Molecular Temperature & Degrees of Freedom

[@dc1049]

I imagine a world where lectures are accompanied by these visuals. It really helps tie a lot of concepts together.

[@ahappyimago]

It’s been my dream for years

[@JuanLopez-zo8os]

yeah, fuck conventional education

[@RickyMud]

Covid and online lectures woulda been the perfect opportunity for it if we could have planned better

[@boredgunner]

Schools are obsolete due to channels like this.

[@Alcibiades586]

I will be using this video exactly as you describe in my lecture tomorrow 😊

[@suspendedtheone2174]

These videos clears all my misconceptions regarding physics, I learn a lot here more than my class. Please keep uploading more videos, thank you.

[@EugeneKhutoryansky]

I am glad my videos are helpful. More videos are on their way. Thanks.

[@Bizarro_na_chapa]

@@EugeneKhutoryansky amazing how clear You are

[@HarshitfromIndia]

@@EugeneKhutoryansky please make more videos on thermodynamics.

[@Hossak]

@@EugeneKhutoryansky I want to add my thanks - my goodness me this was a fantastic video!

[@Om_Namah_Shivayaa]

@Physics Videos by Eugene Khutoryansky You are the teacher the world needs in these times.

[@sachiel197]

A few minutes in I realised this would be about heat capacity Never really thought about how it works till now Thank you for the video

[@EugeneKhutoryansky]

I am glad you liked my video. Thanks.

[@sheldoncooper5522]

The intuition you gain from watching these videos is out of the world. The animation is also amazing. Thanks a lot

[@EugeneKhutoryansky]

Thanks for the compliments.

[@SIDDHANTCPATIL]

Never until today I realised how Degrees of Freedom are related to heat capacities. And all of this because of your videos. Thank you 🙏

[@EugeneKhutoryansky]

I am glad my video was helpful. Thanks.

[@omniyambot9876]

omggg it's always intuitive to me how motion of particles are conserved related to the temperature. I've never considered the rotation of the molecules. thanks again eugene sir

[@EugeneKhutoryansky]

Thanks.

[@aashsyed1277]

hi omni i watch blackpenredpen, eddie woo and this channel.

[@omniyambot9876]

@@aashsyed1277 good, we share things we love

[@aashsyed1277]

@@omniyambot9876 oh wow

[@ckimsey77]

What blows my mind is how gases defy laws of motion, because the collisions between molecules do not loose energy of motion... when laws of physics state that energy is lost in collisions so two objects even with perfect rigidity so theres no frictional losses in deformation of the objects when colliding they still will eventually stop. But atoms defy this and more around bouncing off the container walls and each other without loosing or transferring any energy. By laws, atoms colliding with the container walls should transfer energy to the walls, and since the atoms are tiny in mass compared to the walls they would lose energy to the wall at a high rate, as more massive objects are barely moved when tiny objects strike them. With classical rules the molecules would lose energy to the walls and eventually stop moving, but this does not happen...ever...so how do they get to break the "laws"?? The atomic world breaks all the laws, but it's really too complicated for a chat window to get into...it really me as an chem. engr. that the atomic world and the macro world have two different sets of laws of physics whichcant apply to the other. If everything is made of atoms, should the laws governing atoms not also govern the objects built out of them?? Shouldnt constructed things not behave as the parts they are constructed from? This is like saying wood has laws and properties set to define how wold behaves, but a shed built out of wood has zero properties of the wood pieces and totally different set of laws describing the sheds properties and behavior.

[@StevenG22]

I’ve recommended your videos to many fellow students of physics. The animations and explanations are always top-notch! Keep up the amazing work.

[@EugeneKhutoryansky]

Thanks for the compliments and thanks for recommending my videos. I am glad you like my videos.

[@creationfied]

absolutely love how the music goes from rock to uplifting to a random chopin prelude

[@michaelwang1730]

Those downvotes are from people who are moved to tears by the beauty of physics and the simplicity of your explanation to see the upvote button.

