Why Water Boils In Tall Cups
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- čas přidán 4. 12. 2021
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I show you how high you can lift water up in a tube with one end open to the atmosphere. Here is the video I made with the long straw • Trying To Drink From T...
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Wow, As a firefighter I have known about this problem for 25 years (can't pump if the pump is more than 30 feet above the water), but this is the first time I've actually seen what's going on inside the pipes.
25 years damn
You're a G my man
This is the coolest reply I've seen here. First of all thank you for doing what you do goddamn. And second it's wild to read about that real world problem connected to the phenomenon in this video. I wonder then if you could increase pressure in the truck, or lift it up somehow. Probably not, but it's an interesting problem!
@@michh8901 Since this is a problem with air pressure and vacuum, there is nothing you can do in the truck, however some of our trucks have a second pump you can carry where the truck won't drive.
Worst case there is also a system with three hoses where you actually pump high pressure water down one hose to get twice the amount of low pressure water back.
The whole thing about having to pump water at several levels in the Empire State Bldg. makes sense also.
Been watching this channel since its beginning and been watching the shorts too. Started as a student and now im a Ph.D student. Every video and short that comes out I am amazed at the consistent quality of this channel. Most science channels I've watched seem to run out of ideas quick but I'm glad the action lab still remains to be entertaining and informative
Wow from a student to a ph.d student really amazing
Hopefully me too in a couple years!
I mean, he's often doing what other channels have already done, including in this video.
THIS SHOULD HAVE BEEN EXPLAINED. but hey what do i know? my job it to shut down dumbass comments from nickle back. BTW mom though that was what you get back at pennys
Go ask some people on the street about the boiling temperature of water. Some might say 212°F or even better 100°C-but that's not always true. As you increase your altitude above sea level, the boiling point of water decreases by about 1°F for every 500 feet increase. That means your water in Denver is going to be 203°F and this will have an impact on your cooking.
But why?
Water Vapor Pressure
There are many awesome things about water-one interesting "factoid" is that on the surface of the Earth you can find water in all three phases: solid (we call this ice), liquid water, and as a gas. We call the gas phase of water "water vapor."
You might think that you need to boil liquid water to create water vapor-but you don't. You just need some liquid water at room temperature (or any temperature). Picture a glass of water. If you could zoom in with super vision (not actually possible), you would see that this water is made of a bunch of molecules-water molecules. Although these molecules are themselves made of three atoms (two hydrogens and one oxygen), let's just think of them as tiny balls.
These tiny water balls are moving around in the water but stay fairly close to their ball neighbors. This motion isn't due to currents in the water, instead this is thermal motion. Imagine these tiny balls jiggling around in a giant collection of balls. The hotter the water, the greater the motion of these water balls. But wait! The speeds of the water particles aren't all the same. Although there is an average ball speed, some are going faster and some are going slower. It's just like the height of a group of adult humans. There is an average height, but everyone is not the same. Some people are VERY tall, but that's just a small fraction of the total group.
If you have a glass of water sitting out on a table, the water balls don't just stay as a liquid. Some of these balls have enough thermal energy to break away and become free. Free from the liquid stage means the water ball is now a gas-water vapor. Boiling is not needed to get this water vapor. But wait! It works the other way too. Some of the water balls in the gas stage can interact with the liquid water and join the liquid water balls.
Water in a closed container (like a water bottle) will eventually reach an equilibrium state between water vapor and liquid water. At this equilibrium state the rate that water balls are freed from the liquid state are the same as the rate of water balls entering the liquid state. The pressure of this water gas in equilibrium is called the vapor pressure (assuming it's all water gas and no air in the container).
@@unvergebeneid yes, but you can say that for nearly every other channel.
Worth mentioning that this is how we measure the atmospheric pressure. Only to make the setup more compact we use mercury instead of water as it's much denser and can create same weight in a smaller column.
Correct, he has built a WATER BAROMETER.
The water is NOT BOILING, but rather sea level AIR PRESSURE can only support a HYDROSTATIC COLUMN that is 10.33 meters tall.
Above that height only a zero-pressure vacuum can exist.
which is also why the imperial unit for pressure is mm Hg. Hg is the chemical symbol for mercury
Thats makes a lot more sense now thanks @dsdy1205 !
@@mrhypobaric2532 water lifted above that point BOILS, yes.
@@mrhypobaric2532 Water boils due to low pressure. It is not only because of temperature, if the water goes from liquid to gas, it boils.
He explained and performed a phenomenon very hard to perform in such a simplified way. Loved it
What's so hard about this exactly? This is literally how mercury barometers work.
Did they not teach science with examples in your school?
This is something that trees have to deal with, as not only do they grow taller than this level, they also have use for techniques to dispose of air bubbles that have formed in areas that the tree would normally _succeed_ at passing water through.
Trees exploit the diamagmetic properties of water. So no boiling.
Holy shit how does that work please tell us I am looking at a tree right now seriously I swear on my life I am sitting in the van and I happen to look over to kind of think about what I was going to ask you and I saw a tree and I'm like how in the hell please explain to us that is very interesting I am intrigued thank you please oblige us 💓
@@WiKiTWoNKa you okay bro?
@@N____er lmao they're just curious
Not completely true. Using extremely thin tube eliminates the phenomena. Go for capillary effect to understand trees.
There’s a lot of cool stuff going on here that depends heavily on the geometry of the setup. When I did this I had a waterbottle at the top thinking it would look cool on camera, but it actually slowed the boiling process significantly because the large volume of liquid water that was displaced by a tiny bit of boiling was forced through a pretty narrow tube - the water level in my bucket at the bottom actually went up. After I filmed my experiment I saw that Practical Engineering also made a water barometer by filling a large diameter pipe, closing a valve at the top, and opening a valve at the bottom. His water level stabilized below the actual theoretical boiling height I think because there was so much water flowing at once, its inertia falling down the pipe actually caused it to sink too low and overboil, resulting in too much trapped gas. It looks like you saw a bit of both of these effects while moving the clamp up and down which is really interesting because you didn’t have a diameter change like I did but the inertia apparently still matters.
