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Fazor
2006-Oct-20, 07:01 PM
If light is made of photons, which to my understanding are elementary particles or the most basic (smallest if you will) particle, and "light" displays both the properties of a wave and of a particle....

bear with me here... and we know light is constantly moving, could light be a photon "spiraling" outward from it's originating point? Think of a cone shaped spiral with a plane intersecting it through the middle. as the photon travels along this path, it would intersect the plane at given intervals, or "waves". this doesn't necessarily have to be a cone shaped spiral, could also be cylendrical.

If this were the case that would explain how light demonstrates both wave-like and particle like properties. the spiral path, or revolutions, could be changed but it would still be the photon moving along this path.

any reading material would be cool. just starting to dig into this photon stuff. thanks.

Nereid
2006-Oct-21, 02:27 AM
If light is made of photons, which to my understanding are elementary particles or the most basic (smallest if you will) particle, and "light" displays both the properties of a wave and of a particle....

bear with me here... and we know light is constantly moving, could light be a photon "spiraling" outward from it's originating point? Think of a cone shaped spiral with a plane intersecting it through the middle. as the photon travels along this path, it would intersect the plane at given intervals, or "waves". this doesn't necessarily have to be a cone shaped spiral, could also be cylendrical.

If this were the case that would explain how light demonstrates both wave-like and particle like properties. the spiral path, or revolutions, could be changed but it would still be the photon moving along this path.

any reading material would be cool. just starting to dig into this photon stuff. thanks.A good place to start would be the accounts of the various 'two slit' experiments, especially those set up so that there was never more than one photon in the apparatus at any time ...

Ken G
2006-Oct-21, 04:10 AM
The first thing to realize is that the wave attributes of photons are no different from all other particles-- all particles move according to the rules of wave mechanics. A while back I started a thread to clear up what I think is one of the most misunderstood concepts in physics: "wave/particle duality". I think it should instead be called "wave/particle unity", because what it really means is that particles move according to the rules of waves. When they show up, they are particles, but how they get there, is ruled by wave mechanics. This is true of absolutely all particles, it's just the way the universe works. And the most important rule about waves is the concept of interference: constructive interference makes it likely for the particle to go there, destructive interference makes it unlikely. This is also the source of the Heisenberg uncertainty principle-- constructive interference is of limited precision, as is the localizability of the particle. This is true for photons or electrons or any particle, it's just that when the wavelength of the governing wave amplitudes get very small, the particle motion takes on the flavor of a "trajectory", but even that is a property of a wave in one limit.

gzhpcu
2006-Oct-21, 10:55 AM
I can also recommend Brian Greene's "The Elegant Universe". Highly readable.

ozark1
2006-Oct-24, 11:33 AM
The first thing to realize is that the wave attributes of photons are no different from all other particles-- all particles move according to the rules of wave mechanics. A while back I started a thread to clear up what I think is one of the most misunderstood concepts in physics: "wave/particle duality". I think it should instead be called "wave/particle unity", because what it really means is that particles move according to the rules of waves. When they show up, they are particles, but how they get there, is ruled by wave mechanics. This is true of absolutely all particles, it's just the way the universe works. And the most important rule about waves is the concept of interference: constructive interference makes it likely for the particle to go there, destructive interference makes it unlikely. This is also the source of the Heisenberg uncertainty principle-- constructive interference is of limited precision, as is the localizability of the particle. This is true for photons or electrons or any particle, it's just that when the wavelength of the governing wave amplitudes get very small, the particle motion takes on the flavor of a "trajectory", but even that is a property of a wave in one limit.

I have a slightly different take. There are experimental results on light which are best explained as waves - for example double slit diffraction, and there are results that are best explained as particles - notably the photoelectric effect.

The key is that neither the wave description or the particle description is sufficient to describe the results of all experiments. We need both models to describe light - hence wave/particle duality.

Ken G
2006-Oct-24, 01:21 PM
I have a slightly different take. There are experimental results on light which are best explained as waves - for example double slit diffraction, and there are results that are best explained as particles - notably the photoelectric effect.

My objection to this common approach is not there is anything incorrect about it, but rather that it seems to suggest that there is some sort of strange or unusual contradiction about some experiments giving "wave behavior" and others giving "particle behavior". I have a height and a weight, and some experiments (like if I stand next to a ruler) will indicate my height, while other experiments (if I step on a scale) will indicate my weight. Does this give me "height/weight duality"? Am I best explained as having "height behavior" in some situations, and "weight behavior" in others? They are simply two attributes I possess, there's no need to imply a contradiction. Particles have discrete quantum numbers, and they move around according to wave mechanics. That's the natural way, it applies to all particles, so thinking of that as a "duality" implies some sort of strange contradiction that is not actually there, even though it isn't wrong.

George
2006-Oct-24, 02:05 PM
Polarization should be a problem for this spiraling photon idea. A spiraling photon would not favor any one alignment of my fishing sun glasses.