[@stapler942]

My takeaway from quality videos like this is that university science professors should either learn 3D animation or consult animators more often when designing lectures. They work so much better than chalk and power point.

[@A3Kr0n]

I like the retro feel.

[@Dhardy316]

I dont know who this Adam fella is but he is really energetic

[@smar1k359]

Nice oneee! Hahaha

[@-astrangerontheinternet6687]

😂

[@janew2108]

🤣🤣🤣

[@Nah_Bohdi]

Hiss.

[@theonlyramankumar8359]

Biggest fan of your voice.... No channel can beat this channel... You will be always in the top 5 in the world.

[@EugeneKhutoryansky]

Thanks for the compliments.

[@maxwellsequation4887]

This, 3b1b, and science clic are probably the best channels on KZbin.

[@dibertos]

I finaly understand the heat pump! Thank you so much, you have given me much needed insight over the years about the underlaying physics of electricity and physics in general! Please keep uploading.

[@EugeneKhutoryansky]

Thanks. I am glad that my videos are helpful. More videos are on their way.

[@madeleinecallan3153]

We need to tell our professors to teach like this, and include these videos with the pp presentations they all like to give. Who here agrees? This is the new frontier when it comes to education! Your videos unravel concepts I spend hours reading.

[@EugeneKhutoryansky]

I am glad that my videos are helpful. Thanks.

[@Wintersghost135]

It’s refreshing to see particle physics finally get some love on KZbin. The breakdown of where energy goes in the molecules was fascinating. I especially loved the 3 to 5 ratio of kinetic to rotational energy.

[@EugeneKhutoryansky]

I am glad you liked my video. Thanks.

[@konradswart4069]

Wow! What a clear description of heat capacity! I have always wondered about why the heat capacity changes in jumps when you add energy to a gas. This video makes clear, that this is because with enough heat, the changes of the energy states of the electron 'kicks in'. Although it is just briefly mentioned in this video, I now _for the first time_ understand this phenomenon! Great work!

[@EugeneKhutoryansky]

Thanks for the compliment about my video. It is actually other degrees of freedom that are primarily responsible for changes in the heat capacity with temperature: such as the vibrations between the atoms internal to the molecules, that kick in only at certain temperatures due to Quantum Mechanics. Thanks.

[@konradswart4069]

@@EugeneKhutoryansky Indeed. That had become clear to me thanks to this video. Your videos do not explain concepts only explicitly, but also implicitly. Many of them are _really great!_ I often refer others to you.

[@EugeneKhutoryansky]

Thanks.

[@shakennotstired8392]

this is so much better than physics textbooks, not just the animation, but also the explanation. Putting them together, this is God sent. I have a much clearer understanding of temperatute and heat capacity from watching this than from reading several textbooks

[@EugeneKhutoryansky]

Thanks for the compliments. I am glad my video was helpful.

[@tanvirfarhan5585]

This was...far beyond what i expected. You guys could have gotten away with much, much less of an effort without any pushback. Instead, we are left with this... An absolutely beautiful, visually pleasing, simple yet concise explanations which work hand in hand with the animations to bring us an intuitive, entry-level walk-through of the standard model. I'm honestly awe struck. I can confidently say this is easily one of the best videos on quantum mechanics I have yet had the privilege to enjoy here on KZbin. (and I watch nothing but science and physics docs on KZbin etc) What an absolutely superb masterpiece, what an incredibly engaging tool which undoubtedly will benefit thousands and thousands of inquisitive minds. Thank you so much for everyone responsible for this labor of love. It truly shows your passion for your field, and hoo boy what a treat the whole video was. It is insanely rare that animations , live explanations, and facts all come together so brilliant and organicly organized in such a way that the end product comes together to create something much, much greater than each part on it's own. What an honor. BTW make a video about the partial derivative of a vector field

[@EugeneKhutoryansky]

Thanks for the really great compliments. Derivatives of vector fields is on my list of topics for future videos. Thanks.

