swansont Posted September 14, 2010 Posted September 14, 2010 The work function of a material is the energy required to free an electron, it is not classical work just poor naming. Right. I think it makes some sense in terms of 19th century physics, when the structure of the atom was not known, but this still does not jibe with the claim that an IR photon, whose energy is less than the work function (or, in more modern parlance, ionization energy), somehow does more work than a UV photon whose energy is greater than the work function.
Severian Posted September 14, 2010 Posted September 14, 2010 OK, I agree. So, 1) Where do the photons come from for fusion. 2) Why do they perform more work at the infrared level. I am sensing that vuquta has some sort of agenda in his posts. Vuquta, would you care to clarify what this agenda is?
vuquta Posted September 15, 2010 Author Posted September 15, 2010 The work function of a material is the energy required to free an electron, it is not classical work just poor naming. This is not how Einstein propsed the idesa. He did not make it materially based, though clearly it is. OK, let's assume, if the material is photo electric (perfect) then it obeys Einstein's work function. Otherwise, based on the material, if will obey it in a lesser way. I think this is what you are saying. Either way though, you must agree the work performed to eject an electron is less than that performed by the infrared photon otherwise, the steam engine would not exist. I am sensing that vuquta has some sort of agenda in his posts. Vuquta, would you care to clarify what this agenda is? Yes, I will tell you my agenda. Something is wrong and I am trying to get ideas about the behavior of light. I do not have a theory as I do not have near enough information. But, there is something wrong with the current theory. Right. I think it makes some sense in terms of 19th century physics, when the structure of the atom was not known, but this still does not jibe with the claim that an IR photon, whose energy is less than the work function (or, in more modern parlance, ionization energy), somehow does more work than a UV photon whose energy is greater than the work function. Can you explain this in terms of the steam engine? This is the clearest experiment where the infrared photon does more work that the UV.
darkenlighten Posted September 15, 2010 Posted September 15, 2010 It is not because the current theory is wrong, it is because you current understanding is wrong. This is not how Einstein propsed the idesa. He did not make it materially based, though clearly it is. Please explain what you mean, because this does not make any sense. I'm not familiar what you are referring to, what did Einstein propose then? OK, let's assume, if the material is photo electric (perfect) then it obeys Einstein's work function. This does not make sense either, the work function is not a law or something like that, it's just the minimal ENERGY required to kick an electron out of a material. Otherwise, based on the material, if will obey it in a lesser way. I think this is what you are saying. Either way though, you must agree the work performed to eject an electron is less than that performed by the infrared photon otherwise, the steam engine would not exist. I'm confused on why you are referring to a steam engine, infrared is not directly heat, it can cause things to heat up, but is not itself heat. Heat is simply how fast atoms or molecules are moving or say how much energy it has. Yes, I will tell you my agenda. Something is wrong and I am trying to get ideas about the behavior of light. I do not have a theory as I do not have near enough information. But, there is something wrong with the current theory. Can you explain this in terms of the steam engine? This is the clearest experiment where the infrared photon does more work that the UV. Once again, your view is not correct, but I want to help you to understand why and put you on the right path.
vuquta Posted September 15, 2010 Author Posted September 15, 2010 It is not because the current theory is wrong, it is because you current understanding is wrong. OK, I don't mind. Please explain what you mean, because this does not make any sense. I'm not familiar what you are referring to, what did Einstein propose then? This is a cheesy website but the idea is the same everywhere and it explains it in a simple fashion. Einstein believed that to give a single electron this energy to move, a single photon hit the metal surface (destroying itself), and transferred its energy to the one electron. Since the electron is attracted to the surface of the metal, some minimum amount of energy must be needed just to snap it off. Otherwise, electrons would just be dropping off of atoms all the time. Einstein called this the work function of the material, since you needed to do work on the electron to break it off. http://www.studyphysics.ca/30/Unit4/Light/Photoelectric/note.htm OK, we now know Einstein proposed a work function. (You can find other sources) Once we have introduced a work function for a photon, we must assume it operates this was across frequencies. This does not make sense either, the work function is not a law or something like that, it's just the minimal ENERGY required to kick an electron out of a material. Yea, it is a law. I'm confused on why you are referring to a steam engine, infrared is not directly heat, it can cause things to heat up, but is not itself heat. Heat is simply how fast atoms or molecules are moving or say how much energy it has. Because, one way or the other, infrared photons are delivered to wayter to turn it into steam. By the conservation of energy, we must assume the photons are doing work or transfering their energy to the water. But, energy transfer causes the stream or water molecules to move more rapidly. Now, why do they move more rapidly without work being done? Once again, your view is not correct, but I want to help you to understand why and put you on the right path. This does not offend me and I appreciate your input.
