Like a band on stage counting down the seconds until they face their anxious audience, York astronomy Professor Marshall McCall from the Faculty of Science addressed crowds at Simon Fraser University, UBC Okanagan, Okanagan College, Queen’s University and the University of Windsor in February and March.
McCall was one of a select group of scientists asked to take part in the 2015 Canadian Association of Physicists (CAP) Lecture Tour. CAP is a national advocacy group for the support of, and excellence in, physics research and education.
McCall took the stage at multiple universities with his presentation “Structure in the Near Universe and its Relevance to Your Life.” McCall’s last stop is here at York University. He will present his lecture today (March 17) at 3pm in the Petrie Science & Engineering Building, Room 317.
His research focuses on how galaxies are formed and how they have evolved since. “This is a frontier of research in modern astronomy and links its relevance to the importance of understanding our own origins,” said McCall. “It is challenging because of the great diversity of knowledge, which must be pooled to address fundamental problems.”
Pondering our place in the universe is difficult, as comprehension relies on points of reference. Earth’s sun is tangible and we see it every day. Grasping what lies beyond our corner of familiarity and visualizing the universe in its vastness is a challenge.
McCall succeeded in creating a very precise map of how nearby galaxies are organized. In doing so, he discovered that the Milky Way galaxy, which is where the sun lives, is encircled by a collection of large galaxies confined to a thin layer. “It appears that the formation and evolution of our Milky Way was guided by the unusual environment in which we find ourselves,” said McCall.
As McCall travelled to different cities, hundreds of curious audience members gathered to hear his talk, which covered the path to discovering the astrophysical implications for our development and where we are heading. The audience learned about phenomena traversing vast ranges of both space and time, and in the end gained a detailed understanding of Earth’s place in the universe. McCall refers to the surrounding galaxies as the “council of giants,” because they have stood in “gravitational judgment of the Milky Way, restricting its ability to grow throughout time.
“If you were an intergalactic postman, you would end up with no mail if you listed your address as Earth. Where in the universe is Earth?” asked McCall.
Audiences learned not only that we live on a planet called Earth around a star called the sun in a galaxy called the Milky Way, but that we are surrounded by the council of giants in the “local sheet,” next to the “local void,” at the border of the “local super cluster,” flowing through the cosmic web.
McCall is an astronomer who has spent most of his research life studying the structure, evolution and formation of galaxies and galaxy aggregates. He has spent two years observing southern skies at Mt. Stromlo and Siding Spring Observatories in Australia. His primary research adversary is interstellar dust, and he has spent a good deal of time uncovering what lies behind it, including two hitherto unknown galaxies in the backyard of the Milky Way.