I Can’t Believe I Taught this Wrong for 15 Years... time to fix it!

[@Mahesh_Shenoy]

Go to ground.news/floathead to think critically about the news you consume and be better informed. Subscribe through my link for 50% off unlimited access this month.

[@xpowerst4534]

You are one of the best ones out there . I am in class 9 and i love ypur explanations . Please try one on some things like quantum string theory or forces of nature or something new in chemistry or physics

[@TankEsq]

7:21 isn't she still in space??

[@SatyamSingh-un5sc]

why is this showing 7days ago when the video is uploaded 1 hours ago

[@Oooa61424]

How about using oil and water mixture instead of coffee and milk? How will we make sense of entropy here

[@johnjameson6751]

One of the common themes I like most in many of your videos is that you make the insights of Feynman in his lectures clear and accessible to a modern audience. Great work !

[@gauripriyakandakatla6783]

This is one of the best science communication channels out there. The science is rigorous and grounded, and it’s explained in an intuitive way without confusing the audience with fancy jargon. Every time I watch a video, I come away with a deeper understanding, and the sheer passion with which he talks about these concepts is contagious. Please don’t ever stop making videos!!!

[@TawhaKhan-c4q]

Yeah, the only request is to make videos for us🥹🥹.

[@SPDLand]

I approve of this message.

[@riolopez6755]

100% agree. Like this guy is the goat

[@plranisch9509]

This explanation of yours was the best explanation I have seen in my life! Uniquely and unexampled!

[@kruemmelmonater5282]

But most things are wrong….

[@rodrigoborges3876]

"when you learn something new, try to critique it, try to break it, and see what your logical flaw is, because that's how you deepen your understanding" is one of the most powerful phrases i've ever heard out of an educator. Beautifully said, Mahesh!

[@RudeNubeYouTubeDude]

1. Create, imagine, birth A project, idea, theory, invention, tech, etc 2. If you love & believe in it then immediately put it to the test & try to destroy it. If it stands on its own afterwards ….Gold-Star! 3. Invest .whatever $, time, research, effort, & resources as necessary 4. Repeat steps (2&3) until you are confident it can survive the outside world and can stand on its own

[@davidmcc8727]

I have a degree and PhD in chemistry and your explanation of entropy is the best I have come across. Bravo! 👍

[@geeblenhoff1]

I have a bachelors in physics and I didn’t realize just how surface level my understanding of entropy was till I watched this video. You have a beautiful way of explaining physics

[@RandomToon1]

I thought I understood things. Watching your videos has helped me understand that I did, but not at the level that I thought I did. This has really helped me have some "ah, that is the part that I was missing!" moments, and I adore that. Great stuff, and I love your energy. I wish you much success.

[@priyank5161]

Everyone has this " yeah I know this" phase And soon it evolves into "I don't know a shit" phase

[@maxanimator9547]

​@@priyank5161 more like a cycle than single phases

[@Soham_008]

Oh boy please never stop posting these informational videos that often our teachers just let go under the rug. They just want us to memorize and here you are, the Messiah, reviving my curiosity 😂. Thank you very much. I just came across this entropy thing in thermodynamics and well I can solve questions but I understand nothing about it. I am very confident now I will know after seeing your video. Thanks again

[@Devasia.Thomas]

You, Sir, just increased the entropy of my brain like crazy and that of everyone, collectively, exponentially.

[@tiberiusgracchus4222]

Damn dude. I have struggled for so long with trying to have a more intuitive understanding of what is really being described by the term entropy. I have read books and watched countless videos on it. I have sat around thinking about it for hours. And here you made it so simple and so intuitive and did it in such a short amount of time. I could literally feel the lightbulb go off in my head. It's like a burden has been lifted...lol. You have a real gift. Thank you!

[@kurt1391]

He was kind of off the mark when he talked about irreversibility, as diffusing milk is theoretically reversible and respects T-symmetry. Other than that, he did a really good job.

[@joshuaohuka7719]

​@@kurt1391 no he wasn't... he said the milk won't unmix itself because that would return it to a form with lower potential micro states... so even though it's technically feasible... probability favors mixing over unmixing...

[@aminelahlou1272]

In order to use arrangements probabilities, the positions must be independent from each other. But this not the case here 12:55 because atoms collide with each other so they are not interindependant. So the probability is not 0.02% (0.18/850) but actually lower because collisions maximizes the distance between atoms. (Hence low temperature creates solids)

[@SamiKing-wg6nm]

Bro, explain pauli exclusion principle next... Why bosons are symmetric and stay together and why electrons are asymmetric and can't occupy same quantum state.

[@adntkumara1151]

Yes please 😊

[@lalit-_-]

Yes, this is a base of quantum mechanics.

[@SamiKing-wg6nm]

@@lalit-_- yeah

[@diogocoletto9135]

Yep

[@xinpingdonohoe3978]

Indeed. That's important, and also hard to even describe in some ways.

[@Steaphany]

This explains why I'm compelled to watch more physics videos, the more information in my head means higher entropy

[@michaelpetzold849]

Your enthusiasm is contagious. I have been grappling with the concept of entropy for quite a few years. This really helped!

