How the energy of light changes

[swansont]

Maybe all of the photon needs to pass into the electron to get absorbed, or maybe the photon changes to a different photon as the first part get's absorbed, which means that the thing you were saying would't apply because it's not the same photon once the first part get's absorb. If one wavelength of a 300 nano-meter photon suddenly disappears, is it a 299 meter wavelength or does it stretch out more to become a 301 nn wavelength? A photon has to travel only specific distance in time since it's speed isn't instantaneous, so there's obviously something going, but because of that HUP thing you just said, we know that energy can't be continuously absorbed from a single photon, so I think one of the two things I was saying is true or near-true, although how does a photon that's bigger than the cloud of an electron fit entirely inside an electron without part of it already passing through the other side by the time the end of the photon reaches it?

 

The photon does not behave as you are modeling it.

[questionposter]

The photon does not behave as you are modeling it.

 

So since your not telling me what does happen, I'm guess you don't know what actually happens either, but if you don't know what happens, how do you know what I'm saying is completely wrong? Things like the antennae in cellphones can interact with radio waves, but radio waves are meters wide, so how does whatever a photon is made out of that spreads out over a football field suddenly shrink to a single interaction point when a cellphone absorbs it? What happens to the rest of the photon that was a football field long minus a single point?

[swansont]

So since your not telling me what does happen, I'm guess you don't know what actually happens either, but if you don't know what happens, how do you know what I'm saying is completely wrong? Things like the antennae in cellphones can interact with radio waves, but radio waves are meters wide, so how does whatever a photon is made out of that spreads out over a football field suddenly shrink to a single interaction point when a cellphone absorbs it? What happens to the rest of the photon that was a football field long minus a single point?

The HUP prevents me (or anyone else) from testing specifically what happens. We model the interaction, not the mechanics of it, or at least not the mechanics that cannot be tested. But from what we can test, when photons interact they are localized and they either interact or they don't. Any model you build has to reconcile with those (and other) observed behaviors.

[MigL]

Its very hard explaining the Heisenbrg Uncertainty Principle to someone who keeps trying to put it into common sensical, everyday perspective. I know, I spent years trying to make sense of it.

 

Its not a case of not being able to make accurate enough measurements or knowing the actual mechanism, but the physics will not allow you to measure accurately enough or know exactly. It is actually not allowed and therefore impossible.

[questionposter]

Its very hard explaining the Heisenbrg Uncertainty Principle to someone who keeps trying to put it into common sensical, everyday perspective. I know, I spent years trying to make sense of it.

 

Its not a case of not being able to make accurate enough measurements or knowing the actual mechanism, but the physics will not allow you to measure accurately enough or know exactly. It is actually not allowed and therefore impossible.

 

But the HUP isn't some mystical force, it's the result of particles having wave-like properties and particle properties simultaneously. A wave doesn't have a specific location, that's fine, nothing wrong with a photon having wave properties and therefore not having a specific location, but how is it going form a particle-wave to just a particle at a single point where the rest of it disappears? How does the rest of the waving photon localize? I guess it can't be answered with certainty, but it would be nice to see an educated guess since things like strings and other higg's bosons are also basically educated guesses.

Edited August 31, 2011 by questionposter

[davey2222]

This is what i learned in my university: whether light behaves as a wave or particle depends on the experiment, or detection, method.

 

If we talk about a receiving antenna then assume light behaving as waves. For the photoelectric effect then assume particles. Double-slit experiment then waves. Etc.

[questionposter]

This is what i learned in my university: whether light behaves as a wave or particle depends on the experiment, or detection, method.

 

If we talk about a receiving antenna then assume light behaving as waves. For the photoelectric effect then assume particles. Double-slit experiment then waves. Etc.

 

But light always has properties of both, that's why the higher the wavelength the more localized it is and the lower the wavelength the less localized it is. I jsut don't get how it suddenly goes from both and occupying 3D space to only being one and occupying a 1 dimensional point.

[davey2222]

Nobody understands it perfectly, hence the dual property that depends on the detection/experiment method as the generalisation.

 

Perhaps someone will come up with a better theory.

[MigL]

No. HUP has nothing to do with wave-particle duality which has been around since the time of Newton and Hyugens ( spelling ?? ). A macroscopic wave has no uncertanty, but on the quantum level everything ( time , energy, momentum, position ) is 'smeared out' by the HUP such that nothing is deterministic, but probabilistic.

[questionposter]

No. HUP has nothing to do with wave-particle duality which has been around since the time of Newton and Hyugens ( spelling ?? ). A macroscopic wave has no uncertanty, but on the quantum level everything ( time , energy, momentum, position ) is 'smeared out' by the HUP such that nothing is deterministic, but probabilistic.

 

But a macropscopic wave doesn't occupy a single position, just like waves on the atomic level. And in fact, the HUP determines a bit of properties int the sub-atomic and atomic world as you can figure out the dimensions of 3D space that particles occupy most of the time using the mass of a particle and the uncertainty principal as well as how localized a photon will be based on it's wavelength apparently. Waves don't have a specific position, particles do. When you mix them together, you get a semi-uncertain (still pretty unknown, but you know the "best" areas) location of a particle wave, also knows as the HUP.

Edited September 2, 2011 by questionposter

[swansont]

But a macropscopic wave doesn't occupy a single position, just like waves on the atomic level. And in fact, the HUP determines a bit of properties int the sub-atomic and atomic world as you can figure out the dimensions of 3D space that particles occupy most of the time using the mass of a particle and the uncertainty principal as well as how localized a photon will be based on it's wavelength apparently. Waves don't have a specific position, particles do. When you mix them together, you get a semi-uncertain (still pretty unknown, but you know the "best" areas) location of a particle wave, also knows as the HUP.

 

Except when the wave interacts, it is localized. All of the interaction takes place there, not part of it. Thus, the interaction is not classical, and it's erroneous to think about it in classical terms.

[MigL]

Macroscopic waves can occupy a single position. Take the shock wave where air is decelerated from supersonic to subsonic at a projection ( or air intake lip ), admittedly not a point but a surface, nonetheless it can be located to a very high accuracy by computational methods, and exactly by solving the fluid flow equations.

 

Quantum mechanical equations have the HUP, and the resulting uncertainty or 'smearing out', built into the equations themselves, by definition, making improved accuracy, beyond that allowed by the HUP, impossible.

 

Unless someone comes up with a different theory than Quantum Mechanics for atomic processes, or some hidden variables are identified, we are stuck with the limits imposed by the HUP.