical.
Perhaps some hollow gas filled glass spheres. I agree that it would be fun to watch. It was lazy to use the foam as it doesn't have a well defined density. Glass spheres would have different densities and we would expect some to go to the top and others to sink. Maybe he will try getting those spheres for a future video. Among other things he could go back and forth and watch the same balls sink or rise.
very practical tip, thank you i was on a lake the other day and the pressure coming from all sides of life nearly turned it supercritical, thank goodness i calmed down a bit afterward
Excellent work with the photography to show us such a clear view of the meniscus! I for one appreciated the shaking to see the waves move and visualize the transition.
Cool experiment! Using an incompressible boat material would be better, because styrofoam will get more dense as pressure increases, it might even sink in water at 1000 psi
42 seconds in, I would think whether it floats or sinks depends on its density. Most objects are more dense than supercritical CO2 so they would probably sink. But something of low enough density should float.
The problem is how to manufacture something that is solid, doesn't compress to much under pressure and is then less dense than 0,464 g/cm³? Cyclopentane or CO2 is used to produce styrofoam. You'll more need a foam, that contain Helium or Hydrogen. But Hydrogen might react when you try to press it into hot liquid Polystyrene to get a foam. And the very small Hydrogen molecules and especially Helium atoms will just be squeezed out of styrofoam when it is set under pressure.
It should also depend on the ratio of air and CO₂ in the chamber. More CO₂ would mean a higher density which can more easily float a sufficiently light (relative to volume) object to the top.
@@seneca983 I honestly didn't even think about the air, but it should make a very small difference to the overall density. 99+% of that chamber should be CO2
@@DANGJOS It would've been possible to cram a lot more CO₂ into the chamber and that would've made a difference. I think he wanted the liquid surface to be about halfway in the chamber which makes sense because then it's easier to see.
The question is, would you drown in supercritical oxygen? Accounting you survived the rest of the inhuman conditions lol. I think it's time for a bigger pressure chamber...
I believe there is an important factor that was ignored in the discussion of the experiment. Styrofoam will compress under pressure and thus become more dense which while it still floats will cause it to sink lower into the fluid. For the most part it it should remain compressed when returning to normal atmospheric pressure (some of the air having been squeezed out of it under pressure). By comparing it's volume before and after the experiment you should be able to explain the amount it sank just before the fluid went supercritical. You could probably ignore the weight of the volume of air squeezed out.
Apparently (I'm no expert, mind you) one of the properties of a supercritical fluid is it's ability to diffuse into/through other substances (like a gas). So my conclusion was that the Styrofoam becomes impregnated with the supercritical CO2, and is thus more dense than the surrounding CO2 (Styrofoam density + supercritical CO2 density = more dense than supercritical CO2).
Actually there is more going on here than just density changes. The styrofoam acts like a nucleation point and the opposite side of the chamber as a diffusion point. So particles are diffusing out everywhere but converging near the styrofoam pushing it against the wall kinda like convection
@@caydennormanton9682 The supercritical fluid behaves like a fluid and gas - it doesn't diffuse better than in it's gaseous state (except for any added diffusion due to extreme pressure). In rewatching the video he starts with a shot of the vessel with the dry ice packed in and then jumps to a view at 200 psi which already is 13-14 atmospheres so the shrinking - sinking is already well underway (in fact he says "the Styrofoam is very squished ...") and the bulk of it may already have happened. Had he left the ball intact instead of ripping it in half I may have been able to compare diameters at various pressures to see if the additional shrinkage was measurable.
I don't mind shaking, It was indeed interesting to watch how waves become almost indistinguishable. And around 3:59 waves going all around the "boat", even on top of it. Liquid seems to be still under it, but waves look cloudy.
Makes sense. things float in something because they have lower density than the surrounding medium. When something goes supercritical, the gas density increases, and the liquid density decreases. When their densities are the same, you are at the supercritical stage. This means that your boat was floating on something whose density was going down. As a consequence, its buoyancy was going down as well.
Even after taking thermodynamics I never really "got" a supercritical fluid. My brain was just too rooted in "solid, liquid, gas". This really helped me visualize the concept!
@@Flesh_Wizard -- Well, it's more like a liquid than a gas because it displayed great viscosity. In the "experiment" we say, the density of the super-critical fluid was about half that of the liquid part at a lower temperature.
