Hi, I’m here to tell you that I like my own comment just for fun. Positive narcissism, bad narcissism is when I use my narcissism to unknowingly hurt others amen
I wouldn’t make the distinction between ionising and non-ionising either, since you don’t need sufficient energy to knock an electron out of an atom, just bump it up a level. A gas laser like HeNe will operate around 2eV or so, which I definitely wouldn’t call ionising. To say nothing of a 0.1eV CO2 laser, or the far lower microwave maser. I’m not sure if the maser uses molecular vibrations, but I know that there are light sources that use molecular modes via spontaneous emission like the sulfur lamp. Also see the free-electron-laser, for a laser that works without any atoms or molecules at all.
How does stimulated emission not completely refute the greenhouse gas back radiation hypothesis? The incident radiation emitted from the surface increases the temperature of half the IR active gas, but about half should be cooled - depending on the direction of the gas molecule. If all the IR active gases are warmed by incident radiation that would violate conservation of momentum. Furthermore, if IR active gases "trapped" heat like some sort of special quantum insulator, we'd be putting HFC gases with low thermal conductivities and high molecular viscosities within double pained windows, but it was determined all the way back in 1989 that the emissivity of IR active gases hindered their use for this purpose.
It’s an exponential function; the excited atoms have a half-life before decaying. Turn that 2^(- half-life * t). exponential into a natural e^(- τ * t). exponential, and you should find that the time constant τ is a simple relationship between dN/dt and N. Like N divided by dN/dt. Then you can convert the time constant back into a half-life if you find it more convenient. But that’s just my intuition, it’s been a while since I did laser physics.
Yes but why wouldn’t spontaneous emission be intuitive? It’s how neon bulbs and LEDs and basically any other light source that isn’t a laser or incandescent source works. No clue what kind of background you could come from that spontaneous emission is less intuitive. I’m much more interested in how Einstein predicted stimulated emission, since there’s no real reason to assume it exists. It’s completely vacant from nature, it was probably only ever seen when the ruby laser (or the maser) was invented. Unless it falls into existence for similar necessity as the reasoning in this lecture, which could make sense since I think the Bab and Bba coefficients are equal.
dont you need spe in order to get ste? also in every form of created light im sure there is still some amount of ste happening naturally , also i am wondering if you excite an electron by optical pumping into spe will the emission have a lower energy or longer wavelength photon than that of the photon that excited it? and if so then will this new photon be only allowed to further stimulate another electron that is in the excited state but not one that is in the ground state?
Ngl, an electron randomly falling to a lower energy state and emitting a photon sounds much more intuitive than an electron having its energy lowered when a photon hits it.
4 года назад+1
Einstein is the greatest scientific mind of all time. He derived matter waves based on sound statistical arguments 14 years before De Broglie. He came up with probability waves years before Max Born (as Born always acknowledged) and it was Einstein who led the path to the derivation of the Schrodinger equation (the Einstein-De Broglie wave equation, when combined with the Hamilton-Jacobi equation). It was Einstein that predicted Bose-Einstein condensates (Bose had nothing to do with it) 75 years before their discovery. It was Einstein who came up with quantum entanglement (i.e. epr correlations) - he meant it as a disproof. And he did so many other genius things in physics, it's exhaustive to list them here. Many physicists believe that Einstein should have won 7 or 8 Nobel Prizes. m.huffpost.com/us/entry/us_4948045
How does stimulated emission not completely refute the greenhouse gas back radiation hypothesis? The incident radiation emitted from the surface increases the temperature of half the IR active gas, but about half should be cooled - depending on the direction of the gas molecule. If all the IR active gases are warmed by incident radiation that would violate conservation of momentum. Furthermore, if IR active gases "trapped" heat like some sort of special quantum insulator, we'd be putting HFC gases with low thermal conductivities and high molecular viscosities within double pained windows, but it was determined all the way back in 1989 that the emissivity of IR active gases hindered their use for this purpose.
When stating the condition for thermal equilibrium non-degeneracy is being assumed. Does he mention it anywhere in the previous lectures?
So why not the title is "need for STIMULATED emission"?
