swansont

I don’t think complete reflection is physically possible. Reflection requires a momentum transfer, since the momentum of the light changes, and thus energy transfer. So if energy is lost from the incoming light, the reflection can’t be complete.

I am not aware of this interaction. Can you point to any peer-reviewed literature that says that the cosmological constant interacts with anything? That’s what you said. An equality that you wrote down as an assumption. The casimir effect requires conducting plates, which force a component of the electric field to become zero, something not true in free space.

If you assume they exist, then “they don’t exist” can’t be part of the thought experiment.

How does that work, physics-wise? It looks like you’re just waving your hands to get the answer you want. How does it “become” the cosmological constant? The casimir force can be derived by applying the conductor boundary conditions to the geometry. If L doesn’t matter then you don’t get that answer.

We have ethics for when we expect people to self-police, and others involved to make sure people toe the line. In sports we have referees, because ethics don’t enter into it. If you foul someone, there is a penalty. You have to decide if it’s worth it. The sport makes the penalties harsher in certain situations to reduce the incentive to foul.

I would say your understanding is incorrect. A gap in a conductor in a vacuum will not pass current unless there is sufficient voltage for there form an arc. The impedance of the vacuum is ~377 Ohms. If it were a conductor, having a separation distance has no meaning. If you can make connection it has to be via some physics, not unit analysis I didn’t say it was a force; I used force as an example that unit analysis doesn’t get you a connection between different situations.

The casimir effect is, more precisely, a reduction of the electromagnetic vacuum energy owing to the presence of conducting plates. If you are going to equate this with the cosmological constant, you need to do more than unit analysis. A force is going to have units of force, regardless of the origin of it. You can’t e.g. say an electrostatic force is gravitational, just because they have the same units. IOW your assumption that these are connected would just lead to circular reasoning.

Can you explain what it is you’re trying to show? Just throwing up a bunch of equations isn’t sufficient.

One data point does not make a trend. Why might a particular publisher change a particular book from two volumes to one? Cost might be a factor. It’s possible that eliminating half of the book cover saves a few bucks. But I can find this as a two-volume set. (13th edition, at least. Later editions include modern physics, so the content is not the same)

Sure

Careful - they are not thought to interact via the weak interaction, but via some new method on the scale of, or weaker than, the weak interaction

One explicit avoidance of outright technobabble was the baryon sweep, which was an attempt to not just make something up http://blogs.scienceforums.net/swansont/archives/1043

If it could interact electromagnetically it would emit thermal EM radiation. The ability to emit light has implications about how it behaves - easy dissipation of energy would allow it to “clump” more readily. And “dark” is also an acknowledgement that we don’t know what it is, as beecee has noted.

Part of the reason it’s called dark is because it doesn’t interact electromagnetically, and is thus not visible

Folks, it’s fiction. Things are made up. There are attempts at continuity and they tried to not botch the science too badly, but at the end of it all, they’re telling a story. A friend from high school spent a year as the TNG science consultant (later was on the writing staff); I complained one time about an episode’s science and he admitted he was overruled because the writers liked the story line. There’s an excellent chance the discussion of the efficiency was to advance the story.

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It's all quantized, though, and so a photon being absorbed or emitted changes the angular momentum of an atom by the angular momentum of the photon, which is h-bar.

Not for any of the individual particles, since it's quantized. The only pathway for changing them is flipping the spin of an electron or causing an excitation of an electron to a state with a different orbital angular momentum. I'm not sure how that could happen just by re-orienting a rigid body. There would need to be a corresponding interaction down on the atomic level, and I can't think of a direct connection between the two.

Any alignment of an angular momentum vector is determined locally (it's with respect to the atom), so yes, the direction would have to change in a rigid body. But most electrons are paired up in multi-electron atoms, and there is nuclear spin to consider as well, so the amount of torque needed to achieve this is going to be quite small compared to what's necessary to rotate the body itself. We can see that this is the case because we can see it happen with a permanent magnet, which depends on unpaired electrons having a certain orientation within the material. The magnetic field depends on the orientation of the magnet, so if it is rotated, the spin orientation must have changed as well.

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Have we found few because there are few, or because detecting them is difficult? Like all humans are fascinated by e.g. bugs? Or is it that a few of them would be fascinated by us, and the rest are just going about their duties. No? Where do they get their resources, then?

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It's not the efficiency. Newton is a unit of force. You can get to energy if you are exerting a force through a distance, and thus doing work. Do this at some speed v and you can calculate a power. But you can't just say that something is exerting a force and directly get a power from it. The great pyramid at Giza has a mass of over 6 billion kg, and thus exerts a force of ~60 Giganewtons on the ground, but since nothing is moving there is no work done and the power is zero.

How are you getting from newtons of force to watts of power?

Gosh, I wish I had linked to this last week.