[@hpottergirl317]

I clicked faster than the speed of light

[@Xbd36]

I was at speed of sound in solid medium

[@brodyalden]

And thereafter collapsed into a black hole.

[@xpowerst4534]

Me too

[@IstiakAhmed-uw6jo]

Doesn't seem like you've got infinite energy. Sorry I can't agree with you 🤣

[@soyanshumohapatra]

Speed of light doesn't click

[@crazymathematician88]

Imagine struggling with entropy ,someone find your video. Highly relieved.❤

[@roberttikens4983]

As an electrophysiologist interested in biophysics, I've always found the diffusion phenomenon fascinating. I love how Schrödinger put it in his book "What is life" : "Imagine a vessel filled with a fluid, say water, with a small amount of some coloured substance dissolved in it, say potassium permanganate, not in uniform concentration, but rather as in Fig. 4, where the dots indicate the molecules of the dissolved substance (permanganate) and the concentration diminishes from left to right. If you leave this system alone a very slow process of 'diffusion' sets in, the permanganate spreading in the direction from left to right, that is, from the places of higher concentration towards the places of lower concentration, until it is equally distributed through the water. The remarkable thing about this rather simple and apparently not particularly interesting process is that it is in no way due, as one might think, to any tendency or force driving the permanganate molecules away from the crowded region to the less crowded one, like the population of a country spreading to those parts where there is more elbow-room. Nothing of the sort happens with our permanganate molecules. Everyone of them behaves quite independently of all the others, which it very seldom meets. Everyone of them, whether in a crowded region or in an empty one, suffers the same fate of being continually knocked about by the impacts of the water molecules and thereby gradually moving on in an unpredictable direction - sometimes towards the higher, sometimes towards the lower, concentrations, sometimes obliquely. The kind of motion it performs has often been compared with that of a blindfolded person on a large surface imbued with a certain desire of 'walking', but without any preference for any particular direction, and so changing his line continuously. That this random walk of the permanganate molecules, the same for all of them, should yet produce a regular flow towards the smaller concentration and ultimately make for uniformity of distribution, is at first sight perplexing - but only at first sight. If you contemplate in Fig. 4 thin slices of approximately constant concentration, the permanganate molecules which in a given moment are contained in a particular slice will, by their random walk, it is true, be carried with equal probability to the right or to the left. But precisely in consequence of this, a plane separating two neighbouring slices will be crossed by more molecules coming from the left than in the opposite direction, simply because to the left there are more molecules engaged in random walk than there are to the right. And as long as that is so the balance will show up as a regular flow from left to right, until a uniform distribution is reached." Just beautiful. Thanks for all of your work Mahesh!

[@FreakGUY-007]

Hey doc.. You treat heart diseases right?

[@roberttikens4983]

@FreakGUY-007 No sir. I do research in pancreatic beta-cells. I'm a biologist.

[@FreakGUY-007]

@@roberttikens4983 Oh my bad.. Just wanted to ask something about my grandpa's heart condition.. Anyways thank you for replying 👍

[@roberttikens4983]

@@FreakGUY-007 you're welcolme! Sorry to not be able to help :/

[@naasiroow]

@@FreakGUY-007 What question did you have?

[@jewiesnew3786]

I head read many physics books throughout my life and I'm surprised I'm still learning something new from you! You are a great science communicator, and please, never stop making these!

[@computerrrsingh]

Please never stop posting such content. Love you for this ❤

[@mikebellamy]

This was very good up to Maxwell's Daemon! It is not the information in the Daemon's brain that increases entropy because information is not a random arrangement (high entropy) of symbols! *Information is highly ordered (low entropy) not disordered!* what you are missing is a correct definition of information which is; *INFORMATION: Communication of meaning in a language* What increases entropy in the Daemon is the heat generated by the whole Daemon as required to perform the operation: eyes to see, processing to recognise the fast atoms, processing to calculate the movement of the arm, processing to move the arms, and finally store the information.

[@doomzday66]

Hi, I had several questions 18:37 Q1 Why does the gas heat up? What phenomenon causes the gas to heat up when compressed? 22:01 Q2 What if the demon forgets all the information? Does it mean entropy decreased? Q3 When you stretch a rubber band it heats up slightly They say it's coz the molecules become less chaotic and become straight and arranged. And as entropy cant decrease it heats up But i can't understand why would a molecule decide to heat up... I mean it doesn't have a conscience to follow the laws of physics...

