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After doing nearly all the coursework for a Ph.D. in math, I then did all the coursework for a Ph.D. in statistics and completed that degree.

1d
answered Most intricate and most beautiful structures in mathematics
Jun
29
answered Most intricate and most beautiful structures in mathematics
Jun
15
awarded  Popular Question
Jun
3
awarded  Notable Question
May
30
revised Hyperplane sections of principal homogeneous spaces
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May
25
awarded  Yearling
May
20
comment cumulant problem
While Rota was writing that paper it grew from 10 problems to 14 and then contracted to 12. He published a number of top-10 lists not long before he died, including "Ten lessons I wish I had been taught" and some others. He wrote something called something like "Ten observations on teaching differential equations" but I don't know if he ever published it.
May
20
comment cumulant problem
Rota intended to expand that paper to something twice as long.
May
20
revised cumulant problem
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May
17
revised What are the most misleading alternate definitions in taught mathematics?
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17
comment What are the most misleading alternate definitions in taught mathematics?
@TobyBartels : $\ldots$ and Euclid did not consider $1$ to be a number. ${}\qquad{}$
May
17
comment What are the most misleading alternate definitions in taught mathematics?
People should know that the determinant is the (oriented) volume of the image of the unit cube, but how does one explain why the determinant should be defined in the same way when the scalars are members of a finite field? Does some idea of oriented volume of the image of the unit cube work in that case?
May
11
awarded  Popular Question
May
7
comment Jokes in the sense of Littlewood: examples?
Some things about this kind of derivative are clearer if you first think of it as $\displaystyle\frac{\partial^n}{\partial x_1\,\cdots\,\partial x_n}(fg)$ and then after finding the derivative let the $n$ variables $x_1,\ldots,x_n$ coalesce into indistinguishability. What happens is that before they coalesce, every coefficient in the expansion is $1$, but after they coalesce the coefficients simply count the number of terms in a class of terms that become indistinguishable from each other. ${}\qquad{}$
May
7
comment Jokes in the sense of Littlewood: examples?
I took the liberty of changing "+x+\cdots+x" to "{}+x+\cdots+x". That puts a larger amount of space between the first "+" and the "x", thus: $+x+\cdots+x$ versus ${}+x+\cdots+x$. When you understand why that is just how the software ought to work, then you will understand something about typesetting and about the fact that Donald Knuth (inventor of TeX, among other things) knew what he was doing. ${}\qquad{}$
May
7
revised Jokes in the sense of Littlewood: examples?
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May
7
revised Jokes in the sense of Littlewood: examples?
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May
7
revised Jokes in the sense of Littlewood: examples?
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May
7
revised Is the space of immersions of $S^n$ into $\mathbb R^{n+1}$ simply connected?
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May
1
awarded  Famous Question