Rockets, space-age coatings and the fundamental aspects of the universe were on display Thursday in La Crosse.
The University of Wisconsin-La Crosse hosted the annual Wisconsin Space Grant Consortium conference in the Student Union, bringing together students and professors from across the state to talk about research and career fields in aerospace, astronomy and other related industries. The keynote speaker at the Wisconsin Space Conference was Thomas Corbitt, a professor of physics at Louisiana State University, who talked about the recent discovery of gravitational waves and direct confirmation of the existence of black holes.
Posited 100 years ago, gravitational waves came out of Albert Einstein’s general theory of relativity as the mechanism for communicating gravitational forces through space and time. Because gravity is so much weaker than other fundamental forces such as magnetism — think about how well a small kitchen magnet defeats the gravitational pull of the whole planet — Einstein thought it might never be possible to ever measure or confirm the existence of these waves.
“It is really hard for people to create (measurable) gravitational waves,” Corbitt said. “We have to rely on the universe to create something we can detect.”
Scientists have been working on building detectors sensitive enough to detect the waves for decades, Corbitt said, using lasers and mirrors to try and detect the minuscule stretching and contracting of space-time that gravitational waves would cause as they travel at the speed of light. The modern LIGO detectors in the United States use tunnels four kilometers long to measure these changes, which are no larger than a tiny fraction of the size of an atom.
Overcoming the engineering challenges of measuring on these tiny scales was no small feat, Corbitt said, as the LIGO program has cost more than $1 billion and required refinements since the first detectors went online in the early 2000s. That work paid off when the detectors were turned on in 2015 and detected the first proof of the existence of black holes.
These astronomical bodies are many times more massive than a star and have all that matter compressed into a small amount of space. Because the gravitational pull of a black hole is so large, electromagnetic radiation such as light, radio waves and heat cannot escape a black hole’s grasp, leaving little for more traditional devices like telescopes to detect.
Because of their size, these behemoths are great candidates for detecting gravitational waves, Corbitt said, and the LIGO’s first detection was of the disturbance two of the massive bodies created a billion years ago as they orbited each other at more than half the speed of light and merged, all in the fraction of a second. A few months later, a second black hole merger was detected, and the results of these groundbreaking discoveries were released to the world in 2016.
“This data was the most direct evidence we have for black holes,” Corbitt said. “This breakthrough shows there are still mysteries in the universe and things we haven’t seen yet.”
At LSU, Corbitt is one of more than a 1,000 people who are part of the LIGO program, and he works with his undergraduate and graduate students to study new ways to make the LIGO detectors more sensitive and able to pick up smaller gravitational waves. Student research is a critical part of the space grant program in Wisconsin, director Kevin Crosby said, as it provides a pipeline of qualified STEM professional for careers aligned to the mission of NASA and other aerospace companies.
Two UW-L students presented information on their own research project, where they attempted to study how useful a potential thin film coating would be. Indium tin oxide is used as a film coating on everything from flat-panel screens to solar panels but is expensive, Indium is as costly as silver and has environmental concerns since the metal is toxic.
Instead, physics student Jacob Pfund and math and physics student Avery McLain looked at creating a similar conductive and transparent material using zinc oxide and graphene, a special form of carbon. The research looked into how well the material would work as a thin film as well as its conductivity and other properties, which they conclude make it a promising candidate.
“It was a fascinating experience,” McLain said about the research project. “There are so many important applications this could be used for.”