[@uptothesummit3755]

Very well done. Well may be the best educational channel regarding physics.

[@EugeneKhutoryansky]

Thanks for the compliments.

[@agungbuana6796]

i wish I had this 30 years ago when I took a material science class.. :(

[@xyzct]

I hear you. I'm sure there are many older viewers who weep silently as they watch Eugene's video playlist. (Same with 3Blue1Brown's channel.)

[@jasperhawkins9152]

These videos are by far the best on youtube about physics, just amazing. I understand everything the first time you say them due to the depth of explanation, yet the videos somehow remain relatively short.

[@EugeneKhutoryansky]

Thanks for the compliments about my videos. I also have some long videos too. For example, my video on Maxwell's Laws is almost 50 minutes long. My video on Thermodynamics, referenced at the end of this video, is 36 minutes long. Thanks.

[@jasperhawkins9152]

@@EugeneKhutoryansky Ive watched them also, long is the wrong word considering the quantity of information and depth. My course takes atleast two weeks for each hour of your videos.

[@foxbeef1983]

Eugene, your videos prove the value of a free internet for all…The graphic representations help bridge imagination and reality; something my math teachers couldn’t do, or perhaps it was my brain that was not yet ready for it…I will become a Patreon on my next payday. Thank you kind sir!

[@EugeneKhutoryansky]

Thanks for the compliments about my videos and I really appreciate your support on Patreon. Thank you.

[@maheshkumarsrivastava.505]

Before finding this channel I loved Physics and Mathematics but now, my life is Physics and Mathematics. Thanks for one of the greatest explanations. for one of the greatest inspirations. for telling us the true beauty of nature through Physics and Mathematics.

[@EugeneKhutoryansky]

Thanks for the compliments.

[@MrSharkman19]

I love the thermodynamics videos, keep up the great work

[@EugeneKhutoryansky]

Thanks.

[@75blackviking]

More brilliantly animated, and easy to understand content provided by Mr. K. Easily one of the best channels on KZbin.

[@EugeneKhutoryansky]

Thanks.

[@prashantbharti2650]

I'm in HIGH SCHOOL and I'm glad to watch these content from kind you and clear my Concepts and UNDERSTANDING.🥰

[@simonwatson2399]

Best intuitive explanation of heat capacity I've ever seen.

[@EugeneKhutoryansky]

Thanks. I am glad you liked my explanation.

[@1DR31N]

Your videos visualizes our imagination. Wonderful.

[@EugeneKhutoryansky]

Thanks.

[@fayazelahi]

You have done justice by visualisation art , .None can explain in such simple manner .luv ur way of teaching mam.thumbs up

[@EugeneKhutoryansky]

Thanks for the compliments.

[@sivavenkateshr]

Wow! Learning from these videos is awesome 👌. Really like your style of making videos. The truth is many students like me are learning and driven into science by people like you.

[@EugeneKhutoryansky]

Thanks for the compliments. I am glad you like my videos.

[@cielaczek81]

@@EugeneKhutoryansky I must say your vidoes are amazing!!! Can you comment on my question . What can you say about these fragments in Conceptual Physics which I paste here in another comment? There is something wrong with these statements . How can be called tranasltional motion like ..."By translational we mean to-and-fro linear motion" Is it good definition? It rather refer to oscillation I think. Later we have "how fast the particles move as they vibrate and jiggle in place." - how can It be translational motion? How can you explain that this make sense and does not introduce confusion??

[@madisondampier3389]

@@cielaczek81 An oscillation assumes that there is a state which the particle is attracted towards constantly as a returning position, like being pulled and pushed by a relatively static spring, where translational movement is unbounded, it is inertia and will only cease with another impulse. Two bonded atoms oscillate in the distance between each other, while their position in 3 dimensional space is their translational momentum.

[@tetrahexo5592]

Your videos should be used as educational material in schools😊👍

[@EugeneKhutoryansky]

Thanks.

