Newswise – Scientists have made strides in discovering how to use ripples in space-time known as gravitational waves to look back to the beginning of everything we know. The researchers say they can better understand the state of the cosmos shortly after the Big Bang by learning how these ripples in the fabric of the universe flow through planets and the gas between galaxies.
“We can’t see the early universe directly, but maybe we can see it indirectly if we look at how gravitational waves from that era influenced the matter and radiation we can observe today,” said Deepen Garg, lead author of a paper reports the results in the Journal of Cosmology and Astroarticle Physics. Garg is a graduate student in the Princeton Program in Plasma Physics, which is based at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL).
Garg and his advisor Ilya Dodin, who is associated with both Princeton University and PPPL, applied this technique based on their research into fusion energy, the process that powers the sun and stars that scientists are developing to create electricity on Earth without emitting greenhouse gases or producing long-lived radioactive waste. Fusion scientists calculate how electromagnetic waves move through it plasmathe soup of electrons and atoms nuclei which powers fusion facilities known as tokamaks and stellarators.
It turns out that this process resembles the movement of gravitational waves through matter. “We basically put plasma wave machines to work with a gravitational wave problem,” Garg said.
Gravitational waves, first predicted by Albert Einstein in 1916 as a result of his theory of relativity, are perturbations in space-time caused by the motion of very dense objects. They travel at the speed of light and were first detected in 2015 by the Laser Interferometer Gravitational Wave Observatory (LIGO) through detectors in Washington state and Louisiana.
Garg and Dodin created formulas that could theoretically direct gravitational waves to reveal hidden properties about celestial bodies, such as stars many light years away. As the waves flow through matter, they create light whose properties depend on the density of matter.
A physicist could analyze that light and discover properties of a star millions of light years away. This technique could also lead to discoveries about beating up neutron stars and black holes, ultra-dense remnants of deaths. They could possibly even reveal information about what happened during the Big Bang and the early moments of our universe.
The research began with no idea of how important it could become. “I thought this would be a little six-month project for a graduate student that involved solving something simple,” Dodin said. “But once we started digging deeper into the subject, we realized that very little was understood about the problem and we could do some very basic theory work here.”
The scientists now plan to use the technique to analyze data in the near future. “We have some formulas now, but it’s going to take more work to get meaningful results,” Garg said.
This research was supported by the US National Science Foundation through Princeton University.
PPPL, at Princeton University’s Forrestal Campus in Plainsboro, NJ, is dedicated to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and developing practical solutions for creating fusion energy. The lab is operated by the University for the U.S. Department of Energy’s Office of Science, which is the leading proponent of basic research in the natural sciences in the United States and works to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science