[@nukeeverything1802]

Q1: The piston applies a force to the gas before stopping. When the piston stops, what happens to the work done (i.e the energy) by the piston? Work is done on the molecules, which becomes kinetic energy. And while this kinetic energy can be distributed in many different ways (hence high entropy), the gas as a whole has a higher average kinetic energy. Temperature is a macro property that corresponds to the the average kinetic energy. So if there is a higher average kinetic energy, then temperature will increase. Q2: If the demon forgets then there is some outside process that flips the 1s into 0s such that the number of microstates reduce. We end up having a similar to the fridge, where you have to consider the entire system. If the demon is a computer system for example, then forgetting might be due to cosmic rays hitting the brain, or energy leakage as heat into the surrounding, or physical damage to the brain. In all these cases, the entropy increases, since demon + box of molecules + forgetting process will have more microstates after the demon forgets than before the demon forgets. Q3: This is similar to Q1. When gou stretch a rubber band, it gets thinner, and molecules get aligned into an "ordered" structure. "Ordered" is in quotes because like what the video said, being in a nicely arranged microstate isnt more likely than a disordered microstate. What matters is the number of microstates available. Now your hands also apply work to pull the rubber band apart. Where does the energy from your pulling go to? Here it becomes kinetic energy in molecules to align the molecules and make then vibrate more. (Imagine pulling a slack rope tight and how it starts to vibrate like a guitar string when you do) And since temperature is the average kinetic energy, the rubber band heats up.

[@rashishsaini50]

1) considering an adiabatic system. no heat exchanged) during compression, work is done on the gas, the energy is absorbed by the gas particles, dW=dU in dt time interval energy absorbed "dU" = nCvdT is >0 hence dT>0 hence temp increases. 2)the information while going into the demons brain was increasing entropy, forgetting the information is another task 3) nature decided what happens, we can only accept and study it

[@tivoli7]

@@nukeeverything1802 what happens if all available microstates in maxwells demons memory are 1 then it has low entropy cause there is only one state possible?

[@dannyweiss5001]

​@@nukeeverything1802 say the information is stored in cells surrounded by a dispersed hot gas, when that gas hits the cells, they turn into 0s. The demon will forget automatically without the entropy increasing because the gas is already at maximum entropy. No outside energy is used.

[@nukeeverything1802]

@@tivoli7 That's right. Just want to clarify, upon rereading my answer, that having more 1s does not necessarily correspond to having more information/microstates. Rather I imagined "forgetting" as reversing the process as described in the video, i.e. reverting back to an all 0s state.

[@avisian8063]

Your videos are genuinely my favourite format for this kind of content. Also your t shirt is Fire!

[@svMoorFun]

Phenomenal explanation, Mahesh. One error in the advertisement for Ground News, though. The articles about the hospitalized astronaut are not about Sunita Williams. She is *still* stuck in space -- and her health is at risk. But the articles about hospitalized astronauts are about another, unnamed astronaut who were taken to hospital after landing.

[@bsatyam]

Your enthusiasm is infectious! I wish I had teachers like you when I was a physics grad student in Göttingen. I dropped out due to falling behind and depression. I've moved on to a career in CS, but I still love physics.

[@paulpaulsen7777]

Sir, you are the best in explaining complicated subjects in a very easy and understandable way. Thank you 🙏

[@Maths_is_love3.14]

For comparison, 1 mole of nitrogen is allowed to expand in a box of unit volume ( 1m³) No. Of microstates are e^(41×10^25)

[@visenmaackerman]

please sir, bhaiya, anna , please never stop making these kind of videos, its insipiring and very informative for students those who are passionate about science(physics and chem mainly)

[@sambathkumar634]

Are you tamil nadu

[@Name-yu6ux]

​@@sambathkumar634ya bro im class 11❤ love for phhysics

[@sambathkumar634]

@@Name-yu6ux I am also love with physics. எந்த ஊரு தன்பி

[@varunvaswani4562]

A huge huge yes Mahesh sir!!!!! ✨✨✨🔥 We would love to see more of your videos on such topics. Entropy with Black Holes and Holographic principle sound awesome. The internet is full of videos that either just talk speculatively or dive deep into the maths. But we miss the intuition! It would be heartwarming and enlightening to have a delicacy (as always), from you on the topics.....❤

[@roys4244]

Mahesh, some further points about Entropy to consider: 1. Is a Microstate merely positional? Presumably not if Temperature increases number of Microstates. Momentum values now separate microstates also. 2. Classically we can measure (position) to arbitrary accuracy. So again what is a Microstate? Presumably a range of numbers/positions per microstate. So what is the physical significance of these regions, if any? Do they depend on the measuring apparatus, for example? It has been argued that classical physics never resolved these issues, but that the Planck volumes fixed this. 3. Also why does the Maxwell Demon brain get filled up with all that data? Once it has done a sorting task, cannot it just forget the data and move onto the next molecule? I think that the answer to this is that deleting data generates Entropy, but this could be explained further.

[@theomommsen6875]

Interesting questions

[@robertwaugh7296]

No one believed in microstates and boltzmann suffered a lot. He committed suicide. He was almost expelled and ignored. Only after advent of quantum mechanics when they started explaining extremely new term called allowed energy levels which was very unbelievable for scientists. They did it buy writing waves in term of fourier transform etc. Only after that the term microstates and boltzmann research got approved. It was like as if Einstein had derived an equation using some assumptions even before the Michaelson moraley ether experiment. Similar was done by boltzmann

[@MasterHigure]

Just looking at the first example with coffee and cream (I haven't even watched the rest of the video yet), this is the difference between entropy of a system and the Kolmogorov complexity of the large-scale features of that system. Essentially, the features of the half-mixed coffee-and-cream that are large enough for us to see are complicated and difficult to describe, while the homogeneous mixture is very easy to describe on our scale. But trying to describe the *exact* state of the system, the position of each molecule of fat and caffeine and water and sugar is easier in the half-mixed case. And it is this more small-scale Kolmogorov complexity that's more closely tied to entropy. (Kolmogorov complexity is basically "How many words do you need to describe the thing?" For the macroscopic state of the fully mixed coffee, that basically amounts to listing a few concentrations and a temperature, so relatively low complexity. For the half-mixed, you have to describe the shape of the main boundary between cream and coffee, and you probably have to describe regions of different mixing ratios. All in all a much longer description is needed.)

