Recent Comments

Recent Posts
 Jirka
 AviFest, AviStories and Amazing Cash Prizes.
 Polymath 10 post 6: The ErdosRado sunflower conjecture, and the Turan (4,3) problem: homological approaches.
 Polymath 10 Emergency Post 5: The ErdosSzemeredi Sunflower Conjecture is Now Proven.
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
 More Math from Facebook
 The Erdős Szekeres polygon problem – Solved asymptotically by Andrew Suk.
 The Quantum Computer Puzzle @ Notices of the AMS
 Three Conferences: Joel Spencer, April 2930, Courant; Joel Hass May 2022, Berkeley, Jean Bourgain May 2124, IAS, Princeton
Top Posts & Pages
 A Breakthrough by Maryna Viazovska Leading to the Long Awaited Solutions for the Densest Packing Problem in Dimensions 8 and 24
 The Erdős Szekeres polygon problem  Solved asymptotically by Andrew Suk.
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 Combinatorics, Mathematics, Academics, Polemics, ...
 יופיה של המתמטיקה
 Polymath 10 Emergency Post 5: The ErdosSzemeredi Sunflower Conjecture is Now Proven.
 AviFest, AviStories and Amazing Cash Prizes.
 Extremal Combinatorics III: Some Basic Theorems
 Believing that the Earth is Round When it Matters
RSS
Monthly Archives: June 2009
Test Your Intuition (6)
This is not as clear cut a question as the earlier ones, and if you do not know an answer then it will be difficult to figure one out just based on intuition. (But perhaps possible). If you are intrigued by … Continue reading
Praise For ‘Gina says’
Praise for: ” ‘Gina Says,’ Adventures in the Blogsphere String War (Below the dividing line: Greg Kuperberg, Scott Aaronson, Clifford Johnson, Peter Woit, Motty Perry, Caterina Calsamiglia, Yuval Peres, Eva Illouz, and (right from the comment section) Luca Trevisan, Thomas … Continue reading
Posted in Book review, Gina Says
11 Comments
My Book: “Gina Says,” Adventures in the Blogosphere String War
I wrote a book. It is a sort of a popular science book and it is also about blogging and debating. You can download the first part of the book : It is a 94 page pdf file. “Gina Says,” Adventures in … Continue reading
Posted in Blogging, Gina Says
35 Comments
A Little Story Regarding Borsuk’s Conjecture
Jeff Kahn Jeff and I worked on the problem for several years. Once he visited me with his family for two weeks. Before the visit I emailed him and asked: What should we work on in your visit? Jeff asnwered: … Continue reading
Borsuk’s Conjecture
Karol Borsuk conjectured in 1933 that every bounded set in can be covered by sets of smaller diameter. Jeff Kahn and I found a counterexample in 1993. It is based on the FranklWilson theorem. Let be the set of vectors of length . … Continue reading
Banknotes with Pictures of Mathematicians
Are you aware of any? (current ones? old ones?)
Posted in Uncategorized
12 Comments
Test Your Intuition (5)
(Not such a set) consider a planar set A with the following property. In every direction, the distance between the two parallel lines that touch A from both sides is the same! Must A be a circle?
Answer To Test Your Intuition (4)
Let G be a graph and u and v two vertices. (1) Let H be a random graph where every edge of G is chosen with probability ½. Let p be the probability that there is a path between u … Continue reading
Test Your Intuition (4)
Let G be a graph and u and v two vertices. (1) Let H be a random graph where every edge of G is chosen with probability ½. Let p be the probability that there is a path between u … Continue reading
Posted in Probability
18 Comments