The National Science Foundation has awarded Assistant Professor of Physics Steven Penn a three-year, $300,000 grant to continue his work on the LIGO, the Laser Interferometer Gravitational-Wave Observatory. The LIGO project is a collaboration of over 400 physicists working to detect the existence of gravity waves. Penn will use the grant award to continue his research on improving LIGO’s sensitivity by understanding and minimizing thermal noise.
LIGO, the largest initiative ever funded by the NSF, is an ambitious project that aims to usher in a new era in modern physics and astronomy. The LIGO observatory will be able to see a host of phenomena, including neutron star inspirals, black hole vibrations, and possibly the earliest moments of the Big Bang.
“The LIGO observatories are arguably the most sensitive instruments ever made by science, said Penn. “Over the 2.5 mile length of the observatory arms, we measure the space-time distortion to 1/1000th of the diameter of a proton.
Despite this achievement, the equipment is not yet sensitive enough for frequent observations of gravity waves. Over the past several years, Penn has devoted himself to creating low-noise optics for the next generation of the LIGO. Known as Advanced LIGO, this upgrade should have a factor 10 greater precision and should be able to measure gravity waves at least a few times per month. Advanced LIGO should finally measure gravity waves and unlock a new window on our universe.
The research that Penn and his students conduct in the “HWS Gravity Lab has been highly successful. Their primary achievement has been the reduction of thermal noise in the fused silica optics used in LIGO. Reducing the thermal noise increases the sensitivity of the detector.
“Imagine this, Penn explained, “our fused silica optics are 25 cm in diameter and 10 cm thick, yet there is more thermal noise produced by the mirror coating – just a few microns thick – than is produced in the entire substrate.
The NSF grant will continue funding for Penn’s thermal noise research on Initial LIGO and Advanced LIGO. The grant funds two student researchers for the summers and during the academic year. “The start-up time for this research can be a little long, he said. “Learning the techniques and the science takes time, so it’s important to get involved early. But a dedicated undergraduate student can perform publishable LIGO research, which is a major achievement. Every physicist knows the importance of LIGO research.
Penn earned a doctorate in nuclear structure physics from the Massachusetts Institute of Technology in 1993. After a postdoctoral fellowship at the University of Washington, he joined the experimental gravitational physics group at Syracuse University. Penn has previously been awarded several grants by the NSF for his research.
Hobart and William Smith Colleges is one of only three undergraduate liberal arts colleges in the country participating in the LIGO project.
The image above shows the northern leg (or x-arm) of the LIGO interferometer on the Hanford Reservation facility.