Energy Distribution of EM Radiation ~ One Photon

In summary, the conversation discusses the distribution of energy on a sphere in single photon emission and whether it is evenly distributed or localized at one point. The participants agree that in the latter case, the energy is localized and would be received by a detector. They also reference the Copenhagen Interpretation in relation to the wave function of the photon.
  • #1
kcodon
81
0
Hi All,

I've been recently reading a thread, and a question keeps popping up there. Its not very difficult, it just requires a simple yes or no answer...in a single photon emission, is the energy of the photon distributed evenly on the sphere r=ct, or does this sphere represent the probability of the photon being there, and in fact all the energy of the photon is at one point...i.e. a detector would get all of the energy. Ok not quite yes/no but you get the picture.

I believe in the latter, however I would like to know what others think, thus the poll.

Hopefully this will be short and sweet,

Kcodon
 
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  • #2
The photon cannot be said to be anywhere until it interacts with something. When individual photons interact with matter (like a screen), they always act at discrete locations.

- Warren
 
  • #3
So you're in favour of probability?

Darn, I should've posted this in QM I think...

Kcodon
 
  • #4
The second option is obviously correct.
The first is the average result for a large number of emissions.
 
  • #5
In QM a photon with a spherically symmetric wavefunction, and a similar photon that has been observed are two different scenarios.

By my understanding, for a photon that hasn't been observed, the energy will be distributed symmetrically. The wavefunction that describes the photon represents the probability of the photon being detected at that point.

For a photon that has been observed, the energy will be localised at a point, and as such the detector making the measurement will receive all the photons energy. The wavefunction of the photon in this case is obviously very different to the previous case.

Claude.
 
  • #6
Thanks again Claude,

Your explanation makes sense - I never considered how under QM they are considered as different events so to speak. I suppose I need to clarify then - I am reffering to what energy the detector would observe, and it seems we agree it would get the full energy of the photon.

Kcodon
 
  • #7
I could've sworn I posted in this thread.

The second one is correct, the 'wave' can be understood as a wave until it is detected, in which the wave function collapses and it retains particle-like characteristics.

Look up: The Copenhagen Interpretation
 

1. What is the energy distribution of EM radiation?

The energy distribution of electromagnetic (EM) radiation refers to the way in which energy is spread across the different wavelengths or frequencies of the radiation. This distribution is determined by the source of the radiation and the properties of the medium through which the radiation travels.

2. What is a photon?

A photon is a fundamental particle that makes up electromagnetic radiation. It has no mass but carries energy and momentum. Photons are responsible for carrying the energy of EM radiation and their energy is directly related to the frequency or wavelength of the radiation.

3. How is the energy of a photon related to its wavelength?

The energy of a photon is directly proportional to its frequency or inversely proportional to its wavelength. This relationship is described by the equation E=hf, where E is energy, h is Planck's constant, and f is frequency. This means that as the frequency of a photon increases, its energy also increases.

4. How is the energy distribution of EM radiation measured?

The energy distribution of EM radiation is measured using a device called a spectrophotometer. This instrument separates the different wavelengths or frequencies of the radiation and measures the amount of energy at each wavelength. This data is then used to create a graph of the energy distribution.

5. What factors can affect the energy distribution of EM radiation?

The energy distribution of EM radiation can be affected by the source of the radiation, such as the temperature of the object emitting the radiation, and the properties of the medium through which the radiation travels. Other factors that can affect the energy distribution include the presence of any obstructions or filters in the path of the radiation and the distance the radiation has traveled.

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