[@Damnnnbruh]

I'm so convinced that statisticians made up entropy to stay relevant

[@obiwanpez]

Don’t you put that on mathematicians! ;)

[@nrao8977]

So, was Feyman a physicist or a statistician?

[@dvxc]

I will never stop leaving comments on these videos that say the same thing: I think that you have mastered science communication in a way that nobody else has. I think that you are such a valuable resource to scientific learning, possibly even one of the most valuable. Incredible work as always.

[@Dr.ScoobyDooDoo]

Always happy to see a video that will change my way of thinking about physics, thank you Mahesh

[@nicholaswalker1208]

I love your videos. Takes topics that we’ve all heard of, huge things, and breaks them down into understandable bites until we can digest all of it. Bravo my man

[@akirasthecat]

Pleeeeease increase my brain's entropy and do more videos about all the entropy stuff! 🙏

[@dev_invc]

Learning is the process of minimizing entropy locally in your brain. You organize data from everything you have observed. This happens in some part of your brain but in that process you send the other data to your memory part of the brain, increasing the global entropy of your brain! To be smart is to have high entropy brain but low entropy states in the brain. P.S: I am sorry I don’t know why I wrote this, maybe to increase the entropy of this comment section

[@wiffleblat]

You are one of the best educational channels on this platform. Your enthusiasm and ability to explain complicated (for me) ideas in an understandable way is greatly appreciated. Hopefully your channel will continue to grow.

[@kallewirsch2263]

One of the problems seems to be, that what we call "ordered" is most often made up in our brain. We mean with order: A simple pattern which is easy and fast to recognize. Take your example with the rooms. What is the difference. We consider the room at the left ordered because the pattern is eg. "all the books are in the bookshelf", while in the image on the right everything is distributed throughout the floor, we cannot see a pattern in the items. But eg. arrange those books in a checkerboard pattern, somehow your brain identifies this as ordered. What is interesting is, that in the milk example you reverse that feeling of "ordered". You consider the evenly distributed milk as more ordered, then the milk piling up in one corner. To me it seems that the simplest pattern possible would be the evenly distribution. In the example of the room we refuse to call that more ordered because the items are too large and too random as to be almost indistinguishable to each other and that is why we do not accept that pattern as applicable. (Randomness is another of those concepts which are much more complicated then one might think)

[@theomommsen6875]

Thank you for your interesting thoughts

[@indrekl89]

I think I have the same worry. What constitutes a given macrostate? It seems like it is up to us to describe a macrostate e.g. as "all the books are in the bookshelf" rather than "all the chemistry books are on the lower shelf and all the physics books are on the higher shelf". But the second description would be a description of a lower entropy state than the first description. So, it looks like the amount of entropy in a state dependent on how we choose to describe the state. And that seems like it could be used to formulate trivial counterexamples to the second law of thermodynamics. We could just pick suitable descriptions for that. E.g. we start with a description "all the books are in the room" which is a high entropy state description, and end with a description which specifies the exact location of each book in the room. 🤔

[@damsarotti]

Dios mío, I've just subscribed. I studied chemical engineering 'til 5th year, and these questions and topics have always been on my mind. Entropy has always been a topic that fascinated me deeply, but I always thought I didn't quite get it. I quit studying this career because I learned about myself that I did not care about applying this stuff to industrial growth, and I'd rather think and philosophize about it, but that's a different story. Your videos made me want to get back to this. Get back to science, to question everything. Thank you for that. Greetings from Argentina.

[@coreyyanofsky]

just want to say i really appreciate this style of clickbait title, not least because the videos do actually frame the info as "look what i learned!"

[@denrober]

I am so glad I found your channel, your style and way of rediscovering really helps me understand - thank you!

[@platypi_otbs]

Great video. I feel I understand entropy much more now. Thinking back to the question of the balls thrown into the box, I started asking myself if there's another reason to say the box on the right is more likely. I'm sure they are not a novel idea, but these are what I came up with. Our assumptions about how the balls were put into place affect our logic. We would assume you flung them with no intent of where they land. But what if you've practiced for years and have immaculate aim. The second would be unlikely. We would assume the box is level enough to keep the balls from gathering. We would assume the balls aren't magnetized. Also, our interpretation of the question affects our logic. Because I knew this video was about entropy, I answered correctly, but had I interpreted it in a less academic setting, I might answer based on average distance between the balls or some other aspect.

[@vanshmishra7119]

The notification made me so excited!! I was studying about this recently and yes understood more than I did before but obviously lesser than I should....and wondered if you've made a video on this!! Now I'll save this for tomorrow morning to start off the day the right way but even before watching the video I know this is greatand & rare high quality physics content so massive. THANK YOU!!

