Physics World announced its top 10 breakthroughs for 2011 on December 16th. Coming in at number 10 is Saint Michael's College Professor John O'Meara, with his colleagues Michele Fumagalli and Xavier Prochaska of the University of California, Santa Cruz, for their discovery of clouds of pristine gas from the very early universe- a triumph of Big Bang cosmology.
The team was lauded by Physics World for being "the first to catch sight of clouds of gas that are pure relics of the Big Bang. Unlike other clouds in the distant universe - which appear to contain elements created by stars - these clouds contain just the hydrogen, helium and lithium created by the Big Bang. As well as confirming predictions of the Big Bang theory, the clouds provide a unique insight into the materials from which the first stars and galaxies were born."
See the full announcement
See the story of O'Meara's discovery - Pristine relics of the Big Bang spotted
"We are grateful and delighted to have been named a top10 breakthrough in astrophysics, but there is plenty of work still to be done," Professor O'Meara said.
Criteria for selecting the top 10 breakthroughs award
The top 10 breakthroughs list has been compiled by the Physics World team, who reviewed over 350 news articles about breakthroughs in the physical sciences published on physicsworld.com in 2011. The criteria for judging included:
- fundamental importance of research
- significant advance in knowledge
- strong connection between theory and experiment
- general interest to all physicists
A story of the astronomical break-through discovery appeared in Science, the premier science journal in the U.S., November 10, 2011.
Using the giant 10-meter Keck I telescope in Hawaii, the three astronomers discovered two giant clouds of intergalactic gas whose chemical composition has been unaltered since the dawn of time. The clouds, located over 11 billion light years from Earth, offer direct supporting evidence for the Big Bang model of cosmology.
O'Meara explained that in the Big Bang model only the very lightest elements such as Hydrogen and Helium were created during the first few minutes of the history of the universe. As cosmic time progressed over billions of years to the present, gas containing these few elements form stars and galaxies. As part of the life cycle of stars, the remaining elements, such as carbon, nitrogen and oxygen, are produced and recycled into the gas within and outside of galaxies. Until now, astronomers have always detected these heavy element remnants wherever they've looked.
Gas with no trace of heavy elements was the break-through discovery.
"These clouds are exciting for both what they do and don't have," Saint Michael's Professor O'Meara said. "Specifically, they represent the first detection of pristine gas: gas with no trace whatsoever of heavy element absorption. What the gas does contain, however, is hydrogen and its isotope deuterium in the levels predicted by Big Bang models." Although the discovery is a triumph for the Big Bang cosmology, O'Meara points out that it raises new questions.
"A good overall model of cosmology, but plenty of work to do," O'Meara said. "These clouds have been uncontaminated by heavy elements for over two billion years since the Big Bang. This means that our understanding of how galaxies return heavy elements to their environments is incomplete. Although we've provided great evidence that our overall model of cosmology is a good one, we still have plenty of work left to do."