William Phillips won the Nobel Prize in Physics for his contributions to laser cooling. He tells Edward Duca how a scientist needs to be curious.

Think about something really cold, say, the Arctic. Now, think of something colder. Space? That’s still too warm for what Prof. William Phillips wanted to do back in the 1970s. To date, his work has been used to improve clocks, GPS navigation, study materials and has even helped Felix Baumgartner jump from 39 kilometres above Earth.

I wanted to learn about the way the natural world works – that is what science is all about

Inspiration hit Prof. Phillips in 1978, while at the National Institute of Standards and Technology. He built on the work of Nobel Prize Laureate physicist Dave Wineland, who first showed the laser cooling of atoms.

“Laser cooling is the process by which one can cool a substance […] by shining light on it. The light pushes on the atoms […] that make up the gas to slow them down. This slowing down is the same as cooling the gas,” said Prof. Phillips.

By cooling atoms down to a fraction above absolute zero (-273.15°C, or the coldest place in the Universe), researchers can study unique properties of atoms that are invisible at warmer temperatures.

Wineland was the first to use laser cooling but Prof. Phillips’s innovation was to “do the same thing with neutral atoms. I was also inspired by a publication [by Art Ashkin] which described a way to slow down a beam of neutral atoms using a laser. It took a decade or more to work out the details.”

In 1997, Prof. Phillips won the Nobel Laureate in Physics for this groundbreaking research.

Laser-cooled gases are used to keep an accurate time. This statement might sound trivial, but it has been essential in developing satellite navigation systems such as GPS that help planes, ships and lost commuters arrive at their destination.

They are also being used to study new materials and develop quantum computing, which is possibly the next big leap for computers.

Prof. Phillips’s interest in science started young.

“As a child I was curious. My parents, who were not scientists, encouraged my curiosity and as time went on, I focused more and more on science. I wanted to learn about the way the natural world works – that is what science is all about.”

But Prof. Phillips’s interest went a bit further – he even built a childhood lab in the basement.

“I remember how once, I made a carbon arc lamp from simple household items and produced a very bright light, but also blew out the electrical circuits in our home.”

In November, thanks to Dr Andre Xuereb’s work, Prof. Philips will be visiting Malta. He’s looking forward to “the natural beauty of the islands, art and architecture, and Malta’s rich history”.

He will also be giving a talk whereby he will levitate a small object using a magnetic field.

Prof. Phillips also shares his wisdom on becoming a scientist.

“A scientist needs to be curious. If you want to be a scientist, then nurture your curiosity. Of course, you need to study and learn both science and mathematics, but without curiosity, one is unlikely to learn something new, and learning something new is what science is about.”

Nobel Prize Laureate Prof. William Phillips will be giving a talk on November 9 at 7pm at the Aula Magna, Valletta Campus, University of Malta. Entrance is free. To book, e-mail physics@um.edu.mt or call 2340 2524.

Edward Duca has a Ph.D in Genetics and is the publications developer and editor at the University of Malta.