Strange Posted October 30, 2017 Posted October 30, 2017 1 minute ago, Itoero said: Then what is scattering according to your opinion?https://en.wikipedia.org/wiki/Scattering Is Wikipedia wrong? Clue: https://en.wikipedia.org/wiki/Affirming_the_consequent Scattering is an interaction but not all interactions (with a change of direction) are scattering. 3 minutes ago, Itoero said: This is just a question, no straw man, how do you refract a wave without interacting with its particles? (you just said there is no interaction) No I didn't. There is obviously interaction. But it is not scattering. Because it is refraction. You claiming I said there is no interaction is (a) a straw man and (b) dishonest. 4 minutes ago, Itoero said: How can anything deflect from its path without an interaction? What is wrong with you? NO ONE IS SAYING THAT. Quote What do you mean with this: "that every particle is scattered a different variable amount in a different variable direction" The momentum decides how the photon is scattered, how is that random? Where did he say "random"? Stop the dishonest straw man arguments. You are taking your defence of a simple error to ludicrous extremes. Just admit you made a mistake when you said that refraction is due to scattering and we can all move on. 2
studiot Posted October 30, 2017 Posted October 30, 2017 (edited) 22 minutes ago, Itoero said: On 29/10/2017 at 5:19 PM, studiot said: Yes observable light waves, but the observer has no power whasoever to alter the frequency of the oncoming light waves. I actually said that it was the circumstances which change the frequency and identified these circumstances as being relative velocity in the case of the Doppler effect. Consider two observers, Observer A is not in relative velocity vis-a-vis the source and sees particularly frequency light, Observer B is in relative velocity and observes a different frequency. Both measure frequency by the same method so interact with the light in identical fashion, so it is the circumstances not the interaction that matters. indirectly caused E=hf So observer A sees different energy of light then observer B yet at the source the light is evenly distributed.....You can describe those thing 'classically' but in order to explain it you need to study the particle behavior. Quantum mechanical collapse states that when light does not travel trough vacuum, the photons interact with particles of the transmission medium they are in. I didn't understand this let alone see how it connects to my point. Are you denying that we use the doppler shift to observe and measure many things about distant stars and galaxies? 22 minutes ago, Itoero said: On 25/10/2017 at 3:53 PM, studiot said: That is too wide a definition. Yes scattering is a deflection of path. But scattering is a random effect. From a particle point of view it means that every particle is scattered a different variable amount in a different variable direction How can anything deflect from its path without an interaction? What do you mean with this: "that every particle is scattered a different variable amount in a different variable direction" The momentum decides how the photon is scattered, how is that random? Yes but we have a saying in English "It takes two to tango " A (momentum related) interaction is the photon striking a particle of the medium. This is random for two reasons. 1) All the medium particles are moving about in random directions, so the resultant momentum vectors will be randomly directed (scattered) 2) All the medium particles have a physical size (the unit of this used to be called rather picturesquely a barn). This means that there will be a random cross section of impact from full head on to just glancing or grazing. I have already mentioned this. Edit, If the phton doesn't strike the medium particles in this fashion but meets them in a regular way because they are all lined up in a crystsal then we get diffraction, not scattering. Edited October 30, 2017 by studiot
swansont Posted October 30, 2017 Posted October 30, 2017 1 hour ago, Itoero said: Then what is scattering according to your opinion?https://en.wikipedia.org/wiki/Scattering Is Wikipedia wrong? Is refraction listed as a scattering mechanism? 1 hour ago, Itoero said: There is rayleigh scattering in our atmosphere and oceans but that doesn't mean the moment of refraction is due to rayleigh scattering. And that doesn't matter since scattering implies being forced to deviate from a straight trajectory.https://en.wikipedia.org/wiki/Scattering Scattering implies a change in direction. (Do you deny this?) "Scattering implies a change of direction" in no way implies that all changes in direction are due to scattering. (it's the fallacy of affirming the consequent) 1 hour ago, Itoero said: This is just a question, no straw man, how do you refract a wave without interacting with its particles? (you just said there is no interaction) No, he said the opposite of that. there is an interaction, but it's not scattering.
Itoero Posted November 1, 2017 Author Posted November 1, 2017 Scattering implies a change in direction, something can't change direction without any form of interaction. When you talk about particles, interaction causes scattering. Is this not true perhaps? On 30-10-2017 at 8:51 PM, swansont said: "Scattering implies a change of direction" in no way implies that all changes in direction are due to scattering. (it's the fallacy of affirming the consequent) I 've never said that all changes in direction are due to scattering.
