Albert Einstein Ehrengast Dr. William Phillips at the University of Zürich
22nd of March, Irchel
In the afternoon, when I entered the hall where William Phillips held a talk for interested students, he was sitting there on the front desk, as if he was the most relaxed person I’ve ever met – or at least the most relaxed Nobel laureate. Indeed, William Phillips received this honourable prize for his invaluable contributions to laser cooling in 1997, together with his colleagues Steve Chu and Claude Cohen-Tannoudji. So, there he was, sharing tales and anecdotes from his past all the while showing how much he loves physics. The students also asked very interesting questions about his life, how it changed after getting the Nobel Prize and about his work which he then would all answer in detail. After around an hour, the seminar finished. After leaving the hall, I felt like the talk had left a certain spark of inspiration within me.
Later in the evening, the public talk took place, where everyone could attend. Even though laser cooling is a rather abstract topic for the general public, Prof. Phillips managed to explain it in a very intuitive and at times also humorous manner, often using experiments to demonstrate the effects of the phenomena and the thought processes behind them. This included, but wasn’t limited to: Cooling air with nitrogen, filling a bottle with nitrogen and letting it explode or letting a spinning top float mid-air above a magnetic field. All these examples helped to understand the underlying physical properties of laser cooling. After having learned the basics, Prof. Phillips proceeded to show us more technical details and last but not least, its applications. The most important area in which laser cooling finds use is time measurement, more precisely, time measurement with atomic clocks. Having achieved pioneering feats, such as reaching a temperature in the region of ~100nK, these clocks have become even more precise and reliable.
So, what did I learn that day? Surely, I learned a lot about laser cooling; however, it felt like it went far beyond that. There are two particular phrases which Prof. Phillips would say here and there that conveyed this very well. Firstly, the condition to become a scientist is, in its very core, an insatiable curiosity – the relentless thought of “letting us see what happens”. Secondly, and a consequence of the first phrase, one should learn something new every day, not only for yourself, but learn something new that nobody before you did. That is one of the essential points of pursuing knowledge in science, and well, perhaps in life general.
Pictures © 2018 Frédéric Dux