[@odeia18]

i’m just about to reach this topic in condensed matter course, thank you for the brilliant intuition as always!!!

[@EugeneKhutoryansky]

Thanks.

[@gamlay606]

Great video as always. when I repeat these videos more and more I will gain extra knowledge each time.

[@EugeneKhutoryansky]

Thanks for the compliment.

[@teenlaura18]

I can't thank you enough for your videos they are wonderfully lucid with excellent animation and simple concise captions. Truly a breath of fresh air.

[@EugeneKhutoryansky]

Thanks for the compliments about my videos.

[@Sid_R]

These animations are absolutely beautiful! Thank you sir.

[@EugeneKhutoryansky]

I am glad you like my animations. Thanks for the compliment.

[@maxwellsequation4887]

Yaaay physics upload Wow this video looks awesome

[@babloovyas1080]

Absolutely beautiful Thanks for explaining degree of freedom so intensily yet simple.

[@EugeneKhutoryansky]

Thanks for the compliment about my video. I am glad you liked my explanation.

[@sersalikov]

Спасибо за ваши ролики и канал! Благодаря им, прекрасной визуализации, мне удалость понять концепции, которые не осилил в школе. P.S. Я, владея английским, пишу по-русски, так как полагаю, что автор (судя по его имени) владеет русским языком.

[@Jim-uq1mc]

Terrific video - crisp and clear with great animations.

[@EugeneKhutoryansky]

Thanks for the compliments.

[@CarlosRomeroFilosofia]

Thank you. Visualization is so helpful. You’re a genius and an artist.

[@EugeneKhutoryansky]

Thanks for the compliments. I am glad my visualization was helpful.

[@parshvpatel9644]

Last year only we have been taught this in Thermal physics and Chemistry but could understand this much . Thank you so much

[@EugeneKhutoryansky]

I am glad my video was helpful. Thanks.

[@GauravKumar-dr2yk]

This video is pure Gold..

[@EugeneKhutoryansky]

Thanks for the compliment about my video. I am glad you liked it.

[@academicalisthenics]

This video was quite insightful! Thanks and keep up that amazing work of yours!

[@EugeneKhutoryansky]

Thanks for the compliment. More videos are on their way.

[@TheyCallMeNewb]

Such a fruitful jaunt. Who knew that qualifying something as prosaic as temperature could takes us on such a tour.

[@xyzct]

Eugene, consider doing a video on atmospheric CO2 and radiative forcing, and why it's logarithmic (and all that good stuff).

[@TheChrasse]

Very clear and informative animation, great work Eugene!

[@EugeneKhutoryansky]

Thanks.

[@picksalot1]

Your videos are amazing good at explaining Physics in a clear, concise, and intelligent way. I only recently discovered your Channel, but have become a fan, and subscribed. I'm looking forward to catching up on all the videos that I've missed. It is time well spent. Thanks!

[@EugeneKhutoryansky]

Thanks for the compliments. I am glad to have you as a subscriber. I hope you enjoy all my older videos.

[@Rajeshkr001]

Truly awesome.. if only words could describe the awesomeness of your work.

[@EugeneKhutoryansky]

Thanks for the compliments.

[@babloovyas1080]

Come on dear These clarification of topic through videos, makes my heart to love you. God bless you dear, keep on doing good science work.

[@EugeneKhutoryansky]

Thanks.

[@mittaldevansh]

This is the best video lecture, I have seen on degrees of freedom and how they contribute to temperature. Wonderful Work. Thanks a ton for it. Meritorious. Praiseworthy. Exemplary. Artistic. Admirable. Excellent. Honourable. Distinguished. Special. Splendid. Stupendous. Breathtaking. Marvellous. Fabulous. Spectacular. Magnificent. Majestic. Superb. Remarkable. Incredible. Legendry. Phenomenal. Exhilarating. Stimulating. Inspiring.

[@EugeneKhutoryansky]

Thanks for the many compliments. I am glad you liked my video.