[@Ellie-pc4rc]

Hi Mahesh, I am new fan but I have been loving binging all your content ❤

[@vypmnoo0]

The way you explain the complexities of a topic. The way the idea originated in the authors mind and how he tackled it gives an intuitive way for us to re-learn our own thinking process that we long lost since school times, and thats what makes your videos more fun and intuitive to watch. You bring joy to learning and thats truly an immense talent and hardwork you put in. Thank you for all your videos. Waiting for more.

[@nikku5584]

Hello sir. I was just thinking about entropy last day and here I am. 2 minutes into the video and I am already in!

[@HarshavardhanGavicherla]

You are such a breeze to my life. I spend days without sleep thinking about this stuff. Your explanations are such a relief to my questioning brain. I may be an extreme case of over thinker about reality itself, but your channel is the answer I am seeking all along. Thank you is such a small word. You have no idea how much peace you have brought into my life. 🙏🏻

[@vecna125]

Even at the quantum scale, entropy is increasing since a particle is spread out with more or less probabilities

[@austinlincoln3414]

What about when a measurement occurs? The probability wave collapses to a very localized spot. Isn’t that a less likely microstate of position? I have no idea

[@vecna125]

@@austinlincoln3414 I think when you make a measurement, the quantum particle's wave function collapses resulting in low microstate but since the detector is involved, we need to consider the particle and the detector as closed system. When we do that we observe that the photon from the detector now has more kinetic energy than before. The quantum particle may go to low microstate but the photon gains more microstates which increases the overall system's entropy

[@ChasSimpson]

Fantastic video. Love the way you explained everything just in terms of flow of entropy. But I think a short follow up video on the role work plays in this would be helpful. For example Maxwell's daemon opening and shutting of the hole does work on the system, as does compressing the gase with a cylinder. Absolutely love your channel! Your enthusiasm for fundamental understanding of topics is contagious!

[@RanbirSharma-zp6pw]

I thought I knew everything about entropy(the definition) this completely changes everything thank you so much Mahesh Sir Edit: thank you so much Mahesh Sir for your heart

[@Rangsk]

I was hoping you'd give another example which I struggle with: oil and water will separate over time even if you initially mix them. In general, materials of different densities will separate. This means the separation has a higher entropy than the mix. This is opposite of your earlier arguments, so why is this?

[@aadipandey8237]

bruh these Feynman's lectures seems goated !

[@shilajawani4003]

can you please tell the chapter of Feynman's book

[@aaronallenlmt]

I just discovered your channel. This was the best explanation and visual representations for entropy that I've ever seen. I've subscribed. Thank you!

[@user-np6tf8zx1u]

I clicked to learn about entropy and left with proof of aliens

[@Rezz_RR]

😂

[@Raian-ox1db]

I just want to say how thankful I am and how much I look forward to each new video! "Does the intense gravity inside a black hole keep everything highly ordered, making the interior a "0" - entropy system?" "If nothing, not even light, can escape from a black hole, how is it possible for black holes to emit any kind of radiation? Where does Hawking radiation come from if energy can’t escape from inside the event horizon?"

[@binbots]

Entropy increases overall as a consequence of our expanding observable universe. Statistically as time elapses probabilities increase of where energy can disperse as more space becomes available.

[@sensorer]

As Pauli said: "Not even wrong"

[@blueckaym]

The trouble of your argument is that while the Universe expands globally, it doesn't expand locally, like in galaxies and stellar systems (like ours). So why do we still have Entropy locally? ;)

[@blueckaym]

@@sensorer , no he is actually wrong :)

[@binbots]

@@blueckaym the universe is expanding everywhere. Just because places with high energy negate the effect of that expansion doesn’t mean it’s not there.

[@blueckaym]

@@binbots , actually that's a speculation! We don't actually know why and how it expands. What we DO know is that we don't observe the expansion in the clumped areas like galaxies. It's not clear if it happens everywhere but local forces of attraction overcome it, or if it happens outside of galaxies.

[@xMoomin]

I was explaining entropy to wife with the "gas in room corner spreading out", "coffee", "laundry" examples, and that it is a just result/fact of statistics.. well your video came just in time, and the probabilities being demonstrated out is very helpful.. thanks for your service to humanity bruh

[@MiraOli-lt3fx]

i think the thumbnail is a bit more confusing

[@Mahesh_Shenoy]

Is it, why?

[@MiraOli-lt3fx]

@@Mahesh_Shenoy it just looks like some random picture of ginger and desert 😆 I may be the only one who find the thumbnail a bit absurd I know you have some solid thought behind that thumbnail so don't get me wrong 😊🥰

[@MiraOli-lt3fx]

@@Mahesh_Shenoy and also thank you for making me to look every topic with new perception and I have discovered your channel through khan academy videos and I was wondering who is this teacher who is explainig such confusing topics in simple and visually appealing animation. Once again thank you very much for sparking my curosity and keep me learning❤❤

[@darkknight-nw5nc]

True​@@MiraOli-lt3fx

[@rcmakingtracks18]

Best explanation I ever heard... liked and subscribed. John, in the UK

[@Team_COnSEAL]

I've been searching for the perfect video on entropy for months, and as soon as I saw this one by Mahesh, I knew my quest was over (commenting even before watching it)

[@Mahesh_Shenoy]

Oh boy, very high pressure!