Very cool! I always enjoy your videos but this one is extra interesting. I am a refrigeration guy. There are companies building transcritical CO2 refrigeration systems. They use a very high-pressure compressor to compress CO2 vapor above the critical point. There are then valves and separators to reduce the pressure in a controlled manner to get liquid and gaseous CO2 from the supercritical fluid. This is separated so that the liquid can be used in a refrigeration cycle. I had always wondered what that would look like. Now I know thanks to your very interesting experiment!
That was the best demo of something supercritical I've ever seen. Seeing how the foam moves through it demonstrates its viscosity between the liquid and the gas. It's also a very practical demo for when the lake goes supercritical, which I've never known how to handle in the past :)
Im just a machinist, not a science guy by any stretch. Please check the pressure rating for those brass fittings. I have no idea what they are rated for but 1000 psi has to be pushing your luck. You can get the same fittings and valve in stainless steel for higher pressure. Neat video.
Excellent demo! When I saw the canoe at the end, the first thing I thought of was Lake Nyos in Cameroon, but there the CO₂ was held in supersaturation at the bottom until that fateful morning in 1986.
Wow, fascinating video, thank you. As a process engineer, I used to have to design plant handling supercritical fluids - great to finally see what was going on in those vessels.
Im an actual chemical engineer and that video just made me see all I read in thermodynamics class... this video is a must for all classes.. idk if this is textbook somewhere, but the syrofoam helped me understand supercritical fluid... I wish I've seen stgh like that back when I was struggling the course for the second time 😂
Great question, great experiment, great result. Now we know. That vessel body is way over-engineered for 1,000psi, no worries there. The ultimate failure is in the bolts. And jamming them in with a 6" ratchet (and then a hand drill) without measuring torque was the riskiest thing you did here. Bolts, especially of that diameter to length ratio are VERY susceptible to the tensile forces induced by torque. I'm guessing those are 5/16-18 x 6" or M8-1.25 x 150mm and they appear to be 307A Stainless. - 8 x 307A 5/16 Bolts give about 24,000 Lbf to yield - 2 1/2" bore (?) @ 1,070psi(critical) is ~5,250 Lbf x2 (because, through bolt design is holding both sides) = 11,000 Lbf - A 2.18 Safety factor seems low given the severity of a catastrophic failure. ie: if it were left on the dash of your car in August... you're gonna have a bad day. I've seen this same design used by other 'tubers and I always cringe. If you were to thread 8 shorter bolts (per side) directly into the body, you'll double the weakest link. A 4.36 SF would let me sleep at night, I might even bump them to 3/8 (M10) and go on vacation. Also, the boat is NOT floating on the meniscus. It's floating on the "surface". The meniscus forms above (or below for dense liquids like Mercury) where the liquid is bounded by the container. Maybe a good future episode, "In Search of the Neutral Meniscus". Is there a liquid that lays "flat" in a given container. Easy to demonstrate positive and negative meniscus traits but can you find (develop) a neutral meniscus fluid ? NileRed tie in ? A little "surface" tension ? Also, do gases exhibit a meniscus (hint: yes they do).
I have a 1930s GE Monitor Top fridge in my kitchen. To meter the flow of liquid refrigerant into the evaporator it uses a float, that floats on top of the liquid sulfur dioxide refrigerant, and opens a valve depending on how much refrigerant is in the float chamber. This reminds me of that. Because the float cannot float on a gas, it doesn't float unless the compressor has built up a certain amount of liquid refrigerant. I always thought that was an incredibly clever system.
Guess: Only a lighter-than-fluid boat can remain afloat in a superfluid. Because it does not rely on displacement for bouyancy. All Boats which are denser than the fluid will inevitably sink.
Thermodynamics has such amazing phenomena. Things like this really feel like magic. Just like how dry ice doesnt melt but sublimates, on which I graduated my masters
I’ve always had this question in mind about supercritical fluids and suggested RUclipsrs to do it by leaving so many comments, finally someone did it 😭
Woooooaaa huge thanks to action lab. This finally inspires me to make my own freeze drying riggg. On the DL... the coolest part is the density vs buoyancy as miniscus sublimates (idk what that word means - sounds sort of right and cool). Anyway next just gotta do the upside down boat floating in a similar 2d planar view vessel (like ant container?). To show that in same container a boat can float right side up and upside down in the same exact fluid if a pressure bubble pushes one area of water to top of vessel and one to bottom. I believe it is surface tension of the water that creates a suction force to hold the boat. So would depend on the friction or Reynolds number of sorts of the boat hull vs the water pressure bubbles into the "sky".
