The Nobel Lecture in Chemistry, Stockholm University, December 8, 2011
Courtesy of the American Technion Society
At the official Nobel lecture, Professor Dan Shechtman spoke about his groundbreaking discovery of quasicrystals in 1982. He first explained periodicity and four-fold symmetry and that it looks the same, even if it is rotated. From 1912-1982 all crystals were considered to be ordered and periodic. No one expected something new to be discovered.
Using electron diffraction patterns, Prof. Shechtman was able to observe five-fold symmetry. On the screen he shared a page from his original laboratory log book dated April 8, 1982 that listed the experiments that he performed and his observations on that day. Several years later he was joined by Ilan Blech and other scientists and together their work, initially rejected, was published and finally accepted in the scientific community.
Professor Shechtman asked why this discovery did not happen before 1982 as some 100,000 crystals were studied for a period of 70 years. He said that quasicrystals are abundant, not rare. Aluminum alone has hundreds. They are stable and very easy and inexpensive to make.
He shared the five factors that helped lead to the discovery and acceptance:
1. TEM – Transition Electron Microscope. The discovery could not be made with x-rays and required this powerful tool that enabled scientists to see things at the atomic level.
4. Belief in self as a scientist