# Mass of the photon depends on the frequency?

• hazim
In summary, the conversation discussed the concept of the mass of a photon and whether it is zero or not. The participant argued that a photon must have a real mass, even if it is very small, due to its particle nature. They also suggested that the energy of a photon is related to its mass. However, others pointed out that the photon's energy does not necessarily imply mass and that experimental evidence contradicts the idea of a non-zero photon mass.
hazim
Mass of the photon depends on the frequency??

Hi all,

I'm 4th year electronics engineering student and so my question is curiosity.. We have taught that the photon has no mass, or its mass is zero. They even (the teachers and instructors) say that its mass is not negligible, but it is ZERO. This is for me not logical answer, it is a particle, then it must have a real mass even if this mass is 10^-99999999999Kg!

We have the energy of the photon E=hv, and we have E=mc2

E=E
hv=mc2

this means that m(photon)=hv/c2;
h/c2 is constant and the only variable is the frequency or the wavelength

This means that a photon with high frequency (which has higher energy) has more mass.

The mass of the photon (at a certain frequency) times c2 gives us it's energy (it looks similar to the kinetic energy of a moving mass).

A photon at rest or with no frequency does not exist, and therefore the rest mass is zero is only something theoretical...

And according to my view about the mass of the photon, if one substitute some different values of an electromagnetic wave, he will get logical values for the mass.

For example,
7.36 x 10-51 is h/c2
for a 1MHz frequency, the mass of the photon will be about 7.36 x 10-45 which is logical since it is much less than the mass of an electron.

In dialectical materialism and as the science proved, the energy doesn't vanish. And here I mean by energy both m and E which are in unity. So if we considered the energy E to be a mass of photons (and for example, also phonon for heat energy..), the mass itself would be in unity and the energy becomes only a theoretical explanation of the mass energy particles.

Hazim

No E is not equal to mc^2 in general, the most general formula is

E^2 = (mc^2)^2 + (pc)^2

where p is the momentum and m the rest mass.

hazim said:
Hi all,

I'm 4th year electronics engineering student and so my question is curiosity.. We have taught that the photon has no mass, or its mass is zero. They even (the teachers and instructors) say that its mass is not negligible, but it is ZERO. This is for me not logical answer, it is a particle, then it must have a real mass even if this mass is 10^-99999999999Kg!
Then you have an incorrect idea of "particle". The physics definition of particle does not require that it have mass.

We have the energy of the photon E=hv, and we have E=mc2

E=E
hv=mc2

this means that m(photon)=hv/c2;
h/c2 is constant and the only variable is the frequency or the wavelength

This means that a photon with high frequency (which has higher energy) has more mass.
More energy, yes. That does NOT imply "more mass"

The mass of the photon (at a certain frequency) times c2 gives us it's energy (it looks similar to the kinetic energy of a moving mass).

A photon at rest or with no frequency does not exist, and therefore the rest mass is zero is only something theoretical...

And according to my view about the mass of the photon, if one substitute some different values of an electromagnetic wave, he will get logical values for the mass.

For example,
7.36 x 10-51 is h/c2
for a 1MHz frequency, the mass of the photon will be about 7.36 x 10-45 which is logical since it is much less than the mass of an electron.

In dialectical materialism and as the science proved, the energy doesn't vanish. And here I mean by energy both m and E which are in unity. So if we considered the energy E to be a mass of photons (and for example, also phonon for heat energy..), the mass itself would be in unity and the energy becomes only a theoretical explanation of the mass energy particles.

Hazim

hazim said:
Hi all,

I'm 4th year electronics engineering student and so my question is curiosity.. We have taught that the photon has no mass, or its mass is zero. They even (the teachers and instructors) say that its mass is not negligible, but it is ZERO. This is for me not logical answer, it is a particle, then it must have a real mass even if this mass is 10^-99999999999Kg!

We have the energy of the photon E=hv, and we have E=mc2

E=E
hv=mc2

this means that m(photon)=hv/c2;
h/c2 is constant and the only variable is the frequency or the wavelength

This means that a photon with high frequency (which has higher energy) has more mass.

The mass of the photon (at a certain frequency) times c2 gives us it's energy (it looks similar to the kinetic energy of a moving mass).

A photon at rest or with no frequency does not exist, and therefore the rest mass is zero is only something theoretical...

And according to my view about the mass of the photon, if one substitute some different values of an electromagnetic wave, he will get logical values for the mass.

For example,
7.36 x 10-51 is h/c2
for a 1MHz frequency, the mass of the photon will be about 7.36 x 10-45 which is logical since it is much less than the mass of an electron.

In dialectical materialism and as the science proved, the energy doesn't vanish. And here I mean by energy both m and E which are in unity. So if we considered the energy E to be a mass of photons (and for example, also phonon for heat energy..), the mass itself would be in unity and the energy becomes only a theoretical explanation of the mass energy particles.

Hazim

You are strongly advised to read an entry in our FAQ in the General Physics forum. You should also not make such speculation without paying attention to experimental evidence. For example, you will have a whale of a time trying to reconcile your assertion with this result: A.A. Abdo et al., Nature v.462, p.331 (2009).

Zz.

HallsofIvy said:
More energy, yes. That does NOT imply "more mass"

More mass imply more energy right? Considering the energy being a mass (quantum particles having mass as I said before) means that more energy imply more mass...
I confess that I don't have a good awareness of quantum physics but this may be a start for me in this interesting field.

hazim said:
More mass imply more energy right? Considering the energy being a mass (quantum particles having mass as I said before) means that more energy imply more mass...

This is patently false and incorrect. You wouldn't make such an erroneous statement had you done a little bit of "homework", such as reading the FAQ.

Please make sure you review the PF Rules that you had already agreed to. It is one thing to want to learn about physics, which we encourage. It is another to not care about basic physics (especially when you've been given it) but continue to make speculatively and spectacularly wrong guess work. The latter is not permitted in this forum.

Zz.

## 1. What is the relationship between the mass of a photon and its frequency?

The mass of a photon is directly proportional to its frequency. This means that as the frequency of a photon increases, its mass also increases. Similarly, as the frequency decreases, the mass of the photon decreases as well.

## 2. How does the mass of a photon affect its energy?

The mass of a photon is a determining factor in its energy. The higher the mass of a photon, the greater its energy. This is because the energy of a photon is directly proportional to its frequency, and therefore its mass.

## 3. Is the mass of a photon constant?

No, the mass of a photon is not constant. It varies depending on the frequency of the photon. This is due to the fact that photons are particles of light and behave both as waves and particles. Therefore, their mass is not fixed and can change based on their frequency.

## 4. Can a photon have zero mass?

Yes, a photon can have zero mass. Photons with zero mass are known as massless particles. This means that they have no rest mass and only exist as energy. This is also why photons can travel at the speed of light, as particles with mass cannot reach the speed of light.

## 5. Why does the mass of a photon depend on its frequency?

The mass of a photon depends on its frequency because photons are considered to be packets of energy and mass. The frequency of a photon represents the amount of energy it carries. Therefore, the higher the frequency, the greater the energy and mass of the photon.

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