"There are no magical forces sucking the balls" - Physics Videos by Eugene Khutoryansky

I’m genuinely glad that I’ve been a subscriber for quite a while now. I feel grateful towards you for making physics and mathematics my greatest goal and the center of my life, as I thank you for your constancy and dedication. We all appreciate you a lot around here. Always on point; keep it up!

The content on this channel is always excellent but what I love the most is the music and the voice 😂

This is how osmosis really works. I remember teachers mentioning a mysterious sucking force. Thanks for elucidating !

As noted in the commentary, there are no attractive forces between the particles in this simulation. This means that you are simulating two ideal gases (well, if we ignore the particles' volume). In such a case, the osmotic pressure is equal to the partial pressure of the cubes, while the partial pressure of the spheres will converge to being equal on both sides of the barrier. The simulation is not representative for osmosis in liquids. For liquids, there IS an attractive force between particles, and this is essential for explaining the high osmotic pressures in liquids. For instance, the osmotic pressure between sea water and fresh water is an amazing 24 atmospheres, although the difference in salt concentration is only 3.5%.

This helped my intuition a ton. So hypothetically if the membrane only let the squares through, we'd see the same thing but to the other side. Amazing.

I imagine most sorts of semi-permeable membrane can be abstracted to this kind of visualization? The purpose is to show that a shape-specific filter has that result whether they are simulated shapes or biology, chemistry, and physics doing their things, correct?

Such a fantastic channel, I cannot even explain how glad I am to have found this place, thousand thanks!

Great demo! Another interesting case I can imagine is where there are some attractive interactions between the cubes(so it becomes a liquid) , but keeping only the same hard repulsion with the spheres. You can then demo some things like colligative properties, and also show that the 'vapor' of spheres above the liquid has equal concentration on left and right, at heights where there are few cubes. I've always wondered if there is a clean and intuitive way to visualize chemical potential, and perhaps this approach could help.

You never cease to amaze me! Amazing work as usual.

"This is the beauty of physics" - You just described your channel in a nutshell!

I used to watch your videos back in 2016 and your animation is awesome glad i found you on youtube still making breathtaking animations...That quantum Mechanics video was magnificent

Hey, I just wanna say: Your videos are amazing. They have incredibly insightful and intuitive demonstrations of otherwise hard-to-understand concepts. I get the feeling they're primarily intended for use in schools. But honestly, I enjoy them for their own sake. Keep it up; you're doing great work.

Thank you so much. You have the best intuition on physics, classical or otherwise.

So happy you are back!! ❤️ always supporting this channel since forever ago!!

These particles sure have a broad taste in music!

This is indeed the beauty of physics. Extremely simple laws, profound consequences beyond measure.

I like the heavy metal backing track! The explanation is also very clear, thank you!

Again, a MARVELOUS video! Thank you very much for your work!

Yay! My fav youtuber uploaded!! Brilliant video and explanation, as always :)

Oh god, so awesome channel. Thank you for your work.

Nice simulation I never knew osmosis on a molecular level. You have great taste in music ,listened to quite a few classical pieces while watching your previous videos.

Commendable job in visualizing this,thanks .

Outstanding demonstration of process of 'Osmosis'. Hats off to your efforts, which make the concepts crystal-clear👏🏻👏🏻👏🏻👏🏻👍🏻👍🏻👍🏻👍🏻

Great visualisation of how osmosis works, and what is the difference between osmosis and diffusion. Thanks!

Thanks for this video 🙏. It's one of the best in your playlists. I think I finally understood osmotic pressure. Please correct me if I'm wrong. So, initially we have water(spheres) on both sides and the pressure on both sides of the wall is equal. Suppose, we add NaCl salt and the ions get hydrated immediately and represent the cubes. The cubes owing to their larger size, restrict movement of spheres and even block them from effectively colliding with the barrier. This can be thought of as decrease in the pressure on that side. So, now the other side spheres will cross the barrier more frequently until pressures are balanced again. So, there are more net molecules on the salt side and denotes the increase in height. This decrease in pressure on the salt side is called osmotic pressure and proportional to the concentration of salt added.

I didnt expect that cannonball motion ricochet at 2:07

High quality delivery from Eugene as always. Keep it up!

Thanks so much for sharing! BTW, I love your voice! 😊

Your simulation is very interesting to watch - brought me to the question, if the driving 'force' behind real Osmosis could be a pure filter effect? I'm not sure if this is your conclusion or very far from it. Just from what I saw in the sim, I think it's behaviour is all down to the barrier in the middle, which allows balls to pass from the left to the right side more easily than from right to left. The mid barrier could be seen as a filter with directional permeability, maybe like a coffee filter. For example, imagine a coffee filter installed in an Aquarium, where on the left side is pure water, while on the right we have 'coffee powdered water'. Now in the simulation the squares ('coffee particles') on the right partly block/clog the filter towards the left, so balls (water molecules) which happen to enter the right area have a higher tendency to stay there, than to return back - a bit like a sponge-effect, but without the adhesive forces. The reason why not (almost) all balls end up on the right, is that the right-to-left permeability ("leakage") effectively increases with more balls on the right, due to rising pressure (= particle-particle/-wall collisions per time unit) in this area, just like described in the video. With the filter's/barrier's permeability moving from directional towards unidirectional, the amount of particles on the right grows slower and slower - until a near-equilibrium state is reached.