[@classica1fungus]

Im a visual learner so this helps me alot

[@EugeneKhutoryansky]

Thanks. I am glad that my animations are helpful.

[@Mirage1deluded]

A hearty thanks for making this video 🙏

[@EugeneKhutoryansky]

Thanks.

[@The578unit]

Wow I've never had heat capacity explained so clearly before. Thank you for this understanding.

[@EugeneKhutoryansky]

I am glad you liked my explanation. Thanks.

[@alejandrovizcarra7697]

I just want to say tank's to all of you guys!!!, you are making an exceptional job helping us to understand and expand our imagination

[@EugeneKhutoryansky]

Thanks.

[@wurttmapper2200]

THANK YOU! You are posting about the things I've always wondered about :)

[@EugeneKhutoryansky]

Thanks.

[@ganeshtripathi329]

You are doing great khutoryansky

[@EugeneKhutoryansky]

Thanks for the compliment.

[@whatthefunction9140]

Now I understand. You made me understand more.

[@EugeneKhutoryansky]

I am glad my video helped with the understanding. Thanks.

[@renzox1136]

Whaooo... Such a huge work to make this excellent video. Time well spent! Thank you

[@EugeneKhutoryansky]

Thanks. I am glad you liked my video.

[@cielaczek81]

"Temperature is proportional to the average translational kinetic energy per particle that makes up a substance. By translational we mean to-and-fro linear motion. For a gas, we refer to how fast the gas particles are bouncing back and forth; for a liquid, we refer to how fast they slide and jiggle past each other; and for a solid, we refer to how fast the particles move as they vibrate and jiggle in place. Note that temperature does not depend on how much of the substance you have. If you have a cup of hot water and then pour half of the water onto the floor, the water remaining in the cup hasn’t changed its temperature. The water remaining in the cup contains half the thermal energy that the full cup of water contained, because there are only half as many water molecules in the cup as before. Temperature is a per-particle property; thermal energy is related to the sum total kinetic energy of all of the particles in your sample.** Twice as much hot water has twice the thermal energy, even though its temperature (the average KE per particle) is the same." from textbook Conceptual Physical Science. I was wondering how it can be true what is written. Can you evaluate this piece of text? "By translational we mean to-and-fro linear motion" --- is he refering to 3 degrees of freedom?? Can we apply this to solids? Why he has written TRANSLATIONAL MOTION and TRANSLATIONAL kinetic energy (not just kinetic energy)? This is famous textbook and if he is wrong many students maybe confused. Second Part: "Particles in matter move in different ways. They move from one place to another, they rotate, and they vibrate to and fro. All these modes of motion, plus potential energy, contribute to the overall energy of a substance. Temperature, however, is defined by translational motion."

[@physicslover1950]

Wow my mentor , that was an excellent explanation . . 😍😍✍️💖💖 super brilliant. This is the reason we all love you so much. 😇😇 I was very sad today and getting bored 😥 but as soon as your video came, all my boring feelings were gone in no time and all my sadness converted into happiness .... 😍😍😘😘..... You are the best teacher ever. .... You have visually demonstrated, conceptually clearef and intuitively taught us something in just 11 minutes that 99.9% teachers fails to even give a slight idea behind the concepts. No one can ever teach us heat capacity like the way you taught us today 😍😍💐💐💐💐🏵🏵🏵🏵🌸🌸💮💮🌸🌸🌸🌻🌻🌻🌺🌺🌹🌹🌹🌹🌹🌹.

[@EugeneKhutoryansky]

Thanks for the really great compliments. I am glad you liked my video.

[@ElectronFieldPulse]

You are awesome and so are your videos. I truly thank you for the work you do!

[@EugeneKhutoryansky]

Thank you very much for the compliments.

[@brandonklein1]

I really appreciate that you took the time to explain why rotations are excluded in the case of a single atom, it is often neglected and leaves a very poor understanding of degrees of freedom as well as related results such as the virial theorem.

[@EugeneKhutoryansky]

Thanks.

