4 ms·

But both the sound the frequency of which we hear and the photon which we sense.. are waves

by cee_el2 10y ago

antoineMoPa 10y ago
Wave vs particle all over again
- ccozan 10y ago
  But we don't "see" imdividual photons. The cell reacts to a chemical reaction/ absorbtion in the photopigment, thus dependent of the energy of the photon, which is directly related to the frequency of the wave duality of that photon.
  - function_seven 10y ago
    > The cell reacts to a chemical reaction/ absorbtion in the photopigment, thus dependent of the energy of the photon, which is directly related to the frequency of the wave duality of that photon. This is what we call "seeing" :) This is like saying the atoms in your fingertip never "touch" the elevator button's atoms. Instead, a strong oppositional force develops when the atoms in your skin get close to the atoms in the button. While true, that's exactly what we call "touching"
noobermin 10y ago
Look, I'm in laser plasma physics, and people conflate photons and monochromatic plane waves in my field all the fucking time. Even worse, they conflate plasma waves with phonons * shudder * . There is similar mathematics that describe both but conceptually they are different things.
- 1_listerine_pls 10y ago
  Unrelated question, I want to heat some micro particles in an heterogeneous mixture. However, they need to be heated with precision so that the other components of the mixture don't get melted. So, I was thinking in getting a laser to do that. The laser would need to have a wavelength that targets only the component that I want to heat. picture I drew http://i.imgur.com/RdWRpnHl.png http://i.imgur.com/RdWRpnHl.png Do you think it would be feasible? I am not a physicist.
  - noobermin 10y ago
    So, I am more on the plasma side than the laser side, unfortunately, so get a second opinion :) but I'm not sure it would. First of all, when talking about heating, you're mainly relying on dielectric heating[0], which depends on the dipole moment (perhaps) and polarizability of the things you're looking at. The wavelength might play a role but the idea is dielectric heating is a classical phenomenon, not quantum. I'm don't want to misunderstand your idea, but it sounds like you are applying intuition from QM regarding a material's absorption spectrum, which is,obv., quantum and thus selecting regarding wavelength. Dielectric heating will affect both species regardless given if both can be polarized leading to heating. Now, say one is more polarizable than the other and so is heated first. However, a more important consideration here is that this is a heterogeneous mixture, so I think what is more likely is heat will be even distributed between the species. You're essentially trying to achieve a non-equilibrium state (high temp in one species and not the other) when one species is on top of the other! On shorter time scales, the more polarizable/polarized stuff might be "heated" first but that heat will eventually move to the other species from collisions leading to equal heating. So it all depends. Will your target species be heated to melting before that heat transfers to other stuff? This does depend on the coupling of the laser energy to the particles but it also depends on the time scale it takes to melt too and the collision frequency between target species and other species. So, as you see, it depends specifically on the materials you're thinking of, which you could probably look up. Honestly, you could try something much simpler, like just choosing species based on their melting point. Obviously, your question seemed to imply that they melt at similar melting points and you make to make species A melt before species B. If you just choose species with diff species with diff melting points, you don't even need a laser, just a heat bath. [0] https://en.wikipedia.org/wiki/Dielectric_heating https://en.wikipedia.org/wiki/Dielectric_heating This might be helpful if you want to learn what effect material properties has on effectiveness of dielectric heating. First google scholar result :) [1] http://pubs.rsc.org/en/content/articlelanding/1998/cs/a827213z#!divAbstract http://pubs.rsc.org/en/content/articlelanding/1998/cs/a82721...
    - 1_listerine_pls 10y ago
      Thank for the answer. - Will your target species be heated to melting before that heat transfers to other stuff? = That's the plan, the heat will propagate so I want to apply just enough heat to minimize the amount of heat transferred. They have different melting points: around 50C in difference.
1_listerine_pls 10y ago
The minimum amount of sound you can hear is not measured in terms of frequency [Hz]. It is measured in decibels [dB]. Likewise, the minimum amount of light you can see is not measured in terms of frequency. In other words, higher frequency does not mean more light or sound. So, his analogy does not make sense at all.

