swansont

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.

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/

! Moderator Note What is the connection between old technology and landing on the moon? And why is this posted in politics?

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.

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.

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

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.

! 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.

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.

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.

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

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.

Yes. I was responding to that post. You didn’t answer my questions, which don’t pertain to your calculation.

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.

Dark energy ‘chameleon trap’ wins £100,000 prize for Nottingham scientist

Agree. But why discuss science when you can focus on semantics?

! Moderator Note Moved to mathematics because it sure as heck doesn’t belong in the Lounge

A device that can run itself and produce usable output would run perpetually (from an energy budget perspective).

No? Is prejudice the same problem in different countries/cultures?

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.

! Moderator Note No, you can’t. Advertising is not permitted here. We’re a discussion forum; we expect the material to be posted here.

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.

Without seeing the arguments how can one say? But when one sees places where racial bias appears (e.g. roadway infrastructure built to keep poor people - heavily skewed toward minorities - from getting to the beach) it piques my curiosity. I agree; I’m not going to assume that interpretation in the current vacuum of information. Plus the abstract mentions teaching science. The implication is some kind of institutional bias, but I’ve observed gender bias in physics (of the “women aren’t good at physics” variety), so I can imagine there’s racial bias in play. One who does chemistry, presumably after having studied chemistry in school.

I imagine taking the class would shed light on this, but in the US it is the case (according to this source) that in the field of chemistry, men and whites are over-represented, while black and hispanic/latino populations are under-represented. “The most common ethnicity of chemists is White (66.1%), followed by Asian (16.7%), Black or African American (7.7%) and Hispanic or Latino (7.1%)” https://www.zippia.com/chemist-jobs/demographics/ Is it that hard to believe that certain institutional habits have retained some kinds of bias? True. I think physics has a worse demographic failing. edit yup https://www.zippia.com/physicist-jobs/demographics/ (but more chemists, so more potential for such a class to have critical mass)

Everything? No. I think checking your IQ is an act of vanity in most cases. I've never been asked my IQ in a job interview or any professional setting. It never comes up in social settings. If you are checking your IQ to reassure yourself that you are smart, it's probably because you have an inferiority complex.