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Ah, the mathematician's "obvious", where it clearly isn't :)
by dTal 4y ago
Ah, the mathematician's "obvious", where it clearly isn't :)
- skywal_l 4y agoI am no mathematician but as far as I remember a shear matrix is just half of a rotation matrix (in 2D).
- deleted 4y ago[deleted]
- hgsgm 4y agoas the article states, R = STS, where S is the same shear in both factors.
- jjgreen 4y agoQuestion at a mathematical seminar: "Isn't it obvious that [...]?", the speaker turns to blackboard, writes furiously for 5 minutes muttering to himself, then replies "Yes it is!"
- ben_w 4y agoSounds about right; any code I could write in 5 minutes is necessarily trivial, so I assume similar for other professions that don't have hard time limits.
- hgsgm 4y agoWriting for for 5 minutes is much easier than thinking for 5 minutes. "Obvious" means you know it without thinking.
- defrost 4y agoIn a math lecture context obvious is intuitively true, five minutes on the blackboard is "trust (your gut) but verify". Not everything pans out the way even the best think - and the very best are notorious for "knowing" results in a flash .. but having to diddle about to produce a logical chain that "proves" that flash for minute, hours, days and sometimes years or a century after their death..
- kzrdude 4y agoThat get us to the obvious theorems that are actually false https://math.stackexchange.com/questions/820686/obvious-theorems-that-are-actually-false https://math.stackexchange.com/questions/820686/obvious-theo...
- defrost 4y agoTo be fair many of those "obvious truths" are rapidly discounted by the kinds of teenagers that go on to become university core math students. Fractal surface areas, the re-order of terms in an infinte series, infinite hotel questions, etc. were all high school puzzles in the 80s in my part of remote Australia so I can't imagine them stumping or confusing a university math lecturer.
- deleted 4y ago[deleted]
- ilyt 4y agoThis is domain where one letter variables is not only the norm but expectation.