darkenlighten Posted September 15, 2010 Posted September 15, 2010 This is a cheesy website but the idea is the same everywhere and it explains it in a simple fashion. Einstein believed that to give a single electron this energy to move, a single photon hit the metal surface (destroying itself), and transferred its energy to the one electron. Since the electron is attracted to the surface of the metal, some minimum amount of energy must be needed just to snap it off. Otherwise, electrons would just be dropping off of atoms all the time. Einstein called this the work function of the material, since you needed to do work on the electron to break it off. http://www.studyphysics.ca/30/Unit4/Light/Photoelectric/note.htm OK, we now know Einstein proposed a work function. (You can find other sources) Once we have introduced a work function for a photon, we must assume it operates this was across frequencies. I think this is where you start to mix things up. The work function is not a property of a photon, but a property of the material. And I guess you can say work is being done. Yea, it is a law. It's a property. It would be like saying Energy is a law, it itself is not a "law". But say the Conservation of Energy is a law. Because, one way or the other, infrared photons are delivered to wayter to turn it into steam. By the conservation of energy, we must assume the photons are doing work or transfering their energy to the water. But, energy transfer causes the stream or water molecules to move more rapidly. Now, why do they move more rapidly without work being done? No that's not necessarily how it always works. Once again, infrared does not equal heat, it can cause things to heat up by adding energy to the system. Thermal radiation can be caused by the whole EM spectrum, just not infrared. Wikipedia Article: Infrared: Heat This does not offend me and I appreciate your input. That's good.
swansont Posted September 15, 2010 Posted September 15, 2010 vuquta, For your scenario to to have any validity, it would have to be true that visible light could not heat water, and this is false. __ The work function is the analogue of the escape velocity of a projectile, if one were to express it in terms of energy rather than speed. An electron has an energy deficit as compared to a free electron; it is in a bound state. Energy must be added to free the electron. For a single atom, this is the ionization energy. For a material, we call it the work function.
vuquta Posted September 15, 2010 Author Posted September 15, 2010 OK, I am following you 2's input. I am not claiming visible light will not heat water. But, I am still not getting how the infrared photon heats water. Let's just simplify it to that. Let's just have a match under the water. We have to agree that the infrared photon is heating the water. Otherwise, what is?
IM Egdall Posted September 16, 2010 Posted September 16, 2010 See the following link for an explanation of how light (photons) heat an object. http://www.scientificamerican.com/article.cfm?id=how-exactly-does-light-tr
Klaynos Posted September 16, 2010 Posted September 16, 2010 The photoelectric effect is not the only way a material can absorb a photon, you can have electron interactions that do not create free electrons, or other excited states in molecules such as rotational modes...
vuquta Posted September 16, 2010 Author Posted September 16, 2010 See the following link for an explanation of how light (photons) heat an object. http://www.scientificamerican.com/article.cfm?id=how-exactly-does-light-tr Tom Zepf of the physics department at Creighton University in Omaha, Neb., notes that "Sunlight heats a material such as water or a brick primarily because the long wavelength, or infrared, portion of the sun's radiation resonates well with molecules in the material, thereby setting them into motion. So the energy transfer that causes the temperature of the substance to rise takes place at the molecular rather than the electronic level." Some of those atoms vibrate sufficiently vigorously that their vibrational energy is roughly equal to the electronic energy (photons) absorbed from the sun--in essence, they are in resonance with the solar energy. Those atoms then make a quantum transition from 'electronically excited' to 'vibrationally excited,' meaning that the energy causes the whole atom to move. OK, whereas the UV photon strikes the electon, the IF photon acts as a wave and vibrates the electon and thus the atom vibrates using the electon/proton force to keep them together unless they vibrate too much. Thanks for the link. I know where to go next now. Have a good one.
swansont Posted September 17, 2010 Posted September 17, 2010 Let's just simplify it to that. Let's just have a match under the water. We have to agree that the infrared photon is heating the water. Otherwise, what is? A match under the water is going to heat by mainly by convection — the energy released makes the air molecules move faster and collide more often, and these higher-energy molecules will strike the container and transfer energy to it. Radiation will be a small part of the process. Heat and infrared radiation are not interchangeable terms.
vuquta Posted September 18, 2010 Author Posted September 18, 2010 A match under the water is going to heat by mainly by convection — the energy released makes the air molecules move faster and collide more often, and these higher-energy molecules will strike the container and transfer energy to it. Radiation will be a small part of the process. Heat and infrared radiation are not interchangeable terms. Yea, I am OK with everything.
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