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Why and where did classical mechanics fail to explain blackbody radiation?
Wiki User
∙ 13y ago
Blackbody radiation had been classically treated as cavity radiation, ie. radiation confined within a certain geometrical space. Therefore, the radiating EM waves are treated as standing waves having modes of zero electric field at the walls. Classically, as more and more energy is distributed into the cavity, the wavelengths of the EM waves get shorter and shorter, thereby allowing more and more modes to be possible, all of which have the same chance to be produced. So, the number of modes is proportional to energy which is inversely proportional to wavelength meaning it's directly proportional to frequency.
What all that boils down to, if classical mechanics had been right, is that as continually higher and higher frequencies of EM radiation are distributed into the blackbody, the amount of radiated energy should also continually increase. Experimental data, however, showed that the EM radiation, after a certain point, actually began to decrease, despite the continual increase in the energy put in.
That unexpected event was inexplicable using classical mechanics. The only way that it was eventually understood was by treating EM waves as discrete quanta of energy.
Wiki User
∙ 13y ago
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Where classical mechanics fails and quantum mechanics aeises?
Numerous places: 1) photo-electric effect. 2) black-body radiation spectrum. 3) spectrum of hydrogen emissions. 4) interference patterns of electrons through a slit. 5) compton scattering. All of the above can be easily explained by the existence of 'quanta,' but are impossible to explain through purely classical means.
Is Quantum Mechanics more important than Relativity?
Quantum mechanics and relativity are both parts of the same puzzle: how the universe works. They are both equally important, because they both explain things that are not explained by classical physics.
Can anyone explain the quantum theory?
Richard Feynman stated once that "if you think you understand quantum mechanics then you don't understand quantum mechanics". However it is possible to learn how to write and solve the equations of quantum mechanics to get answers that can be verified experimentally.
Why classical mechanics fails to explain Compton effect?
Classical mechanics assumes that light energy is a self-propagating, harmonic wave of electro-magnetic fields. It assumes that there is no limit to how small the energy in a light beam can be. QM, on the other hand, assumes there is a limit to how small the energy within a "chunk" of light can be, and that size is given by the frequency of the light times Planck's Constant. With this assumption, the formula for frequency shift of scattered photons as a function of angle can be easily explained. Using only classical mechanics, deriving the formula is impossible.
Why the classical theory of solids cannot explain the theory of solids?
please explain
What is the division of mechanics in physics?
the classification of mechanics are:- # Classical Mechanics # Statistical Mechanics # Quantum Mechanics
Why you need quantum mechanics or modern physics while classical physics existed already?
Because there were a couple of things observed that were inexplicable with classical physics, namely: Blackbody radiation - Radiated energy doesn't continually increase as the frequency of the radiation increases. Classically, this relationship is given by the Rayleigh-Jeans Law, however, this law goes to infinity as frequency goes to infinity. The Photoelectric Effect - The energy of electrons emitted from a surface when a light is shined on it had nothing to do with the light's intensity, just it's frequency. Quantizing electromagnetic energy was the only way to explain these phenomena.
Can classical physics explain the photoelectric effect?
No. To explain the photoelectric effect, you have to think of light as a particle, not a wave. The fact that light can be both a wave and a particle is part of quantum mechanics, not classical physics.
Where classical mechanics fails and quantum mechanics aeises?
Numerous places: 1) photo-electric effect. 2) black-body radiation spectrum. 3) spectrum of hydrogen emissions. 4) interference patterns of electrons through a slit. 5) compton scattering. All of the above can be easily explained by the existence of 'quanta,' but are impossible to explain through purely classical means.
Why classical mechanics is unable to explain black body radiation?
Classical mechanics contains the mathematical assumption that everything is infinitely divisible; no matter how small something is, it can always be cut in half. When this idea is applied to calculations of black body radiation the result is what was known as the ultraviolet catastrophe, which is that as the wavelength decreases, the amount of radiation increases without limit, rising asymptotically to infinity. That is, of course, not anything like what we observe in the real world. The solution of quantization, meaning that light (and everything else) just comes in pieces of a certain irreducible size, and no smaller, solves the problem and gives calculations that agree with experimental observations.
Why does classical physics fail to explain the photoelectric effect?
You have to take into consideration quantum mechanics and the fact that electrons absorb and emit in packets of energy.
What are the reason the classical physics failed?
It is a macroscopic theory. Their theoretical values are not equal to the experimental values. The classical theory cannot explain the photoelectric effect,compton effect,magnetic properties briefly..... it obeys the classical mechanics. it does not briefly explain the atoms internal parts . hence it is rectified by quantum physics....!
Is Quantum Mechanics more important than Relativity?
Quantum mechanics and relativity are both parts of the same puzzle: how the universe works. They are both equally important, because they both explain things that are not explained by classical physics.
How do you explain Classical Conditioning Theory?
Explain Classical Conditioning Theory?
What are drawbacks of classical free electron theory?
The classical free electorn theory is not able to explain conductivity for semiconducter and insulators
Can anyone explain the quantum theory?
Richard Feynman stated once that "if you think you understand quantum mechanics then you don't understand quantum mechanics". However it is possible to learn how to write and solve the equations of quantum mechanics to get answers that can be verified experimentally.
Classical physics CANNOT explain why?
There are many examples of what classical physics can not explain. (By classical physics we mean that which has its theoretical foundations before about 1900.) Quantum mechanics is absent from classical physics. Classical physics can not explain why atoms (positive nucleus attracted to surrounding electrons) is stable. Even the simplest atom, a hydrogen atom, would be unstable and the electron orbiting the proton would gradually radiate its energy and the orbit would decay. The photoelectric effect is an important historical example of the failure of classical physics. In that case, electromagnetic theory said that light was an electromagnetic wave. That was true enough but it does not account for the quantum nature of light and the characteristics that allow a photon to act like a discrete bundle of electromagnetic energy with properties like a particle. Virtually all of our understanding about the atomic structure and properties of matter depends on quantum mechanics, so the example of hydrogen is just symbolic of the need for modern physics for the entirety of our understanding about electronic properties of matter. One can choose to define classical physics to include relativity or not as one wishes, but it is fair to say that Newtonian mechanics does not explain relativistic mechanics. In particular, time dilation and length contraction are purely relativistic effects.
