MathOverflow is a remarkable recent platform for research level questions and answers in mathematics. Joe O’Rourke have asked over MO wonderful questions. (Here is a link to the questions) Many of those questions can be the starting point of a research project usually in discrete and computational geometry and sometimes in other areas. Many of the questions remained open, quite a few have led to definite quick solutions, and for many others substantial answers were offered. Usually Joe’s questions (and also his MO answers) contain beautiful and illuminating pictures. Amog the highlights: Joe’s question on Billiard knots; a poetic question about “light reflecting off christmantree balls“; rolling a random walk on a sphere – with a definite answer by S. Carnahan; Pach animals of high genus; Fair irregular dice (with a nice answer by Bill Thurston); Parabolic envalope of fireworks; Coiling rope in a box; A convex polyhedral analog of the pentagram map ; Randompolycubeshapes ; Which convex bodies roll along closed geodesics and many more. The 100th question is The rain hull and the rain ridge.
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Recent Posts
 What is mathematics (or at least, how it feels)
 Alef’s Corner
 To cheer you up in difficult times 22: some mathematical news! (Part 1)
 Cheerful News in Difficult Times: The Abel Prize is Awarded to László Lovász and Avi Wigderson
 Amazing: Feng Pan and Pan Zhang Announced a Way to “Spoof” (Classically Simulate) the Google’s Quantum Supremacy Circuit!
 To cheer you up in difficult times 21: Giles Gardam lecture and new result on Kaplansky’s conjectures
 Nostalgia corner: John Riordan’s referee report of my first paper
 At the Movies III: Picture a Scientist
 At the Movies II: Kobi Mizrahi’s short movie White Eye makes it to the Oscar’s short list.
Top Posts & Pages
 To cheer you up in difficult times 21: Giles Gardam lecture and new result on Kaplansky's conjectures
 To cheer you up in difficult times 5: A New Elementary Proof of the Prime Number Theorem by Florian K. Richter
 What is mathematics (or at least, how it feels)
 The Argument Against Quantum Computers  A Very Short Introduction
 Cheerful News in Difficult Times: The Abel Prize is Awarded to László Lovász and Avi Wigderson
 Extremal Combinatorics VI: The FranklWilson Theorem
 Amazing: Simpler and more general proofs for the gtheorem by Stavros Argyrios Papadakis and Vasiliki Petrotou, and by Karim Adiprasito, Stavros Argyrios Papadakis, and Vasiliki Petrotou.
 TYI 30: Expected number of Dice throws
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
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Joe has become quite renowned for his figures :). He also has two new books out (How to Fold It, Discrete and Computational Geometry) that are filled with many such great images, which are produced using Mathematica I believe.
Wow, I am truly honored, Gil (and thanks, Andrew)! Gil, I owe you one. Request refereeing, whatever … 🙂
GK: my pleasure Joe, keep the wonderful question comming
Wonderful post!
Would it be at all possible to tag this post “planetMO” so that it can be found via mathblogging.org/planetmo ?
Sorry about the typo, there’s a ” missing — here’s a working link planetMO
On September 2018 Joe asked his 600th MO question!