Strange Posted November 1, 2017 Posted November 1, 2017 4 minutes ago, Itoero said: Scattering implies a change in direction, something can't change direction without any form of interaction. When you talk about particles, interaction causes scattering. Is this not true perhaps? It is true. Interaction causes scattering. That doesn't mean that all interactions are scattering. https://en.wikipedia.org/wiki/Affirming_the_consequent Refraction implies a change in direction, something can't change direction without any form of interaction. When you talk about particles, interaction causes refraction. Reflection implies a change in direction, something can't change direction without any form of interaction. When you talk about particles, interaction causes reflection. Diffraction implies a change in direction, something can't change direction without any form of interaction. When you talk about particles, interaction causes diffraction. But not all interaction is scattering. Not all interaction is refraction. Not all interaction is reflection. Not all interaction is diffraction. I don't know how else to help you see your error. But just in case: https://en.wikipedia.org/wiki/Affirming_the_consequent
Itoero Posted November 1, 2017 Author Posted November 1, 2017 Refraction, diffraction, reflection is all due to scattering. Scattering explains the particle behavior While diffraction, reflection and refraction are about observable waves. -2
Strange Posted November 1, 2017 Posted November 1, 2017 It occurs to me that (approximately) scattering is an effect related to individual particles (whether atoms, dust or flaws in a material) while refraction, reflection and diffraction depend on the bulk properties of a material. Does that help you see the difference? Just now, Itoero said: Refraction, diffraction, reflection is all due to scattering. Scattering explains the particle behavior While diffraction, reflection and refraction are about observable waves. Not really, because refraction, and the others, can be described in terms of photons interacting with atoms as well. I'm not sure why you think that scattering is more fundamental. It is just one type of interaction. 1
StringJunky Posted November 1, 2017 Posted November 1, 2017 (edited) 19 minutes ago, Itoero said: Refraction, diffraction, reflection is all due to scattering. Scattering explains the particle behavior While diffraction, reflection and refraction are about observable waves. The difference between scattering and reflection is that, in the former situation, an ensemble of incident photons will not act predictably and uniformly after they strike a non-uniform surface. What distinguishes all those phenomena are the end products of each. Quote ..,Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more paths due to localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection. Reflections that undergo scattering are often called diffuse reflections and unscattered reflections are called specular (mirror-like) reflections. https://en.wikipedia.org/wiki/Scattering Edited November 1, 2017 by StringJunky 1
swansont Posted November 1, 2017 Posted November 1, 2017 1 hour ago, Itoero said: I 've never said that all changes in direction are due to scattering. But you are using a change in direction to conclude scattering.
Strange Posted November 1, 2017 Posted November 1, 2017 4 minutes ago, swansont said: But you are using a change in direction to conclude scattering. "I'm not saying it's scattering but ... it's scattering." 1
Butch Posted November 3, 2017 Posted November 3, 2017 In my understanding light is a wave without dimension, hence no mass. Upon encountering matter it creates a dimensional wave when giving up it's energy.
Strange Posted November 3, 2017 Posted November 3, 2017 13 minutes ago, Butch said: In my understanding light is a wave without dimension, hence no mass. Upon encountering matter it creates a dimensional wave when giving up it's energy. Then your understanding is seriously flawed. How can a wave have no dimension? And if light gives up its energy, then it no longer exists therefore the wave no longer exists.
studiot Posted November 3, 2017 Posted November 3, 2017 46 minutes ago, Strange said: 1 hour ago, Butch said: In my understanding light is a wave without dimension, hence no mass. Upon encountering matter it creates a dimensional wave when giving up it's energy. Then your understanding is seriously flawed. How can a wave have no dimension? And if light gives up its energy, then it no longer exists therefore the wave no longer exists. It's that overmarinaded tuna agian.
Butch Posted November 3, 2017 Posted November 3, 2017 4 hours ago, Strange said: Then your understanding is seriously flawed. How can a wave have no dimension? And if light gives up its energy, then it no longer exists therefore the wave no longer exists. How much dimension does a frequency shift have? A photon can have a frequency measured over an infinitesimal amount of time. Indeed if a photon gives up it's energy( which they do) what is left of it? 4 hours ago, studiot said: It's that overmarinaded tuna agian. The fool on the hill, sees the sun going down, but the eyes in his head see a world spinning 'round.
