Planck Theory of Blackbody Radiation - Only Resolution to Ultraviolet Catastrophe! (DERIVATION)

[@FortheLoveofPhysics]

1. Blackbody Observations - kzbin.info/www/bejne/fIPHY2t5gduAh68 2. Rayleigh Jeans Law - kzbin.info/www/bejne/oXndZ62YedacnLM 3. Planck Energy Distribution - kzbin.info/www/bejne/qnK9in6EgNCrqZY 4. Summary - kzbin.info/www/bejne/gYObhKCQast6f8k

[@tesukim4338]

300 page book worth of physics laid out less than an hour in a super easy and kind manner. This is unbelievable.

[@dougiev9287]

BS! This is a great video but is in no way a substitute for a textbook. 300 pages? Name the book that covers UV catastrophe in hundreds of pages that is less than this video. Again, this is a great video but be serious.

[@benstallone6784]

Another brilliant lecture - really appreciate the clarity and completeness of your approach. If the quality remains the same then perhaps we can delete all the other QM lectures off the internet and just use yours to save everybody time and confusion

[@himanshuupadhyay8529]

Same feeling.

[@maurofabris6527]

"clarity and completeness" u took the words straight out of my mind.

[@aafeer2227]

If you make a PDF I will buy it, and probably I will not be the only one. This really associates the formal math and the intuition in a striking way. Well designed, brilliant accomplishment.

[@TheJara123]

What a wonderful physics teacher!! A delight to watch his way of lectures!!

[@Rudraansh63]

Just Want to Tell...You're Doing a Commendable Job in every video you make...Thank You 🙏

[@umarhashmi6759]

Sir please start a comprehensive lecture series on Statistical mechanics

[@seekingrafael5630]

Yes please

[@flyingbirds6794]

This is a REALLY excellent and amazing video!! Concepts are explained in an excellent manner!! Thank you very much sir

[@farehaaslam5177]

wow sir so beautifull lecture ,we can feel your love for physics

[@sohamnath3229]

its just extremely amazing how he delivered everything so well. trying to make us understand the way planck thought, the types of examples he gives...its all just simply amazing. i expect to see more of your videos in the future ,sir.

[@carlosalbertoperesdesousa6077]

Finally, i start understanding QM...the best teacher ...

[@aachacon31]

That is an amazing explanation of Black body radiation! 🎉

[@muhmmadawais7769]

Mashallah! How beautifully you explained the whole topic, I really became your fan. You are a brilliant teacher. Love you and thank you sir!❤❤

[@eternalthoughts-wu5lo]

Brilliant lecture....very clear explanation...all Physics studentsMUST WATCH this lesson

[@souravkundu4372]

Hello sir. Your videos always inspired me. You are one of the best teachers in KZbin. I am also started quantum mechanics in my graduation course in college. Your videos helped me a lot to understand quantum. My request to you that upload videos more frequently.

[@kushagradixitkushagradixit242]

you are genius sir!!! explaining so well !!

[@alinemoreira5518]

It's impressive the way you explain such a difficult matter. QM is far from being my favorite subject at College but your explanation and excitement are helping me to understand what's the whole point of QM. Thanks a lot !!

[@irshadbaig9946]

No words to your teaching ability. Stunned !!.

[@Tzadokite]

here is an interesting derivation using the time dilation expression of STR: we have t(v)=t(0)*(1-v^2/c^2)^1/2. we write this as frequency 'f', which is defined as frequency = 1/time. hence we have f(v)=f(0)/(1-v^2/c^2)^1/2. for constant 'v' we have df=df(0)/(1-v^2/c^2)^1/2. we have dE=dP/dt *dx or dE*dt=dP*dx=k. this gives us dE*dt=k and dP*dx=k. from these one can obtain the heisenberg's uncertainty expressions. however, if we take dE*dt=k and write it as dE=k/dt we get dE=k*df, because df=1/dt as frequency = 1/time and for frequency = df we have df = 1/dt where dt = time. from dE=k*df we obtain E=kf+C where C is the integration constant. if when f=0 we have E=0 then C=0. hence, E=kf. of course from we can shown that k=h and obtain the general expression E=hf of which the planck expression for energy quanta or photon is a special case. hence E=kf(0)/(1-v^2/c^2)^1/2. from E=kf we get E(0)=kf(0). hence, E=E(0)/(1-v^2/c^2)^1/2. again for kinetic energy E(KE) we have E(KE)=E(v)-E(0) or {E(0)/(1-v^2/c^2)^1/2 } - E(0) = E(KE). for v

[@ajainarayan8889]

Beautiful Brother .... if only our science teachers EVEN at Universities take the same interest in teaching students.

