User Jim Belk

229 votes

Accepted

Perfectly centered break of a perfectly aligned pool ball rack

answered Feb 1, 2014 at 20:52

60 votes

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Are there any "related rates" calculus problems that don't feel contrived?

answered Dec 10, 2011 at 17:39

46 votes

Function with range equal to whole reals on every open set

answered Jul 16, 2010 at 7:35

45 votes

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An explicit example of a finitely presented group containing a subgroup isomorphic to $(\mathbb Q,+)$.

answered May 6, 2020 at 9:59

40 votes

Not especially famous, long-open problems which anyone can understand

answered Jun 7, 2015 at 19:12

26 votes

Can non-homeomorphic spaces have homeomorphic squares?

answered May 26, 2011 at 2:16

25 votes

Existence of a strange measure

answered Feb 19, 2020 at 11:17

25 votes

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A question about connected subsets of $[0,1]^2$

answered May 19, 2021 at 22:18

23 votes

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How is the Julia set of $fg$ related to the Julia set of $gf$?

answered Jan 4, 2012 at 5:32

18 votes

Folner sets and balls

answered Nov 15, 2013 at 22:40

16 votes

Constructing 4-manifolds with fundamental group with a given presentation.

answered Jul 9, 2010 at 18:55

14 votes

Two-dimensional random walk

answered Jul 9, 2010 at 17:33

14 votes

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Group with non-trivial center containing trivially-intersecting copies of itself

answered Mar 3, 2021 at 22:41

12 votes

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Conformal structure does not see conical singularities

answered Feb 25, 2012 at 4:14

12 votes

Decision problems for which it is unknown whether they are decidable

answered Nov 6, 2019 at 21:47

11 votes

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Generalized root systems and reflection groups

answered Dec 2, 2019 at 21:29

11 votes

Accepted

Isomorphism problem among Thompson's groups

answered Dec 3, 2019 at 20:30

10 votes

Accepted

Are finitely generated amenable groups positively finitely generated?

answered Mar 28, 2016 at 14:17

9 votes

Total spaces of $TS^2$ and $S^2 \times R^2$ not homeomorphic

answered Jun 13, 2015 at 16:10

9 votes

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Growth rates of surface groups

answered Dec 16, 2019 at 10:46

8 votes

Suggestions and feature requests for the design of a font for math articles/books

answered Feb 12 at 0:10

8 votes

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Asymmetry of outer space - injectivity radius

answered Dec 1, 2019 at 10:15

8 votes

Distinguishing pro-finite completions

answered Sep 25, 2010 at 22:21

8 votes

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Counting $(n,k)$-forests of binary trees

answered Jul 13, 2010 at 17:22

8 votes

Accepted

Bases for infinitely generated free groups

answered May 24, 2011 at 17:25

7 votes

If a result is apparently provable with AC, is actually independent of ZF?

answered Feb 5, 2011 at 19:44

7 votes

Accepted

Extending a map from $S^n\to M^n$ to a nice map from $B^{n+1}\to M^n$

answered Dec 8, 2019 at 10:07

7 votes

Approximating fractal curves

answered Jun 20, 2012 at 19:19

6 votes

What's a non-abelian totally ordered group?

answered Jun 18, 2013 at 17:24

6 votes

Best tablet computer for mathematics

answered Sep 2, 2010 at 1:06

Stack Exchange Network

44 Answers

Perfectly centered break of a perfectly aligned pool ball rack

Are there any "related rates" calculus problems that don't feel contrived?

Function with range equal to whole reals on every open set

An explicit example of a finitely presented group containing a subgroup isomorphic to $(\mathbb Q,+)$.

Not especially famous, long-open problems which anyone can understand

Can non-homeomorphic spaces have homeomorphic squares?

Existence of a strange measure

A question about connected subsets of $[0,1]^2$

How is the Julia set of $fg$ related to the Julia set of $gf$?

Folner sets and balls

Constructing 4-manifolds with fundamental group with a given presentation.

Two-dimensional random walk

Group with non-trivial center containing trivially-intersecting copies of itself

Conformal structure does not see conical singularities

Decision problems for which it is unknown whether they are decidable

Generalized root systems and reflection groups

Isomorphism problem among Thompson's groups

Are finitely generated amenable groups positively finitely generated?

Total spaces of $TS^2$ and $S^2 \times R^2$ not homeomorphic

Growth rates of surface groups

Suggestions and feature requests for the design of a font for math articles/books

Asymmetry of outer space - injectivity radius

Distinguishing pro-finite completions

Counting $(n,k)$-forests of binary trees

Bases for infinitely generated free groups

If a result is apparently provable with AC, is actually independent of ZF?

Extending a map from $S^n\to M^n$ to a nice map from $B^{n+1}\to M^n$

Approximating fractal curves

What's a non-abelian totally ordered group?

Best tablet computer for mathematics