by Pasko Vrbat
Many of us would like to turn our childhood dreams into reality. However, few of us achieve this by studying the nature of reality.
But Professor Elisabetta Barberio does. The physicist and winner of the 2013 Women in Physics Award discussed the latest research done at the world’s most powerful particle accelerator, the Large Hadron Collider (LHC), at the Sydney Observatory recently.
Located 100 metres underground near Geneva, Switzerland, the Large Hadron Collider is a 27 kilometre-long, ring-shaped tunnel in which hadrons – the subatomic particles that comprise atomic nuclei – are fired at each other at near-light speeds.
Such collisions have made the LHC, as Professor Barberio explained, the world’s “fastest and most brutal racetrack”. But such collisons have also allowed scientists to study the nature of the particles that make up the universe, as well as the conditions of the universe’s birth, an event some 13 billion years ago known as ‘the big bang’.
In July 2012, our understanding of this cataclysm became clearer. After decades of speculation, researchers at CERN, the organisation that operates the LHC, announced that they’d discovered a new particle: the Higgs boson. Named after Peter Higgs, the physicist who proposed its existence in the 1960s, the Higgs particle gives all other particles their mass. Without it, the particles that make up atoms and, ultimately, our world, simply wouldn’t exist.
Professor Barberio likened the effect that the Higgs boson has on other particles to the effect that a Nobel laureate has on her peers as she walks though a crowded room. Because of the laureate’s status, others are drawn to her, the crowd of people around the laureate growing larger as she moves across the room.
Similarly, as subatomic particles move through the Higgs field, a field that pervades the universe and of which the Higgs boson is an indicator, they gain mass, which is essential to their role as the building blocks of matter.
Professor Barberio also discussed the development of the LHC and, in particular, its ATLAS component. Measuring 46 metres in length, 25 metres in width and weighing 7,000 tonnes, the ATLAS is one of the largest particle detectors ever built, and it played a crucial role in the discovery of the Higgs boson.
Researchers from 35 countries, including Australian postgraduate students, worked feverishly to complete the detector’s development. As Professor Barberio pointed out, “these people didn’t sleep for two years” as they worked on the project.
The important role that Australian researchers played in the LHC’s development was welcomed by the audience.
Ian Bryce, a retired aeronautical engineer with a life-long passion for physics, was particularly impressed with Professor Barberio’s presentation.
“I thought it was the best ever,” he said, after giving Professor Barberio a copy of a poem that he wrote about the Higgs boson. Named Ode to the Higgs: A Celebration of the Scientific Discovery of the Decade, the poem touches on the religious issues that the particle’s discovery raised, which caused some journalists to dub it ‘The God Particle’.
But the greatest consequence of the Higgs’s discovery can, perhaps, be sensed in the scientific endeavours ahead. The particle has already renewed discussions over other enigmas, such as ‘dark matter’: a type of matter that physicists know little about, even though it permeates over 90 per cent of the universe. It’s hoped that the Higgs’s discovery will lead to the discovery of other particles that will shed light on this mysterious darkness.
Back on earth, the particle’s discovery will also foster greater global collaboration between scientists. As a member of the Experimental Particle Physics Group at the University of Melbourne, Professor Barberio is already a part of the growing cooperation between Australian scientists and those who work at the LHC, a fact that testifies to the trait that all humans share – curiosity.
“Human beings are curious about the world around them,” she said, before discussing how particle physics has always tried to answer questions such as “What are we made of?” and “What are the basic constituents of matter?”
Professor Barberio hopes that such questions will also resonate with school children, especially schoolgirls. Although the history of physics illustrates the contributions of female physicists, the science is not an obvious career path for female students.
Professor Barberio has been working to change this and recently visited several Australian high schools to share her experiences.
The physicist attributes her passion for her field to her mother, who was also physicist, as well as her own “curiosity” and interest in problem solving. These qualities continue to inspire her.
“I never feel like I work,” she said, before joining her audience.