Strange

There are threads that ask a straightforward question and get responses that clearly answer the question, often with an acknowledgment to that effect from the OP. Should we have a policy for those threads that we mark it as "SOLVED" (in the title) and close it? The solved tag could help people looking to see if the question has been asked and answered. The point of closing would be to stop further random, and possibly unhelpful, contributions. Thoughts?

This also highlights a second way in which I was wrong (or not completely accurate). In the case of the photoelectric effect, where the electron is expelled from the atom then the photon causing this can have more energy then just the energy to free the electron (the ionisation energy) because any extra energy will be converted to kinetic energy of the electron. So the photoelectric vending machine does give change. But in the form of credit rather than a "smaller" photon.

As I wrote that, I did wonder ...

Historically, they are usually fought for political or economic power. That is partly why the European Union has been so successful in preventing further European wars. Careful. Not all Christians think war is acceptable. But most countries have very precise definitions of unlawful killing (eg murder) and distinguish it from things that are allowed during war. Obviously people will sometimes try to push/break these boundaries.

! Moderator Note Moved to Speculations. Please make sure you read the rules for this forum, in particular: "Speculations must be backed up by evidence or some sort of proof." ! Moderator Note As you admit you cannot present any evidence for this idea, is there any reason to keep this thread open?

No. It is define by the curvature of spacetime. We only have approximations of quantum theory under these conditions. One of these leads to the concept of Hawking radiation. Others show some paradoxical things so are probably not correct. More work needed...

Not in the case of black holes. There are no atoms! The temperature comes from the concept of Hawking radiation. This is a result of quantum effects near the extreme conditions of the event horizon. It is often explained in terms of virtual particles - but I'm not sure that is a very accurate analogy. The radiation comes from outside the event horizon, to from the singularity. It is possible that matter falling towards the event horizon gets heated to extremely high temperatures by friction and pressure but, if so, that would have no effect externally. And, related to that, the Hawking radiation from real black holes would not be measurable. However, most real black holes will have matter falling into them at some time. In this case, the infalling material will create high temperatures and lots of radiation. Some of the brightest things in the universe (quasars) are the result of matter falling into black holes.

That is a good summary.

Your beliefs seem to be irrelevant. Unless you can show some objective calculations of these odds ...

Because of Hawking radiation, a black hole with the size of an asteroid (say, Janus) would be white hot (but very, very faint). One that was twice as massive would be a dull red glow. Any realistic black holes (ie the mass of the sun or more) would be black.

Only for really small black holes.

The temperature of a black hole is inversely proportional to its mass. In other words, smaller black holes are hotter than large ones. Uhm ... black? (Not that simple ... more later ...)

Yes. That just says that a photon, a quantum of light, is indivisible. A given photon can have any frequency (ie energy) at all but when it interacts with something (eg absorbed by an atom) then all of that energy is absorbed. It can't be partly absorbed. So the photoelectric effect says that the photon must have exactly the energy required to raise the energy level of an electron: it can't be done with two photons with half the energy, or with a photon with the energy plus a bit. It is a bit like a vending machine that says "exact money only; no change given."

I don’t believe you.

Why? It is fundamental to your argument. Your entire “theory” is based on a physical impossibility. This has no place on a science forum.

Good article about research on how the brain manages location and how the same mechanism seems to be used for conceptual spaces: https://www.quantamagazine.org/the-brain-maps-out-ideas-and-memories-like-spaces-20190114/ Interesting that in mathematics we also have a more abstract concept of "space" that seems to map on to this. Another argument for the "mathematics is invented, not discovered" side?

MIT students claim to have built an ion powered craft: https://en.wikipedia.org/wiki/MIT_EAD_Airframe_Version_2 Judging by the video on their website, it just looks like a not very effective glider! I have seen paper planes fly further. http://news.mit.edu/2018/first-ionic-wind-plane-no-moving-parts-1121

Ah. Apparently he was "a chain-smoking, atheistic, foul-mouthed, British drunken smartarse" (https://rationalwiki.org/wiki/Christopher_Hitchens)

Send up the bat signal !

The electrolyte is one of the electrodes of the capacitor. Is that what you are suggesting: to use the semiconductor as one of the electrodes? What would the insulating layer be?

As KB75 only seems to be a carrier (and none of her siblings have the disorder) couldn't that come from just one parent? If the gene came from her father, presumably any of her full sisters and half-siblings could also be carriers (with a 50:50 chance). If the gene came from her mother, then only her full sisters could be carriers (again with a 50:50 chance). Or have I misunderstood how it works?

I don't know who Christopher Hitchens was, but I came across this quotation from him, that would be a good "mission statement" for the forum: Any better suggestions?

I don't understand what you are saying. But if you have something that is conductor because of either free holes or free electrons, it will be a conductor that carries current. That current can flow from a metal wire (electrons as charge carriers) into the semiconductor (holes as charge carriers) and into another metal wire. If that were not true, then transistors would not work. So if you try and make a capacitor by separating two pieces of metal with a material that has holes as charge carriers, then you will end up with a resistor (with very low resistance).

A conductor is a conductor. It doesn't matter (much) whether the charge carriers are holes or electrons. (Holes have higher effective mass and so generally lower mobility, which means the conductance is higher ... if I remember correctly.)

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magint.html#c1