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 christman-tree 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 ; Random-polycube-shapes ; Which convex bodies roll along closed geodesics and many more. The 100th question is The rain hull and the rain ridge.

### Recent Comments

dinostraurio on Seven Problems Around Tverberg… Matthew Cory on The Quantum Computer Puzzle @… Matthew Cory on The Quantum Computer Puzzle @… The Quantum Computer… on A Breakthrough by Maryna Viazo… The Quantum Computer… on Stefan Steinerberger: The Ulam… The Quantum Computer… on Polymath10-post 4: Back to the… Philip Gibbs on Stefan Steinerberger: The Ulam… Philip Gibbs on Stefan Steinerberger: The Ulam… Daniel on Stefan Steinerberger: The Ulam… Philip Gibbs on Stefan Steinerberger: The Ulam… Gil Kalai on Stefan Steinerberger: The Ulam… Gabriel Nivasch on Stefan Steinerberger: The Ulam… -
### Recent Posts

- The Erdős Szekeres polygon problem – Solved asymptotically by Andrew Suk.
- The Quantum Computer Puzzle @ Notices of the AMS
- Three Conferences: Joel Spencer, April 29-30, Courant; Joel Hass May 20-22, Berkeley, Jean Bourgain May 21-24, IAS, Princeton
- Math and Physics Activities at HUJI
- Stefan Steinerberger: The Ulam Sequence
- TYI 26: Attaining the Maximum
- A Breakthrough by Maryna Viazovska Leading to the Long Awaited Solutions for the Densest Packing Problem in Dimensions 8 and 24
- Polymath10-post 4: Back to the drawing board?
- News (mainly polymath related)

### Top Posts & Pages

- The Erdős Szekeres polygon problem - Solved asymptotically by Andrew Suk.
- A Breakthrough by Maryna Viazovska Leading to the Long Awaited Solutions for the Densest Packing Problem in Dimensions 8 and 24
- Why Quantum Computers Cannot Work: The Movie!
- The Quantum Computer Puzzle @ Notices of the AMS
- Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
- Can Category Theory Serve as the Foundation of Mathematics?
- Polymath10: The Erdos Rado Delta System Conjecture
- Polymath10-post 4: Back to the drawing board?
- Rodica Simion: Immigrant Complex

### RSS

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 commingWonderful 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