Written by Tony Malkovic Tuesday, 10 November 2009 14:00
WHEN theoretical physicist Igor Bray and his colleague Andris Stelbovics came up with their groundbreaking theory to explain what happens when electrons collide with atoms, there was a slight hitch.
Their calculations didn’t agree with some experiments carried out by other scientists.
“Initially, the theory did not agree with the experiments,” says Professor Bray.
“But we were so confident of its mathematical foundation that we suggested that the experiments needed to be re-visited – that the problem was not with the theory but the experiments.
“Which is a rather unusual thing to do in physics.”
But it turned out that new experiments did show that their calculations were right.
“Since then, we’ve been able to solve problems with this theory that nobody else has been able to,” says Bray, the director of the Institute of Theoretical Physics at Curtin University of Technology.
That sort of breakthrough thinking has resulted in Professor Bray becoming one
of the three finalists – along with mathematician Cheryl Praeger and astronomer Peter Quinn, both professors at the University of WA – for the $50,000 Scientist of the Year award to be announced on 2 December.
Professor Bray is a leader in the field of quantum mechanics, and his work involves particles colliding at the atomic level. He has published almost 300 papers which have attracted over 5000 citations, and won numerous national and international awards.
“Collisions on the atomic scale happen all around us. All light that we see is either due to or is influenced by such collisions. All chemical reactions are also examples of atomic collisions,” he says.
“This includes interactions between electrons, photons, atoms, molecules and even anti-matter particles such as positrons.”
Professor Bray is the Deputy Director of the Australian Research Council for Antimatter-Matter Studies, where beams of positrons are made in the laboratory and made to collide with matter.
Applications for such research can include astrophysics, plasma displays, lasers, lighting, fusion energy, materials and medical diagnostics.
“In order to understand how these particles interact with each other, we had to develop a new complete theory for such collision processes,” explains Bray.
“And this is what we developed, it’s called the Convergent Close Coupling theory.
“At this scale, the laws of quantum mechanics govern the interactions.
“Our theory solves the underlying equations of motion for particles in a systematic way, so that as the calculations get bigger and bigger, they should converge to the correct answer. Hence the theory’s name.”
As a theoretical physicist, Professor Bray usually works with high-powered computers to crunch the numbers to test his calculations against experiments or to provide the required data for applications.
He’s also a consultant to NASA’s Jet Propulsion Laboratory in Los Angeles, and the International Atomic Energy Agency in Vienna.
The 2009 WA Science Awards are administered by the Department of Commerce. The winners will be announced on 2 December 2009.
(Disclosure: the Department of Commerce is a sponsor of ScienceNetworkWA.)
Good on ya Igor, I hope you get it.