Public Events Calendar

On October 19, Nobel laureate Professor William D. Phillips will give a lecture at the Department of Physics on the fundamental transformation of the International System of Units (SI) and its quantum foundations.

The International System of Units (SI), the modern metric system, has undergone its most far-reaching reform since its origins during the French Revolution. Instead of relying on physical artifacts such as the meter bar or the kilogram, all SI base units are now defined by fixed values of fundamental constants of nature.

This change makes today’s measurement system, both philosophically and practically, deeply rooted in quantum physics. In his lecture, William D. Phillips will explain why this reform was necessary, how the new definitions work, and what they mean for modern measurement.

Professor William D. Phillips is an American physicist best known for his pioneering work on laser cooling and atomic trapping. For the development of techniques that use laser light to slow atoms to extremely low temperatures – enabling breakthroughs in precision measurement and atomic physics - he was awarded the 1997 Nobel Prize in Physics, jointly with Steven Chu and Claude Cohen-Tannoudji. Phillips spent much of his career at the National Institute of Standards and Technology and also served as a professor at the University of Maryland, where he is highly regarded for both his research and his commitment to science education.

The lecture will be held in Lecture Hall 1.03 and will last approximately one hour. There will be an opportunity to ask questions at the end, and the lecture will be followed by an apéro.