Why is photon massless particle?

In summary, the conversation discusses the concept of a photon and its properties, specifically its mass and how it interacts with the Higgs field. It is explained that the photon is not a traditional particle and its existence does not necessarily imply a mass. Furthermore, the possibility of the photon having a small mass is mentioned, but it is difficult to prove without assuming it is massless.
  • #1
disky
1
0
i'm still wondering,
i know a bit of quantum mechanics and general relativity. well... very very little, if photon is a particle, it must be "something" right? i mean, something that exist in this space and time. why is "something" that "exist" don't have a mass? what is it consist of? or something that really small is different with something big like table? or is photon just a wave that going through space and time? but if it is just a wave, how does it come through vacuum space? please help me, I've done browsing but i got nothing. i am still at high school and the farthest thing i got is classical physics and really excited to modern one but too dumb-_-. and i am new here. thank you
 
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  • #2
disky said:
i'm still wondering,
i know a bit of quantum mechanics and general relativity. well... very very little, if photon is a particle, it must be "something" right? i mean, something that exist in this space and time. why is "something" that "exist" don't have a mass? what is it consist of? or something that really small is different with something big like table? or is photon just a wave that going through space and time? but if it is just a wave, how does it come through vacuum space? please help me, I've done browsing but i got nothing. i am still at high school and the farthest thing i got is classical physics and really excited to modern one but too dumb-_-. and i am new here. thank you

This is a very familiar question, and I suggest you browse the forums, especially the Quantum Physics forum, for a bit to see all the ad nauseum answers that have been given.

A photon isn't an ordinary "particle". Rather, it has been defined as having a clump of energy. It has not been defined as having a definite physical boundary in real space, the way we see a ball, for example.

Secondly, for something to "exist", it must be detectable. We must be able to detect and measure its characteristics. That's it. Nothing here says that for something to exist, it must have a mass. Before quantum mechanics and special relativity came along, we detected light regularly. Yet, none of the theories at that time showed a "particle" picture of light, and thus, no question on whether it has a mass.

The lesson that you should learn here is to think carefully what your logic and sequence of thinking is. Is the existence of A automatically implies the existence of B?

I can already anticipate your subsequent questions on this (if it has "energy", then https://www.physicsforums.com/threads/do-photons-have-mass.511175/ "). You should also read, before you go any further, the FAQ that we currently have on this topic.

Zz.
 
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  • #3
In the book "Beyond the God particle" Lederman try to explain in a simple manner why photon is massless. The responsable is the Higgs field that permeates all the universe: for example in the case of the weak interaction, being a beaking simmetry, the bosons interact with it acquiring mass. He says that for the particles with mass the chirality oscillates from a right to left handedness while for massless ones it is unique and then they can't interact with Higgs field: so the photon cant't obtain mass and they are free to go at maximum speed.
 
  • #4
I don't know that we can truly rule out that the photon has a very small mass that we simply can't measure. I doubt that is the case, but it will be hard to theoretically show that it must be massless without assuming that it is massless.
 

Related to Why is photon massless particle?

1. Why is a photon considered a massless particle?

A photon is considered a massless particle because it has no rest mass, meaning it does not have any mass when it is at rest. It only has energy and momentum, which are related to its wavelength and frequency. This is due to the fact that photons are elementary particles, meaning they do not have any internal structure or components that would contribute to their mass.

2. How can something exist without having any mass?

While it may seem counterintuitive, the concept of massless particles has been confirmed through numerous experiments and observations in physics. The fact that photons have no rest mass does not mean they do not have any energy or momentum. In fact, photons have energy and momentum that are related to their frequency and wavelength through Planck's constant. This is what allows them to exist and travel through space without having any mass.

3. Does the masslessness of photons affect their behavior?

Yes, the masslessness of photons does affect their behavior. Being massless, photons can travel at the speed of light, which is the maximum speed in the universe. They also do not experience gravitational forces, meaning they do not follow the laws of gravity as other massive particles do. Additionally, their energy and momentum are directly related to their frequency and wavelength, which determines their behavior in different mediums and interactions with matter.

4. Are there any exceptions to the masslessness of photons?

As far as we know, photons are considered to be massless particles. However, there have been some theories and experiments that suggest that photons may have a very small mass. This is known as the "massive photon" theory and is still being researched and debated in the scientific community. However, the current consensus is that photons are indeed massless particles.

5. How does the masslessness of photons impact our understanding of the universe?

The masslessness of photons has a significant impact on our understanding of the universe. It plays a crucial role in our understanding of electromagnetism, which governs a wide range of phenomena, from light and electricity to the behavior of atoms and molecules. It also helps explain the behavior of particles at the quantum level and the nature of space and time. Without understanding the properties of massless particles like photons, our understanding of the universe would be incomplete.

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