How Does Planck's Quantised Energy Theory Address the Ultraviolet Catastrophe?

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Discussion Overview

The discussion revolves around Planck's quantised energy theory and its implications for addressing the ultraviolet catastrophe, focusing on the nature of quantisation in relation to blackbody radiation and spectral distribution of energy across wavelengths.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions what exactly is being quantised in Planck's theory, suggesting it may relate to the oscillator atoms of the blackbody cavity.
  • Another participant asserts that the energy of the oscillators is quantised, leading to a spectral distribution that does not diverge for any portion of the electromagnetic spectrum.
  • A participant seeks clarification on the meaning of "didn't blow up for any portion of the em spectrum," expressing confusion about the distribution of wavelengths and the intensity of longer wavelengths compared to middle wavelengths.
  • It is noted that Planck's distribution is bounded and the area under its graph is finite, which contrasts with classical predictions.
  • One participant introduces a metaphor involving spending money to explain the distribution of wavelengths, suggesting that the number of combinations available affects intensity.
  • Another participant mentions that understanding the distribution may require knowledge of Bose-Einstein statistics and quantum statistical physics.
  • A later reply suggests that this topic is standard in physics and can be found in freshman physics textbooks.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and interpretation of Planck's theory and its implications, indicating that there is no consensus on the specific mechanisms behind the spectral distribution or the nature of quantisation.

Contextual Notes

Some participants express uncertainty about the concepts discussed, indicating potential gaps in understanding related to the mathematical and statistical foundations of the theory.

oheaveno
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can i ask ... how could Planck's idea of quantised energy explain the ultraviolet catastrophe?
WHAT is being quantised? the oscillator atoms of the blackbody cavity? or?

thanks
 
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The energy of those oscillators.

It yielded a spectral distribution which didn't "blow up" for any portion of the em. spectrum.

Daniel.
 
thanks for replying:D but what do you mean by "didnt blow up for any portion of the em spectrum"??
you know that graph of wavelength VS intensity... i understand that the higher the temperature the peak of the graph shifts towards the shorter wavelength because there is more energy (tell me if I am wrong) but why is the distribution of wavelength the way it is? why can't there be more longer wavelengths with higher intensity?

one website explains this idea by saying this:: say now you have a certain amount of money. you can spend it on one expensive stuff, or several middle priced stuff, or a lot of cheap stuff. you are still spending that definite amount of money but it is just HOW you decide to spend it. so in the case of BBR, there is a lot of middle wavelengths, a few short wavelengths and a few long wavelengths.

that is what i don't understand. why are there a lot of middle wavelengths but not more shorter wavelengths? i can still distribute the same amount of energy but just in a different way.
i hope you get what i mean because i think my understanding of the concept is very bad
 
oheaveno said:
thanks for replying:D but what do you mean by "didnt blow up for any portion of the em spectrum"??

Planck's distribution is bounded (for any temperature) and moreover the area under its graph is finite.

oheaveno said:
you know that graph of wavelength VS intensity... i understand that the higher the temperature the peak of the graph shifts towards the shorter wavelength because there is more energy (tell me if I am wrong) but why is the distribution of wavelength the way it is? why can't there be more longer wavelengths with higher intensity?

Thta's tipically for Bose-Einstein statistics. If you study both mathematical statistics and quantum statistical physics, everything will be clear.

Daniel.
 
As the example you posted, the main point of it is that if you are going to buy cheap stuffs, you'll have more choices(more combinations) to distribute your finite money, while for the expensive ones, you'll have much less choices. More choices means larger probability. Thus higher intensity.
 
Since this is a very standard part of physics, details can be found in virtually any freshman physics book.
Regards,
Reilly Atkinson
 

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