After watching Grady’s vid with the PVC pipe, I spent a week trying to get a leak-free 30’ length of pvc vertical and filled with water so that the flow resistance would be low but I never made it work. The insta-boil has proved elusive! I love the fold-and-clamp method you used though - it’s so beautifully simple and therefore an EXCELENT way to make the experiment more accessible - my “how to” needed way too much glue and made way too many leaks…
Hey its you
@@hamondorf9355 oh hey Hamondorf, how's it going?
Writing an essay on yt? Lmfao
@@axylotl1878 I'd rather see this interesting comment rather than bots or someone being toxic af
@@axylotl1878 are you new to these types of videos?
Neat. If anyone tries this experiment, remember to de-gas the water before starting. Boil the water to remove dissolved air, then use immediately or store without contact with air (a layer of oil can help). This will help you keep a better vacuum at the top and give more consistent results.
Record your starting point above sea level.
Just curious, what would happen if we didn't and used straight tap water?
@leethebruce1605 When water is mixed with other solutes, it can rasie or decrease the boiling point as i believe the boiling point then jsut becomes an average of the substances in the solution. Well i don't know if its related to that, but its just something of what i know
Well, that's good for a baseline, but the curious might want to vary the experiment to see what happens. You can try distilled water, but you can also try tap water, salt water, dirty/stagnant water, dyed water (to see any effect on the dye as you get closer to the top), just lots of ways you can do this.
Maybe use milk or juice, or even put a big helping of cooking oil into the top end of the tube before you seal it off and bring it upward. That oil has a boiling point, too, and it's different from that of water!
@@KazmirRunik I REALLY want to see someone boil cooking oil like this. Crazy long tube!
I learned all of this early on in high school from my physics teacher. This particular idea wasn't even part of the curriculum at that time yet, but he was so passionate about physics, he often went off on tangents to explain us random ideas. Great teacher, he's one of the reason why I like physics so much, and probably the only class where is wasn't bored to death.
Still, great video explaining this phenomenon!
Well you were so lucky I love physics and maths but the teachers just drain you out of curiosity
I had a great physics teacher in high school, too. Mr. Bradford. 💜
Seriously? Not part of curriculum? I thought it was basic knowledge. I think I was twelve when I learned that in school.
I find it super interesting that the water boils at just over 33’ above the surface of the bucket. It makes perfect sense though. At the surface of the water in the bucket the pressure is 1ATA (atmospheres absolute). If you were diving down into a body of water the pressure increases by 1 atmosphere every 33’ that you descend. It makes sense that by raising the tube by 33’ would basically negate any atmospheric pressure present on that water at the very end of the tube causing it to vaporize. Very cool experiment. 👍
yup, also how clouds exist ^_^
This comment helps me understand why a bit better.
a bit late but now this comment has 33 likes, how fitting
@@oliversmith1981I know! I was confused as hell haha
Yeah the weight of a 1 square inch column of water 33 feet high is 14.7 pounds the same as typical atmospheric pressure of 14.7 psi.
you did the similar video, the longest straw to explain the boiling phenomena really helped me in my exams to understand the concept of vapor pressure should be equal to surrounding pressure in order to boil, thankyou james sir
wasn't the same actually..a lil bit different
They're different
@@mrDUBtaker similar enough he should have mentioned it earlier, if only to avoid this
@@chrstfer2452 If you had watched the whole video you would've seen that he did mention it
@@Void_Serenade he said similar
This was really cool to watch! Just took a test in fluid dynamics over hydrostatics and it’s awesome to see it pushed to the extreme
I've known since I was a kid that you can't siphon water above 32 feet, but until today, I never knew why.
I learned this in my fluid mechanics chapter but didn't quite understand it well. Thanks now the concept is crystal clear to me
Also for those wondering 33.8 feet is 10.3 meter coz in the chapter it was in meters
Ah! I was a little confused as to what was causing the pressure until the end. I mean my intuition (from doing this in the bathtub as a kid with a cup lol) told me it was the weight of the water pulling down that caused it but it wasn't really explained until the end. Thank you for this!
Makes sense since every ten meters you get one atmosphere of pressure.
@@ubershmekel what does not makes any sense is people still using imperial units
Why 10,3 meters and not 9,8?
@@user-od4yl3rf4n because it comes from p=ρgh, therefore h=p/ρg, which is about 10,3 m
Nice demonstration! This was discovered by Torricelli in the 17th century, Galileo's secretary, after Galileo was called for help by engineers wondering why the pumps used in fountains could not draw water higher up than around 10 meters. This gave rise to the invention of the barometer.
Hands down your channel is the best science channel in YT. Always entertaining and sometimes creative. You are my hero.
This is great video and interesting experiment. I hadn’t thought of the boiling thing. But I think you should clearly mention that the 33 feet limit is due to the fact that much height of water has a weight which is equal to the atmospheric pressure and hence atmospheric pressure cannot push it further.
Oh Americans. It is 10 meters. The boiling point is based on the metric system.
That experiment of course will indicate atmospheric pressure at varying altitudes, the higher your altitude, the less that distance becomes.
I loved the practical demonstration, it worked well.
Kind regards,
South Africa
Yep, he just made a water based barometer. That's why they use to use heavier mercury. So instead of 33.8ft, it only needed to be 760mm (~30 inches) tall.
Whoa so wait, YOU'RE South Africa!? I've heard so much about you... I LOVE your accent!
Jeez
This is how we made our water barometers when we were kids. These included a steel can with a nipple so we could adjust a partial vacuum and have about 6 ft water column on the wall. Otherwise, you have to have a column long enough to balance air pressure of ca. 15 lbs per square inch. That works out to about 32 foot column.
it would be interesting to leave it like this for a while and see if the level rises and falls with outside air pressure, and also to see what the temperature is inside the tube at different levels. The base would have been cool to observe also.
