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From: BURT on 2 Dec 2009 16:43 On Dec 2, 1:04 pm, George Herold <ggher...(a)gmail.com> wrote: > On Dec 2, 3:16 pm, BURT <macromi...(a)yahoo.com> wrote: > > > > > > > On Dec 2, 3:43 am, p.kins...(a)ic.ac.uk wrote: > > > > BURT <macromi...(a)yahoo.com> wrote: > > > > What wave is the particle of light in? the electric opr > > > > magnetic wave? > > > > Here's how the theory can be described (simplified, obviously): > > > > (a) solve Maxwell's equations for a suitable system, and get a set > > > of normalizable basis functions allowing you to describe any field > > > configuration. > > > > (b) these basis functions usually have both electric and magnetic > > > field contributions; they are usually called "mode functions", and > > > tend to oscillate in space and time (although not all will). > > > > (c) quantize the field inside each mode; this gives you a countable > > > series of possible mode excitations. > > > > (d) to describe some chosen field configuration, you combine a > > > suitable set of modes containing appropriate quantum excitations. > > > You may need to account for non-trivial correlations between the > > > modes, and between the quantum states in the same and different > > > modes. > > > > There is no "particle of light". Instead there are countable > > > excitations of the wave-like field modes. These modes usually > > > combine both electric and magnetic contributions. > > > > It's not a particle, it's a wave. But you _can_ count the > > > excitations. > > > > -- > > > ---------------------------------+--------------------------------- > > > Dr. Paul Kinsler > > > Blackett Laboratory (Photonics) (ph) +44-20-759-47734 (fax) 47714 > > > Imperial College London, Dr.Paul.Kins...(a)physics.org > > > SW7 2AZ, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/ > > > There are only a very few quantizations in light energy quantities of > > the atom. Certainly not enough for white light we see. This does not > > correspond to the reality of the full spectrum produced by the white > > light. A light bulb passed through a prism produces a full spectrum of > > energy levels but does not have enough quantized states in its atom to > > do so. > > > Mitch Raemsch- Hide quoted text - > > > - Show quoted text - > > Mitch, The light bulb can be thought of as a black body radiator. It > doesn't matter what kind of atoms the black body is made of. All that > is important is the temperature.http://en.wikipedia.org/wiki/Blackbody_radiation > > George H.- Hide quoted text - > > - Show quoted text - George my point is that energy transitions cannot be quantized in the case of a white light. You might have a light filliment composed of a few different atoms but these could not produce the full spectrum of all the light energies noticed when its light is passed through a prism. Evidently only sometimes is light energy quantized. Mitch Raemsch
From: George Herold on 2 Dec 2009 17:09 On Dec 2, 4:43 pm, BURT <macromi...(a)yahoo.com> wrote: > On Dec 2, 1:04 pm, George Herold <ggher...(a)gmail.com> wrote: > > > > > > > On Dec 2, 3:16 pm, BURT <macromi...(a)yahoo.com> wrote: > > > > On Dec 2, 3:43 am, p.kins...(a)ic.ac.uk wrote: > > > > > BURT <macromi...(a)yahoo.com> wrote: > > > > > What wave is the particle of light in? the electric opr > > > > > magnetic wave? > > > > > Here's how the theory can be described (simplified, obviously): > > > > > (a) solve Maxwell's equations for a suitable system, and get a set > > > > of normalizable basis functions allowing you to describe any field > > > > configuration. > > > > > (b) these basis functions usually have both electric and magnetic > > > > field contributions; they are usually called "mode functions", and > > > > tend to oscillate in space and time (although not all will). > > > > > (c) quantize the field inside each mode; this gives you a countable > > > > series of possible mode excitations. > > > > > (d) to describe some chosen field configuration, you combine a > > > > suitable set of modes containing appropriate quantum excitations. > > > > You may need to account for non-trivial correlations between the > > > > modes, and between the quantum states in the same and different > > > > modes. > > > > > There is no "particle of light". Instead there are countable > > > > excitations of the wave-like field modes. These modes usually > > > > combine both electric and magnetic contributions. > > > > > It's not a particle, it's a wave. But you _can_ count the > > > > excitations. > > > > > -- > > > > ---------------------------------+--------------------------------- > > > > Dr. Paul Kinsler > > > > Blackett Laboratory (Photonics) (ph) +44-20-759-47734 (fax) 47714 > > > > Imperial College London, Dr.Paul.Kins...(a)physics..org > > > > SW7 2AZ, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/ > > > > There are only a very few quantizations in light energy quantities of > > > the atom. Certainly not enough for white light we see. This does not > > > correspond to the reality of the full spectrum produced by the white > > > light. A light bulb passed through a prism produces a full spectrum of > > > energy levels but does not have enough quantized states in its atom to > > > do so. > > > > Mitch Raemsch- Hide quoted text - > > > > - Show quoted text - > > > Mitch, The light bulb can be thought of as a black body radiator. It > > doesn't matter what kind of atoms the black body is made of. All that > > is important is the temperature.http://en.wikipedia.org/wiki/Blackbody_radiation > > > George H.- Hide quoted text - > > > - Show quoted text - > > George my point is that energy transitions cannot be quantized in the > case of a white light. You might have a light filliment composed of a > few different atoms but these could not produce the full spectrum of > all the light energies noticed when its light is passed through a > prism. > > Evidently only sometimes is light energy quantized. > > Mitch Raemsch- Hide quoted text - > > - Show quoted text - Ahh, there are two types of quantization here. For an atom you have quantized electron states. The photon emmited when the atom goes from one state to the other has a particular 'quantized' frequency. But this is just because of the uderlying quantized electron states. There is then the quantization of the EM field that is called a photon....(And I'll never call it a particle again.) When you measure light you either see one photon or none....never some fraction of a photon. (OK, most times you see lots of photons, but always an interger number.) George H. (I was afraid you were going to ask, "From where comes the photon emmited by a black body?" I don't have a good picture of that process.)
