Category Archives: Blogging

A New Appearance

I have changed the appearance of the blog. The main feature of the new appearance that I like is that the comments are with the same size fonts as the posts themselves. This is especially useful for the polymath3 posts. (I will make some tuning to the new appearance once I will learn how to.)

Budapest, Seattle, New Haven

Here we continue the previous post on Summer 2010 events in Reverse chronological order.

Happy birthday Srac

In the first week of August we celebrated Endre Szemeredi’s birthday. This was a very impressive conference. Panni, Endre’s wife, assisted by her four daughters, organized a remarkable exhibition by mathematicians who are also artists. Panni also organized tours and activities for accompanying people which my wife told me were great. A few mathematicians chose to attend the tours rather than the lectures. In Hungary, Endre has a nickname “Srac” which means “kid”, and, to my amazement, people (including young people) really call him Srac.

Szemeredi Kati and Zsuzsa

After-dinner speech. The distinction between surprising and amazing, and the question of do we age when it comes to our emotions and inner soul experiences

Being asked to give the after-dinner speech for Endre in the festive boat dinner ranks second in my life among cases where I was chosen for a job for which so many others were much, much more deserving and qualified. Continue reading

Mabruk Elon, India, and More

I am starting this post in Jaipur. My three children are watching a movie in our Jaipur hotel room and I watch them while I begin to write this post. Hagai is in the middle of a long-planned three-month trip to India, and when I told my family about the ICM in Hyderabad, my two other children Neta and Lior jumped at the opportunity, and decided to come to India for three weeks, and in the last week give me a taste of India.  Hagai started his visit in Leh and experienced the flooding there. By the time we heard about it, already two days after the flooding, the Israeli foreign office’s emergency room had already made contact with the Israelis in Leh, including Hagai.  Hagai decided to stay in Leh to help clean houses and (mainly) the local hospital of the huge amounts of mud. He spent almost a month there and took a bus to meet me at Delhi. Neta and Lior were in Hampi, before we all met in Agra.

India is overwhelming and I do not even begin to comprehend her. Perhaps it will be easier to comprehend why so many young Israelis fall in love with India.

In this post (which I split to two parts), I wish to describe some of my Summer 2010 excitements in reverse chronological order.

Before that, here are the slides of my lecture on combinatorial and topological aspects of Helly-type theorems from the Szemeredi birthday conference, and my laudation paper and lecture slides on Dan Spielmen’s work from ICM 2010.

ICM 2010, India

Monday evening was the end of the fourth day in ICM 2010. ICM stands for the International Congress of Mathematicians. This is an event that has taken place once every four years for over a century. This was the second meeting of the Combinatorics session featuring Henry Cohn, Brendan McKay and Benny Sudakov as invited speakers.  It was followed by a session of short 15-minute communications in combinatorics. Laci Lovasz, the president of IMU, had a lot on his mind in these four days. Due to his duties he had to miss many important lectures and events, but he nevertheless set aside time to attend this “contributed talks” session and I found it very nice. Continue reading

Math Overflow

So I did try mathoverflow a bit and it is a cool site. Over the few days I spent there I gained 593 reputation points, and no less than 9 bronze badges. The first answer I proposed gave me a badge as “teacher”,  and the first question I asked gave me a badge as “student”. In fact, if I will only reveil my age I would gain also a badge as “autobiographer”.

Indeed, mathoverflow is ran by an energetic and impressive group of very (very very) young people (more precisely, very very young men).  Here is the link to the 35 users with highest reputations.

Update: Well, I got a little addicted and visited quite a bit this nice site.  Among other things, I tried to promote my fundamental examples question. Basic examples can give a quick invitation to wide areas of mathematics. (Maybe to most areas, I find it hard to think about a counterexample.) Overall, there are not that many basic examples and I think there will be a consensus about most of them so lists of different mathematicians will not be so different. More examples of important examples are welcome. 

In my profile you can find there the six questions that I asked and the 10 answers or so that I offered (to other questions).

Continue reading

Gina Says Part two

Download the second part of my book “Gina Says.”

Link to the post with the first part.



 “Gina Says,”

Adventures in the

Blogosphere String War

selected and edited by Gil Kalai


Praise for “Gina Says” 


After having coffee  at the n-category cafe,  Gina moved to  Clliford Johnson’s blog “Asymptotia” where she mainly discussed Lee Smolin’s book “The Trouble with Physics.”

Among the highlights:  Too good to be true (Ch 17); Dyscalculia and Chomskian linguistics (Ch 19); Baker’s fifteen objections to “The Trouble with Physics” (Ch. 25); Maldacena (Ch. 28);  High risks endeavors for the young (Ch 31);How to treat fantastic claims by great people (Ch. 33); Shocking revelations (Ch. 38); How to debate beauty (Ch 41.)

Some little chapters appeared also as posts: Continue reading

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 the

Blogosphere String War

selected and edited by Gil Kalai


Praise for “Gina Says” 

To download the second part.


Debates portrayed in books, are the worst sort of readings,                        Jonathan Swift.


In the summer of 2006 two books attacking string theory, a prominent theory in physics, appeared. One by Peter Woit called Not even wrong” and the other by Lee Smolin called “The trouble with Physics.” A fierce public debate, much of it on weblogs, ensued.

Gina is very curious about science blogs.  Can they be useful for learning about, or discussing science? What happens in these blogs and who participates in them? Gina is eager to learn the issues and to form her own opinion about the string theory controversy. She is equipped with some academic background, even in mathematics, and has some familiarity with academic life. Her knowledge of physics is derived mainly from popular accounts. Gina likes to debate and to argue and to be carried by her associations. She is fascinated by questions about rationality and philosophy, and was exposed to various other scientific controversies in the past.

This book uses the blog string theory debate to tell about blogs, science, and mathematics. Meandering over various topics Continue reading