Stop worrying

January 30, 2009

Riemann girlfriend



December 6, 2008

They would start about 9 P.M. when Tarski was just getting going. He always smoked, and he kept the door of his study closed so the smoke would stay in the room because he thought that made him concentrate better. “It was awful for me,” Chang said, “because I had asthma, but what could I do? I was his student. I wasn’t really a night person either and after a while it was a struggle to keep my eyes open. Around 2 A.M. he’d ask me if I wanted some coffee and I’d say yes. Sitting at his desk, with the door closed, he’d scream, ‘Mariaahh, Mariaahh,’, as loud as he could. If there was no answer, he’d repeat it, sometimes three or four times until Maria finally opened the door, half asleep, saying ‘Yes, Alfred?’ He’d ask her to bring us two cups of coffee and she trudged into the kitchen to make the coffee and bring it to us. I’ve never seen anything like it before or after.”


One of the many many many amazing stories from the “Alfred Tarski. Life and logic” by Anita and Solomon Feferman

This paper extends interplanetary trade theory to an interstellar setting. It is chiefly concerned with the following question: how should interest rates on goods in transit be computed when the goods travel at close to the speed of light? This is a problem because the time taken in transit will appear less to an observer traveling with the goods than to a stationary observer. A solution is derived from economic theory, and two useless but true theorems are proved.


From an abstract to “The theory of interstellar trade” by Paul Krugman, Nobel prize in economics 2008 winner.

A fair present for all of us in the profession:

Shelah mug


From (they also have sweatshirts, caps, keychains and more). And no, I was not looking for a mug.

Mathe rockt

July 18, 2008

Pure, pure madness!

I am your good friend

June 18, 2008

On another occasion, Erdos met a mathematician and asked him where he was from. “Vancouver,” the mathematician replied. “Oh, then you must know my good friend Elliot Mendelson,” Erdos said. The mathematician replied, “I am your good friend Elliot Mendelson.”


From “My brain is open ” by Bruce Schechter


February 18, 2008



Main ingredient of the Lindstrom’s theorem proof (first order logic is the strongest one with both compactness and Löwenheim–Skolem), from “Mathematical Logic” by Ebbinghaus/Flum/Thomas.

Update. Ok, the picture seems to be a universal one. Hatcher uses it in his topology book for somewhat different purpose , with slight variations