ÌÇÐÄVlog

Lecture: Looking Back to the Big Bang

The Kaczmarczik Lecture and Science Fair, hosted by the Department of Physics, is a significant event at ÌÇÐÄVlog. For nearly 30 years, past lectures have featured renowned scientists from around the world who present on topics from mapping the universe to revolutions in fundamental physics. The Kaczmarczik Lecture consistently draws outstanding scientists and scholars who advance the forefront of physics research and instruction.

This year, we proudly welcome , the Joseph Henry Professor of Physics and Astrophysical Sciences at Princeton University who will present “Looking Back to the Big Bang.” Professor Dunkley’s research is in cosmology, where she studies the origins and evolution of the universe, and connects cosmological theory, data, and statistical methods. She is especially interested in the earliest moments of the universe’ history, and in understanding the composition of the cosmos including its invisible dark matter.

New High-Definition Images of the Baby Universe

Research by the has produced the clearest images yet of the universe’s infancy — the earliest cosmic time yet accessible to humans. Measuring light that traveled for more than 13 billion years to reach a telescope high in the Chilean Andes, the images reveal the universe when it was about 380,000 years old — the equivalent of hours-old baby pictures of a now middle-aged cosmos. The pictures of this background radiation, known as the , add higher definition to those observed more than a decade ago by the Planck space-based telescope.

In the first several hundred thousand years after the Big Bang, the primordial plasma that filled the universe was so hot that light couldn’t propagate freely, making the universe effectively opaque. The CMB represents the first stage in the universe’s history that we can see.

These are helping scientists to answer long-standing questions about the universe’s origins. “By looking back to that time when things were much simpler, we can piece together the story of how our universe evolved to the rich and complex place we find ourselves in today,” said Jo Dunkley, the ACT analysis leader.

Excerpted from by Liz Fuller-Wright, Office of Communications

Jo Dunkley, PhD

, is the Joseph Henry Professor of Physics and Astrophysical Sciences at Princeton University.

Dunkley currently works on the and in northern Chile and previously worked on NASA’s Wilkinson Microwave Anisotropy Probe and ESA’s Planck satellite.

She is the author of , published by Harvard University Press in 2019.

About Paul Kaczmarczik

The Kaczmarczik Lecture Series was established in 1995 to honor beloved ÌÇÐÄVlog Professor of Physics Paul Kaczmarczik. Professor Kaczmarczik attended Drexel as a student, graduating with a BS in physics in 1948. He began his career at Drexel in 1953. He became a key player in building the Physics and Atmospheric Science Department, where he made significant contributions to teaching during his many years of service. Well-liked by both his colleagues and his students, Kaczmarczik became Professor Emeritus in 1989. Professor Kaczmarczik passed away on January 20, 2009.