Cuddles
2006-Oct-24, 03:42 PM
The best explanation I have seen is basically - if we measure something as if it is a particle, it behaves like a particle; if we measure something as if it is a wave, it behaves like a wave. Neither waves or particles actually exist, they are just different aspects of whatever it is that is really there.

Ken G
2006-Oct-24, 04:20 PM
Again this is the understanding that I feel leads to misleading implications, even though it is not wrong, just as in the height and weight analogy. If we measure my height, we get a heightlike result, if we measure my weight, we get a weightlike result. Everything is like this, there's no need to see anything unusual in such a "duality". Part of a description of me requires the concept of height, part of it requires the concept of weight. The "duality" descriptions often seem to imply there is something mysterious about that, like we are controlling reality based on our measurements. (That can happen in quantum mechanics for other reasons that have nothing to do with wave/particle duality, but rather simply the wave component itself).

Fazor
2006-Oct-24, 05:06 PM
Polarization should be a problem for this spiraling photon idea. A spiraling photon would not favor any one alignment of my fishing sun glasses.

Not at all: Polarization is simply adding lines of light reflecting materials to a lense, so that some of the light is blocked. if the photons were spinning or moving straight, regardless, some would be blocked while others would not be. of course, this doesn't have to be stripes. it's probably more like a grid of dots or some symetrical pattern that would block the same percent from any angle. but this would work regarless if the photon was spiralling or moving straight.

George
2006-Oct-24, 10:54 PM
Not at all: Polarization is simply adding lines of light reflecting materials to a lense, so that some of the light is blocked. if the photons were spinning or moving straight, regardless, some would be blocked while others would not be. of course, this doesn't have to be stripes. it's probably more like a grid of dots or some symetrical pattern that would block the same percent from any angle. but this would work regarless if the photon was spiralling or moving straight.
This would seem to work fine with non-polarized lenses, but with polarization, the angle of the lens alters the amount of light that passes. I don't see how spiraling photons could be more numerous through the lens only at certain lens angles.

Fazor
2006-Oct-25, 12:44 AM
that's what i was saying. it wouldn't matter the angle. it was in response to the post a few back. just don't know how to properly do the quote thing

George
2006-Oct-25, 01:38 PM
that's what i was saying. it wouldn't matter the angle. it was in response to the post a few back. just don't know how to properly do the quote thing
I am not clear what you are saying. Are you saying a spiraling photon would not conflict with observation of light through a polarized lens? A polarized lens is very angle sensitive to reflected light which can be explained by the mainstream wave nature of light. Is there a way a spiraling photon can behave in a similar manner?

[You can click on the “Quote” button on the bottom, or insert the phrase you wish to quote by inserting between the commands…. [quote] <insert phrase> [\quote], but use "/quote" instead of "\quote" .]

arasuat
2006-Oct-25, 03:26 PM
`particle moves according to the rules of waves' -- yes, these lines may
be read along with the fact that ` the rest mass of a photon is nil '.

Fazor
2006-Oct-25, 04:19 PM
George: I guess it doesn't really matter now, after delving deeper into some materials the only thing i think that's really in a (downward) spiral now is my desire to be stuck here at work on such a nice day. Kinda have a better understanding of the term wave-particle duality now,the only real mystery to this term is why so many texts act like this is some strange phenomenon, as if the two terms are contradictory when really they're not (refer to my wave-particly duality post) thanks.

George
2006-Oct-25, 04:40 PM
...the only real mystery to this term is why so many texts act like this is some strange phenomenon, as if the two terms are contradictory when really they're not (refer to my wave-particly duality post) thanks.
Understanding light has been a problem for physics since Newton. He was convinced they were particles, corpuscles, and not waves. Others argued light consisted of waves and were not particles. The idea that they both could be right seemed absurd. Ken's analogy of height and mass demonstrates duality, but no analogy I know fully gets us the real grip on what is really there.

Ken G
2006-Oct-25, 05:00 PM
I think the problem is with what we think we understand about particles. For a long time, we could observe in our macroscopic world, particles that followed "trajectories" and Newton's laws for particles (like cannon balls), and waves that worked according to wavelike applications of Newton's laws (like sound). They seemed very different, so imagine our surprise when it was discovered that at the level of elementary particles, there was no such thing as a trajectory-- it isn't a precise concept. Elementary particles move according to the rules of waves, but they are particles, so that's why the term "duality" was created. But the unfortunate implication that many get from this is that macro particles act like particles all the time, whereas elementary particles act like particles part of the time and waves the rest of the time, and this all seems very mysterious. The actual discovery is that waves can create behavior just like trajectories, if the wavelength is small enough. Also, if there are enough particles and enough "noise" in the system, coherences are destroyed so that even wave mechanics no longer produce interference patterns. So what this all means is that everything moves like waves, it's just not always necessary to use this fact in practice. "Duality" is really "unity".