[@bedoalaa7029]

thank you it is now clear for me why specific heat of water bigger than for iron

[@goclbert]

I learned all of this stuff at college and did well enough but it never really clicked for me that this is what heat capacity is. Thanks

[@EugeneKhutoryansky]

I am glad my video was helpful. Thanks.

[@PotionsMaster666]

Such awesome gift you guys have given us...❤️ A question- Why do we only count translational K.E as temperature ? Suppose a molecule is moving slowly (translational motion ) toward the container's/thermometer's wall, and also spinning very fast... now upon collision wouldn't that revolving atom hit it with it's angular momentum very hard relative to its translational momentum ? Imagine throwing a stick from its end so that it flies off spinning, aimed at a steel plate . Now wouldn't the spinning end of the stick hit harder than if the stick wasn't spinning and just moving translationally ? Thank you

[@EugeneKhutoryansky]

In your scenario, prior to the collision, the energy has not yet equally distributed among all the different degrees of freedom. After the collision, some of the energy from the rotation has now been transformed into the kinetic energy of motion.

[@Jetstreamer0]

I've also been thinking of this scenario and, up to now, I have concluded that the addition of linear and rotational motions, which result in a more violent collision with the wall, is only half the story. There should also exist molecules hitting the wall whose rotation partly cancels their linear motion, thus leading to a net zero effect on average across all molecules in the system. Therefore, we can safely ignore the rotational component of motion when defining temperature. (I may be overlooking something, so by all means, correct me if I'm wrong).

[@alonsoavila9894]

just...AMAZING! what an incredible explanation of temperature

[@EugeneKhutoryansky]

Thanks. I am glad you liked my explanation.

[@reinia127]

I'm gonna have my thermodynamics midterm exam. You really save my life lol. Thx a lot!!

[@EugeneKhutoryansky]

I am glad my videos are helpful. Good luck on your exam. Thanks.

[@A3Kr0n]

These videos put me in a nice place.

[@radhwanazeez23]

Some times I feel sad when I see like this channal have less than million subscriber and when I see non scientific channal have more than millions subscriber All respect to you from kurdistan/Iraq

[@EugeneKhutoryansky]

Thanks.

[@farhanahmed2508]

The person who uploaded this is God

[@EugeneKhutoryansky]

Thanks for the really great compliment.

[@rohitkasgar4840]

All these concepts were there with me, but in a hazy way. Got them cleared. And also, the music taste is great. Classical is my type! Cheers!

[@EugeneKhutoryansky]

Thanks.

[@v44n7]

this is the best channel in youtube!

[@EugeneKhutoryansky]

Thanks for the compliment.

[@loveistheonlything3626]

Thanks a thousand times! Your videos are amazing!

[@EugeneKhutoryansky]

Thanks for the compliments.

[@KrishFizix]

Ooo mann what a coincidence! Thank you so much because i am teaching kinetic theory this year!! You are a life saver 🙏

[@EugeneKhutoryansky]

I am glad my video is helpful. Thanks.

[@ocayaro]

Pressure must then be the rate of impact on container surfaces. Note that the atoms don’t actually touch due to the attraction/repulsion threshold of minimum potential energy i.e. the Lenard-Jones 12-6 potentials.

[@9bananenschalen632]

Impuls der Aufprallgeschwindigkeit(90° zur Behälteroberfläche)*Anzahl der aufprälle pro zeit

[@9bananenschalen632]

Und Anzahl der Aufschläge pro zeit hängt von der Geschwindigkeit der Atome ab

[@intotheabyss3842]

This is the 2nd time you've made a video on the same topic taught by my teachers

[@GCSEPhysicsExplained]

Great video. I'm trying to learn Blender to make animations for my GCSE Physics students. These animations are tremendous and are inspiring me to keep learning.

[@EugeneKhutoryansky]

Thanks for the compliment. Though, I don't use Blender. I make my 3D animations with "Poser." Thanks,.

[@sandeshbirla4331]

awesome and great video...!