Also a bigger tube
I would think it would change with the outside air temperature.
Boiling requires energy, which is taken from the water and its surroundings, so the water will be colder as it boils.
I technically knew why this happens, but for me the interesting part was that this is what happens atmospheric pressure is no longer enough to push the water up. I knew it couldn't go higher, I just never thought about what would have to exist above in a situation like this.
Since he didn't say where the magical 33.8 ft came from I figured it could be nice to come up with it. When the water hasn't boiled yet we know that at the surface level the pressure is equal to the atmospheric pressure. But the pressure inside the tube is "only due to" the weight of the column of water. So the force at the surface is equal to the mass of the water inside the tube times the acceleration of gravity
F = mg
If the total volume of water if V in its density is rho, then we get
F = rho V g
If the cross sectional area of the tube is A and its height is h, then we get
F = rho A h g
F/A = p = rho g h
And we get the pressure dividing the force of the water column by the cross sectional area.
Therefore, the pressure at an elevation h above the surface is equal to the atmospheric pressure minus the pressure due to the column of water that has been risen
p(y) = p_atm - rho g y
When the water hasn't boiled yet we can calculate the pressure like this. But the pressure can't drop indefinitely, it certainly can't drop below 0, but it certainly won't hit 0. Just like water boils at different temperatures if you change the pressure (for example it boils at lower temperatures than at sea level in higher altitudes), if you keep the temperature steady and drop the pressure it will also boil, the two actions are equivalent. That means that just as there are a boiling temperature at a given pressure, there is a "boiling" (saturation) pressure at a given temperature.
You can read these pressures in a saturation table, but at 20 C (68 F) the saturation pressure of water is 2.31kPa (0.33 psi). Then we say
p( max_height ) = p_sat( 20 C )
p_atm - rho g max_height = p_sat( 20 C )
max_height = ( p_atm - p_sat ) / ( rho g )
max_height = 10.1 m = 33.13 ft
Thanks for the supporting info...and double thanks from the 95% of the population that uses metric
@@amalieemmynoether992 you always use metric for science in america
He could've got 33.8ft cauz he used a small tube and there could've been capillary effect supporting the water up
@@basidhsajan2398 Yeah, and I estimated the temperature, so that could change the results as well
@@e4Bc4Qf3Qf7 then why do I constantly see science shows/YT vids that still state units in imperial measures often with no conversion to metric?
You can demonstrate the concept that the boiling point of water can change with pressure and can be brought down to room temperature if the pressure is low enough by using a clear syringe. You fill it halfway with water, plug the end and pull on the plunger and the water boils.
The problem with that is that some people are so closed-minded to anything that conflicts with their understanding of the world that they will say that the bubbles are just air leaking into the syringe. You can hold the syringe horizontally to show them that the bubbles isn't air leaking in through either end. You can show them that when you release the tension on the plunger the gas inside the syringe all condenses back into liquid, proving that it is truly a closed system and that no air had leaked inside. But they will still deny it because they can't accept that the world works in ways that are counterintuitive to them sometimes.
I've found this to be even worse if you try to explain the Monty Hall problem. It's great when you blow someone's mind with counterintuitive stuff like this. But it is hella painful when they are too closed-minded to let it happen.
Yes, as you can see, I am fun at parties.
i'd hang out with you at a party!
Thunderf00t did an experiment where he showed pressure changing the temperature of an area. This was interesting as well.
I have one complaint about the Monty Hall problem the way is was told to me though.
I was NOT told the crucial point that Monty KNOWS which door holds the prize and is NOT ALLOWED to open it. I thought the he just had to pick a random door just like me.
Once you know that constraint, it becomes a lot more obvious. Too many people leave out that critical detail.
Hella? Please don't.
@@lakse123 Yes, knowing what’s the sample and what’s the sample space is absolutely crucial. It still tends to confuse people, though.
Very cool video! As the head pressure of the water column approaches the boiling pressure of water at air temperature, the air pushing down on the water surface of the bucket can't support the column of water. The liquid level will always fall back to this equilibrium point
Metric system???
Who else remembers when this channel was small and he just crushed stuff in his garage with a press?
Good times huh? Man how time flies
Holy I didn't even realize he has almost *four million subs* now when did that happen?? I still thought of them as a smallish CZcamsr
@@WulanDari-uv8bg Hey guys look, it’s a bot! The future of CZcams!
Doesn’t this look so great?
@@naga_serpentis actually.. terrible..
@@naga_serpentis I'd love seeing a future full of bots talking nonsense and promoting their crap!
One project I've always wanted this channel to do is to use a Projector on a Glow in the Dark Wall, and see if the glow in the dark wall stores the projector image
Ripleys believe or not has that I thinnk
I did a shadow freezer thing
Interesting idea. It would be similar to a black in white film soundless film
yes. well, The King Of Random channel did it by pushing a smartphone with a bright image to a glow in the dark wall and the image could be seen afterwards
Only parts of the image would be stored; namely the parts which contain blue light. Neither red or green light are energetic enough to excite the common green phosphor.
I have some paper treated with the stuff and I can write on it with my 405nm violet laser and cast long lasting shadows with a blacklight, but neither my 660nm red nor my 532nm green lasers affect it at all despite being quite a bit more powerful.
You can get phosphorescent spray paint at any hardware store. You should pick up a can and try it yourself. If you search for strontium aluminate glow powder on line it's supposed to be way better than the older zinc sulfide stuff that's in everything. Way brighter and glows for hours. Anyways have fun.
It’s nice how his experiments are easily understandable but the approach is interesting. Like I won’t be surprised if one of his little experiments is a gateway to a new type of technological advancement from basic physics.