[@cy3er_hawkzz287]

Watch the video by veritasium its great as well!!!

[@thelife5628]

Totally agree

[@aidanwebster75]

Veritasium's vid is also worth a watch

[@Team_COnSEAL]

@@aidanwebster75 i watched that too but got confused more instead. my bad, i believe.

[@chrmrt_music-wy8eg]

Your explanations are top notch! Thank you so much for your effort! I just wanted to point out an explanation for why entropy cannot reverse, even though your (very nice) marbles example allows for it to be "technically possible". It's only technically possible because the marbles in the example move in a discrete grid. If they were moving in a continuous space, there would be infinitely many possible arrangements, and thus, the probability of them moving back to a previous state is infinitely small (aka. 0)

[@WolfRaven-jm1cm]

There is one problem with the example about the balls in the slots. It assumes that balls will take a random position at any point in time. Assuming that each ball will pick an initial cardinal direction to move when the space is opened then they could try to move into the wall. Since they can't move then they will remain in place. Same with the other balls if they try to move in a space that is occupied. That means some patterns are more likely that others as those patterns would be repeated in the set. So not every single pattern is just as likely. Also, if we assume each ball starts with an amount of energy, that energy slightly dissipates every time it has an interaction with another ball or the wall. Also, each ball will transfer it's energy to the other ball it comes in contact with. This means the patterns cannot be random and would be deterministic. Some patterns are more likely than others. So, in the end, when all meaningful energy is lost in the system, we are more likely to see a pattern of balls that are evenly spread throughout the space than to see them clustered in a corner. That's why when gas fills a chamber, it spreads throughout the chamber and not remaining or rearranging at any point to stick into a corner because that would require more energy to put it there and then more energy to negate the new high energy state that it would be in. High Energy = Low Entropy Low Energy = High Entropy

[@sharpshooterrus]

Thank you Mahesh for your videos. I really enjoy your enthusiasm and excitement when you are breaking down complex concepts with intuitive examples. In this video, I want to point out a counter argument to your idea that information increases entropy, which you mentioned on 21:30 Your argument is that when there is no information, then everything is 0, which only has one possible configuration, and when there is information, then the combinations are 2^bits (in a binary storage for example). But I think it's actually the opposite. When no information is stored, the data is not 0, it's undefined, in which case any value can exist, making the combinations = 2^(capacity in bits). But when information is recorded, it is forced into a specific configuration. For example, if we're storing the position and velocity of individual particles, there is only one combination that is correct. So recording data _reduces_ entropy in the harddrive. This explains why over time data in physical devices starts to corrupt. The number of combinations starts to naturally increase, corrupting the original precise recorded data. So while I don't disagree that Maxwell's Demon does not decrease entropy, it doesn't make sense in the way you explained it. It cannot happen because it's recording data.

[@AjitSharma-km6ev]

I thought I knew a bit a bit about the entropy. But this video blew my mind and altered my fundamental concepts. Kudos!

[@stevenpike7857]

In my uneducated opinion, the marble thought experiment is not taking into account the energy you're putting into the marble as you throw it into the box and how they strike or hit each other dissipating that energy. The odds of lining up like that, as you throw marbles into the box while they bounce around transferring energy into each other would make them lining up like that in tight formation highly unlikely if not impossible. Now yes, if you had partitioned the box with those small boxes, restriction the marbles from being knocked out of place / and or limiting the amount of energy being transferred to other marbles - the odds would be the same.

[@UjwalJ211]

Wtf brother!!! For god's sake I don't think there is another channel on KZbin that is as underrated as yours But u r growing fast these days. Hoping it will continue nd good luck But .....ur accent........

[@andrewn7365]

This is why I subscribe to you! Entropy was difficult for me to understand in school but this has helped me build an intuition about it.

[@KAZVorpal]

"Probooblity"

[@greyshopleskin2315]

Please make more videos about entropy this is very interesting and transcendental. I think entropy does not necessarily generate life because as low entropy gets transformed into high entropy, it could result in a macro state that cannot support life. For example a planet really close to its star will get tons of low entropy which will get transformed into heat. However a planet at a temperature of thousands of Celsius will not generate life.

[@cloudprecept]

Mahesh, Thank you again for yet another beautiful and intuitive explanation. As many have commented entropy was just a mysterious concept just learned as a theory. Teachers/Books teaching entropy could not push my brains entropy higher and it only got increased by learning from this video. Also I saw many interesting conversations happening within the comments and I think it would greatly help if you could start a discord so that all of us can join and exchange ideas and information 🎉

[@SPDLand]

Mahesh's videos are of a vital importance to 1) give gifted minds the ability to really finally understand important concepts they never could grasp staring at formulas in dull books. 2) intelligent minds the actual understanding behind the theories they thought they knew and now maybe also finally able to teach to others in a comprehensible fashion . 3) Maybe even the weak to normal minds to feel a spark of exitement or even more if it were only for his enthusiasm. That is a wide range of intellect served while most only address a certain group which makes such videos basically unwatchable for others no matter how hard they try. That is a great gift.

