Genady

@joigus is correct. However, would you elaborate on your question and on how it relates to that quote?

It looks like concepts in geometry are idealizations of perceptions and intuitions about space, concepts in algebra are idealizations of perceptions and intuitions about counting, and concepts in analysis are idealizations of perceptions and intuitions about acting.

Yes, I did. It has a beautiful and appropriate name, Voluta musica. Here is Wikipedia article about it. BTW, this article doesn't list "my" island in their distribution. Also, it appears that my specimen was especially large, and at a more shallow depth. Voluta musica - Wikipedia (att. @StringJunky)

What do you mean, Humans are important: All humans are important all the time All humans are important at some time Some humans are important all the time Some humans are important at some time ?

On top of that, having many quotes, even with citations, was discouraged. Not as a plagiarism, but just as a sign of laziness. You better interpret and say it in your own words., with reference to the source.

Zee, A.. Einstein Gravity in a Nutshell: "the equivalence principle leads us directly to an understanding of the gravitational field as a manifestation of curved spacetime." (p. 280) "the gravitational field and curved spacetime are effectively the same thing." (p. 285) "We could say that there is no such thing as gravity, only curved spacetime. But you could say with equal justification that spacetime does not exist; there is only the gravitational field. To me, it is just a matter of words, and the only relevant issue is which language you find more useful to think in." (p. 285) "In Einstein’s theory, the gravitational field is equivalent to curved spacetime." (p. 302) And so on.

Yes. And my picture, being made with an unprofessional equipment, doesn't convey the whole beauty. Plus, the real thing has an extra effect being in fact three-dimensional. I was watching it until I ran out of air. (No problem at 3 m.) They were crawling see floors long before Minoans. Hmmm... They are very rare now. For an obvious reason, I think.

Of course. This rule is designed to be used by a human, who can distinguish between a common speech and the content of an assignment, biology related in this case.

Chemistry?

Here is a conceptual explanation of the mechanics of this phenomenon:

In the school that I've mentioned in the OP, the definition was simple and technical: four or more consecutive words without citation - plagiarism.

"in GR, geometry is the field" is said repeatedly by Zee in "Einstein Gravity in a Nutshell" (I think, there.)

Sorry @swansont , I don't understand. What I have in mind is, take 5 kg of water around me, convert it to 5 kg of something dense, and use this something dense as my diving weight.

Back to physics now. Or, maybe, chemistry (?). Is it impossible to have a light something such that one turns it ON in the water and it converts, say, 5 l of water into 5 kg of a dense solid material? Is there a law prohibiting such thing?

This is just a question, How. On the other hand, maybe it was a Law professor ...

Where I live and dive now I don't need a suit and thus don't have this problem. This is the best solution. Also allows to use smaller tanks for the same time under water. But it was an issue back in NE of USA.

As a SCUBA diver, the one of the most irritating aspects of the activity for me is a need to carry weights when out of water. I've noticed that there are quite a few SCUBA divers here, they might agree. Is it possible to solve this problem, or it would be against the laws of physics?

Quote: A UCLA professor bet $10,000 that the video was wrong, saying it broke the laws of physics. I wonder, which laws of physics it supposedly broke?

One more question (for now): Should it do it continuously as long as the wind is there? Or, it is OK if it moves in some "stop and go" manner?

Perhaps the puzzle also requires the vehicle to be self-contained or autonomous in some way. Otherwise, it could have two parts: one converts the wind into, say, electricity, the other uses it to go wherever it wants.

Oh, I didn't realize that it has to be straight in the wind direction.

Isn't it equivalent to travelling against the wind? Sailboats do it.

Being an atheist, I wouldn't say, Thanks God for SFN. But I sure am glad it is here and a little bit sorry for not finding it sooner.

I agree with everything @MigL says here, with two small additions: what I refer to as "propagation of the field" is an idealized situation of a change from zero field to non-zero field = from no-field to field = from flat to curved; this is perhaps semantics I don't know if the answer to GR is necessarily Quantum gravity

Newton didn't ask for an explanation of gravity or for its fundamental underlying mechanism. My point is that we got the answer to what Sir Isaak asked for. The answer is GR. @Markus Hanke says, that GR is not final in its own right. Susskind, Zee, and other authors say that many, or most theoretical physicists think so. Just 150 years more, since 100 years have already passed ... @geordief says, that it is wrong to think of gravitational field as a physical object. I don't know what physical object means in this context. Are gravitational waves detected by LIGO "just a set of measurements in space and time" or a physical object? Didn't these waves mediate between those colliding stars and us? Gravitational field, "like any field" ( @geordief ), propagates with finite speed and carries energy. Doesn't this tell that it is (they all are) more than just a set of measurements in space and time?