Strange Posted November 3, 2017 Posted November 3, 2017 1 hour ago, Butch said: How much dimension does a frequency shift have? That doesn't mean anything. It is like asking "how much window does walking down the road have" 1 hour ago, Butch said: A photon can have a frequency measured over an infinitesimal amount of time. No it can't. As the time period over which the measurement decreases, the frequency becomes increasingly less defined. For an infinitesimal time there would be no frequency. (See also: Heisenberg.) Quote Indeed if a photon gives up it's energy( which they do) what is left of it? Nothing. It is an ex-photon. It is no more. It has expired. It has ceased to be.
John Cuthber Posted November 4, 2017 Posted November 4, 2017 (edited) On 11/1/2017 at 11:58 AM, Itoero said: Refraction, diffraction, reflection is all due to scattering. Scattering explains the particle behavior While diffraction, reflection and refraction are about observable waves. Which part of "no" don't you understand? However, in fairness, I think that you can model things like refraction by treating the atoms as particles that (only) scatter light. For example, the "traditional" model of refraction treats the gaps in a diffraction grating as separate (but coherent) sources. The interference pattern formed by those sources is the diffraction pattern. That model, in effect, assumes that whatever is in the gaps acts as a scatterer . It's not clear how that model works if you have a set of opaque wires in a vacuum acting as a grating. Edited November 4, 2017 by John Cuthber 1
dimreepr Posted November 4, 2017 Posted November 4, 2017 6 minutes ago, John Cuthber said: Which part of "no" don't you understand? The part that doesn't agree it would seem...
Phi for All Posted November 4, 2017 Posted November 4, 2017 21 hours ago, Butch said: How much dimension does a frequency shift have? A photon can have a frequency measured over an infinitesimal amount of time. Indeed if a photon gives up it's energy( which they do) what is left of it? The fool on the hill, sees the sun going down, but the eyes in his head see a world spinning 'round. ! Moderator Note Don't make me take weekend time to split your off-topic, unsupported, raggedy-ass pet theory off into the trash. Mainstream science only in mainstream science sections, please!
Itoero Posted November 5, 2017 Author Posted November 5, 2017 On 30-10-2017 at 8:51 PM, swansont said: Is refraction listed as a scattering mechanism Where should it be listed? In the science bible (this is a joke, plz laugh) If you have to believe Wikipedia then evolution (not the theory) is only a biological process. Wikipedia gives info, it's not an authority. When light doesn't travel through vacuum, then the light (the photons) interact with particles. When photons interact with particles they scatter. Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more paths due to localized non-uniformities in the medium through which they pass. (Wikipedia-definition) Vacuum is the transmission medium and localized non-uniformities are particles. Water can also be a transmission medium in which case the localized non-uniformities are particles other then H2O.
swansont Posted November 5, 2017 Posted November 5, 2017 2 minutes ago, Itoero said: Where should it be listed? In the science bible (this is a joke, plz laugh) If you have to believe Wikipedia then evolution (not the theory) is only a biological process. Wikipedia gives info, it's not an authority. You cited the article. 2 minutes ago, Itoero said: When light doesn't travel through vacuum, then the light (the photons) interact with particles. When photons interact with particles they scatter. Refraction is a classical effect. It obeys Fermat's (the least-time) principle. And, as I pointed out earlier, it doesn't behave like scattering. In a scattering process, there has to be the chance that the light doesn't scatter. If you double the thickness of a material, the number of photons undergoing scattering doubles. Sunsets/sunrises look red because some of the blue light is scattered, and the sky looks blue for similar reasons. But you don't lose all of the blue light when the sun is near the horizon. Can you ever get just some of the light to refract? 2 minutes ago, Itoero said: Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more paths due to localized non-uniformities in the medium through which they pass. (Wikipedia-definition) Vacuum is the transmission medium and localized non-uniformities are particles. Water can also be a transmission medium in which case the localized non-uniformities are particles other then H2O. The classical description of refraction does not depend on localized non-uniformities. It depends on the bulk property, the index of refraction.
Itoero Posted November 5, 2017 Author Posted November 5, 2017 1 hour ago, swansont said: You cited the article. Because I agree with the scattering definition of Wikipedia. Do you deny that photons scatter when light doesn't travel through vacuum? When particles interact , they scatter.... 1 hour ago, swansont said: Refraction is a classical effect. It obeys Fermat's (the least-time) principle. True but that's about observable light. 1 hour ago, swansont said: And, as I pointed out earlier, it doesn't behave like scattering. In a scattering process, there has to be the chance that the light doesn't scatter Can you explain that? The momentum of particles causes scattering, it's not random. 1 hour ago, swansont said: The classical description of refraction does not depend on localized non-uniformities. It depends on the bulk property, the index of refraction. That's true but that's only the classical explanation. In order to explain those processes in regards of conservation of energy, you need to study the interaction (which causes scattering) of photons with localized non-uniformities.