*@The Action Lab* 8:30 The liquid has a higher density & the gas have a lower density. This means that there exists SOME combination of gas/liquid CO2 combination that when super-critical becomes the PERFECT density to keep that Styrofoam floating in mid"air" (midCO2?). Judging by how slowly the "styro" fell in the super-critical fluid, I guess you need more liquid CO2, probably somewhere about 2/3 of that volume to be liquid? Maybe like 650 g/L density?
For those who didn't like the shaking, I motion stabilized the entire video and posted it on my second channel. Here you go! ruclips.net/video/acFkZiELN2g/видео.html.
Sorry for shaking it so much! I thought one of the most interesting things is watching how the liquid waves change. And also when the meniscus is almost gone, you can’t really see anything unless it’s moving. But point taken if I ever do this again, I will do less shakes, lol.
Dumb question maybe but why if it is 1000 psi the Styrofoam not crush?
Make sure the table wont screak so bad next time 😂
it was a little bit annoying to watch, but reading your explanation makes it less annoying. so maybe being more descriptive with your actions would help next time. thanks for doing what you do.
Shakes were cool btw
I liked them. Please do it as you did, cause this is the reason we are here!
I didn't mind it honestly :D
Buddy I think I've got bigger problems if I'm on a lake thats going supercritical
🤣
lmfao
Like instantly dissolving/oxidizing in the supercritical water!
Thats an US moment
That's probably why he's testing boats and not humans lol
"scientist shakes a bomb for 9 minutes"
Scientists write stuff down, he's more like messing around
@@Neuro_nActivation They say the difference between science and screwing around is writing down your results
@@Neuro_nActivation recording it on video is kind of a way of writing stuff down
@BelieveandrepenttoJesusChrist8feel better for writing that down?
Him holding a bomb moving it around up and down shaking it and playing with it lol
Everyone is supercritical about the shaking.
Yes, I got motion sick.
*hypercritical
Yeah. I kept thinking about how he said that that pressure makes him nervous, and then he keeps shaking it, lol.
The problem is the whole table appears to shake at a low enough intensity that everything on screen moves a LOT but there inst much affect on the actual container relative to the movement. Which is very disorientating.
@@drb0mb ._.
"I'm kinda nervous about using this much pressure" proceeds to shake the apparatus over and over. :D
do you think a gentle shaking will dislodge loads of very long bolts? lol
@@KarldorisLambley I do not. But it's amusing to see someone go from nervous to confident with the equipment. Less funny when you explain the joke.
Proceeds to heat it, which weakens the material
@@Qermaqwhat joke. him shaking it is not going to raise the pressure. he just wants to make the layers combine faster and to show the liquid surface disappearing.
@@HuyVhe heats it to raise the pressure. its part of the experiment and what the chamber is built for XD
My boss: "This report is super critical."
Me: "Ah! So much pressure!"
"This report is super critical, if you don't do your job in time, you'll sink."
ah
Here dammit, take my like. Sucker for dad jokes.
Read this comment and immediately thought of mark normand.
Good to know I'm not the only one who couldn't handle the shaking.
I just had a job interview for a company that uses supercritical CO2 as a solvent in industrial processes, I wish I had seen this video before my interview, very cool to actually *see* the phase transitions! Note that both liquid and supercritical CO2 are compressible, so those density figures are pressure and temperature dependent.
don't swim in it
Was it super-critical CO2 or just liquid CO2? It's pretty easy to have industrial quantities of liquid CO2 but a real PITA to have even relatively small amounts of super critical CO2.
If they use knowledge of supercritical phenomenon as a hiring filter, they are fucking idiots. That's about as job-specific as it gets and it's THEIR job to teach you any pertaining knowledge.
