swansont

In another thread I saw a comment about Hawking radiation, which I found confusing, and it's repeated in other online sources: that Hawking radiation is electromagnetic. I'm not a cosmologist, so I'm missing something here. The common explanation for Hawking radiation (e.g. https://www.universetoday.com/40856/hawking-radiation/) is "this process is also called black hole evaporation. In brief, this theoretical process works like this: particle-antiparticle pairs are constantly being produced and rapidly disappear (through annihilation); these pairs are virtual pairs, and their existence (if something virtual can be said to exist!) is a certain consequence of the Uncertainty Principle. Normally, we don’t ever see either the particle or antiparticle of these pairs, and only know of their existence through effects like the Casimir effect. However, if one such virtual pair pops into existence near the event horizon of a black hole, one may cross it while the other escapes; and the black hole thus loses mass. A long way away from the event horizon, this looks just like black body radiation." So the process creates particles, but the radiation is deemed electromagnetic. That does not jibe. What is being glossed over here, in the transition from particles, to electromagnetic radiation? Is it as simple as the particles interacting and creating EM radiation, and that radiation has a blackbody spectrum? (not unlike the CMBR having a blackbody spectrum)? And that this is just a terminology shortcut, when really it's the signature being electromagnetic, even though the radiation itself is comprised of massive particles?

I'm confused. Blackbody radiation is electromagnetic. Alpha, beta, EM are forms of radiation. Blackbody describes the spectrum and something about the process (i.e. it's thermal). If neutron stars emit non-thermal radiation, it would not be blackbody.

No. "Our results show that the transfer efficiency remains near unity over a distance variation of approximately one metre, without the need for any tuning." The Ars Technica link is almost physics-free, and the Nature article is paywalled. And searching is fraught with problems, because CPT also stands for "capacitive power transfer"

Are you asking what it represents, or are you looking for the actual equation? For the latter, I suggest using a search engine. If it's the former, it tells you information about the electron. From it you can find probabilities for where the electron might be found, and the energy state of the electron.

! Moderator Note Saying it like that declares you have nothing of value to discuss

Thermal fission of U-235 produced an average of 2.43 neutrons. For the reactor to be critical, one of those neutrons must induce another fission. If you can get any of the other 1.43 neutrons to be absorbed in a nucleus that runs into fuel (e.g.U-238, forming U-239, which then undergoes two steps of beta decay to become Pu-239) then you have produced fuel. If you could arrange it so that more than one neutron per fission undergoes that reaction (not an easy task), you will have a net increase in the amount of fissile material.

It's not, but freedom's just another word for nothing left to lose. What science do you wish to discuss, and what do you have to support your claim?

But the Pu is fissile. It doesn’t know not to undergo fission. The core will reach an end of life and you can extract the remaining fissile material, just like any other core, but since you are creating more fuel, and also burning up the U-238, which is another poison, I would expect you could run longer before end-of-life.

Not seeing why a new core is necessary to “burn” the plutonium. It would be interspersed in the fuel just as the U-235 is.

What is the obstacle to doing this, in principle?

! Moderator Note One topic per thread, please.

Let’s see your calculation of the effect.

Terminology detail: It would not necessarily transfer heat, as heat is specifically from a temperature difference. Any EM radiation would suffice. In “National Treasure” they use a green laser to do this. It’s a matter of efficiency - you prefer that the target absorb and not reflect.

Yes, considering you could explain what’s going on. Too much to ask, I guess. One definition of pin is a cylindrical object. Yes, that’s what happens with forces. You get an acceleration “Throws the center out of it’s (sic) circumference”? The ball you call “the pin” is not the center of mass. Please explain what you mean by “pin”

! Moderator Note So, you didn’t invoke Wigner’s friend and shared history and a conscious observer in the Mandela effect post? How odd.

! Moderator Note Similar threads merged

! Moderator Note You were told to do this kind of blogging elsewhere

So the pin is a ball, and not a pin. Do I really need to point out that nobody can read your mind?

It’s possible, but might require a large number of interactions to detect anything. High-energy electrons in a discharge leave tracks in plastic. They are called Lichtenberg figures.

! Moderator Note Your beliefs are irrelevant. Science is based on evidence. Support your ideas with evidence, and stop posting nonsense in mainstream threads.

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

there’s more than one grey pin in these drawings. left and right are on top of each other? That’s less than intelligible. I see two pins. Which one is the “center”? One thing you could try is starting at the beginning, and disclosing all if the information, instead of jumping in at the middle and only explaining a third of what’s going on and assuming we know what you’re talking about. Now there’s a fourth ball. Where did it come from?

Momentum doesn't "counter" gravity. The latter is a force, which gives rise to a change in momentum. The only context I can think of where this might make sense is escape velocity. You need to provide more information. A screen shot of the system at the very least.

Right and wrong can't be assigned when the situation is as ambiguous as your discussion is. You have not presented a clear problem, have not been consistent in what you are asking for. You seem to be quoting from various web pages as if you know what you're talking about, and then post things that suggest you don't. It's like trying to hit a moving target that moves erratically if not randomly. I can't hit that target. IOW, I can't give you the answers you are looking for, with the presentation you have provided. You have a code, you say. If that tells you position as a function of time, integrate that twice (while applying the initial conditions or other boundary conditions) and you will have acceleration as a function of time. F = ma. You'll have the force needed to produce that motion. (if you have velocity as a function of time, you only have to integrate once). That's if it's an object with mass. But you have also discussed electrical/digital behaviors, which don't have to follow Newton's laws of motions (see above comment about inconsistency)

AFAIK the size was determined by the amount of light detected, not from resolving an image. If you look at the estimated diameter in the NASA link, all of those asteroids have diameter estimates that are just a bit more than a factor of two from the low end to the high end (it's the square root of 5) which is because they use albedo values of 0.05 to 0.25 (it says so in the hover tag on 'diameter') to estimate the size. So that range is an error bar. If it had a decidedly non-spherical shape, you'd expect oscillations in the amount of light detected, and one might expect that to be reported.