Everything posted by swansont
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Nuclear spent fuel rods.
I’m not sure how tritium would be formed from fuel rods in a cooling pool. I think the concern would be damage to the control rods and contamination by fission products.
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climate change
Why is this the expected amount? Citation? Looks to me like it’s just over 100 ppm https://www.co2levels.org Citation? My understanding is that it’s a logarithmic dependence, and you get a certain increase for each doubling of concentration. Can you explain why you think this is a valid test?
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Laser
No, they aren’t. They tend to be in the ground state. And you can’t use photons of the laser’s wavelength to get the excess atoms in the excited state (the population inversion), because of the stimulated emission. So you have to use some other method. In a HeNe laser, an electric discharge excites the He, and collisions with Ne causes Ne excitations. You have more atoms in an excited state than a lower state, so stimulated emission can give you amplification. In diode lasers, there is an electronic excitation of the electrons to a higher band.
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Laser
The photon isn’t consumed. It induces another photon to be emitted from an excited atom or molecule. That’s the stimulated emission, and the cause of the amplification. One photon in, two photons out.
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Einstein Light Clock Conundrum
You’re mixing frames. The up/down cycle is 1 sec in the clock frame (t), but you can’t use 1 sec in the lab frame (t’) to say it moves 0.866 m, since t ≠ t’ It travels a distance L = vt’ The light travels ct’ For a half cycle, solve with the Pythagorean theorem. vt’^2 + d^2 = ct’^2 t’ = d/(sqrt(c^2-v^2) d=0.5m For v =0.866c, you get 1 sec for the half-cycle and thus 2 sec for the complete trip. Exactly as expected You can see the derivation here. https://www.ck12.org/book/ck-12-physics---intermediate/section/22.2/
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Do you believe the USA really landed on the moon?
! Moderator Note What is the connection between old technology and landing on the moon? And why is this posted in politics?
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Is Carnot efficiency valid?
My point is this: If the reservoirs are at 20 C and 100 C, tell me from that information alone how many watts of mechanical power are being extracted. You suggested that you could.
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Is Carnot efficiency valid?
You spoke of “minimum percentage of heat rejection required for the engine to complete a single revolution.” and I was pointing out that this is an energy (the mechanical work that it does) and not something you get from the efficiency. Using a 100 W source means that’s the maximum, but the actual QH is likely much less But you’ve insulated the device. Which means the hot side can be hotter and stay hot. Before insulation the heat differential is likely smaller.
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Is Carnot efficiency valid?
That’s percentage. It doesn’t tell you the amount of heat rejected so you don’t know the energy it takes to rotate the wheel
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Is Carnot efficiency valid?
I don’t consider it to be complete or thorough. You don’t have the temperatures that exchemist asked for, for starters. You don’t give the rotation rate of the wheel. You need to describe the experiment such that it could be replicated, with all the pertinent data.
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Is Carnot efficiency valid?
! Moderator Note One of the reasons that we require text descriptions to be posted, rather than relying on videos The temperatures (using an absolute scale) give the efficiency, but I don’t see how that gives you the heat rejection to complete a revolution.
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Homophobia, nature or nurture?
Homophobia is a fear. Not just a lack of attraction towards those of the same sex, but fear of those who are gay, and/or (especially) that you might be gay. That sounds like learned behavior.
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Any MENSA members here?
Are all MENSA members scientists? Did Einstein need an IQ test to encourage him to be a scientist? We were talking about IQ tests. Don’t move the goalposts.
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Can Stern-Gerlach spin alignment be seen as a result of EM radiation of precessing magnetic dipole?
What I asked was how you came to conclusion that the power would be radiated in femtoseconds. But there are things that we would also expect from classical physics that don’t happen. Has anyone detected the radiation you expect? The explanation is the same - two orientations are allowed. The objection is to the claim that this is a classical situation. The observed results are not what is expected of classical physics, which is why it was a groundbreaking result
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Can Stern-Gerlach spin alignment be seen as a result of EM radiation of precessing magnetic dipole?
Yes, this is what I asked you about. How did you arrive at this conclusion? I want your reasoning, not just a repetition of the statement. But other effects are not classical (the deviation of the beam), so why should the alignment be classical? The discrete deviation is an indication that you do not have randomly-aligned spins that come into alignment over some period of time.
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Can Stern-Gerlach spin alignment be seen as a result of EM radiation of precessing magnetic dipole?
Yes. I was responding to that post. You didn’t answer my questions, which don’t pertain to your calculation.
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Can Stern-Gerlach spin alignment be seen as a result of EM radiation of precessing magnetic dipole?
Why femtoseconds? If there was radiation why wouldn’t it be at the precession frequency? That assumes that there is precession, as if this were a classical system. QM says that you only have two possible spin orientations - once you have a quantization axis, as provided by the magnetic field, you only have these two choices. The random spin orientation is a probability that it will be one spin or the other.
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Dark energy chameleon force experiment rules out some dark energy possibilities
Dark energy ‘chameleon trap’ wins £100,000 prize for Nottingham scientist
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hijack from Quick question about perpetual motion.
Agree. But why discuss science when you can focus on semantics?
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The largest numbers
! Moderator Note Moved to mathematics because it sure as heck doesn’t belong in the Lounge
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hijack from Quick question about perpetual motion.
A device that can run itself and produce usable output would run perpetually (from an energy budget perspective).
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White Supremacy in Chemistry - Apparently
No? Is prejudice the same problem in different countries/cultures?
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White Supremacy in Chemistry - Apparently
Which is not, last I checked, in the US, so I don’t see how it’s relevant to a course at East Carolina State U.
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Global disasters have struck humanity several times and may strike again
! Moderator Note No, you can’t. Advertising is not permitted here. We’re a discussion forum; we expect the material to be posted here.
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Some ancient philosopher / Scientists
It would be helpful if 1. You clarified what you wish to discuss 2. You provided actual quotes rather than paraphrases. You’re giving your interpretation of what they said. Others need to know what they actually said. 3. You got your keyboard fixed. Your “.” key keeps sticking. Makes it difficult to read.