@@GilmerJohninsightful question! The company currently has commercial processes that use supercritical CO2, but the owner just got a patent for a new process that will use liquid CO2, for precisely the advantages you cite, much lower costs for pumps, pipes, and containers.
Did you get the job?
I only thing I thought during this entire video was: "STOP SHAKING THE DAMN THING!".
wow so many people apperently got distracted by that XD
he was shaking it to show the effect, otherwise youd just be watching a line slowly disappear which wouldve been far more boring, the number of people complaining about this is insane
@@SpydersByteyou really believe everything you read on the Internet... Lmfao clown
@@SpydersByte Shake it every once in a while. Not continuously. Was so irritating
@@SpydersByte"otherwise youd be watching a line disappear l" thats the fucking point of this dude. Get a grip.
That's the coolest demonstration of a supercritical fluid I've seen. Kudos
Have you seen NileBlue's video? I think that one is on the same level, maybe a little better in some places.
wouldn't you mean, hottest?
A missing observation here is that the styrofoam got absolutely crushed. While it's in there you can tell the surface that was mostly smooth at the beginning is dimpled inward significantly. But then at the end 7:51 when he's handling it, you can see that the former half sphere is now a bowl. Styrofoam is normally less than 100 g/L density, so for it to sink in a 400 g/L fluid means that it must be squished to less than a quarter of its original volume.
You could basically get the same result here with regular water and compressed air, I remember a children's science experiment where you can make a toy submarine dive and surface just by squeezing the bottle it's in... Foam gets a lot of its buoyancy from the air trapped in it, increasing the pressure around it and compressing the trapped air in it reduces it's buoyancy
The real answers are always in the comments. The videos are shaky at best.
@@user-lb9cd2dx5l Ha! Nice pun, have my like.
This needs to be done with something that isn't a foam. And then the question is easy, and just depends on how dense the object you choose is - is it more of less dense than the mass of the CO₂ you use divided by the volume of your chamber.
@@user-lb9cd2dx5l haaa
Shaky
The sound of that shaking table was painful.
So is the voice.
Cope
Super cool idea, but I need to criticise some things:
- you covered the thing with your hand at the beginning when releasing the pressure;
- stop shaking it please;
- the word you're looking for is "interface"; the meniscus is the bending or "climbing" of the liquid along the walls of the container.
Well he was shaking it to make the line visible. I guess most people don't want to see that part of transition?
Interesting thing on Google: meniscus seems to be the bending of the liquid on the surface directly. In the middle not the walls.
@@sszone-yt6vb The definition I got was simply "the liquid-gas boundary".
@@caydennormanton9682 The word comes from the Greek for "crescent" and refers to the curved part of the surface of the liquid where it meets the container, not the centre of the surface. Unless there is very little surface and it is all curved, as in a capillary tube. The OED has: "The convex or concave upper surface of a body of liquid resulting from the effects of surface tension and capillarity where the surface meets the walls of a container."
@@pattheplanter I looked into this further, and the definition you provided is the most accurate, and my simplified definition is incorrect:
"A meniscus is the curved surface of a liquid in a container, influenced by the interplay of cohesive forces within the liquid and adhesive forces between the liquid and the container. The meniscus forms at the interface where the liquid contacts the container walls. If the adhesive forces between the liquid and the container are stronger than the cohesive forces within the liquid (as with water in glass), the meniscus is concave, curving upwards at the edges. Conversely, if the cohesive forces are stronger (as with mercury in glass), the meniscus is convex, curving downwards at the edges. This phenomenon is a result of surface tension and capillarity, and it is particularly pronounced in narrow containers like capillary tubes."
@@sszone-yt6vb I could see the line just fine when it wasn't shaking.
3:14 MY GOD MAN STOP SHAKING THE THING!!!
Pi timestamp
Why? Do you think a little shake will cause it to explode or something? Or is it just annoying to see? As he points out in his pinned comment, that's the best way to see it.
@@kindlinnk, that's just annoying, you can still clearly see it wave because of the right side becoming supercritical and Moving around the whole "liquid"
@@mif4731 so? he need to make a bad experiment just because you think it is annoying?
@@KDYinRUclips It wouldn't be a bad experience if he didn't shake it.