We can quite easily calculate which pressure must be in the tube so that the water boils. I study chemistry and we just had thermodynamics this semester !
I'll give you the answer directly: Only 2.78% of atmospheric pressure at surface level (2823 Pa, or 0.41 psi)
Here's the calculation: We can use the integrated form of the Clausius-Clapeyron equation to calculate the partial pressure (= pressure in the tube). All we need is the normal boiling point T0 (in Kelvin, 373.15 K), atmospheric pressure in Pascal p0 (101300 Pa), the temperature of the water in the video T (I suppose 20°C, so 293.15 K), the ideal gas constant R (8.314 J/K mol) and the enthalpy of evaporation of water per mol Delta vap Hm (Lit. value 40700 J/mol).
The equation, rearranged for the partial pressure of water is: p = p0 * exp { [delta vap Hm / R] * [(1 / T0) - (1 / T)]} = 2823 Pa.
Btw, according to the barometric height formula, this is the atmospheric pressure at a height of 301.3 km above surface, though I am not so sure if this formula is that exact for such great heights.
Wow, that is incredibly easy to understand and visualize. I was taught all that in school but never REALLY understood it and now I do and it's actually really simple and intuitive! Thanks!
schools never do good at explaining things. the reason why a lot of us fail at calculus
@@arlynnecumberbatch1056 Teachers play a big role in that, and the fact that they are underpaid makes it really hard to find one that actually cares to teach people. (plus some of them have psychological problems and should not be allowed to work as teachers, yet they do)
now i know why my watercooler sez "glub glub"
@@MindFlayeR57 wow, no wonder why a lot of kids today hate teachers
You don't have to suck-start a syphon if the tube is long enough. Just submerge most of the tube under the surface of the liquid, plug the open end with your thumb then pull out enough of the tube so that the liquid in the tube falls below the level of liquid in the container. Very useful trick for non-potable liquids.
Thank you for making this video. This is so cool.
I'd like a longer version with more details on how the vacuum affects the water temperature and what's the mathematics behind it. How does the tube width affect it? How does the water surface area and volume affect it?
width doesn’t matter probably.
You double the pressure at 10m depth regardless of how big your body of water is at sea level. Thus going 10m up decreases pressure from +1 bar to -1 bar. So from sea level 0 at 10m water depth above sea level. Just as how you get 2 bar at 10m below sealevel
Temp yes,
Width /volume no effect...
At sea level you can do this with Hg (Mercury) up to 29.92 inches. Mercury is also better because it doesn't vaporize nearly as much as water and you have a nearly full vacuum at the top of the flask.
This is where altimeter settings come from on airplanes. When the altimeter setting is 29.92 this means that the air pressure at your location corrected for your elevation or altitude is normal. If your altimeter setting is higher (say 30.00), then you're in a high pressure area. Conversely, if your altimeter setting is below 29.92, you're in a low pressure area.
An altimeter would then compare the current air pressure and the set altimeter setting (which is what the air pressure would be at sea level in inches of mercury for your location) to derive your altitude above mean sea level.
I've always wondered how altimeters compensated for pressure before computers, thanks for explaining!
@@Ruiluth Even a computer needs some sort of input. Your transponder Mode C broadcasts your pressure altitude (using an altimeter setting 29.92) and their radar screens compensate with the local altimeter setting to display your altitude (assuming you're below FL 180 in the USA).
The only other real way to derive altitude is via GPS assuming a minimum of 4 satellites are in view. Either way, a glass cockpit or other computer system would still need altitude information from a measurement device.
As an aid to understanding what is happening, there isn't any water doing any pulling (5:20) (that would be a capillary effect, which might be important in a thinner tube, but it is not the point of this experiment). Rather the water at the top of the tube is pushing down (because it is being pulled by gravity in the Newtonian sense) on the water below it, which in turn is pushing down on the water below it. At some point the weight of the water pushing down is equal to the force of the weight of the air trying to push its way up into the tube. If you lift the tube higher the water outweighs the counterforce of the air and the water column drop until the two opposing forces are equal. Basically, you have a shorter column of denser water in equilibrium with a much longer column of air (the Earth's atmosphere). (And you can't suck water either (4:55) , again it gets pushed up by the force at the other end. This is kind of like cold vs. heat. Cold is not a thing; its just the absence of hear. Suction is not a force, it is just the absence of an opposition to a force.) Sorry if I am getting into technicalities (and someone else can probably give a better explanation than I just did), but the point of these videos is to explain how things work and I hope that this comment helped a little.
You don't get much "capillary effect" in a tube of that diameter. The hydrogen-bonding responsible for the capillary effect is the same thing that causes the meniscus, but it's immensely dependent on the narrowness of the tube.
@@TROOPERfarcry it says water is boiling, does it mean that it's temperature was around 100°C on that level in the tube ?
@@xs1190 i was also thinking that, adding on to our question:
is it boiling or is it just air (and formed air bubbles) and water mixture moving around due to pressure differences?
@@xs1190 nope, water can boil at lower temperatures if the pressure around is less, by boiling it means that the water starts to evaporate very quickly with
( bubbles forming), the termperature of water in the tube is same as the water in the bucket
@@SSSPrince both, cuz due to the vaccum the trapped air get driven out of it and also cuz of the vacuum the water starts to boil due to the lower pressure
This in an important concept with pumps.
I had a pump recently that we had to shutdown because even though the water was under pressure feeding the pump ~140kpa the water was at over 100 degrees C.
As soon as the pump was run the impeller lowered the pressure on the suction boiling the water. As it passed the impeller it was pressurized above its boiling point causing it to condense, a case of extreme cavitation.
This was caused by a process change in the plant process where the cooler stream to the pump was isolated.
Cool video 👍😎👍
Big brother you are crazy , so are we your viewers ,so glad to see someone satisfy our questions and introduce us to the world of science , please stay crazy like this always 😄🙏🙏
What is the elevation above sea level in the city you’re in?