From: BURT on 2 Dec 2009 17:19 On Dec 2, 2:09 pm, George Herold <ggher...(a)gmail.com> wrote: > On Dec 2, 4:43 pm, BURT <macromi...(a)yahoo.com> wrote: > > > > > > > On Dec 2, 1:04 pm, George Herold <ggher...(a)gmail.com> wrote: > > > > On Dec 2, 3:16 pm, BURT <macromi...(a)yahoo.com> wrote: > > > > > On Dec 2, 3:43 am, p.kins...(a)ic.ac.uk wrote: > > > > > > BURT <macromi...(a)yahoo.com> wrote: > > > > > > What wave is the particle of light in? the electric opr > > > > > > magnetic wave? > > > > > > Here's how the theory can be described (simplified, obviously): > > > > > > (a) solve Maxwell's equations for a suitable system, and get a set > > > > > of normalizable basis functions allowing you to describe any field > > > > > configuration. > > > > > > (b) these basis functions usually have both electric and magnetic > > > > > field contributions; they are usually called "mode functions", and > > > > > tend to oscillate in space and time (although not all will). > > > > > > (c) quantize the field inside each mode; this gives you a countable > > > > > series of possible mode excitations. > > > > > > (d) to describe some chosen field configuration, you combine a > > > > > suitable set of modes containing appropriate quantum excitations. > > > > > You may need to account for non-trivial correlations between the > > > > > modes, and between the quantum states in the same and different > > > > > modes. > > > > > > There is no "particle of light". Instead there are countable > > > > > excitations of the wave-like field modes. These modes usually > > > > > combine both electric and magnetic contributions. > > > > > > It's not a particle, it's a wave. But you _can_ count the > > > > > excitations. > > > > > > -- > > > > > ---------------------------------+--------------------------------- > > > > > Dr. Paul Kinsler > > > > > Blackett Laboratory (Photonics) (ph) +44-20-759-47734 (fax) 47714 > > > > > Imperial College London, Dr.Paul.Kins...(a)physics.org > > > > > SW7 2AZ, United Kingdom. http://www.qols.ph.ic..ac.uk/~kinsle/ > > > > > There are only a very few quantizations in light energy quantities of > > > > the atom. Certainly not enough for white light we see. This does not > > > > correspond to the reality of the full spectrum produced by the white > > > > light. A light bulb passed through a prism produces a full spectrum of > > > > energy levels but does not have enough quantized states in its atom to > > > > do so. > > > > > Mitch Raemsch- Hide quoted text - > > > > > - Show quoted text - > > > > Mitch, The light bulb can be thought of as a black body radiator. It > > > doesn't matter what kind of atoms the black body is made of. All that > > > is important is the temperature.http://en.wikipedia.org/wiki/Blackbody_radiation > > > > George H.- Hide quoted text - > > > > - Show quoted text - > > > George my point is that energy transitions cannot be quantized in the > > case of a white light. You might have a light filliment composed of a > > few different atoms but these could not produce the full spectrum of > > all the light energies noticed when its light is passed through a > > prism. > > > Evidently only sometimes is light energy quantized. > > > Mitch Raemsch- Hide quoted text - > > > - Show quoted text - > > Ahh, there are two types of quantization here. For an atom you have > quantized electron states. The photon emmited when the atom goes from > one state to the other has a particular 'quantized' frequency. But > this is just because of the uderlying quantized electron states. > There is then the quantization of the EM field that is called a > photon....(And I'll never call it a particle again.) When you measure > light you either see one photon or none....never some fraction of a > photon. (OK, most times you see lots of photons, but always an > interger number.) > > George H. > > (I was afraid you were going to ask, "From where comes the photon > emmited by a black body?" I don't have a good picture of that > process.)- Hide quoted text - > > - Show quoted text - The electron state is simply which of the 4 shells it is in. There are only 4 fundamental sizes to the atom because of these round shells that science calles energy levels of the electron. White light from a surface composed of a few different atoms is evidence that emmision is not always quantized. Mitch Raemsch
From: Darwin123 on 2 Dec 2009 19:39 On Dec 2, 6:43 am, p.kins...(a)ic.ac.uk wrote: > BURT <macromi...(a)yahoo.com> wrote: > There is no "particle of light". Instead there are countable > excitations of the wave-like field modes. These modes usually > combine both electric and magnetic contributions. However, in quantum mechanics the amplitude of this wave is quantized. A wave with a quantized amplitude is fare different than a wave that has an amplitude that can be contiuously varied. > > It's not a particle, it's a wave. But you _can_ count the > excitations. I don't think there is always a large difference between a wave with quantized amplitude and a particle. If one has a "wave" at a high quantization state, then I suppose it acts a bit like the classical "wave". However, at small energy densities the energy has to become somewhat localized. I remember far back reading a mathematical analysis that showed that a boson field with a quantized amplitude behave in all ways like a "boson particle," except with regard to the ground state of the excitation. The ground state of the boson excitation tends to have "nonparticle" properties no matter how weak the field. However, at quantum amplitudes that are not too low and not too high, a particle description is valid. Hence, describing photons as a "particle" is somewhat accurate. I agree with your larger point. Photons are not classical particles, and shouldn't be presented as such. Newton's corpuscular theory is dead. However, his corpuscular theory is a -well- reanimated corpse|;-)
From: Bill Taylor on 2 Dec 2009 23:54
The nature of light is "?" . The upper part represents the wave aspect; the lower part represents the particle aspect. -- Befuddled Bill ** They travel as waves but arrive as photons. |