[@Uri1000x1]

Many microstates will result in the same gas temperature, for example where temperature is a state variable of interest. Entropy, as a quantity is the number of microstates possible. The box of gas has several state variables, such as particle position, velocity, momentum, etc. The set of all these variables is the state space. Each variable is a function of time. Maybe the entropy must remain unknown since there are infinite locations for the gas particles to occupy. When the gas is spread to the whole box, the entropy is constant at it's highest, an equilibrium macrostate. No matter what the fully specified state of the system is then, with particles moving around, entropy is a constant. Before this equilibrium, particles were isolated and couldn't immediately move to occupy every part of the box. Compressing the gas reduces the state space based on heat or kenetic energy but that adds heat (increases particle velocities), I guess keeping entropy, S, still constant. I guess the demon adds to the physical system, and it's brain has increasing combinations of state variables, S still constant? If it's not a closed system heat flows out of the box as particles bump the walls, entropy increases.

[@prajjawal4148]

29:27 sir, I don't get the idea of 'don't waste energy' connected with low entropy and high entropy energy. I have one thing in my mind... If we use a heater continuously, it will consume energy and according to you, it is converting low entropy energy to high entropy energy and we cannot use the high entropy energy. But what if I use the heater to heat up gas and use it in a hot air balloon? I used the electrical energy, which according to you is low entropy energy. Then heat energy is formed at high entropy energy, which according to you can't be used but I used it. Sir, please tell me where's the flaw in my thinking🙏. But I am very thankful that you explained so well. Thanks sir🙏

[@PanchoTheSneaky]

I also made the mistake of thinking it was a measurement of order and disorder because the most classic examples are the tidy room and the sand castle. After this video I finally grasped what entropy truly is. And for that I thank you!

[@diogocoletto9135]

Feynman Lectures always show us the reality and infallible logic behind complex and apparently abstract concepts that we used to take for truth through unfounded acceptance. Bring more Feynman Lectures plot-twists, Mahesh! *please also bring up pauli's exclusion principle, something tells me only you can make me really understand this, so don't disappoint me

[@siddhant005]

At 18:50 just nailed it. That was a hit on the nail point of view❤❤❤❤ In last 2 minutes, I am really feeling greatful to god because I clicked this video to watch.

[@Galileosays]

@3:57 The issue with the particle in a box view is like the Zeno problem: Achilles cannot pass a turtle which is 10 meter in front of him. Zeno states that when Achilles has made the 10 meteres, the turtle is already one meter ahead. And when Achilles goes for the 1 meter, the turtle is 10 cm ahead, etc. The issue is that Zeno' ignored the speed of Achilles and the turtle. The same holds for the particles in a box. One forgets that the particles must obey the Maxwell-Boltzmann velocity distribution. There must be equal amount of particles moving to the right, left, top, bottom, front and back.Therefore it is impossible that all will be at one side of the box. Initially, one can place the particle at one side of the box, which mimics the situation of a crystal, but after agitation (heat input) the particles disperse and they never go back to the initial distribution without cooling, because of the constant velocity distribution.

[@windubitably]

Wow, halfway through I thought, “Okay cool, I think I have a good understanding.” And then the entire second half of the video was even more mind blowing! So informative, all the way to the end. I love your way of explaining, and the way you talk to yourself as if you’re others: “First, Feynman says, ‘Calm down Mohesh’.” 😂

[@jasonzhou3152]

Love your content Love your passion Could you do a video on Pauli’s exclusion principle

[@coolatma]

So the universe started with a low entropy- the Big Bang and the chances of a Big Crunch are negligible then! Great brainstorming, Mahesh👍

[@Jon-o7j]

I studied this 30+ years ago and stumbling on your videos has been wonderful, so better explained than the books I used

[@xmatterdaily]

11:36 if the first one has one arrangement, then obviously you are considering all marbles to be equal. In that case the second and third will not have that many arrangements. If each marble is distinct then the first one will have much more arrangements. Correct me if wrong.

[@MichaelRau-n3e]

Since i watched a video about entropy some moths ago i am very fascinated by it and could explain all the problems and questions of this video by myself. I find it mind-blowing that the tendency of enegy wanting to go into a lower state of energy is basically a engine that creates states of more or less probability. And once the less probably states occur back to back complexity develops and once the complexity is able to build more complexity by itself by tranforming energy to a lower state the point of life is reached. And now life is so complex that it explores its creater (the universe). But we are also the universe. So the universe became conscious. (Correct me if i said something wrong)

[@iddiiddrisu5971]

Just a small note. The arrow of time does comes from physics. The microstates are physics rules basically and we just use stats to average over the large numbers that would make the macrostates.

[@Cavraged]

These videos are just amazing, been watching you from last 3 years on khan academy and discovered this channel last year only, i feel bad when i see videos getting lesser views and i feel like if you'll just stop posting if this continues, but still I'll keep watching your videos and keep supporting you, man you have really changed my understanding about science, hats off to you

[@abhijeetgaikwad837]

The best explanation i could ever get from any other sources. Keep it up bro.