Could be that this experiment subtly changes depending on location as the atmospheric pressure would be lower when your starting elevation is higher
Yh, but that would make such a small a difference that it wouldnt even matter
Air pressure working on the diameter of the water column will support a certain weight. A column of fresh water 33 feet tall exerts 1 atmosphere of pressure at the bottom. A column of sea water 30 feet tall does the same thing.
A column of mercury (yucky stuff) does the same trick in about 30 inches.
Air pressure is supporting the fluid, so you can only support the cross section of the pipe times 14.7 pounds of fluid if the pipe is cylindrical.
Why does the shape matter? It doesn't matter to the pressure gradient or the height, but it makes a difference in how many pounds of water will be supported. Tricky, here - a pipe that flared from one square inch at the bottom to 100 square inches at the top would still rise to 33 feet of fresh water even though the weight of the water would exceed the pressure of air at the bottom.
Physics isn't broken, though. The slope of the walls of a flaring tube support the excess weight. Think of the slope of the walls pressing against the water in two vectors, one horizontal, and one vertical.
When the walls are cylindrical, the walls don't have any vertical influence. As a flare is added to the walls, they start to support more and more of the weight of the water.
The fluid/gas boundary is not necessarily from the water, btw. Starting just above the bottom of the column there is less than 1 atmosphere of pressure. If the water had dissolved gases in it, they would be released before the water would start boiling.
The height you see is also dependent on gravity since that drives air pressure. Results will vary on other planets.
Why the does people do this for example Wulan Dari just stop it
@@johnnyragadoo2414 Mercury isn't "yucky." When we were kids, we used to play with it whenever a thermometer broke!
@@maindepth8830 The difference is not all that subtle. The weather report for today says my local pressure is 29.97 inches (of mercury). At just 1,000 feet higher in a little Cessna, it would be about 28.97 inches. At low altitudes, there is about one inch of mercury pressure lapse per thousand feet.
The 33 foot column is basically a water barometer, reflecting air pressure at the bottom of the column of water.
I’ve never actually thought that much about it before Thank you for the awesome demo and explanation
An excellent video as usual 👍🏻
In a "cup" that narrow in relationship to its height, capillary force becomes a significant factor adding to the max height you can achieve, depending on the material of the vessel wall.
Love ❤️ your thinking process!
What an impressive channel you’ve managed to make here. I never even had any idea this could be a thing, much less had I ever given any thought to how you could test it. You’ve accomplished something really amazing here.
Thanks action lab once again for making me smarter today
Great experiment! Shows why those of us living rural need a submersible pump to pump water up and out of the well instead of pumping from the top (unless you have a sandpoint well).
Thats because water pumps are terrible at pumping air so everyting must be filled with water
Would love to see this with a wider tube like the video's picture. This is so awesome.
Thank you for your very interesting videos that have taught me a lot. A comment about this program: The all thing is about pressure balance between the water surface free to the atmosphere and the pressure from the water inside the hose. The atmospheric pressure is almost 1 bar, that is equivalent to ca 10 meter of water in the vertical hose. It means that when the hose reaches about 10 meters above free water surface, the water stops to follow the hose upwards. Of course some of the water evaporates when in the vacuum that comes up at the top.
Please note that the gas at the top also includes small amounts of gases previously dissolved in the water
The volume at the top was sometimes referred to as a vacuum. But just to be clear, it’s full of mostly gaseous water (steam), right?
@@Kevin-S yea, it would be great to somehow get a pressure reading in that space at the top of the tube which has displaced the water.
@@Kevin-S
Right: let's assume there was an actual vacuum. Then random molecules at the vacuum-water interface would achieve enough kinetic energy to free themselves into the vacuum. This process would keep going until an equilibrium was reached.
Something that would also be interesting is to attach a vacuum gauge to the top of the tube to measure how much it is at differing heights. The other question is where does the boiling begin in tube vs the level of water?
water boils at 100C or 212F at sea level. and it boils at lower temps at higher elevations because the atmospheric pressure is lower there. and the water vapor pressure, usually provided by adding heat can be lower to create a boil. when water vapor pressure equals atmospheric pressure water boils. When the pressure above water is very low as in this test, water will boil at room temp. so how does water from the roots get to the top of trees taller than 34'? Water is moved up the tree by using cohesion-tension, transpiration pull from leaves, and the root pressure. water can rise to the 40m mark so it can get to the leaves. nature is amazing
We should say that the 33.8 foot limit is at sea level, The higher the elevation the lower the limit. Thanks for the great video.
true
This was actually really really cool. I love how the water wants to stay at the exact same height
Ok but then how do trees work?
The xylem fibres are narrower
Also it has dissolved salts in it which lowers it vapour pressure ( relative lowering of vapour pressure) that's why it doesn't boil in trees
Basically capillary action
I believe it is the evaporation from the leaves that pumps the fluids up the tree.
@mtbkmaniac1 it's a lot of things but less of that and more like how fibers absorb fluid and pull them up. Like a rag hanging half out of a cup full of water drains the cup. There is also an electromagnetic force pulling on the ionz of the water that have added salts from the tree. The top of the tree is charged with a positive charge, and the base is negative. Between the capillary action of the fibers of the tree and electromagnetic force that is pulling on every single molecule of water, you end up with enough scaffolding to have water at the height of the tree without the boiling problem.
They have check valves built in
Very cool! Thank you for sharing!
Boiling is nothing more than the kinetic energy of the liquid overcoming the force of pressure to transition from the liquid phase to the gas phase. That’s why you usually need to increase the energy or temperature for the transition to happen. Also, every liquid has its own characteristic “vapor pressure” meaning different liquids will transition more or less easily from liquid to gas, and take more or less energy to do so. But since boiling is just the point where vapor pressure exceeds the surrounding atmospheric pressure, you can also make the vapor pressure exceed the atmospheric pressure just by lowing the pressure using a vacuum. This is also, the principle behind pressure cookers. Instead of decreasing the pressure to make the liquid boil with less energy, you actually increase the pressure so that the water has to hold on to more energy than it would at sea level to transition from liquid to gas. This makes the water able to be heated above 100 degrees and cook things faster.