But both the sound the frequency of which we hear and the photon which we sense.. are waves

by cee_el2 10y ago

But both the sound the frequency of which we hear and the photon which we sense.. are waves

antoineMoPa 10y ago

Wave vs particle all over again

ccozan 10y ago
But we don't "see" imdividual photons. The cell reacts to a chemical reaction/ absorbtion in the photopigment, thus dependent of the energy of the photon, which is directly related to the frequency of the wave duality of that photon.
- function_seven 10y ago
  > The cell reacts to a chemical reaction/ absorbtion in the photopigment, thus dependent of the energy of the photon, which is directly related to the frequency of the wave duality of that photon. This is what we call "seeing" :) This is like saying the atoms in your fingertip never "touch" the elevator button's atoms. Instead, a strong oppositional force develops when the atoms in your skin get close to the atoms in the button. While true, that's exactly what we call "touching"

noobermin 10y ago

Look, I'm in laser plasma physics, and people conflate photons and monochromatic plane waves in my field all the fucking time. Even worse, they conflate plasma waves with phonons * shudder * . There is similar mathematics that describe both but conceptually they are different things.

1_listerine_pls 10y ago
Unrelated question, I want to heat some micro particles in an heterogeneous mixture. However, they need to be heated with precision so that the other components of the mixture don't get melted. So, I was thinking in getting a laser to do that. The laser would need to have a wavelength that targets only the component that I want to heat. picture I drew http://i.imgur.com/RdWRpnHl.png http://i.imgur.com/RdWRpnHl.png Do you think it would be feasible? I am not a physicist.
- noobermin 10y ago
  So, I am more on the plasma side than the laser side, unfortunately, so get a second opinion :) but I'm not sure it would. First of all, when talking about heating, you're mainly relying on dielectric heating[0], which depends on the dipole moment (perhaps) and polarizability of the things you're looking at. The wavelength might play a role but the idea is dielectric heating is a classical phenomenon, not quantum. I'm don't want to misunderstand your idea, but it sounds like you are applying intuition from QM regarding a material's absorption spectrum, which is,obv., quantum and thus selecting regarding wavelength. Dielectric heating will affect both species regardless given if both can be polarized leading to heating. Now, say one is more polarizable than the other and so is heated first. However, a more important consideration here is that this is a heterogeneous mixture, so I think what is more likely is heat will be even distributed between the species. You're essentially trying to achieve a non-equilibrium state (high temp in one species and not the other) when one species is on top of the other! On shorter time scales, the more polarizable/polarized stuff might be "heated" first but that heat will eventually move to the other species from collisions leading to equal heating. So it all depends. Will your target species be heated to melting before that heat transfers to other stuff? This does depend on the coupling of the laser energy to the particles but it also depends on the time scale it takes to melt too and the collision frequency between target species and other species. So, as you see, it depends specifically on the materials you're thinking of, which you could probably look up. Honestly, you could try something much simpler, like just choosing species based on their melting point. Obviously, your question seemed to imply that they melt at similar melting points and you make to make species A melt before species B. If you just choose species with diff species with diff melting points, you don't even need a laser, just a heat bath. [0] https://en.wikipedia.org/wiki/Dielectric_heating https://en.wikipedia.org/wiki/Dielectric_heating This might be helpful if you want to learn what effect material properties has on effectiveness of dielectric heating. First google scholar result :) [1] http://pubs.rsc.org/en/content/articlelanding/1998/cs/a827213z#!divAbstract http://pubs.rsc.org/en/content/articlelanding/1998/cs/a82721...
  - 1_listerine_pls 10y ago
    Thank for the answer. - Will your target species be heated to melting before that heat transfers to other stuff? = That's the plan, the heat will propagate so I want to apply just enough heat to minimize the amount of heat transferred. They have different melting points: around 50C in difference.

1_listerine_pls 10y ago

The minimum amount of sound you can hear is not measured in terms of frequency [Hz]. It is measured in decibels [dB]. Likewise, the minimum amount of light you can see is not measured in terms of frequency. In other words, higher frequency does not mean more light or sound. So, his analogy does not make sense at all.