Monthly Archives: May 2008

Is More Sex Safe? A book review.

Posted on May 29, 2008 by Gil Kalai

I was asked by the Notices of the AMS to review the book “More Sex is Safe Sex: The Unconventional Wisdom  of Econmics” by Steven E. Landsburg.  My review entitled “Economics and Common Sense”, will appeared in the June/July issue of the Notices and … Continue reading →

Posted in Book review, Economics | Tagged , , , , , | 11 Comments

Nati’s Influence

Posted on May 26, 2008 by Gil Kalai

When do we say that one event causes another? Causality is a topic of great interest in statistics, physics, philosophy, law, economics, and many other places. Now, if causality is not complicated enough, we can ask what is the influence one event has … Continue reading →

Posted in Combinatorics, Computer Science and Optimization, Open problems, Probability | Tagged , , , , , , , , , | 21 Comments

Is Mathematics a Science?

Posted on May 25, 2008 by Gil Kalai

Many people do not regard mathematics as a science since it does not directly probe our physical reality; some mathematicians even like to think about mathematics as being closer to art, music or literature. But is there really a big … Continue reading →

Posted in Open discussion, Philosophy, What is Mathematics | Tagged , | 7 Comments

Mathematics to the Rescue

Posted on May 23, 2008 by Gil Kalai

  It was my first day as a postdoc at MIT, and after landing at Logan Airport I took a taxi to a relative in Beverly, north of Boston, where I was going to stay for a few days while looking for a … Continue reading →

Posted in Mathematics to the rescue, Taxi-and-other-stories | Tagged , | 5 Comments

Local Events, Turan’s Problem and Limits of Graphs and Hypergraphs

Posted on May 20, 2008 by Gil Kalai

I will write a little about how hectic things are now here at HU, and make two (somewhat related) follow-ups on previous posts: Tell you about Turan’s problem, and about Balázs Szegedi’s lecture from Marburg dealing with limits of graphs and hypergraphs.  Local Events … Continue reading →

Posted in Combinatorics, Open problems | Tagged , , , | 4 Comments

Jerusalem Combinatorics ’93

Posted on May 16, 2008 by Gil Kalai

Jerusalem Combinatorics ’93 is the title of a conference I organized that took place fifteen years ago in May 9-17, 1993 at the Hebrew University of Jerusalem. It was a conference that was devoted to all areas of combinatorics. The other … Continue reading →

Posted in Combinatorics, Conferences, Women in science | Tagged , , , | Leave a comment

Rationality, Economics and Games

Posted on May 14, 2008 by Gil Kalai

1. The “Center for Rationality” “Founded in 1991, the Hebrew University’s Center for the Study of Rationality  [at first it was simply called “Center for Rationality”] is a unique venture in which faculty, students, and guests join forces to explore the … Continue reading →

Posted in Controversies and debates, Economics, Rationality | Tagged , , , , | 7 Comments

Drachmas

Posted on May 12, 2008 by Gil Kalai

“The fixed price to JFK is 28 dollars” said the taxi driver; “toll and tips not included, and I want the two dollars and seventy five cents for the toll upfront.” I reached to my wallet, dug eleven quarters and … Continue reading →

Posted in Taxi-and-other-stories | Tagged , | 7 Comments

Five Open Problems Regarding Convex Polytopes

Posted on May 7, 2008 by Gil Kalai

   The problems  1. The conjecture A centrally symmetric d-polytope has at least non empty faces. 2. The cube-simplex conjecture For every k there is f(k) so that every d-polytope with has a k-dimensional face which is either a simplex … Continue reading →

Posted in Combinatorics, Convex polytopes, Convexity, Open problems | Tagged , , , | 20 Comments

A Meeting at Marburg

Posted on May 5, 2008 by Gil Kalai

  Just returning from a cozy two days discrete-math workshop in Marburg. A very nice mixture of participants and topics. The title of my talk was “Helly theorem, hypertrees and strange enumeration” and I plan to blog about it sometime soon. A few hours before … Continue reading →

Posted in Conferences | Tagged , | 2 Comments