You and your channel one of the most incredible places to visualize and learn physics. Specially understand it. YOU ARE GREAT

Fantastic as always Eugene!

Your clips are wonderful art! I am looking forward for Navier-Stokes equations to be visualised ;-) Why not, it worked with Maxwell as well?

Oh my God yes! I tutor chemistry and this is so helpful. Thank you!

This is one of my favorite topics. Very very well done.

You're on the right track with this whole background music thing. Hopefully very soon, you'll decide to drop the whole thing. Believe me, your voice is mesmerizing, music here is unneeded.

Отличные видео как всегда) где они были, когда я учил физику в школе?

Your channel is the prime example of an extremely gifted educator doing excellent work on visuals!

The blistering guitars in the background were a nice touch

I feel those squares desperation, in struggling to get through the barrier

This is a great visualization! but I'm curious if the squares would reach the same height as the spheres with a non-permeable membrane. I noticed that the squares could transfer rotational energy to each other and the spheres couldn't.

I've been subbed too this channel for years and love it

I think it helps to imagine the diffusion scenario with the cubes-- left side has more pressure obviously. Add a few balls at a time. Now we see this increases the pressure of both sides, reducing the ratio of the two pressures. Dilute it enough with balls and they basically have the same pressure. I guess the paradox that people may be confused by is that the transition rate is not proportional to pressure. The transition rate of each individual particle is proportional to its partial pressure, times some coefficient determining the penetrability of the barrier, e.g. a partial diffusion timescale. Each particle type has its own diffusion timescale-- it may be infinity, as in the case here with the cubes.

Isn't it fascinating? You look at a simple household phenomena, and deep down it's a bunch of particles bouncing around, just so many of them that it looks like e.g. coffee going up a paper filter.

I never thought of it this way, but could it be explained as simply as the cubes block the path to the barrier, so the balls on the left have a greater opportunity to pass through than than the balls on the right? Equilibrium is reached when the right side has enough "extra" balls in it that the occurrence of barrier interaction is equal on both sides? This is very enlightening! Thanks for the great videos!

Hi! Thank you so much for such genuine information! Kindly upload more! Thank you so much.

So glad I came across your video. Many thanks.🌹🌹

Nice video! Also, good to consider that in equilibrium, at the side with solute, decrease of stability of solvent due to increase of pressure as osmotic pressure is compensated and balanced by increase of stability of solvent due to entropic effects (ideal behaviour) beside possibly solvent-solute interactions giving rise to non-ideal behaviour.

Wonderful and very instructive as all of your videos! We must be careful with "entropy" here. If you consider a time-series of consecutive, fully described microstates for which you know everything you cannot define entropy. Entropy can only be defined if you set only marcoscopic quantities and ask in how many microscopic ways they can be achieved. What is meant here is that initially we have a microstate that is part of the low entropy "all particles in one side" set and we end up with a microsate that is part of the high entropy "particles equally spread on both sides" set. This happens because the initial velocities were randomized by the collision (no-gravity-simulation). Newtonian mechanics says that if we play the video backwards we will have a thermodynamics defying system which lowers its entropy. I only do not know how random is the motion of the diaphragm.

Awesome work as always

This video scratched an itch I had for a long time. So many explanations (even in chemistry textbooks!) calls upon spooky entropy magic to explain osmosis. I'm going to have to watch the simulation a bunch more. But this is very helpful for me. Thank you!

How does an increase in pressure cause a displacement of molecules with equal densities? Why did the squares rise?

It would have been really cool if you let the simulation at 05:05 run to equilibrium, and then beyond that (maybe sped up). Just to see how it plays out. Especially to see how far beyond equilibrium the system oscillates.

This is a very accessible way of teaching it. You can probably append even more intuition to this without really having to get into the weeds with statistics. This is already useful as-is in a classroom where an instructor can provide an extra bit of explanation, but it would probably benefit this video as a supplement if there was a visual aid for what's happening at the level of the single particle: What I imagine is that every time a particle interacts with the barrier, there's a chance that it's either a ball or a square. Because squares can't pass through the barrier, then even though there might be just as many particles interacting with the barrier on both sides, the side with the squares won't send as many particles across the barrier, resulting in the side with the squares gaining more particles from the other side. I believe this would be another fairly intuitive addition to point out while still maintaining its accessibility to people less versed in higher math.

Great video! Thanks so much for making these!!