[@EugeneKhutoryansky]

Thanks.

[@lopezb]

I have a request: a couple of videos on change of state in physics: showing the difference between gas and liquid, liquid and solid. In particular, I wanted to explain to my son (11) why water increases in volume when it freezes, and I have a mental image but would love to see one of ypur beautiful visualizations on this! Thanks for all ypur hard work which does so much to inform, inspire and educate.

[@EugeneKhutoryansky]

I will add that to my list of topics for future videos. Thanks.

[@blacktimhoward4322]

Your stuff is a bit over my head but I see you leaving very polite comments on Sci Show videos quite often so I wish you much success

[@WildEngineering]

once again, a brilliant explanation.

[@EugeneKhutoryansky]

I am glad you liked my explanation. Thanks.

[@sr-kt9ml]

Fascinating and enlightening as always

[@EugeneKhutoryansky]

Thanks.

[@snekmeseht]

This video was brilliant. I wish I had seen it 50 years ago.

[@EugeneKhutoryansky]

Thanks for the compliment about my video.

[@sudhanvagr]

Calm voice.

[@SirBroadside]

Thank you Black Mesa Lady for making me understand more things.

[@zack_120]

Animation videos are changing the world of education in physics and many other fields !!

[@EugeneKhutoryansky]

Thanks.

[@jlpsinde]

This video is too good to be true. I loved it!

[@EugeneKhutoryansky]

Thanks. I am glad you liked my video.

[@ksk_futuremvrcreator]

This video was a life saver to my understanding

[@EugeneKhutoryansky]

I am glad my video was helpful. Thanks.

[@garnetg987]

"The energy associated with the atom's rotation is there extremely small and can be neglected." Neglected in terms of what? What purpose would there be in ignoring it? Isn't it the point of physics to understand, with absolute certainty, how everything works together?

[@andrewbetz535]

At 8:40 you can see the contrast with the other molecule whose 3rd rotational dimension cannot be ignored due to its non negligible moment of inertia in all 3 spacial dimensions. He gives the red molecule 6 degrees instead of 5

[@no-better-name]

then you'll be sad to learn (probably just remember) that this is an ideal gas and this model neglects collisions between molecules etc. physics is about good enough precision because you can't fully describe the universe with human models because we're imperfect and don't quite have a peek at what's behind the curtain and whatnot. mathematics, on the other hand...

[@carultch]

If you scale the atom of helium up to the size of a baseball stadium, the nucleus would be the size of a grain of sand, and would have a mass of 500 thousand tonnes. The vast majority of the mass is concentrated in this nucleus, which is at the center of the atom. It might as well act as a point mass. Compared to the rotational inertia of a hydrogen molecule of approximately the same physical size per atom, and 1/4 the mass, the hydrogen molecule has a hell of a lot more rotational inertia than the helium nucleus

[@riderpaul]

Wow. Clear as day. Great video!

[@EugeneKhutoryansky]

Thanks.

[@MrGustavier]

this is so good ! You have answered a question that I asked myself a few days back. thank you !

[@EugeneKhutoryansky]

I am glad you liked my video and that it answered your question. Thanks.

[@VoidHalo]

Heh, I started reading Ohanian Physics 2nd Edition yesterday and this was one of the first things he started with. Kind of tedious since I already know it all, but it never hurts to brush up on the fundamentals. Plus you never know when you might have a revelation that lets you see/understand something from a different poin of view. That's always fun.

[@ooffoo5130]

thank you for your videos

[@EugeneKhutoryansky]

You are welcome and thanks.

[@lightspeed9762]

Hello! Love Your content!

[@EugeneKhutoryansky]

I am glad you like my videos. Thanks.

[@megamaser]

I wish I had this content when I was studying statistical mechanics in college.

[@Jetstreamer0]

Excellent! One question though: Why does the rotation of molecules (with more than one atom) get left out of temperature? If it's not thermal energy, then what type of energy is it? Mechanical? But I thought mechanical energy at atomic scales is temperature.