Besides he could have shaked it way less. It's clearly visible without shaking so it wouldn't have ruined the experience and would have also be way less annoying
the shaking wouldnt be as bad if you either stabilized the footage to the tank, or mounted the camera directly on it, so we just see the liquid moving, and not the whole tank. BUT i didnt mind it that much and it was a very interesting demonstration!
That shaking and squeaking was driving me crazy.
you're not the only one there
Now call Styropyro and shoot some lasers in there
You sir, have just made the best idea ever!!!!
I...must....see ....this....
Probably should be done in a separate shielded room for safety reasons
@@Nulley0 The Action Lab and Styropyro should be in separate shielded rooms for safety reasons
literal styropyro
put a hollow black sphere inside to shine the lasers on
ARRRRRRR STOP SHAKING IT !
state of peace became supercriticical listening to those shakes
i too came to the comments to complain about the shaking. god damn that was annoying 😭
XD
Glad to know I wasn’t the only one
Every time he shook it I couldn’t help but think the sound it made was the same as my bed while doing a certain activity.
@@dasfoot ...or together...
Careful. You'll get calluses on your palms.
Please, i cant take the shaking anymore i cant do it
then go to the motion stabilized video that he linked in his pinned comment
I don't even like it when he shakes it in the motion stabelized video either. it's just annoying me as much with both x.x
I feel sick after this video
Squeak squeak shake shake.
@@ekipoghwhy ??
You promised a yellow boat but all I see is a semisphere of styrofoam.
I think it would be interesting to find a material which has lower density than supercritical CO2 but greater density than gaseous CO2. This means it should rise up to the top when it becomes supercritical.
Perhaps some hollow gas filled glass spheres. I agree that it would be fun to watch. It was lazy to use the foam as it doesn't have a well defined density. Glass spheres would have different densities and we would expect some to go to the top and others to sink. Maybe he will try getting those spheres for a future video. Among other things he could go back and forth and watch the same balls sink or rise.
yew
@@GilmerJohn Yes; glass (while brittle) is very strong. And a sphere is an inherently strong shape.
Couldn't you get that to work with this very setup, by just using more CO2? The more mass you pack into the chamber, the denser it will be.
aerogel
very practical tip, thank you
i was on a lake the other day and the pressure coming from all sides of life nearly turned it supercritical, thank goodness i calmed down a bit afterward
A rear screen of black & white stripes would have made the liquid/gas interface easier to see (due to refraction).
Excellent work with the photography to show us such a clear view of the meniscus! I for one appreciated the shaking to see the waves move and visualize the transition.
The shaking made me really uncomfortable
thank you! it was killing me
I guess I'm the only one that disagrees. I liked seeing how the surface moved when shaking. I was also watching in fast speed though.
The shaking was super annoying
@@DANGJOS it was the kreeking table.
Wow, I have never noticed 39 likes before, well, think I relate to some of you.
"Damn the earthquake, I've gotta get this filmed, edited, and uploaded by tonight!"
STOP SHAKING IT!!!
SHAKE IT MOAR!!!
@@holycow666*Mooooo r?
was about to say the same, stop shaking it !
Agree. I don't understand the compulsive shaking and it diminished the experience.
Someone had to say it. So frustrating to see it keep getting shaken.
Cool experiment! Using an incompressible boat material would be better, because styrofoam will get more dense as pressure increases, it might even sink in water at 1000 psi
Stop shaking it 😭
was worried it would go boom
Exactly this nighore is not stopping at all
Dude I’m glad I’m not the only one.
Or at least attempt to stabilise the footage a bit
ywnbaw
This really paints a great picture of what’s going on in a supercritical fluid. Thank you!
42 seconds in, I would think whether it floats or sinks depends on its density. Most objects are more dense than supercritical CO2 so they would probably sink. But something of low enough density should float.
A bot copy pasted your comment
20:56 (6) 24/05/2024
The problem is how to manufacture something that is solid, doesn't compress to much under pressure and is then less dense than 0,464 g/cm³?
Cyclopentane or CO2 is used to produce styrofoam. You'll more need a foam, that contain Helium or Hydrogen. But Hydrogen might react when you try to press it into hot liquid Polystyrene to get a foam. And the very small Hydrogen molecules and especially Helium atoms will just be squeezed out of styrofoam when it is set under pressure.