[@entangled5428]

Enjoying this beautiful journey of learning Quantum mechanics 😊😊

[@kentykatele4353]

You have the power to explain physics in a very special Way 🔥🔥🔥🔥🔥

[@swapnilgupta2112]

thank you sir for this great lecture, my concepts are becoming clearer and clearer!

[@brotherstech3901]

Watching again after 3 months. Still fascinating.😍

[@achalumrigar]

Thank you very much sir❤

[@SabihaAktar-f2p]

Sir salute to you,,,,the way you explain each and everything with that much of patient is really praise worthy. Take love sir❤️

[@piyushbothra7976]

Best of the best lecture sir 🎉🎉

[@OjaswiRai-s7x]

awesome sir

[@me0wAnna]

Brilliant Lecture sir. thankyou sir

[@sohamsinha2k4]

Thank you very much sir.....❤

[@himanshuupadhyay8529]

Sir, Aap QM me itna crystal clear concept ke saath hi harek topic pe video bana. Chahe time aap extra laga lo but your content quality is outstanding.

[@FortheLoveofPhysics]

I will try. Thank you :)

[@sahil-pu3cc]

Sir one of most inspirational video.those who love physics.

[@Dipayan21485]

Thank you so much sir for this amazing lecture

[@batuhanyank9381]

Abim çok büyük adamsın saygılar! 🇹🇷🇮🇳

[@drbitanmaity]

best lecture till date inthe whole arena of internet world

[@arnabbanerjee417]

Unbelievable lecture...

[@sonamchan...7093]

Sir your name is Divyjoti 🙂 sachme aapne mere andr Jyoti jla di Gyan ki ❤😊

[@BHBima]

I've been really enjoying the lectures so far! Thank you so much sir

[@linanahak588]

Thank you so much sir 🙏 for making the love of physics ..

[@nicu_danciu]

Magnificent!

[@MamtaRathore-o6q]

I am interested know history of plank's constant (h) and now I know it because of your lecture Thanks😊

[@conceptualphysicsadvancephysic]

When the energy emitted by discrete fashion, so why the graph is in continuous fashion. Please anyone explain this phenomenon. Thanks

[@FortheLoveofPhysics]

Because the y-axis in graph is the *average* energy density. An individual frequency is associated with discrete energies hv, 2hv, 3hv, 4hv,.... But the *average* energy for such a distribution comes out to be 1/(exp(hv/kT)-1) which varies continuously with frequency, v

[@mayankmishra5532]

Sir, at 36:35 The final result can also be obtained using summation of ∞ GP series solution...

[@rostamostmann9657]

Very coherent teaching.

[@aymanfarhat7251]

Great lecture

[@nimnim5149]

This is art ...

[@KipIngram]

I don't in any way regard what Planck did as "cheating." He was allowing the behavior of the the world (the Stefan-Boltzmann data) to guide him in trying to understand the world. In the end he found one way to get the theory to match the data - if he'd found four or five ways, then he'd have tried to suggest experiments to distinguish which one was right. That's how science is done. The step from classical to quantum theory was a BIG one, and literally nothing we'd ever learned before had indicated to us that such an approach was required. Even today they say you can't "derive" quantum theory using classical methods, though I have seen at least one paper that comes pretty close. So there really wasn't a viable theoretical path for Planck to follow.

[@VijayKumarT-o3s]

Very good explanation

[@abhijitshaw9431]

another wonderful lecture ....i just love this channel😍😍😍😍😍😍😍😍😍😍😍

[@ramasubbu2890]

The fundamental ideas of quantum mechanics is well understand sir and I willing for next video sir

[@akakichkhaidze1]

Excellent!

[@bishwajitbhattacharjee-xm6xp]

Nice lecture and simple mathematics. Is zero ∆€ is classical limit that is a continuum or line segment of plotted area.Supplying energy to electrons linearly is a different transformation without collision. A amplified conversation. A QM reality problem.

[@brotherstech3901]

Very nicely explained sir,

[@GoutamDAS-ls1wb]

May I inquire why classically it is not 3*k*t instead of k*t since we are dealing with 3-dimensional harmonic oscillators? Maybe because of the 2 different directions of polarization--each parallel to the mode--but then it should be 2*k*t. Thanks in advance.

[@marvynhsu9696]

16:10 My result of the integral and division is kT while in video is 1/2kT, is there anything I forgot to do in the integral? or it comes from some other assumption for molecules in thermodynamics?

[@sanjayyashwantsohani4820]

Sir at around 42:55, -1 was not written which appears immediately afterwards.Please explain why ? Thanks.

[@sandymondal]

Thank you sir.

[@Goldslate73]

44:16 HALLELUJAH!!!

[@durarararara]

sir aapki english to boht hi zyada achi hai

[@umarhashmi6759]

thank You so very much Sir........

