Pulteney Street Podcast: Astrophysics and the Observable Universe – Hobart and William Smith Colleges \
The HWS Update

Pulteney Street Podcast: Astrophysics and the Observable Universe

Episode 11: Steven Penn

In the final episode of the fall semester, President Joyce P. Jacobsen sits down with Associate Professor of Physics Steven Penn on the Pulteney Street Podcast to discuss black holes, the origins of the universe and Penn’s decades-long research with the LIGO Scientific Collaboration, which has made some of the most exciting physics discoveries of the century.

An MIT-trained physicist, Penn joined the HWS Physics Department in 2002 following postdoctoral fellowships at University of Washington and Syracuse University. It was at Syracuse, in 1998, that he became a member of the LIGO Scientific Collaboration (LSC), an international group of more than 1,300 researchers focused on the direct detection of gravitational waves as a means to explore the fundamental physics of gravity and to advance astronomical discovery. Hobart and William Smith became one of the first small colleges to join the LSC when Penn joined the faculty.

Penn was a co-author of the Physical Review Letters article announcing the 2015 detection of gravitational waves by LIGO, confirming for the first time ripples in the fabric of spacetime, a major prediction of Albert Einstein’s 1915 general theory of relativity.

In 2017, for his work pioneering the discovery of gravitational waves, Penn was among the international team of scientists recognized with the prestigious and highly selective Special Breakthrough Prize in Fundamental Physics, through which Penn was awarded a “Breakthrough Prize: Scientists Changing the World” medal. Later in 2017, the Nobel Prize in Physics was awarded to Rainer Weiss of MIT, and Barry Barish and Kip Thorne of California Institute of Technology for the discovery of gravitational waves, a scientific breakthrough made possible thanks to the global LSC research team, including Penn.

Penn’s original LSC research was on the mirror design for Advanced LIGO (Laser Interferometer Gravitational-Wave Observatory). He discovered how to significantly reduce the thermal noise in the material fused silica, which led to the selection of fused silica for the Advanced LIGO mirror substrates and suspensions. With that upgrade, scientists will be able to increase the amount of the universe that can be probed by a thousandfold.

In 2019, Penn was elected Chair of the LSC Council. In the LSC organizational structure, akin to a parliamentary body, the position of Chair corresponds to the Speaker of Parliament, a central role in the management and execution of the group’s mission and goals. The LSC spokesperson is the position that, like the Prime Minister, is the leader of the collaboration. Penn has previously chaired the LSC Coating Working Group, a subcommittee of the Optics Working Group, which is developing coatings for future detectors.