It should also depend on the ratio of air and CO₂ in the chamber. More CO₂ would mean a higher density which can more easily float a sufficiently light (relative to volume) object to the top.
@@seneca983 I honestly didn't even think about the air, but it should make a very small difference to the overall density. 99+% of that chamber should be CO2
@@DANGJOS It would've been possible to cram a lot more CO₂ into the chamber and that would've made a difference. I think he wanted the liquid surface to be about halfway in the chamber which makes sense because then it's easier to see.
This whole video was full of amazing shots. The way the meniscus of almost supercritical CO2 moves is fascinating
The question is, would you drown in supercritical oxygen? Accounting you survived the rest of the inhuman conditions lol. I think it's time for a bigger pressure chamber...
My guess is the opposite - you’d die from oxygen toxicity. Oxygen becomes toxic when its partial pressure is greater than 1.4 atmospheres
No, you'd die from the toxicity.
oxygen becomes toxic under high pressure
@@brooksbryant2478 You would die regardless of the pressure as it would be too much oxygen for you.
There's actually a good chance you'd catch on fire. High pressure oxygen is extremely unfriendly to organic compounds.
I believe there is an important factor that was ignored in the discussion of the experiment. Styrofoam will compress under pressure and thus become more dense which while it still floats will cause it to sink lower into the fluid. For the most part it it should remain compressed when returning to normal atmospheric pressure (some of the air having been squeezed out of it under pressure). By comparing it's volume before and after the experiment you should be able to explain the amount it sank just before the fluid went supercritical. You could probably ignore the weight of the volume of air squeezed out.
Apparently (I'm no expert, mind you) one of the properties of a supercritical fluid is it's ability to diffuse into/through other substances (like a gas). So my conclusion was that the Styrofoam becomes impregnated with the supercritical CO2, and is thus more dense than the surrounding CO2 (Styrofoam density + supercritical CO2 density = more dense than supercritical CO2).
Actually there is more going on here than just density changes. The styrofoam acts like a nucleation point and the opposite side of the chamber as a diffusion point. So particles are diffusing out everywhere but converging near the styrofoam pushing it against the wall kinda like convection
@@caydennormanton9682 The supercritical fluid behaves like a fluid and gas - it doesn't diffuse better than in it's gaseous state (except for any added diffusion due to extreme pressure). In rewatching the video he starts with a shot of the vessel with the dry ice packed in and then jumps to a view at 200 psi which already is 13-14 atmospheres so the shrinking - sinking is already well underway (in fact he says "the Styrofoam is very squished ...") and the bulk of it may already have happened. Had he left the ball intact instead of ripping it in half I may have been able to compare diameters at various pressures to see if the additional shrinkage was measurable.
Action lab is always in action
I don't mind shaking, It was indeed interesting to watch how waves become almost indistinguishable. And around 3:59 waves going all around the "boat", even on top of it. Liquid seems to be still under it, but waves look cloudy.
Yeah i think the shaking made it easier to see where the line between liquid and gas was when it started getting hard to tell
Seemed excessive to me.. once pr twice, fine. Also the shaking was too strong as well.
Makes sense. things float in something because they have lower density than the surrounding medium. When something goes supercritical, the gas density increases, and the liquid density decreases. When their densities are the same, you are at the supercritical stage. This means that your boat was floating on something whose density was going down. As a consequence, its buoyancy was going down as well.
states of matter have always been super fascinating to me
Even after taking thermodynamics I never really "got" a supercritical fluid. My brain was just too rooted in "solid, liquid, gas". This really helped me visualize the concept!
It's like a liquid and a gas in one.
It's a liqass
@@Flesh_Wizard -- Well, it's more like a liquid than a gas because it displayed great viscosity. In the "experiment" we say, the density of the super-critical fluid was about half that of the liquid part at a lower temperature.
It's a really dense gas
Like how the earth's core is solid due to the immense pressure
There is active research work in determining if a supercritical state is "gas-like" or "liquid-like", so both answers are valid!
@@longemen3000 -- Well, I vote for ... LIQUID.
Very cool! I always enjoy your videos but this one is extra interesting. I am a refrigeration guy. There are companies building transcritical CO2 refrigeration systems. They use a very high-pressure compressor to compress CO2 vapor above the critical point. There are then valves and separators to reduce the pressure in a controlled manner to get liquid and gaseous CO2 from the supercritical fluid. This is separated so that the liquid can be used in a refrigeration cycle. I had always wondered what that would look like. Now I know thanks to your very interesting experiment!
