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If the positron has a negative mass -m, and the electron has a positive mass +m, their sum is-m+m=0
Can we explain why the photon mass is zero (its rest-mass is 0)?
Is it 0 because the photon is the particle into which the positron-electron pair is transformed in the annihilation?
First off, welcome to the forum!
Next: That's a really big if. What gave you the impression that such a thing is possible?
I don't follow. The diagram you showed is a Feynman diagram but it is not the diagram of an electron annihilating a positron because you have an electron and positron coming out of the reaction. In between where you have the single photon that's a virtual photon and virtual photons have a mass which is off-the-shell of a real photon's energy-momentum curve. That means that the proper mass (i.e. rest mass) of the photon can be non-zero. Virtual photons can't be observed.
I don't see that from the actual diagram and its correct interpretation.
Are you asking why I think that whether mass can be negative?
I told that negative mass can explain why the photon mass is 0, or rather why its rest-mass is 0.
It is true that Feyman diagrams always repesent an action at distance, or an interaction between two particles.
Forces don't happen because of any sort of action at a distance, they happen because of virtual particles that spew out of things and hit other things, knocking them around. However, this is misleading. Virtual particles are really not just like classical bullets.
Feynman diagrams are not supposed to represent a head-on collision of two particles.
The problem is, my picture represents a head-on collision of a positron and an electron.
In other words, a Feynman diagram can represent a collision of two particles, although it is not generally admitted or understood.
My picture should not be understood as representing an interaction between two particles transmitted with a virtual photon.
Because if that were true, what are the particles interacting with each others?
A pair creation happens when an electron and a positron are created out of the photon.
If there was during the "annihilation" a transformation of the pair positron-electron into a photon,..
then the correct interpretation of the diagram is that there did not happen any actual annihilation.
Instead there was a transformation of the pair positron-electron into a photon.
The misunderstanding starts at the beginning. The e-p annihilation produces two photons, not one.
It is unclear to me what you mean by negative mass. Do you mean mass which has a negative charge or anti mass I think your mixing the 2 together which is why your question dose not make sense.
Quote from: Courier of darknessAre you asking why I think that whether mass can be negative?No. It's clear to me that you think that it can be negative. I'm asking you exactly what I posted, i.e. What gave you the impression that such a thing is possible? I.e. we already know that you believe that it's true. What we don't know is why you believe its true.
But, as I explained above, your diagram and your argument don't support your assertion.
If it wasn't then photons wouldn't be able to travel at the speed of light. That's the explanation.
There's no such thing as action at a distance. Charged particles create electric fields. When another charged particle is placed in that field it exchanges virtual photons with the original charge. However it takes time for the virtual photons to move. But this can't be seen as action at a distance. See: http://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.html [nofollow]
The fact that gauge bosons are invisible to us, and that we can only observe the effects they produce rather then the particles themselves, has led to the phrase "action at a distance" to describe the way in which they work
That's incorrect. That's exactly what your diagram means.
I don't understand that question. It was poorly stated. I.e. what does "..., what are the particles interacting with each others?" mean? I.e. "interacting with each others" I have no clue what that's supposed to mean and I doubt anybody else does. I think you must have made a mistake and not have seen it.
Why are you bothering with this anyway? Is it because you thought that when the electron and positron annihilated each other than the end result was zero rest mass? If that's what you thought then you were mistaken because the result wasn't a photon, which has zero rest mass, it was a virtual photon, which doesn't have zero rest mass.
Anyway photons should have mass because they have energy.
Ditto for positron mass. It doesn't have a negative mass, it has a positive mass.
I already said why: negative mass explains why the photon has zero rest-mass.
If the positron has a negative mass -m...
Agreed John.....................the positive and negative signs here only relate to charge and not to the mass of the particle. Should be very logical and simple to understand that charge and mass are separate and singular attributes of these particles.
They expect that if you dropped an atom of Hydrogen and an atom of anti-Hydrogen simultaneously, they will hit the bottom at the same time.
Quote from: Ethos_ on 08/03/2015 16:54:09Agreed John.....................the positive and negative signs here only relate to charge and not to the mass of the particle. Should be very logical and simple to understand that charge and mass are separate and singular attributes of these particles.And moreover, positive and negative charge is merely a convention. If you google on positron chirality you appreciate that the positron has the opposite chirality or "handedness" to the electron, and that this is related to its opposite charge. Now look at your hands. They have the opposite handedness. But your left hand isn't actually some negative version of your right hand.
Quote from: evan_auThey expect that if you dropped an atom of Hydrogen and an atom of anti-Hydrogen simultaneously, they will hit the bottom at the same time.They know it. General relativity is one of the best-tested theories we've got, and its energy that interacts gravitationally, not just matter. It doesn't matter what form it takes. Light curves down, we make electrons and positrons out of light in pair production, they will both fall down. I'm afraid does antimatter fall up? is just a soundbite to attract the attention of the popscience media.
If the mass goes into a negative number then any particle of negative mass would be going faster then the speed of light (perhaps backward in time) if it had any energy in it. BUT could such a particle have Negative energy? If so then it might as well have negative velocity meaning that the particle would be going backward in time. Right?
Lets say there is a particle with normal mass, it has some kinetic energy and is moving through space. Like any thing with mass, this particle has a tiny gravitational field. If this hypothetical particle's gravitational field gets weaker and weaker over time then it's mass will diminish over time.Just because the particle is loosing it's gravitational field (Mass) does not mean that it's kinetic energy is decreasing (it would still remain the same) because of this scenario, the equation E=mc² comes into play. The energy E of the particle remains the same and M is decreasing so the velocity of the particle therefore must be increasing until the mass of the particle gets to zero (at which point the particle would be going the speed of light)If the mass goes into a negative number then any particle of negative mass would be going faster then the speed of light (perhaps backward in time) if it had any energy in it. BUT could such a particle have Negative energy? If so then it might as well have negative velocity meaning that the particle would be going backward in time. Right?