Strange

Then please provide a reference to support this. (And I should recommend this is moved to Speculations.) That is not a constant current and not a static field.

Not really, it is just matter that is in orbit around the black hole (rather like the rings of Saturn, or the planet around the Sun). Stuff is in the accretion disk because it has been pulled there by the black hole and will end up in the black hole (the clue is in the word "accretion" ) Absolutely not. Apart from anything else, the mass of the black hole is insignificant on these scales. As far as I know, there is no reason to think that dark matter is moving significantly slower than normal matter. (On average.) Good question. Probably not quite the same, because it doesn't interact so will presumably have a larger range of velocities than normal matter. Apparently, it does: https://www.outerplaces.com/science/item/17611-scientists-say-track-speed-dark-matter-using-old-stars https://astrobites.org/2017/12/13/how-fast-is-dark-matter/

They will absorb a lot less dark matter than normal matter for the same reason that dark matter is distributed evenly around the galaxy, rather than forming structures like stars and planets. Because it doesn't interact electromagnetically, it has no way of slowing and forming clumps in the same way that matter does. So while matter will form accretion disks around black holes (either formed from material pulled from stars or passing clouds of gas) the density of dark matter around a black hole will not be significantly different from anywhere else. That calculation is only considering radiation. Even a black hole that is completely isolated will still absorb some of the interstellar gas around it. In that case, it will probably absorb more dark matter than matter. But we can't (yet) measure minute changes like that in black holes. We can only observe the effects when they absorb large amounts of matter and become "active" (or, indirectly, from the stars orbiting them).

A constant current means a current that doesn't change, which results in a magnetic field that doesn't change. The only thing "moving" is the current.

Indeed. But the reason to say it must have been "born cold" is because we know it is moving (relatively) slowly now. ("Relatively slowly" means not at a significant percentage of the speed of light. I don't know what kind of range of speeds this allows.)

Stop just posting invented equations. Explain how they are derived and what they mean.

You could have a mirror that only reflected visible light but not other frequencies of radiation (but you didn't say that). In which case, any radiation that escapes will reduce the energy and hence mass of the object. But you are, again, confusing electromagnetic radiation and a magnetic field. A (static)magnetic field will not carry away energy. A changing magnetic field will generate electromagnetic radiation. Yes it does. That is exactly what it means.

Current attempts to detect it are based on assumptions about the mass, speed, types of interactions, etc. depending on the dark matter model used. No doubt there are whole ranges of models that would render it undetectable. At the extreme, that it just doesn't interact with normal matter at all, under any conditions. Which would make it impossible to detect (unless it decays or interacts with itself).

That probably depends on the type of interaction. Some might require the dark matter particle to have a certain kinetic energy. This is why we can't currently detect neutrinos below a certain energy (ie. speed). Ah, I see what you mean: detecting dark matter particles interacting with the proton beam? I think that is pretty unlikely because the density of dark matter is very low. They are hoping that some unknown particle interactions might be seen as a result of the protons collisions.

An EMP has energy. This can be treated as mass (E=mc2) although it is not usually done (just because there is no particular benefit to doing so). Worth noting that even if you consider the energy of this EM radiation as relativistic mass, calculating the gravitational effect (which you mentioned earlier) is more complicated because gravity depends on more than just mass-energy; you also need to take into account momentum and other things. Incidentally, if the box is perfectly reflecting (inside) then it is also perfectly opaque from the outside so EM radiation could not pass through it. If it is a constant current then any magnetic field would be static and not carrying away energy. If it is AC, then any radiation that escapes from the box would reduce the mass of the box. This seems to be setting up unnecessarily complicated scenarios. If energy escapes then the mass decreases. That is all there is to it. Opening the box would release however much light and heat had accumulated. At some point, the bulb would stop radiating because it would be in equilibrium with the box.

The observed distribution requires them to be moving reasonably fast. Also, I'm not sure why the speed would affect how easy they were to detect. But maybe that depends on what properties they have. They have been looking for any unexpected behaviour that could be evidence of dark matter. (Not sure what "as they travel means"; particles can, in general, only be detected when they hit a detector. There are some exceptions like Cherenkov detectors and cloud chambers.)

Good article on everything we know and don’t know about dark matter here: https://www.forbes.com/sites/startswithabang/2019/09/19/was-dark-matter-really-created-before-the-big-bang/

! Moderator Note Because it is science fiction. That is not a suitable basis for scientific speculation.

No you would not. In fact dark matter is passing through you all the time (although the density of dark matter around the Earth is very low). Just like neutrinos. It would be invisible, because it doesn't interact with light.

That may have changed and, in some cases reduced, some forces of selection but it certainly hasn't removed humans from natural selection.

There are multiple lines of evidence for the existence of effects caused by something we label "dark matter". These include the orbital speeds within galaxies, the speeds of orbits with galaxy clusters, gravitational lensing, the spectrum of the CMB, the formation of large scale structures in the universe, and probably more. Nearly all of this evidence points to dark matter being a form of matter which does not interact electromagnetically. So, similar to neutrinos but it must be more massive because the distribution shows it to be moving more slowly. Not "see" it because it doesn't;t interact with light. I guess the question means will we ever have a more "direct" detection of the particles that make it up? Probably. It took over a decade to detect neutrinos "directly" before they were first detected. Obviously, it is harder to detect dark matter particles (otherwise we would have known what they were, perhaps even before observing the effects). It is rather inevitable that each new type of particle is going to be harder to detect. I don't know what that means. Neptune was a "wildcard thrown in to a mathematical equation to make the equation work". The same could be said of electrons, photons, gravity, energy ... Physics is described in terms of equations. When we discover new things, they are are included in those equations. That would be true whether dark matter is a modification to gravity or some form of matter. So the question doesn't really make sense.

The only force present is gravity, which acts downwards. So you are right that the reason the relatively less dense air goes up is because the denser cold air is pulled down. This is basically the same mechanism for hot air balloons going up or for bubbles rising through water.

Not really. SR is just a subset of GR that can be used under certain conditions (when the system can be approximated by an inertial frame of reference). The GR definition if more generic (because it is the general theory of relativity). While the SR definition is a special case of that.

! Moderator Note Passenger, you have not explained what this thread is about, you have not answered any questions and your use of English is so idiosyncratic that it is almost incomprehensible. ! Moderator Note It would be better to use the Report function for this sort of comment to ensure it is seen by the moderators. If you think the other thread is worth continuing, please report it and make a case for keeping it open.

If you don’t have access, you could try your local university library

I think you would have to look in some journals, find papers about the measurement of the value, look up the references in those papers, and so on, to track through the historical measurements. This would probably be a good place to start: https://iopscience.iop.org/article/10.1088/0034-4885/76/1/016101

Another (slightly more detailed) article here: https://www.quantamagazine.org/physicists-finally-nail-the-protons-size-and-hope-dies-20190911/

! Moderator Note You were told not to bring this up again.

It is exactly that. The m is the rest mass, so there is no kinetic energy. So "all E except KE" = "all E". The equation for a moving object is: [math]E^2 = (mc^2)^2 + (pc)^2[/math]

"we can observe galaxies that have, and always have had, recession velocities greater than the speed of light." https://arxiv.org/abs/astro-ph/0310808 That is assuming an expanding universe. It isn't clear if the OP is trying to deny expansion. But if so, it wouldn't be possible for galaxies to be receding faster than light.