A book that changed me: Birdsong

Book Review: The Undoing Project: A Friendship that Changed Our Minds

“Not Everything That Is Faced Can Be Changed, but Nothing Can Be Changed Until It Is Faced”: A Response to Recent Commentaries

A memorandum that changed the world

In the summer of 1939 Otto Frisch, who was in Copenhagen, received an invitation from Mark Oliphant, a professor of physics at Birmingham, to come to Birmingham for the summer to see if some arrangements might be made for Frisch to emigrate to Birmingham. War came that fall and Frisch could not return safely to Denmark. He was given a lectureship that enabled him to stay. The previous Christmas...

A Patient That Changed Our Practice

Problems that stumped me

Here, subgroups of = G(Z) are called congruentially conjugate if their images in G(Z=mZ) are conjugate for each m 2 N (where G is a linear algebraic group de…ned over Q). The result (b) is proved in [GS] using respectable mainstream mathematics (…niteness properties of arithmetic groups, due to Borel and Serre). Problem 1 is to …nd a natural and attractive way to do (a); the existing proof is m...