[@niflheims]

Awesome as always 😃🤯 Your enthusiasm is contagious and I feel as if I drunk lots of irreversible latte macchiato. Your statistics example with the micro states also illustrates why playing the lottery is not really a good idea. Looking forward to your grasp on the Fermi Paradox (which is disturbing) and all the juicy stuff you mentioned! Kudos

[@paulstahman3533]

I have a vision of entropy based on gas diffusion similar to your depiction of 10 balls in the 10, 20 and 40 microstate system. But rather than computing the probabilities for each to determine the likely time line when the container size increases, consider the motion of each ball having equal chance of moving left or right. So at the interface between the empty and occupied region of the container half the balls will move left (further into occupied region) and half to the right. Thus spreading out into unoccupied region of the container. Applying this principle throughout the container at increasing time steps will eventually spread out the balls evenly throughout the containner. This is the basis of deriving the diffusion equation and to seems to have roots in entropy on a microscopic scale.

[@vyvianalcott1681]

"Probablity" is so much more efficient and fun to say lol, great video as always!

[@deaconsyxx322]

i love your explanations Mahesh, always great content!

[@syhansolo3589]

I'm a new subscriber here, so I have to say that this guy has a contagious sort of style that makes me smile. Hard to explain, or maybe not, but I'm attracted to it. Not in a geh way or anything, but strange anomaly all the same.

[@Mahesh_Shenoy]

Welcome. Glad to hear that. That's the main motto of the channel - "Rediscover complex ideas intuitively, with a smile". So I am glad you could resonate :)

[@fredfurner]

As you were explaining this and you were explaining that the direction of time flows in the direction of entropy, I immediately thought about how gravity is a perception of the curvature of space and time, but then I have this contradictory position in my head that all electromagnetism and kinetic energy is explainable through newtons laws. The only exception to this seems to be gravity which so far as I know does not seem to participate in this chain of electromagnetic interactions of matter, but instead is a result of mass and the curvature of space-time. Gravity also seems to decrease entropy, at least locally. So it seems that gravity works in the opposite direction to entropy. I'm sure you'll show me how I'm wrong lol. But thank you so much for what you do. I hope you are finding success with the God-given talents you've been blessed with. We live in an amazing, mysterious, intricate machine which follows a programmed logic that people like you are slowly helping us to discover and understand. Thanks so much.

[@knutritter461]

M. Sc. of chemistry here: A lecture in statistical thermodynamics opened my eyes as well. I highly recommend it and it gives a really good understanding! And btw: It's more mathematics and maybe a little bit physics than chemistry! 😂

[@craigsymalla25]

Love your t-shirt. I need one of those. You have a real gift as a teacher. Thanks for making your vids

[@babakmahmid]

I admire your ability to explain such a difficult concept in such an understandable language!!

[@xXNoamsChannelXx]

perfect timing on this vid for me. it took my professor 2 hours to increase the entropy in my brain the same amount that you did in 15 (I watched on x2 speed). thank you.

[@courage936]

I'm glad more people are finally talking about this, from the moment I learned about entropy as part of my IB chemistry, I knew that something was philosophically off-putting

[@DieBieneFranz]

You say that life is increasing entropy and thereby should be very common in the universe, but don't we also have to consider the chance that an ordered state of molecules first have to form in order for life to be possible? I mean, couldn't it be very unlikely that molecules arrange in a certain way, but WHEN they form in this way the evolution of life is very probable, because it increases entropy even more than a universe without life? Couldn't this be a solution for the Fermi paradox? Maybe the formation of ordered molecules that could form a structure which makes life possible is as unlikely as a spontaneous formation of gas-molecules in a chamber on only one side. Which like you showed here is nearly zero. But in an infinite huge universe after billions of years, maybe these states will form at some time. Which would make life very rare. But maybe I didn't understand something? Very cool content by the way, keep it on man!!!

[@azuraselenite]

I remeber learning probability and statistics at school and being like "Not only do I not like this, I don't need it" Boy was I wrong lmao. Great video!

[@jimmyniful]

Bro, your enthusiasm makes it so much fun to learn!

[@asadakbar2945]

An incredulous explaination of something that made no sense to me last year when i was studying my fsc physics book....I've watched almost all of ur videos sir and ur videos helped me alot to fully understand what i studied last year....keep up the good work please.... But i do have a question regarding what you discussed in this video and that would be.. "Why do living beings(humans,plants,animals etc) want a low entropy state?" Do they need it to lower their temperature to optimum temp bcz otherwise the sun will burn us if it constantly shines at us?

[@aadilansari5997]

Saare jawab hain Qur ane Paak main. In hinduon ki jagah Islam ke talib ilmon par zyaada tavvzon dein.

[@ChemistryWallah-KartarKumar]

I searched your whole channel for this video of entropy 1 week ago cuz I didn't find intuition and rational explanation of this topic. But I knew Mahesh Shenoy is only one guy who really feels and understands physics with logic Thanks Dear Yara