Many tutors are more or less exactly that.

Books are enough for understanding anything, you'd just need good from-the-ground-up textbooks and probably months or years to read them.

In practice, this isn't true. Some people really do have trouble learning from books. Simply reading the book aloud to them is enough to overcome the block.

I don't know where the problem originates, however. It seems strange to chalk it up to lack of motivation or stupidity, given the people I know.

In other words, books contain all of the knowledge necessary to understand anything but not everyone can pick up the understanding itself from a book. Why, I don't know.

The latter.

Most of the points carry over to other domains as well (e.g., music, art, ballet, stage acting, spiritual traditions that have "gurus" or "masters").

For example, there are many (e.g.) piano teachers who can trace their lineage back to Beethoven (and they know it off the top of their heads if you ask them), who are similarly overly deferential to historical masters, who see their knowledge and music in general as sacred knowledge. There is also the same extreme conservatism, and different teaching techniques and performance techniques cannot easily be tested.

[Edit: a pretty good test for whether these sorts of problems are characteristic of at least some practitioners of a given domain is whether (or how often) they get angry in the way preachers get angry at blasphemy and utter sentences that begin with "how dare (s)he ...".

Can anybody think of a domain where students spend decades learning, often with the same teacher or very few teachers, where the domain is the center of their life, which has existed for at least a few centuries, and where these problems do not occur with great frequency?]

A plastic bottle out of the trash. It's transparent but flexible and almost weightless. See how well the lid has been made? It makes a water-tight seal.

It might be the most valuable object in Greece.

I would sort of expect any woman who showed up with apparently magical powers to be put into the goddess category. Even someone like Aristotle, who probably didn't believe that gods and goddesses literally existed, would be culturally conditioned to treat a woman who appeared to have super-powers with some respect.

How would you implement that? What do we have the tech to build today for a reasonable outlay of money (less than a million euros, for example) that could blow minds in that era?

or bring bad weather, surely we would all agree that if anyone deserved the death penalty, then these filthy quislings did.

For bad weather? As in... 3^^^3 days of sleet is worse than 50 years of torture?

I had the cold water procedure done at a GP to flush out an earwax obstruction. It was absolutely horrible, and I don't recommend it for self-testing.

The flushing took a minute or two. Then there was a minute of starting to feel more and more strange, while everyone asked, "Are you all right?" Then, for the next five or ten minutes....

Notice the reference to REM. If you've ever been so drunk as to see the room spin... you have a slight idea of what my eyes were doing. Closing them didn't help. The staff made me lie down, which made no difference -- I was still clinging desperately to the wall, disoriented and frightened out of my wits.

Eventually the vertigo went away, but I still felt wonky for the next few minutes. Best analogy: being woken from deep sleep and asked to do calculus. Only awake.

Life-changing realizations: none. Perhaps you have to be on-topic at the time. I'm not going back to find out.

Hope this at least slows people down a bit.

[Also, blindsight is an interesting tangent.]

And, now I see why I am skeptical of hypercomputation. It seems to all necessitate some form of computation over an infinite number of steps. This would require some severe bending of the rules or constraints of physics, wouldn't it?

timtyler's comment below mine seems to be appropriate:

It is a field with an imaginary object of study.