This means that everything is possible
Wow
Einstein was right about everything
Wow
Super cool
Hi, I’m here to tell you that I like my own comment just for fun. Positive narcissism, bad narcissism is when I use my narcissism to unknowingly hurt others amen
Does stimulated emission only pertain to ionizing radiation or do the different states also apply to molecular modes of vibration?
I wouldn’t make the distinction between ionising and non-ionising either, since you don’t need sufficient energy to knock an electron out of an atom, just bump it up a level. A gas laser like HeNe will operate around 2eV or so, which I definitely wouldn’t call ionising. To say nothing of a 0.1eV CO2 laser, or the far lower microwave maser. I’m not sure if the maser uses molecular vibrations, but I know that there are light sources that use molecular modes via spontaneous emission like the sulfur lamp.
Also see the free-electron-laser, for a laser that works without any atoms or molecules at all.
How does stimulated emission not completely refute the greenhouse gas back radiation hypothesis? The incident radiation emitted from the surface increases the temperature of half the IR active gas, but about half should be cooled - depending on the direction of the gas molecule. If all the IR active gases are warmed by incident radiation that would violate conservation of momentum.
Furthermore, if IR active gases "trapped" heat like some sort of special quantum insulator, we'd be putting HFC gases with low thermal conductivities and high molecular viscosities within double pained windows, but it was determined all the way back in 1989 that the emissivity of IR active gases hindered their use for this purpose.
How can we determine probability per unit time for spontaneous emissions of radiation.
It’s an exponential function; the excited atoms have a half-life before decaying. Turn that 2^(- half-life * t). exponential into a natural e^(- τ * t). exponential, and you should find that the time constant τ is a simple relationship between dN/dt and N. Like N divided by dN/dt. Then you can convert the time constant back into a half-life if you find it more convenient. But that’s just my intuition, it’s been a while since I did laser physics.
Yes but why wouldn’t spontaneous emission be intuitive? It’s how neon bulbs and LEDs and basically any other light source that isn’t a laser or incandescent source works. No clue what kind of background you could come from that spontaneous emission is less intuitive.
I’m much more interested in how Einstein predicted stimulated emission, since there’s no real reason to assume it exists. It’s completely vacant from nature, it was probably only ever seen when the ruby laser (or the maser) was invented. Unless it falls into existence for similar necessity as the reasoning in this lecture, which could make sense since I think the Bab and Bba coefficients are equal.
dont you need spe in order to get ste? also in every form of created light im sure there is still some amount of ste happening naturally , also i am wondering if you excite an electron by optical pumping into spe will the emission have a lower energy or longer wavelength photon than that of the photon that excited it? and if so then will this new photon be only allowed to further stimulate another electron that is in the excited state but not one that is in the ground state?
Ngl, an electron randomly falling to a lower energy state and emitting a photon sounds much more intuitive than an electron having its energy lowered when a photon hits it.
Einstein is the greatest scientific mind of all time. He derived matter waves based on sound statistical arguments 14 years before De Broglie. He came up with probability waves years before Max Born (as Born always acknowledged) and it was Einstein who led the path to the derivation of the Schrodinger equation (the Einstein-De Broglie wave equation, when combined with the Hamilton-Jacobi equation). It was Einstein that predicted Bose-Einstein condensates (Bose had nothing to do with it) 75 years before their discovery. It was Einstein who came up with quantum entanglement (i.e. epr correlations) - he meant it as a disproof.
And he did so many other genius things in physics, it's exhaustive to list them here. Many physicists believe that Einstein should have won 7 or 8 Nobel Prizes.
m.huffpost.com/us/entry/us_4948045
How does stimulated emission not completely refute the greenhouse gas back radiation hypothesis? The incident radiation emitted from the surface increases the temperature of half the IR active gas, but about half should be cooled - depending on the direction of the gas molecule. If all the IR active gases are warmed by incident radiation that would violate conservation of momentum.
Furthermore, if IR active gases "trapped" heat like some sort of special quantum insulator, we'd be putting HFC gases with low thermal conductivities and high molecular viscosities within double pained windows, but it was determined all the way back in 1989 that the emissivity of IR active gases hindered their use for this purpose.