Naty1 said:The problem was that classical theory gave an infinite (silly) answer for black body radiation...quantum theory via Planck solved the riddle...
This is a good explanation...
http://en.wikipedia.org/wiki/Ultraviolet_catastrophe
sophiecentaur said:That bit involving lengths of string is a bit fanciful. How ever is it supposed to show the difference in powers? The rms power is the same for all frequencies of waves of similar shape and same amplitude. What has the length of a piece of string got to do with it? How does the string relate to photons?
Born2bwire said:Are you talking about the wiki link? I don't see such contradictions in the very brief mention of harmonics on a string. They just used it as a brief analogy to help show that the density of states for a classical harmonic oscillator increases with the frequency.
sophiecentaur said:Wow - I'm sorry. I was referring to (complaining about) the UTube clip in the other post. I just quoted the wrong post - durr.
In the UTube movie, they were showing a progressive wave with the string (referring to light ) and relating the length of the string that they unwound off some pins to the energy of the wave. That passage made no sense to me as the string was no more than a graph of displacement (possibly?) with distance. How does that relate to energy? It was so bad that I really couldn't go along with any more of it.
The Wiki link was fine btw.
The Ultraviolet Catastrophe is a phenomenon in physics where the classical theory of blackbody radiation predicts that the intensity of radiation emitted by a blackbody should increase infinitely as the frequency of the radiation increases. This is known as the "ultraviolet catastrophe" because it would result in an infinite amount of energy being emitted, which is physically impossible.
The Ultraviolet Catastrophe was first observed by German physicist Max Planck in the early 1900s. Planck was studying the properties of blackbody radiation and found that the classical theory was unable to accurately predict the observed intensities at high frequencies.
The Ultraviolet Catastrophe was a major problem for classical physics and led to the development of quantum mechanics. It showed that classical theories were unable to fully explain certain phenomena and led to the understanding that energy is quantized, rather than continuous.
The Ultraviolet Catastrophe was one of the key pieces of evidence that led to the development of the quantum theory of light, which explains the photoelectric effect. This effect is the emission of electrons from a metal surface when it is exposed to light, and it cannot be explained by classical theories.
While the Ultraviolet Catastrophe was solved by the development of quantum mechanics, it is still a significant concept in physics and is often used as an example of a problem that classical theories were unable to explain. It also serves as a reminder of the limitations of our current understanding and the need for continued research and development in the field of physics.