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thetexan
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is a photon a particle?
Tex
Tex
Yes, you can consider a photon as being a particle in some contexts. BUT it is not a particle like a tiny bullet and you cannot make any 'mechanical' type assumptions about how it will behave. You cannot, for instance, tell 'where it is', until it has interacted with something. It can be literally anywhere, which is an odd notion until you come to terms with its abnormal particle nature.thetexan said:is a photon a particle?
Tex
The word "particle", as used in quantum electrodynamics, has a specific meaning. A photon is a particle according to that definition.thetexan said:is a photon a particle?
thetexan said:If a single photon is emitted must you be in its "line of fire" to detect it? If I was 30 feet left or right wouldn't I miss detecting it?
thetexan said:Let's say a photon is emitted from a source and we know the direction that's it emoted
Neither of these "this assumes" statements are correct. You are asking classical questions about a quantum system.thetexan said:Only the person in the direction of the emission will be able to detect the emission. This assumes the particle acts like a particle or a little bullet so that only someone in its line of fire will detect it. Or...
Everyone will be able to detect it. This assumes it acts like a wave and everyone will be hit by the wave and thus able to detect it. If it acts as a wave its potential energy will be continually reduced by the inverse of the distance and would be nearly non existent after only a short distance ( many miles).
It doesn't work like that. Photons are not bullets that can be fired from a little gun.thetexan said:let's say it is emitted in the direction of point A on the sphere using a little photon emitting gun
DaleSpam said:It doesn't work like that. Photons are not bullets that can be fired from a little gun.
thetexan said:If I have a powerful point or nearly point light source and surround it with a light proof sphere no light will get out. Now if I put a pinhole in the sphere only someone in line with the source and the hole will see the light. No one even slightly to one side will see the light. In fact there will only be spot of light on a distant surface.
Everyone will be in line with the source and a hole: given two points in space, there always is a straight line passing through them.thetexan said:If I have a powerful point or nearly point light source and surround it with a light proof sphere no light will get out. Now if I put a pinhole in the sphere only someone in line with the source and the hole will see the light.
Cannot understand here.No one even slightly to one side will see the light. In fact there will only be spot of light on a distant surface.
They are clearly distinct if you generate them in such a way, but they are not clearly directional. They don't have "nadelsstrahlung" (needle-like radiation) as even Einstein initially believed. Prove: light diffraction.Therefore the photon(s) are clearly distinct and directional.
Maybe you intended "corpuscles". In fact they are particles: as Nugatory wrote, "particle" in QM means something which has both corpuscolar and wave behaviour.Whether they are particles or waves is at dispute.
It's easy to describe this behaviour as waves, instead. You only have to take a monochromatic wave with low enough wavelenght (low with respect to all the other dimensions involved in the experiment = geometrical optics approximation) and which is very collimated (you can obtain this making the radiation pass through distant holes made on parallele screens). Nothing particularly difficult.Particles would explain the observation. If waves then one would have to explain how the waves AS WAVES could be so precisely contained to a ray of light. A laser is a good example of this.
thetexan said:What is the something? Jillions of photon particles or a sea of photon waves?
thetexan said:I
Therefore the photon(s) are clearly distinct and directional. Whether they are particles or waves is at dispute. Particles would explain the observation. If waves then one would have to explain how the waves AS WAVES could be so precisely contained to a ray of light. A laser is a good example of this.
thetexan said:What is the something? Jillions of photon particles or a sea of photon waves?
This is not the way light works even classically. Because of diffraction a small pinhole acts essentially as a point source.thetexan said:Now if I put a pinhole in the sphere only someone in line with the source and the hole will see the light. No one even slightly to one side will see the light.
Classical EM works fine for this. There is no need to consider quantum effects. It is just a field of essentially spherical incoherent EM radiation.thetexan said:Therefore every cubit centimeter of space is filled with "something" from the one star.
What is the something? Jillions of photon particles or a sea of photon waves?
I suggest you read some general stuff about QM because I think you need to immerse yourself in this stuff. At the moment, you seem to want a Classical answer to your questions and there are actually no satisfactory classical answers (which is why 'they' had to invent QM).thetexan said:What is the something? Jillions of photon particles or a sea of photon waves?
I actually think that the problem is almost the opposite. There is simply no reason to introduce quantum concepts to answer his underlying question. The problem is actually that he has brought quantum terminology into a classical question and seems not to recognize that the quantum terminology requires a quantum theory to make sense.sophiecentaur said:At the moment, you seem to want a Classical answer to your questions and there are actually no satisfactory classical answers (which is why 'they' had to invent QM)
His first question was about photons, though, so you can hardly answer it without pointing out their quantum nature. But clearly, confusion rules. (as with all of us, I guess)DaleSpam said:no reason to introduce quantum concepts to answer his underlying question.
sophiecentaur said:His first question was about photons, though, so you can hardly answer it without pointing out their quantum nature. But clearly, confusion rules. (as with all of us, I guess)
Yes, that is true. It wasn't until quite a bit later that the clarification was provided indicating that the underlying question was classical.sophiecentaur said:His first question was about photons, though, so you can hardly answer it without pointing out their quantum nature. But clearly, confusion rules. (as with all of us, I guess)
Maybe because light can also propagate in the void and someone still believe that only corpuscles/spaceships/asteroids/planets/etc (and not waves) can propagate in the void. Furthermore, tv programs and popular books talk about "photons" very often (and quite never about phonons) and people easily and quickly makes in his head an image of flying corpuscles like little bullets.Nugatory said:Edit: Maybe someday I'll understand how people can go years without feeling a compulsion to introduce phonons into discussions of sound waves, but somehow when it comes to light the first thing they think of are photons.
I would say "charge" or "current". There is rarely a need to talk about electrons in classical EM. I find that a lot of unnecessary confusion for circuits comes from "electrons" which are not needed.my2cts said:What about electrons? Should we say charge pulse, unless we are using QM? I don't advocate that.