[@abdurrauf7525]

Sir, the energy is associated with standing electromagnetic waves inside the cavity. Can we say that half of the energy is associated with the electric field and half of the energy is associated with the magnetic field of electromagnetic waves?

[@tunlinaung5668]

If we use following binomial theorem, ∑𝑒^(−𝑛𝑥) = (1−𝑒^(−𝑥) )^(−1) and ∑𝑛 𝑒^(−𝑛𝑥) = 𝑒^(−𝑥) (1−𝑒^(−𝑥) )^(−2) I think that the calculation will be more simple.

[@samiranguchhait350]

thank you sir

[@abhaydubey3725]

Sir please put more videos on physics

[@harry-ho9ti]

Tq very much sir.

[@ai6mk897]

At last, someone who explains how Planck arrived at his ground breaking equation. Bravo Sir ! I am a little disappointed that you only gave Willie Wien credit for his Displacement Law. In 1896 Wien formulated a very good approximation to describe the full spectrum, but with arbitrary constants. Planck himself gave Wien much of the credit for the basic equation correcting it for low frequencies and fleshing out the arbitrary constants. Then came the hard slog for Planck to try and explain mathematically how it came about. I am surprised that faith was put into the Equipartition Theory for so long. Just looking at the energy part = KT, RJ should have realized this part was wrong since the other parts of their equation are constants. Your genius revealed itself in how you explained the evolution from integration (continuous distribution) to summation (discrete distribution). This was the part I had been searching for a long time. Planck must have been totally puzzled why he needed to do this, but mathematically it was correct. As has been said many times, for him it was just a mathematical "trick" to get the right answer. It took another genius, Albert Einstein, in 1905 to fully appreciate what Planck had stumbled on. We may not say it often enough but we are so grateful for what you do and of course share your "Love of Physics".

[@tomasnunez1136]

Muy buen video

[@samiranguchhait350]

we wating for your lecture

[@abdurrauf7525]

Sir, thermal radiation has a continuous spectrum of energies and is explained on the basis of the discrete nature of radiation. HRK 4th edition (page# 1035, article 49-8: line spectra) explains that the discrete (quantized) nature of the photon energies is hidden in the broad distribution of energies. I do not clearly understand. Could you please elaborate it a little bit. Thanks

[@FortheLoveofPhysics]

Each frequency emitted by cavity walls corresponds to many energies (hv, 2hv, 3hv, etc) hence energy is quantised. But the average energy density of the cavity corresponding to a frequency has a continuous graph (which is the blackbody spectrum)

[@abdurrauf7525]

@@FortheLoveofPhysics . Thank you Sir.

[@divyakumar8147]

thanks sir

[@sushmamishra9268]

Next lecture please 🙏

[@abubakarsattar9925]

Sir Please upload the videos soon

[@Youcan.-.]

Sir I am from kolkata and your videos have really helped me in my graduation. Sir just for my curiosity if you don't mind can you tell us where do you live in kolkata?

[@Khandwa_beniwal]

Rajasthan

[@michamazur8705]

My current understanding was that energy of the photon is directly correlated with frequency. Now not so sure. Does E=nhf means that lets say green photon may have energy X but also 2X, 3X and so on?

[@FortheLoveofPhysics]

You are correct. That's what the energy of a photon is. This video is simply in the context of the resolution provided by Max Planck for the case of blackbody radiation, which means that energy corresponding to a given frequency= n times hv

[@michamazur8705]

​@FortheLoveofPhysics Then I do not fully understand these discrete distribution graphs. Their purpose is to chop off probability from 0 to dE. That's ok. But these "higher harmonics" n*dE seems to be still there. And since each graph is for given frequency i would expect some energy emitted for every dE slot. Will watch video on photoelectric effect now, maybe it will help.

[@sabiralisahil429]

If energy is quantized and from special reletivity we know that energy and mass are two different form of matter. Then is mass quantized also?? Plz explain sir !!

[@dougiev9287]

Yes. This topic is covered in a small subfield called quantum mechanics.

[@martinakonig1174]

Why ist the average Energy 1/2 kT. If I solve this eqaution I get E + kT. What am I doing wrong?

[@FortheLoveofPhysics]

For harmonic oscillator its 1/2 KT contribution from PE and 1/2 KT contribution from KE, so total KT

[@souravdey1227]

Wow.

[@rishukumar7158-h1w]

27:23

[@nadeemsaleem]

Sir G Laser Physics Start kar do please

[@naveedArt13]

❤❤❤❤

[@misbahmir2789]

❤

[@jacobvandijk6525]

This is Max Planck at the age of 85: kzbin.info/www/bejne/eGqpoXR9gJ2VoJo

[@ADITYASINGH-d9o7d]

sir please use hindi

[@naomirill]

Dont, English is much better

[@ramasubbu2890]

The fundamental ideas of quantum mechanics is well understand sir and I willing for next video sir