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‘Stuff of which dreams are made:’ Physical cosmology looks to explain the universe

Oct 8, 2019 | 1:56 PM

WINNIPEG — When James Peebles was acknowledged by the University of Manitoba for his work in physical cosmology, the research was described as “the stuff of which dreams are made.”

The Canadian-American scientist shares this year’s Nobel Prize in physics for his work examining cosmic microwave background radiation, evidence of the big bang which is still observable today. It changed how we understand the universe, and even our place within it.

Physical cosmology is a branch of the science which looks for answers to the big questions about the universe: how it was formed, changed and if or how it will end. Peebles has been called both the founder and father, and has written multiple books on the subject.

“Cosmologists are among the most intrepid of scientists, speculating, as they do, about the course of events in the first second after the big bang, thought to have been the initial event in our universe’s history; about the evolution of galaxies of hundreds of billions of stars; about the distribution of galaxies in space; and about the future of the universe, and its possible end,” Arnold Naimark, president of the University of Manitoba, said in 1989.

Andrew Frey, associate professor in physics at University of Winnipeg, said physical cosmology builds on Albert Einstein’s theory of general relativity. It applies basic physical principles rather than just making observations of the universe and relies on different areas of theoretical and applied physics.

Frey said there was a debate in the early 1960s about how the universe came to be. Peebles’ most well-known work importantly reinforced the theory of the big bang — when the universe started expanding from its hot, dense beginning about 13.8 billion years ago.

His research looked at the remnant heat left over from that event, the ancient radiation in the light that has been travelling for billions of years. Peebles interpreted these traces of radiation from the start of the universe and it led to new discoveries of physical processes.

“By studying the detailed physical properties of the radiation, we can learn about conditions in the universe on very large scales at very early times, since the radiation we see today has travelled over such a large distance,” NASA’s website explains.

It tells us about the formation and structure of things such as galaxies in the universe, Frey added.

“It makes you different in how you think about the universe and possibly our place in it.”

Peebles’ work has also helped the understanding of dark matter and dark energy — which largely remains unknown and constitutes about 95 per cent of the universe. NASA has called it the new cosmic challenge.

If those mysteries are solved, Frey said, it will largely be linked to Peebles and his decades of research.

“It’s a question of: What is the state of our universe going to be?”

This report by The Canadian Press was first published Oct. 8, 2019.

Kelly Geraldine Malone, The Canadian Press

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