# Exploring Planck's Theory of Quantised Energy for UV Catastrophe

• oheaveno
In summary, the conversation discusses Planck's idea of quantized energy and how it explains the ultraviolet catastrophe. The energy of oscillators in a blackbody cavity is quantized, resulting in a spectral distribution that does not "blow up" for any portion of the electromagnetic spectrum. The distribution of wavelength vs intensity is due to Bose-Einstein statistics, where more choices for distributing a finite amount of energy result in a higher intensity. This is a standard concept in physics and can be found in freshman physics books.
oheaveno
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

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

## 1. What is Planck's theory of quantised energy for UV catastrophe?

Planck's theory states that energy is not continuous, but rather exists in small, discrete packets known as quanta. This theory was developed to explain the discrepancy between classical physics and experiments on blackbody radiation, known as the ultraviolet catastrophe.

## 2. How does Planck's theory explain the UV catastrophe?

According to Planck's theory, the energy of a system can only change by discrete amounts, or quanta, rather than in a continuous manner. This explains why classical physics predicted infinite energy at high frequencies, whereas Planck's theory predicts a finite amount of energy at these frequencies.

## 3. What is the significance of quantised energy in relation to the UV catastrophe?

The concept of quantised energy is crucial in understanding the UV catastrophe and has far-reaching implications in the field of quantum mechanics. It fundamentally changed our understanding of the behavior of matter and energy at the atomic and subatomic levels.

## 4. How did Planck's theory contribute to the development of quantum mechanics?

Planck's theory of quantised energy was a groundbreaking concept that challenged traditional notions of classical physics. It provided a foundation for the development of quantum mechanics, which revolutionized our understanding of the behavior of particles at the atomic and subatomic levels.

## 5. What evidence supports Planck's theory of quantised energy?

Several experiments, including the blackbody radiation experiments that led to the discovery of the UV catastrophe, have provided evidence for the existence of quantised energy. Additionally, the success of quantum mechanics in predicting and explaining various phenomena further supports the validity of Planck's theory.

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