On my first pass, i didn't see much of a justification for how this happens. I'll watch it again... Alright. it's easy to miss this, you mention that the influence of the squares is important, but you don't really explain why except in empirical terms: it happens, here's it happening. The balls can pass, but not the squares. The explanation would probably involve something like... The balls, being able to pass through, are able to exert a pressure through the membrane, while the squares are not. The effect of the squares is not the same as it would be had they been balls, because for a square to oppose the balls entering the right side, the squares must force each ball back through the membrane, while when there are only balls on both sides, a ball on the right side only has to pass through the membrane, NOT just force a different ball through. Therefore it is much more likely that, when there are balls on both sides of the membrane, that the balls on one side can resist an imbalancing flow of balls; and it is less likely that, when there are squares on one side of the membrane, that the density of particles would remain similar, because for this to occur, the presence of the squares would have to have an equivalent likelihood of decreasing the number of balls present in the right side as would an equivalent number of balls, which is not true because the barrier prevents the squares from performing one of the two ways a ball could achieve this: by passing through.

I really like these models, super facinating representations

Great video, truly visually superb!

Wow thanks I finally totally get osmosis thanks to this illustration, seriously thank you so much!

This is beauty of the Physics. I love it!!

I love your videos. Thanks for always teaching me something new

Another great video. I love it. 👍🏻

Great dedication...❤️👍

Another banger. Keep it up. Today I learned how osmosis works. Didn't even consider it before.

Interesting video, especially the concept of entropy which fixes the direction of occurance of every natural process is beautifully depicted in this video in terms of balls and squares motion.

Very well explained and visualized. Thank You

Hey man great videos, the ability to visualise/intuit physical phenomena is a super cool possibility with youtube and I really appreciate people who make these vids. Also I was wondering if you could also include equations in ur videos which would allow to easier transition from the KZfaq landscape to books and papers or text in general.

One word, beautiful. carry on my friend

I love the animations and always want more .

Much needed for the future as a starting point

Amazing! Completely kinetic!

really really good demonstration

Great as always.

It was amazing to review concepts from high school times! Thanks a lot!

this is such a simple but perfect way to show osmosis and diffusion, basic stuff but still i never saw it this way... makes things much easier to understand my suggestion is to make an animation barrier with "channels" that only certain shapes can pass, to simulate passive transport? as it still is physics based, i think it would be fun to see how it goes!!

This is amazing! Thanks for making it!!

I am so lucky to find you !!!! You're a genius!!!

this channel is pure liberation.

So squares block balls from escaping the square side of the barrier. Equilibrium is reached with more objects on the square side of the barrier.

The average number of collisions with the balls and the barrier is larger on the left side. Note the relative volumes or areas for both left and right are roughly the same. It follows that if the area or volume on one side is larger than the other, then a similar migration might be expected. My thanks for the insightful presentation.

I think about it in the way that each ball has equal chance to pass to other side (and squares are making it equally harder to pass in both directions so we their only influence is slowing down the process) so balls try to be equall on both sides liki in diffusion but on the right side there are extra particles - squares

how i see it makes sense to me, as only water can travel through, the right side always gains energy as some of the energy is transferred to particles that can't cross the barrier unless it happens to transfer back to a particle that can cross back, (paired with density/pressure being increased)

They just that kind of charm to this kind of videos randomly appearing

Forced me to re-evaluate how I understand osmosis, great job! The dialogue and narration is also wonderfully concise and clear.

Brilliant video!!!

Excellent representation of Osmosis! Makes it super easy to understand. :)

Awesome, as always

Thank you so much to help me understand the change in fluid levels.

Awesome demo. Thanks!

Your animations make even the most boring concepts easier and interesting. You definitely deserve more recognition. Btw, never forget to double the dots

THE MUSIC IS SO HYPE THOUGH

Great animation and contents....

Nifty as always !

The area of the squares is higher which also causes a rise on the right. I think there are a few more details there which could be explored. Neat visualizations, thanks for sharing.

You can explain most of Osmosis more easily by looking at a container pressurized with Helium gas. The container is able to hold any gas except Helium which slowly leaks out of any container. As the Helium leaks out other gases are not able to leak into the container and over time a perfect vacuum will form. Looking at this example allows you to use only one gas and the vacuum as the two liquids with the vacuum being a non-participant. This exact situation was also a full days' mystery when my container developed an excellent vacuum all by itself over a weekend. Turns out this is one of the steps to create really deep vacuums (Roughing, TMP, Helium-Vacuum washing, Helium-Thermal pumping).

I learned, in college, we use some kind of membrane made of a permeable material to select different sizes of proteins to further analysis.

If we have a solvent of a molecular size even smaller than water molecules (liquid hydrogen?), then it may be possible that the particle wave duality may happen when the molecules pass through the pores of the membrane. The region of higher solvent potential could be interpreted as a stronger wave source while in other region is a weaker wave source, so that when there is a net wave front passing from the stronger wave side to the weaker side through the pores of the membrane. And when we observe it, all waves suddenly collapsed back to particles.

Fascinating and a great learning tool

This blew my mind and helped me understand concepts better than bio class all those years ago. But why was the music so rocking? I think I heard a shredding guitar solo in there? And then she says "this is the beauty of physics" and the solumn reflective piano softly plays a beautiful tune

Excellent video.