Two dense stars begin to orbit one another. As they spin faster and tighter, they move closer. Eventually, they merge in a collision so violent, it creates waves that pulse in all directions throughout the Universe.
Known as gravitational waves, these products of violent cosmic events travel unimpeded at the speed of light through space and time. Much like neutrinos, this allows them to travel vast distances on an even trajectory. But it also makes them incredibly difficult to detect.
Michael Landry, a physicist with the California Institute of Technology and the Head of the LIGO (Laser Interferometer Gravitational-Wave Observatory) Hanford Observatory, knows first-hand the importance of this discover. As the keynote speaker for this year’s Neutrino Day, Landry will discuss LIGO’s exciting discoveries.
“Discovering gravitational waves is akin to acquiring a new sense that allows us to listen to the universe instead of just looking at it,” Landry said in a TEDX Talk. “It alters our perception and allow us to access things we haven’t seen before.
Researchers at LIGO developed detectors that can monitor gravitational waves. Using mirrors to detect the shortening and lengthening of laser beams between them results in recordable events that are transmitted as sound (“chirps”) and recorded at unique facilities.
The phenomena was first observed in a collision of two black holes that occurred 1.3 billion light years ago. In the most recent observation, the two black holes collided about 3 billion light years away. “Whether they were born as an isolated system, or if they were gravitationally captured in dense stellar regions such as globular clusters or the centers of galaxies, is currently unknown,” Landry said. “The increased distance of this system allows for finer tests of Einstein's General Theory of Relativity than those of the first detections.”
By studying the frequency of gravitational waves, scientists can pinpoint the exact location of the cosmic event, gaining the ability to study it further. For example, the data collected could tell us what the universe was like moments after the Big Bang, how the Universe is evolving and, perhaps, even predict how it could evolve in the future. Essentially, they want to understand the story of our Universe.
“After many decades of searching, we now have a new tool to apply to the universe, to learn about physics, astrophysics and cosmology,” Landry said.
Landry’s keynote presentation will be held Saturday, July 8, at 4 p.m. at the Homestake Opera House in Lead. Go to www.sanfordlab.org/neutrinoday for more information.