@sourand jaded Everything? Only corpuscular matter I presume you mean.
A magnetic field doesn't have vapour pressure. And what is the vapour pressure of a black hole?
😉
@sourand jaded Well, on a more serious note: does diamond have vapour pressure? Those bonds are strong enough, I don't think there is an equilibrium. Or salt even? Titanium? I guess you could say its vapour pressure is zero, but that is stretching the concept just as much as I did.
@@landsgevaerDiamonds are actually quite easy to vaporize. Takes a lot of heat and oxygen to break those bonds under a blowtorch u can vapourize a diamond.
When digging a well, if you use a standard hand pump, it's advised to not pump from a well deeper than 25 feet. This of course varies with altitude and changing air pressure. But that's the usual advice.
Nice video. Thank you. Can you make this into a water distiller? Perhaps bending the top into an upside-down U shape and cooling the empty side slightly allowing the water vapor to condense down on the other leg of the U shape? Could be far less expensive than steam distilling water.
Why would it be less expensive? Are you one of those who think you can get water from thin air for free?
@@NGC1433 because the end result you want is room temperature water, not nearly boiling water. You need to waste a lot of energy to boil water, and it's not possible in practice to get all that energy back.
He's referring to the fact you not using a heat source to produce steam
You would need to move the tube up and down,
I've thought about this quite a bit...
This made me think about jet pumps for wells since they are not down hole, their max head must be a similar height. Well looking it up their max suction depth is 30 feet, 3.8 foot tolerance so you can still get some flow instead of just pull a vacuum and get vapor. I never would have thought of that.
I think this is the reason some old cook books have adjustments to recipes for high altitude cooking. They usually adjust the cooking time because the boiling point is at a lower temperature.
That must be very so. Boiling water reference provides a known temperature (relative to elevation) without a thermometer and eliminates any diversity from LOW-MED-HIGH burner size.
If I seen him doing this experiment, I'd probably be playing w/ it more than he would have.... It's so fascinating I can't even explain.
Yeah, for example, in the rush to make the video short, he did not really allowed the level to stabilise.
@@olmostgudinaf8100 - IKR.... I was thinking about moving it above and below to find the exact moments it started boiling and seeing if temperature has any effect.
It is really fascinating phenomenon. Thank you for your channel 😍😍
That's one I never thought of! Nice experiment. Thanks
Would be interesting to leave it overnight and see if the drop in temperature would cause the water to rise, or maybe air pressure changes would cancel it out.
2:41 skip sponser
Those Mel Science Kits are a great idea. Gonna get one going for my nephew….but I’ll probably end up doing it myself!!
Would love it if you annoted future videos with SI units in addition to imperial units.
It could be interesting to try the same experiment with alcohol, because it evaporates at a lower temperature. Maybe it will evaporates at a lower pressure too.
Yep, interesting. Everything evaporates at any temperature, until the vapour pressure is reached. At 20.0°C, the vapour pressure of ethanol is 5.95 kPa, which is higher than for water. However, its density is also slightly lower at 789 kg/m³. So that would give a column that is taller than that for water.
@@landsgevaer This would be cool experiment.
Q--How much of the tube is hot or producing warmth, at what temperature? Can you use metal pipes at the top for emergency heat? With a ram pump at the top to release hot water into an insulated reservar? Can the bucket of water be placed in the basement to increase lower level boiling? Can the tube be bent to produce lower level boiling? I'm loving this.
Uuuuhh...It's boiling not because it's hot
But because "lower the pressure means lower the boiling temperature"
Boiling point is a function of heat and pressure. Decrease in pressure with no increase in heat will cause boiling. There is no change in temperature of the water or air. You can get around this in two ways: pushing the water vs pulling, or doing it in stages with resevoirs placed in increments less than the height of the boiling point.
It's not hot...
I can hear that Odeum of Illusions in the background :D Solid track choice.
Love when I know the answer before watching the video. Makes me feel smart
I would have loved to see some temperature measurements incorporated into this experiment. What was the exact temperature of the water at the top of the tube? How does that relate to the boiling point of water at sea level?
The water at the top of the tube will be basically that of its surroundings, less a bit due to evaporative cooling. I'd recommend googling a phase diagram for water. There should really have been one in the video.
@@chaos.corner Thank you so much for the info! I'm a bit of a geek and I love to learn about these things.
Be interesting to do this with degassed water to see how much difference this makes. I noticed some hysteresis when raising and lowering the tube, probably due to previously dissolved gas that came out when (or shortly before) the boiling started -- water vapor will go back to liquid when the pressure rises, but other gases that have bubbled up to the top of the tube will not go back into solution very quickly and will be trapped there.
Exactly. This video is wrong in multiple accounts. The gases bubbling out were most likely N2, O2, some inert gases and maybe a little CO2, and I bet little to no.water vapor. The water is degassing, not boiling.
@@joelafrite7850 I don't think this video was all wrong, or even very far off. The pressure at 10 meters or 33 feet (depending upon who is doing the measurement) is already known to be about 1 atmosphere, so the results shown here aren't too far off (and depending upon the atmospheric pressure at that particular place and time, could even be pretty close to correct). But dissolved gases are clearly throwing off the results at least a little bit.
You really do learn something new everyday. Subscribed!
I love your channel and everything you do on your channel. I will buy the product advertised in this video.
