100 reputation
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bio website twinelogic.com
location Seattle, WA
age 42
visits member for 4 years, 2 months
seen Feb 20 at 15:53

Jan
27
comment A challenge by R. P. Feynman: give counter-intuitive theorems that can be translated into everyday language
@ShreevatsaR. Excellent point. Please cite a publication of the Monty Hall problem in the popular culture which explicitly clarifies the point in question. I submit you won't find any. From that assumption I infer that the version of the problem stated in the media or popular culture is not a math problem, but a psychology problem, perhaps a game theory problem.
Jun
6
awarded  Commentator
Jun
6
comment $\sqrt 2$ is even?
@Arjang -- That comment may explain your intent. What it does not explain is how you could prove $even(n^2) \implies even(n)$ without the stipulation that n is an integer. If you can only prove this for the case where n is an integer, then, yes, you can extend the definition of even, but, no, the usual definition of even does not apply to $\sqrt 2$. When you extend the definition, you are changing the language and anything which comprises the extended definition becomes an axiom of your new system, whether useful or not.
Oct
4
comment A challenge by R. P. Feynman: give counter-intuitive theorems that can be translated into everyday language
@Dour - Are you unaware? By stating that the probability is 0% because the game would otherwise be pointless, what axiom have you invoked? You are reasoning from psychology. Yes, the game would be pointless. What does that have to do with math?
May
25
comment A challenge by R. P. Feynman: give counter-intuitive theorems that can be translated into everyday language
The Monty Hall problem is a psychology problem, not a math problem. If it were a math problem, there would be a defined probability that Monty opens the door which contains the prize, thus giving the contestant certain knowledge. Readers of the problem make the reasonable-for-humans assumption that Monty will not choose the prize door. Further analysis depends on Monty making an IID choice of non-prize doors, or a biased choice. It's a psychology problem.
Aug
8
comment Why is Gimbal Lock an issue?
I think he means mathematical gimbal lock, not physical gimbal lock. I don't think he was referring to the magnetic field, but an abstract spherical globe with poles.
Aug
7
comment How do you estimate the flow rate of one fluid into another like the Deep Horizon Oil leak?
I'm not sure it belongs on stats, either -- but it does not belong here. Numerical estimation could be its own stackexchange, but it's not mathematics.
Aug
7
comment What is a symmetric group?
@Ninefingers: The $f_i$ are the bijections themselves. The members of $X$ represent the corners of a triangle, canonically numbered clockwise for the identity triangle. Each of the $f_i$ transform that triangle by flipping, rotation, or identity -- these are all symmetries. Thus, "symmetry group."
Aug
7
awarded  Critic
Aug
7
comment Dividing a disk into 7 equal pieces with 3 line segments
@Andrea, indeed. -1
Aug
6
comment Prime satisfying a given condition
If you consider 1 as a prime, which most do not, then p=5 is also a solution.
Aug
6
comment How did the notation “ln” for “log base e” become so pervasive?
lg is too similar to log but lx (the roman numeral "x") seems workable. ;)
Jul
28
comment Why are derivatives specified as d/dx?
In other words, in Leibniz notation, the use of the division notation is intentional.
Jul
23
awarded  Supporter