That was the best demo of something supercritical I've ever seen. Seeing how the foam moves through it demonstrates its viscosity between the liquid and the gas. It's also a very practical demo for when the lake goes supercritical, which I've never known how to handle in the past :)
Im just a machinist, not a science guy by any stretch. Please check the pressure rating for those brass fittings. I have no idea what they are rated for but 1000 psi has to be pushing your luck. You can get the same fittings and valve in stainless steel for higher pressure. Neat video.
Where is the yellow toy boat from the thumbnail?
sadly he photoshops the thumbnail putting in a fake situation
Gone. Reduced to atoms.
at 4:47 the foam reminded me of a lil tardigrade. Go Lil foamy tardigrade dude.
6:24 whoa, now I'm seeing a man shaking a small white brain in a low gravity capsule.
Excellent demo! When I saw the canoe at the end, the first thing I thought of was Lake Nyos in Cameroon, but there the CO₂ was held in supersaturation at the bottom until that fateful morning in 1986.
The shaking pissed me off an unhealthy amount
Wow, fascinating video, thank you. As a process engineer, I used to have to design plant handling supercritical fluids - great to finally see what was going on in those vessels.
I like that your styrofoam boat accidentally looks like a brain.
When I first saw it in the video, I didn't know it was just randomly cut, I thought it was intentionally shaped to look like a brain.
I love how you push very far our curiosity!
How this guy do not run out of good video ideas? Amazing!
Truly is!
Forget the shaking, handling dry ice with bare hands was just 😬😬😬
The shaking was unnecessary and really annoying, we could see the meniscus just fine if you wanted waves put it on a gently moving platform next time.
you can always do the experiment yourse- never mind that could go wrong
This is like the best science demo i have ever seen. Didn’t know there was a state called super critical
Let’s get you to 5M subscribers!🌟
Im an actual chemical engineer and that video just made me see all I read in thermodynamics class... this video is a must for all classes.. idk if this is textbook somewhere, but the syrofoam helped me understand supercritical fluid... I wish I've seen stgh like that back when I was struggling the course for the second time 😂
please a video about superfluid like helium
Won't be (easily) obtainable... temperature is 5 Kelvin or -268 Celcius (-450.67 Fahrenheit) compared to the 31C of CO2
Great question, great experiment, great result. Now we know.
That vessel body is way over-engineered for 1,000psi, no worries there.
The ultimate failure is in the bolts. And jamming them in with a 6" ratchet (and then a hand drill) without measuring torque was the riskiest thing you did here.
Bolts, especially of that diameter to length ratio are VERY susceptible to the tensile forces induced by torque.
I'm guessing those are 5/16-18 x 6" or M8-1.25 x 150mm and they appear to be 307A Stainless.
- 8 x 307A 5/16 Bolts give about 24,000 Lbf to yield
- 2 1/2" bore (?) @ 1,070psi(critical) is ~5,250 Lbf x2 (because, through bolt design is holding both sides) = 11,000 Lbf
- A 2.18 Safety factor seems low given the severity of a catastrophic failure. ie: if it were left on the dash of your car in August... you're gonna have a bad day.
I've seen this same design used by other 'tubers and I always cringe. If you were to thread 8 shorter bolts (per side) directly into the body, you'll double the weakest link.
A 4.36 SF would let me sleep at night, I might even bump them to 3/8 (M10) and go on vacation.
Also, the boat is NOT floating on the meniscus. It's floating on the "surface".
The meniscus forms above (or below for dense liquids like Mercury) where the liquid is bounded by the container.
Maybe a good future episode, "In Search of the Neutral Meniscus". Is there a liquid that lays "flat" in a given container. Easy to demonstrate positive and negative meniscus traits but can you find (develop) a neutral meniscus fluid ? NileRed tie in ? A little "surface" tension ?
Also, do gases exhibit a meniscus (hint: yes they do).
This has to be one of the coolest videos you have made!
Ths video culd be so dam satisfying, but no we gotta shake the god dam table, it annojd the hell out of me
The boat can float but my overweight self would be drowning fast in acid.