The problem with this is that you used a flexible tube. It needs to be a solid container with no flex to maintain the atmospheric pressure. Otherwise it can bow in on itself, distorting the results
Also plastic lets air through. That is the reason why the plastic water tubes inside of a house got an aluminum layer. It is to prevent air getting into the water. He needs to use these house water tubes and put a glass on top to see how much air is sucked out of the water - e.g is boiled out and how much air is sucked through the plastic surface.
Pressure in water depends only on height, nothing else.
@@wurstelei1356 No air got in, since he showed the water condensing back into liquid when he lowered it.
@@Owen_loves_Butters I see air that is forced into the tube. Watch the video, the air isn't getting out fully. That is the reason why you use PEX tubes with aluminum core in your house. See the PEX tube part on Wikipedia here: en.wikipedia.org/wiki/Cross-linked_polyethylene
@@wurstelei1356 …air is not “forced into the tube”. The Wiki article refers to “oxygen DIFFUSION”, in which oxygen molecules can diffuse across the matrix, and be absorbed into the water.
Diffusion is a totally different process from just “air getting through” or “air is sucked through”.
Main difference is the rate of penetration… diffusion is generally the slow movement of atoms or molecules of an element, such as hydrogen or oxygen.
The air that you think is “being sucked through the plastic surface” is actually the air coming out of solution in the water, in other words being boiled out, due to lowering the air pressure (vacuum)… when the vacuum is released (pressure raised), the air is again pushed back into solution, and “disappears”.
Maybe this is the first time I hear a misconception in your videos. You said that inside the tube there will be a perfect vacuum, technically this is not true because what you create is a strong decrease of pressure inside the top part of the tube and this will let the oxygen molecules inside the water to evaporate and so you will have a lower pressure environment still filled with some molecules of water and oxygen, so NOT a perfect vacuum. Although at the beginning you may think that there should be a small perfect vacuum but still even there the water start to evaporate little by little, but it does..
Yeah, he just kinda didn't care about that part
didnt he say theoretically tho, assuming its just water with no oxygen dissolved maybe
I think it was understood that he meant a hypothetical perfect vacuum - so that you could run the numbers and find a limit to how high you could ever get the water level. James does glaze over key talking points in his video as he's catering to a younger crowd.
I agree with you. The same thing can be observed with a plastic syringe filled half way with water and all the air expelled. There's dissolved air in the water and when you pull the vacuum you expand those micro-bubbles. When you release the vacuum the bubbles shrink back to their original size. Interesting but inaccurate to call it boiling. Yes, water will boil at lower pressures. I live at an altitude of 4500 feet and water boils somewhere around 209˚F. The reason why there's no water in space is because of the extreme vacuum. Water boils away.
@@WulanDari-uv8bg Do you squirt and bubble if you're raised above 34 feet and somebody attaches a vacuum pump to you? GTFO
Nice experiment! For the benefit of the international audience, 33 feet is approximately 10 m. The symbol m standard for meter, and is the unit used in most of the world, and universally adopted in physics, to measure length. 😉
Now I understand why 1 atmosphere is appx equal to 32'. Very cool. I wish we had done this in physics class, it has a lot of practical applications.
We did this in school, it was impressive. :)
Also my first thought was: "Okay... they are doing this in feet. That's... complicated. Just do standard units, so you immediately know that in a height of 10m (= 1 bar pressure of air) the boiling point will be reached." :D
If there was a giant tube like this that you could swim up into, what would happen to your body especially once you reached the top of the water vapor pocket?
It would feel like you’re swimming in a hot tub
You would probably faint
@@Gibbs2Gothe temperature of the water does not change
@@wvking ohh, I just figured if the water is boiling, it would be hot.. I watched again and realized that you could lower the boiling point by reducing the pressure.. that is crazy, thanks for pointing my error out!
This is such a cool application of physics. Thanks!
aaaaah, saturated gas release point actually. HVACR has a video that talks about this and there's some stuff from one of the other lab channels that discusses vapor vacuum pumps. Once you deplete the saturated gas you CAN hit a "boiling" point but its gonna deplete a LOT of gas first. You can end up spending more time pulling gas out of compressor oil than it takes to actually fully evacuate the actual mechanical volume of a refrigerant system at times.
The way you determine if you're actually at a boiling point is if your body heat causes the level in the tube to drop rapidly. This experiment is better done in the winter somewhere just above freezing. It DOES happen and in system process its actually an interesting way to generate pure moisture vapor even tho the apparatus is huge.
The limit on height is not due to the temperature of the water, its due to the pressure of the atmosphere.
The boiling point of water does change with temperature and pressure, but it doesnt just boil more to maintain the height.
I would have pinched off were the top has degassed itself just to see if it could go a little higher.
You should do this same experiment with different types of fluids to see what boils where.
I would like your opinions on this idea I have for an underground electricity generating system. There is a reservoir of ferrofluid at the top of the system, from which a tube goes downwards about 500metres where it drives a turbine. The ferrofluid then collects in a bottom reservoir. I then have thousands of tubes (straws), immersed in the ferrofluid, that go upwards for about 34feet where they curve back downwards for a couple of inches. Underneath the downward curved end of every tube, is a magnet, which pulls the ferrofluid onto itself forming a nice prickly blob. The magnet can only hold so much ferrofluid, and the excess will fall into yet another reservoir just beneath the magnet. This reservoir has thousands of tubes leading up to thousands of magnets, filling yet another reservoir about thirty feet above. I repeat this process until I fill a reservoir that is above the original reservoir, which it feeds.
Obviously the tubes and reservoirs would have to be pre-filled before the system would start working and it would be a nightmare to build, but is it possible? How high can a magnet pull ferrofluid? I've heard that neodymium magnets can last 700 years, so have I just invented a clean energy source?
So flowing water thru a 40ft down pipe, if you cut the flow at the top, this would create water vapor? Would it be desalination?
Interesting!
This would only work if the top of the pipe was completely sealed off by some sort of valve and the flow was going into some sort of vessel with the pipe exit under the surface of the water. But yes I assume there could be some issues with the water boiling if the pipe wasn't allowed to drain.
