I think it might be helpful for anyone who doesn't yet see the point of what I've said so far to look at two examples of what I think were preventable misunderstandings which led to hurt feelings (and even a one-week ban for an ad hom). Since my goal here is to illustrate the kind of problem which can result from misjudging the educational background and psychology of an inquirer in Q&A, I have suppressed some names; anyone who wishes to study the quoted interactions in their original context can see the original threads.
In a recent thread
http://www.bautforum.com/questions-a...-universe.html
one poster asked, in part:
Quote:
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You start with a 4-dimensional semi-Reimannian manifold, in particular a Lorentzian manifold. That manifold is topologically withouth boundary, and may be either an open manifold or a closed manifold -- don't know which. If the Gaussian curvature is positive it is open. If the Guasian curvature is zero it is still open. It the Gaussian curvature is negative it could be either closed or open.
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where clearly he is thinking of the FRW models (in older books these are classified into open, flat, or closed, but this terminology is potentially misleading and seems to be disappearing from more recent books). He also wrote
Quote:
So far as I am aware the only [curvature singularities]
contemplated [in GTR]
are associated wth black holes.
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Both I and KenG, attempting to employ the so-called Discovery method, tried to encourage him to realize that he was forgetting that the FRW dust models possess an initial curvature singularity, generally identified with "the Big Bang".
Unfortunately, the inquirer reacted badly. As I explained in my post #72 in the thread, there are many more issues involved in the relation (in gtr) between geometry and topology--- which turned out to be the point which was really troubling our correspondent--- than most students could possibly guess. I saw three choices:
- try to guess which of many relevant issues was most important to try to explain to the inquirer, who is a stranger to me,
- try to outline all the potentially relevant issues; this would be not only too time consuming for me but might overwhelm most readers (in other threads I've contributed to, such an effort on my part has resulted in a charge of "grandstanding"),
- try to toss out hints to induce the inquirer to do more work in trying to recognize and overcome mental blocks; done well, the "Discovery method" can result in a student overcoming misconceptions without the teacher struggling to elucidate precisely what is confusing the student; unfortunately, the "Discovery method" is notoriously difficult and in that thread I failed miserably (but my intentions were good).
As I said in my post #72, I have recently encountered bad reactions from some posters to all three options. I believe this could often be prevented if such posters were aware of some of the issues to be discussed in the proposed new Q&A sticky.
In another recent thread
http://www.bautforum.com/questions-a...ell-drive.html
a second inquirer asked, in part:
Quote:
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I was reading that article on non-propellant travel methods and I had a thought... how well would something like a gravity well drive work... What I mean by GWD (gravity well drive, easier to type) is that a ship would produce some sort of gravitational anomaly just in front of itself at a distance that remains constant so that the gravity of this thing would pull the ship forward and as it does since the ship is creating the anomaly it too would move forward. couldn't something like this work?
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I responded, in part:
Quote:
This sounds very much like a popular description of the celebrated Alcubierre warp drive spacetime and related constructions, which naively would yield effectively superluminal transport of a warp bubble, with the inhabitants of the "bubble" feeling no accelerations and thus perfectly comfortable, in the manner of Star Trek (hence the name). See
http://arxiv.org/abs/gr-qc/0009013
Note that the eprint version dates from 2000 but is substantially identical to the printed paper, which was published in 1994. This paper lead to a large literature on warp drives. Unfortunately, very bad popularizations at cranky organs like New Scientist has lead many amateur fans of Star Trek to believe that these are "solutions of the EFE". The short story is that are not, although the reasons why require tedious explanations. They are however Lorentzian manifolds and their physically implausible properties (when they are interpreted as spacetime models) have pedagogical value for getting some intuition about what kinds of "weird" Lorentzian manifolds are (mostly likely) ruled out by gtr and other viable theories.
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The inquirer responded:
Quote:
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chris, I don't mean to sound rude but I know very much that this will. Please stop with the overly physics geek speak when explaining things. I appreciate your answer, but I understand very little of it... and it does very little to give at least an understandable answer to the common person. I have to imagine...as with a lot of the questions that have come up... not everyone knows all this stuff nor most of what your talking about and it defeats the point of you answering... I don't mean to sound rude I just don't like reading lines of stuff that mean very little to most people without a physics degree.
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In other words, the second inquirer became infuriated when I
overestimated the level of sophistication of response he wanted, while the first inquirer became infuriated when (as he seemed to feel) I
underestimated his ability (FTIW, I myself felt in retrospect that in inviting him to overcome a mental block by throwing out a few hints, KenG and I were hardly denigrating his intellectual ability!). I hope it is clear why I feel that my proposals above could ameliorate such problems. No doubt this kind of thing would still occur even if a new Q&A sticky is put up, but then we could at least respond to bad reactions on the part of a n00b by pointing at the sticky.
I am a bit unnerved by the strong reaction of several posters who practically said that they don't want to see any hard math or physics in BAUT, period. As I said, I have received some positive feedback, but I am beginning to wonder whether only a tiny minority here appreciates posts which draw upon advanced knowledge of math/physics.
I've been looking for an opportunity to raise another point: I have been amazed and disturbed by angry responses from several posters when I cited a book. Some literally seemed to be regard the friendly suggestion that they might like to read a particular book as an outright insult. (When I cite a book, I almost always give an indication of tis level of sophistication, incidently--- another suggesion worthy of inclusion the proposed new sticky.) I've seen that attitude before but recently I seem to observe it much more frequently, and I am sorely troubled. I hope that it is not true that there is no-one among the younger generation who still reads books!