[@Bl00drav3nz]

I don't know the answer, but my guess is that the rotational energy stored in molecules does not contribute to the macroscopic properties like pressure and temperature. For example consider the ideal gas law pV=nkT, where pressure manifests as molecules bumping into the walls. Let the volume and molecule count stay constant, and you see that an increase in temperature causes an increase in pressure (p = nk/V * T). The pressure is directly related to the motion of the molecules in the x,y,z directions (pressure is defined as force per unit area). Now I'm not entirely sure if this argument works for 2-atom molecules, but let's say you had a 2-atom ideal gas, and you could add energy in such a way that you only increase the energy of the rotational degrees of freedom. To make it simpler let's also assume that the molecules where at T=0K so nothing was moving at all. Now looking back at the ideal gas law, we didn't increase the pressure of the gas, because the molecules didn't pick up any linear motion, they are now just rotating in place - that means the left hand side of the equation is zero, which means that the temperature is still zero. So in the end, we added energy to the system without increasing the temperature (and pressure). If anybody has a better explanation, I would be glad to learn about it!

[@EugeneKhutoryansky]

Because that is how we defined the word "temperature." Think of it this way: When we increase the temperature, we increase the pressure in the box. However, the rotations of the molecules don't contribute to the force on the walls of the box, hence the rotations don't contribute to the pressure, and hence the rotations don't contribute to the temperature.

[@Jetstreamer0]

Thanks! I see how the linear speed is definitely related to pressure. But rotating sticks hitting the walls on the advancing side (the side where rotation and linear motion add rather than cancel) would impart more force than ones that don't rotate. Then again, rotating sticks (or long molecules) that hit the wall on the slow side would impart less energy on the wall, so perhaps the answer to my original question is that these perturbations to the linear component due to rotation actually cancel out, on average!

[@specific_pseudonym]

@@EugeneKhutoryansky maybe I'm missing something, but this seems like a great way to confuse people. You're defining a non-monatomic system with more than 3 degrees of freedom, taking note of the fact that those other degrees of freedom can contain energy, but then calculating the temperature considering only those 3. You can treat temperature in this way for monatomic systems, but this isn't one, per your own definition. Considering that temperature for non-monatomic gases simply ISN'T defined by only their kinetic energy (and it really isn't; that's objectively incorrect) this is...not great >.

[@AhmedHassan-pn9lb]

Great channel. I wish you would publish a series or lecture on how the linear accelerator works in detail and produces x-rays for medical applications. With Arabic translation available. Thank you very much

[@EugeneKhutoryansky]

I have a video on linear accelerators (for producing neutrons), with Arabic subtitles available, at kzbin.info/www/bejne/Z6S0iWSpqZqVmNk

[@richardaversa7128]

1:04 Great video, as always. But I'm having trouble seeing how this statement could be true: "The rotational energy of a single-atom molecule can be neglected because the mass is concentrated in the nucleus so there is no significant moment of inertia." I'm pretty sure there's no rotational energy because atoms are spherically symmetrical (in free space). That is, they are not made of little electron balls, proton balls and neutron balls that are stacked together. The particles are governmed by perfectly symmetric wave functions described by quantum mechanics. An atom is like a perfectly spherical cloud, with the particles smeared out in perfectly symmetrical patterns. I've always been given the impression that rotation is meaningless for a perfectly spherical object because it lacks a mathematical degree of freedom (you can't "tell" when a perfect sphere is spinning unless it's not a perfect sphere); this suggests that the moment of inertia is irrelevant and the true reason is the symmetry.EDIT: Nevermind, I see this was addressed in more detail around 7:30. Always good to learn something new. Thanks!

[@tototoday7609]

Temperature definition. I have been confused internal energy and freedom and temperature. Thank you very much.

[@zakirreshi6737]

Your videos are great 😊😊 Can you please tell me...why thermal conductivity of QGP (quark gluon plasma) is considered nearly equal to zero? And could you please make one video related qgp.