Would be great if there was a way to vent/collect the vapor and refill with water in pulses.
I think this is related to how ram pumps create compressed air
@@David_Mash It would create similar concentrations of water vapor that already exist in the atmosphere, so the question would be how to re-condense it.
Good morning everyone.
I had guessed at the start of this video that it would be around 10m, since that is 1 atmosphere's worth of pressure - at which point the pressure at the 10m mark would be equivalent to deep space vacuum (presumably) and therefore nothing stopping it from creating a vacuum void.
I considered the de-gassing of o2 and co2 from the water, but didn't consider it boiling off. Glad at least I got part of it right on my own though.
This is so cool. I wonder what it would look like to have a thicker tube with something suspended in it. Or a thicker tube filled with water going up 25m instead of 10 that was then unplugged. Would all the water suddenly and instantly condense?
One comment: I find it inaccurate to describe the column of water as being sucked up (01:04). There's no "sucking force", the column is being pushed up.
things get pushed into vacuums
When you say “ sucking juice with a straw” its still the same thing. There is no sucking force, you are just making vacuum over the top and water is being pushed up by atmospheric pressure. In fact, there is no such thing as sucking force. It’s this whole phenomena of atmospheric pressure pushing juice up the straw that we call sucking. So he is right here
@@karansandhu4827 Well there actually is such a thing as a sucking force; it's just not possible with gases because they have virtually no intermolecular forces (if it's an ideal gas), which means they can only push through collisions. However, liquids and solids have intermolecular forces that allow them to both push and pull. So you can suck on a liquid, and this can lead to *negative pressures.*
"suck" is a word that describes being pushed into a lower pressure environment by higher pressure outside that environment. It is just semantics. There is nothing wrong with using the word "suck" as long as you know what it actually means.
It's the same thing. It's a pressure difference. You're saying the pressure is higher at the bottom, he's saying it's lower at the top. As the top pressure is the one that is changing during the experiment, I'd say that is the more interesting one.
“Impossible? We did a lot of impossible things on this journey. I’m tired of hearing that things are impossible or useless. Those words mean nothing to us.” - Jotaro Kujo
I officially ❤️ this comment
damn i haven't expected a jojo referece here, but they are always appreciated. Fuckin legend, part 6 is awesome too.
@@somerandomguy3298 I just started watching where I think it’s josuke traps the stand in bottle whichever season that is. Damn I love it lol
@@alejandrospeed6399 ahaha yeah thats part 4, i love that one
This also explains why my 180' deep well has to have the pump at the bottom. Cool. Thanks.
I'm surprised that this simple PVC tube is able to withstand atmospheric pressure. Great visualisation 👍
The liquid is withstanding the atmospheric pressure. The tube is filled 100% with liquid before taking it up the stairs and liquid doesn't compress very much.
First view
No
You want a fkn cookie?
This made me want to look at a pressure vs temperature, phase diagram for water. Take that as a compliment.
So you could use this to create small sealed vessels of room temperature steam. Use a very long tube, keep raising it, then clamp off the vapor portion and the liquid portion, cut the tube between the two clamps, repeat.
I dunno what you would do with those. It just seems neat to have bottled steam.
Great question, great splution, great job!
How do you know if it's water that's boiling or just the dissolved air escaping the water at lower pressure??
My personal opinion is it's the latter as if there's vaporization of a liquid due to pressure reduction, then the molecules with most energetic states (i.e. the ones on the top) should start evaporatinf first.
And just to address a follow up question, in kitchens, the source of the heat is at the bottom and thus the water molecules at the bottom increase their thermal energy first. That causes the water in your utensils to boil off from the bottom
At that extreme height of 33 feet (around 10 meters), there is a significant decrease in atmospheric pressure at the top of the tube compared to the pressure at the bottom near the water level.
This large pressure differential causes the boiling point of water to decrease dramatically at the top versus the bottom. The lowered vapor pressure requirement at the top allows bubbles to form even though the bulk water is not near its normal boiling point.
Here's a more detailed explanation:
Atmospheric pressure decreases with increasing altitude due to less air weight above
At 33 feet higher, the pressure is noticeably lower than at ground level
Boiling occurs when vapor pressure equals the ambient pressure
So this lower ambient pressure at 33 feet allows boiling/bubbles to happen at a much lower temperature
This is not just due to the tube being tall, but the extreme height difference creating a genuine low pressure environment at the top. Basic physics shows every 10 meters of height decreases air pressure by around 1 psi or 7 millibars.
So in your experiment, rather than a small boiling point change, you were likely observing the fairly dramatic effect of greatly reduced ambient pressure on the boiling conditions. An interesting practical demonstration of vapor pressure principles!
The height is dependent on the atmospheric pressure; about 14.7psi at sea level equates to 33.9ft of head. Do the same experiment at 10,000ft above sea level at about 10.1psi and you should get about 23.3ft of head (assuming average air pressure). Just think of the atmospheric pressure as the max pressure rating on a pump trying to pump water up an equivalent open-ended tube.
I have been figuring out multistage water pumping for off-grid system lifting water hundreds of vertical feet of head from a stream. Ironically it’s the burst strength of the lightweight hose/tubing (I need a 1100-1200ft run and have to backpack it in, so no heavy pvc or fiber reinforced flexible hose) that is the limiting factor even more so than the pumps. With an expensive pump I could do single stage; with 2 inexpensive pumps I can do 2 stage but the static head alone would burst the tubing so I have to do 3 stages with open mini reservoirs that feed the pump for the next stage.
Needs a re-do with pressure/vacuum guage on top and to go significantly higher (60+ feet) then work your way back down. Might need to use tube which is braced so it wont collapse under vacuum. Putting an empty hose in a water source and using a vacuum pump to pull the water up the length might be an interesting method to watch. Also thick water could be interesting.