It's been years since I've been this fascinated by a video. Thank you sir 🙏
Very practical advice. Thanks!
The reverting back to liquid from supercritical almost looks,
Magical.
Really feels weird saying this as a Science guy
Who else is annoyed that he keeps shaking the table?
100%. I keep screaming "stop shaking the f-ing table"
The only video that illustrated the behaviour of a supercritical fluid for me.
STOP SHAKING THE DAMN THING!
I minored in physics, but this is the coolest demo I've seen regarding state transitions. Awesome video!
0:09 wtf is that thing the glass is on?
Brutha eww
Magic puddy
I've seen some great science on RUclips, but this one is the most interesting and well done demos I've seen!👍
The jiggling made me nauseous.
I've watched dozens and dozens of these videos and this is definitely top 2 of all time
Holy shit stop shaking it
I have a 1930s GE Monitor Top fridge in my kitchen. To meter the flow of liquid refrigerant into the evaporator it uses a float, that floats on top of the liquid sulfur dioxide refrigerant, and opens a valve depending on how much refrigerant is in the float chamber. This reminds me of that. Because the float cannot float on a gas, it doesn't float unless the compressor has built up a certain amount of liquid refrigerant. I always thought that was an incredibly clever system.
i dont like that shaking noise
this is for sure one of the cooler videos on this channel
This is the most interesting video about supercritical fluid I've ever seen, thank you a lot!
dude you are amazing . I love your scientific channel. I always wanted to see a critical fluid and you did it . keep it going 😍
That tip is invaluable, some would say super critical. It’ll save many from getting sucked out the hole
Shaking it a couple times made sense but he was just stimming with the setup the whole video. 😭
Very cool demonstration/experiment. Seeing a liquid turn supercritical is something I’ve never seen before.
Guess: Only a lighter-than-fluid boat can remain afloat in a superfluid. Because it does not rely on displacement for bouyancy.
All Boats which are denser than the fluid will inevitably sink.
You keep shaking the experiment, I really enjoyed seeing the little waves
Thermodynamics has such amazing phenomena. Things like this really feel like magic. Just like how dry ice doesnt melt but sublimates, on which I graduated my masters
Definitely one of the neatest videos I’ve ever seen on your channel A++
This is one of the coolest experiments I've seen in a long time!
Your channel has taught me so much over the years! Thank you 😊
I’ve always had this question in mind about supercritical fluids and suggested RUclipsrs to do it by leaving so many comments, finally someone did it 😭
Woooooaaa huge thanks to action lab. This finally inspires me to make my own freeze drying riggg. On the DL... the coolest part is the density vs buoyancy as miniscus sublimates (idk what that word means - sounds sort of right and cool).
Anyway next just gotta do the upside down boat floating in a similar 2d planar view vessel (like ant container?). To show that in same container a boat can float right side up and upside down in the same exact fluid if a pressure bubble pushes one area of water to top of vessel and one to bottom. I believe it is surface tension of the water that creates a suction force to hold the boat. So would depend on the friction or Reynolds number of sorts of the boat hull vs the water pressure bubbles into the "sky".
Some scenes would have looked so cool with the music but you had to shake it aaaaaaaaaaaa
Thank you for such an amazing demonstration. The practical tip was legendary.
*@The Action Lab*
8:30 The liquid has a higher density & the gas have a lower density.
This means that there exists SOME combination of gas/liquid CO2 combination that when super-critical becomes the PERFECT density to keep that Styrofoam floating in mid"air" (midCO2?).
Judging by how slowly the "styro" fell in the super-critical fluid, I guess you need more liquid CO2, probably somewhere about 2/3 of that volume to be liquid? Maybe like 650 g/L density?
That was way cool seeing it go to different states! Also loved the retro at the end!
This was really cool, the shape of the styrofoam reminded me of a tardigrade too 😂
😆🤣 i enjoyed too much of that deadpan delivery of practical tip for boating in supercritical fluids, thanks! 😂👍
Ignoring the danger factor, this would make one awesome coffee table conversation starter.
Wow! It really stimulated and then satisfied my curiosity. Thank you for sharing this amazing experiment! 👍
I think one of the coolest parts of this experiment is being able to see the convection.