Thursday, October 6, 2011

2011 Nobel Prize in Chemistry

I was pleased to see that the Chemistry prize was awarded to Dan Shechtman for the discovery of quasi-periodic materials that led to a new definition of crystal (quasi-crystals). Back in 2003 APS News published a nice discussion of the background to the paper which appeared in PRL in 1984 and is the 8th most cited PRL of all time.

An earlier post discusses why I teach undergraduates about quasi-crystals. It illustrates the fundamental logical principle that A implies B does not mean that B implies A. Specifically, just because a periodic arrangement of atoms is a sufficient condition for a discrete X-ray pattern does not mean that it is a necessary condition. It also shows students that what they read in textbooks may be wrong.

Shechtman is not the first condensed matter physicist to be awarded the Nobel Prize in chemistry. Other recent examples include Walter Kohn and Alan Heeger.


  1. I think the periodic arrangement is sufficient, but not necessary!