Sydney Science Forum explores why antimatter matters
5 October 2010
Professor Joss Bland-Hawthorn, Federation Fellow of the University of Sydney's School of Physics and Leverhulme Professor at the University of Oxford, will explore the mysteries of antimatter in his upcoming lecture Nemesis: the Search for Antimatter.
Antimatter has mystified scientists since its discovery in the early 1930s, which revolutionised existing theories of particle physics.
"We were used to talking about opposites in the sense of plus and minus when we talked about numbers: electric charges, bank charges," says Professor Bland-Hawthorn.
"But now we had a whole new concept of physics: matter and antimatter. When Dirac proposed the idea in about 1931, no one believed him.
"How are we to understand it? What we can say is that when matter is combined with antimatter, both particles are annihilated and converted into pure energy," he explains.
While the universe today fortunately contains very little antimatter, the laws of physics dictate that it began with matter and antimatter in equal quantities.
The origin of today's asymmetry of matter and antimatter is unknown, and remains one of the greatest unsolved mysteries of modern physics.
"The universe was half filled with antimatter at the time of the Big Bang, yet today it is almost nonexistent. What is it? Where has it disappeared to?"
In an intriguing development to the mystery, the annihilation signature of antimatter has recently been observed emanating from the centre of the galaxy at a rate that corresponds to the annihilation of 16 billion tonnes of antimatter every second.
"This is very exciting because it means that the stuff exists in space, it's not completely gone," Professor Bland-Hawthorn says.
"But what is it doing there? There is a massive black hole four million times the mass of the sun in the centre of our galaxy. Is it somehow related to that?"
Professor Bland-Hawthorn will examine this violent creation of antimatter in the centre of our galaxy, which bring us another step closer to understanding this perplexing phenomenon.
Nemesis: the Search for Antimatter forms part of the Sydney Science Forum, a series of free talks from leading scientists held by the Faculty of Science.
What:Nemesis: The Search for Antimatter in the Universe, a free public lecture for the University of Sydney's Sydney Science Forum
When: 5.45pm, Wednesday 6 October
Where: Eastern Avenue Auditorium, Camperdown Campus
Bookings: Faculty of Science website, calling 9351 3021 or by email to Sydney Science Forum
Contact: Katie Szittner
Phone: 02 9351 2261