Deriving Planck's Law | The Equation That Began Quantum Physics
In the first part of the fifth video of 'Introduction to Quantum Mechanics', we will discuss the derivation of Planck's law. In the previous video, we learned what is a black body and how Rayleigh and Jeans, and Wein failed to explain the black body spectrum. They considered blackbody radiation to be made of standing waves inside a cubical box. Using classical statistical mechanics, they calculated the number of modes of vibrations or the number of standing waves inside a frequency interval. They associated average energy to each of the standing waves - kT where k is the Boltzmann's constant and T is the temperature.
By multiplying this average energy with the number of modes, we get the energy density - the Rayleigh-Jeans law. However, the Rayleigh-Jeans law can only explain the black body spectrum at low frequencies. It blows up at high frequencies. This is known as the Ultraviolet Catastrophe.
The black body radiation spectrum was finally explained by German Physicist Max Planck. He assumed that the standing waves can only have a particular energy, in the multiples of hv where h is the Planck's constant and v is the frequency. Using this assumption, Max Planck mathematically derived Planck's radiation law that could easily explain the shape of the black body spectrum. We can also derive the Rayleigh-Jeans Law, Wein's law, and Stefan's law from Planck's radiation law. This will be covered in the second part of the video.
Видео Deriving Planck's Law | The Equation That Began Quantum Physics канала The Secrets of the Universe
By multiplying this average energy with the number of modes, we get the energy density - the Rayleigh-Jeans law. However, the Rayleigh-Jeans law can only explain the black body spectrum at low frequencies. It blows up at high frequencies. This is known as the Ultraviolet Catastrophe.
The black body radiation spectrum was finally explained by German Physicist Max Planck. He assumed that the standing waves can only have a particular energy, in the multiples of hv where h is the Planck's constant and v is the frequency. Using this assumption, Max Planck mathematically derived Planck's radiation law that could easily explain the shape of the black body spectrum. We can also derive the Rayleigh-Jeans Law, Wein's law, and Stefan's law from Planck's radiation law. This will be covered in the second part of the video.
Видео Deriving Planck's Law | The Equation That Began Quantum Physics канала The Secrets of the Universe
Показать
Комментарии отсутствуют
Информация о видео
23 октября 2020 г. 12:30:12
00:16:20
Другие видео канала
![Understanding Black Body Radiation, Rayleigh-Jeans Law, & Ultraviolet Catastrophe - Quantum Physics](https://i.ytimg.com/vi/7CvYoXqXIxg/default.jpg)
![Switching From Quantum Mechanics To Classical Mechanics With Planck's Law | Quantum Physics Series](https://i.ytimg.com/vi/1OuEsIv6L1k/default.jpg)
![](https://i.ytimg.com/vi/5vrCsfn_2Ic/default.jpg)
![Blackbody Radiation: the Laws of Stefan, Wien, and Planck!](https://i.ytimg.com/vi/h5jOAw57OXM/default.jpg)
![A Simple Method For Measuring Plancks Constant](https://i.ytimg.com/vi/q0jLUpBqess/default.jpg)
![The Photoelectric Effect | Einstein's 'Nobel' Contribution To Quantum Physics](https://i.ytimg.com/vi/3IAVJq9fIxc/default.jpg)
![Breaking barriers with quantum physics | Dr. Shohini Ghose | TEDxNickelCity](https://i.ytimg.com/vi/TlmwLyeWv5M/default.jpg)
![The de Broglie Waves and the Davisson-Germer Experiment](https://i.ytimg.com/vi/Hx1gjOGEeEg/default.jpg)
![Pair Production | Where Energy Converts Into Matter](https://i.ytimg.com/vi/oMXnsntnJ74/default.jpg)
![What is the Ultraviolet Catastrophe?](https://i.ytimg.com/vi/rCfPQLVzus4/default.jpg)
![Dance of Two Black Holes Proves Hawking Right (And Wrong)](https://i.ytimg.com/vi/PGZEBVynFmY/default.jpg)
![More on Planck's Quantum Theory, Chemistry Lecture | Sabaq.pk |](https://i.ytimg.com/vi/uvNpf_gaU0s/default.jpg)
![Quantum Physics - Part 1 (Blackbody radiation, Wien's Displacement Law, Planck's Law)](https://i.ytimg.com/vi/nAMApxYWVuA/default.jpg)
![Planck's Constant and The Origin of Quantum Mechanics | Space Time | PBS Digital Studios](https://i.ytimg.com/vi/tQSbms5MDvY/default.jpg)
![Young's Double Slit Experiment | What It Really Tells Us? Quantum Physics Lectures](https://i.ytimg.com/vi/kuayIBr41tM/default.jpg)
![Physics - Chapt. 66 Quantum Mechanics (4 of 9) Planck and Planck's Law](https://i.ytimg.com/vi/1eefA8kHR7U/default.jpg)
![Origin of Plank's Constant | Birth of Quantum Mechanics | PHYSICA](https://i.ytimg.com/vi/2dgau46ZCqs/default.jpg)
![What Is Quantum Mechanics & How's It Different From Classical Mechanics? | Quantum Physics Lectures](https://i.ytimg.com/vi/7RmBH96QNyQ/default.jpg)
![Rayleigh - Jeans Law | Blackbody Radiation | Derivation of Rayleigh - Jeans law](https://i.ytimg.com/vi/g2U82tQ3ti4/default.jpg)
![The Compton Scattering | Where Astronomy Meets Quantum Mechanics | Derivation And Theory](https://i.ytimg.com/vi/RQC8j2Ll0h4/default.jpg)