Strange Posted November 5, 2017 Posted November 5, 2017 17 minutes ago, Itoero said: Because I agree with the scattering definition of Wikipedia. Which doesn't say that scattering and refraction are the same thing. So you don't agree with it. Quote Do you deny that photons scatter when light doesn't travel through vacuum? When particles interact , they scatter.... What is wrong with you? No one is denying that photons scatter. And that scattering is caused by interaction. You keep pretending that people are denying this. This is either a serious comprehension problem on your part or you are being deliberately dishonest. The point of contention is that refraction is not the same thing as scattering, as you keep claiming. Both scattering and refraction can be described as the interaction of particles, but they are not the same thing.
swansont Posted November 5, 2017 Posted November 5, 2017 4 hours ago, Itoero said: Because I agree with the scattering definition of Wikipedia. Do you deny that photons scatter when light doesn't travel through vacuum? When particles interact , they scatter.... But in the definition, refraction is not included. Diffraction is another thing that is not scattering. 4 hours ago, Itoero said: True but that's about observable light. Um, what? Refraction happens outside of the visible range. 4 hours ago, Itoero said: Can you explain that? The momentum of particles causes scattering, it's not random. To scatter you have to hit a target. You can miss the target, and those particles will not scatter. 4 hours ago, Itoero said: That's true but that's only the classical explanation. In order to explain those processes in regards of conservation of energy, you need to study the interaction (which causes scattering) of photons with localized non-uniformities. refraction doesn't conserve energy in classical physics? (for fun look up the Abraham Minkowski controversy for difficulties in applying conservation laws)
Itoero Posted November 8, 2017 Author Posted November 8, 2017 On 5-11-2017 at 9:28 PM, swansont said: But in the definition, refraction is not included. Diffraction is another thing that is not scattering. That's because refraction, diffraction, reflection, doppler effect are only about observable waves. Scattering is normally about particle behavior but it's also used to describe wave behavior. "Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more paths due to localized non-uniformities in the medium through which they pass." Scattering is a big word...it refers to particle and wave behavior. On 5-11-2017 at 9:28 PM, swansont said: Um, what? Refraction happens outside of the visible rang Fermat's principle is the principle that the path taken between two points by a ray of light is the path that can be traversed in the least time. It's a ray of light (observable light), it's not about photons. Why outside visible range? You can see how light refracts in water. On 5-11-2017 at 9:28 PM, swansont said: To scatter you have to hit a target. You can miss the target, and those particles will not scatter Ok but there position/direction still decides if they hit a target or not...it's not random. And it doesn't matter, when photons do hit the target, they scatter. On 5-11-2017 at 9:28 PM, swansont said: refraction doesn't conserve energy in classical physics? Of course it does. But in order to know why refraction is an elastic process you need to study the elastic scattering of the photons. The interaction photons-H2O causes Rayleigh (elastic) scattering in our atmosphere but when the concentration H2O rises (to form liquid water) you don't call the interaction photons-H2O to be scattering anymore...why not?
Strange Posted November 8, 2017 Posted November 8, 2017 16 minutes ago, Itoero said: That's because refraction, diffraction, reflection, doppler effect are only about observable waves. The sky is blue because of scattering so that is certainly observable. 17 minutes ago, Itoero said: Scattering is normally about particle behavior but it's also used to describe wave behavior. And it is equally true of refraction, diffraction and reflection - they can all be described in terms of either waves or "particles" (photons, not really particles). (I don't know why you are bringing the Doppler effect into it. That seems completely irrelevant.) Quote Scattering is a big word...it refers to particle and wave behavior. Not all such behaviour. Only scattering. It doesn't refer to refraction, diffraction or reflection. Quote Why outside visible range? You can see how light refracts in water. You are the one who keeps saying that one is observable and therefore, by implication, the other isn't. 20 minutes ago, Itoero said: but when the concentration H2O rises (to form liquid water) you don't call the interaction photons-H2O to be scattering anymore...why not? Because it is refraction. A different mechanism. (Although you get scattering as well.)
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