William Daniel Phillips

While in high school he met Jane Van Wynen who he dated for a few years before marrying in 1970. The couple has two daughters.

He is a practicing Christian known for his faith and is a founding member of the International Society for Science and Religion.

William Daniel Phillips was born to William Cornelius Phillips and Mary Catherine Savino on November 5, 1948, as one of their three children. He is of Italian descent on his mother's side and of Welsh descent on his father's side. Both of his parents were professional social workers.

Interested in science from a young age, he was encouraged in his pursuit of knowledge by his parents. They bought him chemistry sets and let him perform experiments in a lab he had made in the basement of their house. In addition to science, he was also engaged in activities like fishing, baseball, bike riding and tree climbing.

He graduated from high school as valedictorian of his class and continued his studies at Juniata College. His college years were interesting and he did some serious research in physics under the guidance of Wilfred Norris, the Physics Department chairman. He rebuilt an X-band electron spin resonance (ESR) spectrometer and tried to resolve discrepancies in the literature about ESR linewidths. He received his degree in 1970.

He then proceeded to the Massachusetts Institute of Technology (MIT) for his doctorate and measured the magnetic moment of the proton in H2O for his thesis research. After completing his PhD in 1976, he accepted a Chaim Weizmann fellowship to work on projects of his choice at MIT for another two years.

In 1978, he joined the staff of the National Bureau of Standards (now the National Institute of Standards and Technology) in Gaithersburg. There he worked in Barry Taylor's division, collaborating with the likes of Ed Williams and Tom Olsen on precision measurements of the proton gyromagnetic ratio and of the Absolute Ampere.

While Phillips found these projects exciting, his true interest was in lasers and atomic physics. He devoted part of his time to these fields and experimented on finding newer methods to improve measurement capabilities in laser cooling.

By that time, physicist Steven Chu had already performed research focused on atomic physics by developing laser cooling techniques and the magneto-optical trapping of atoms using lasers. Phillips built upon Chu’s work and developed newer methods for measuring the temperature of laser-cooled atoms.

Furthering his research, in 1988 Phillips discovered that the atoms reached a temperature six times lower than the predicted theoretical limit. The French physicist Claude Cohen-Tannoudji provided the explanation for the new results with a refined theory and also worked alongside Phillips to further study methods of trapping atoms cooled to even lower temperatures.

Phillips is also a professor of physics at the University of Maryland College of Computer, Mathematical, and Natural Sciences at University of Maryland, College Park. In addition he serves as a member of the USA Science and Engineering Festival's Advisory Board.

William Daniel Phillips is best known for his work in laser cooling and has developed techniques in which atomic and molecular samples are cooled down to near absolute zero through the interaction with one or more laser fields. His collaborative research with Claude Cohen-Tannoudji and Steven Chu led to the first observation of the Bose-Einstein condensate in 1995.

He developed the Zeeman slower which is a scientific apparatus that is commonly used in quantum optics to cool a beam of atoms from room temperature or above to a few kelvins.