University of British Columbia
Probing for flaws in our understanding of the universe
Ingrid Stairs’s job is to peer deep into space, looking for signs that might contradict our fundamental understanding of physics. The University of British Columbia astrophysicist does this by measuring radio waves that emanate from pulsars, which are rapidly spinning, superdense neutron stars. As a pulsar spins, it emits lighthouse-like beams of radio waves. The timing of these radio pulses tells a story about black holes and the nature of gravity.
While it may sound complex, the broad strokes are easy enough to grasp: Black holes describe a region of space with a gravitational field so intense that no matter or radiation can escape. Scientists can’t see them, but they know they are there based on what happens around them.
Get two black holes together and their interaction results in gravitational waves that travel through space toward Earth. Those waves can “jiggle Earth up and down,” says Stairs. “This makes pulsar beams look like they are arriving (on Earth) a bit later or sooner.” Stairs and collaborators are trying to detect this jiggling so they can learn how many pairs there are of black holes with masses a billion times as great as the sun, and so they can study their gravitational effects on each other
Stairs also studies the effect of gravity in systems with two neutron stars. So far, the research shows Einstein’s theory of general relativity, and his description of the nature of gravity, are bang on. That’s important because there are competing theories, that if true, would force us to shift our understanding of how the universe works.
The work requires robust networks that can link data from high-powered telescopes around the world. It also relies heavily on high-powered computing and astronomical amounts of storage space: “Data backup saved my life once before, when one of our servers went belly up,” says Stairs.