In 2016, scientists confirmed the existence of gravitational waves when observing data from two massive black holes merging. These ripples were absolutely tiny but were instrumental in confirming the astronomical theory. Since then, it was believed these ripples should be measurable everywhere in the universe. The idea congealed that some sort of “gravitational wave background” should be detectable elsewhere. But where?
Theorists believed that pulsars could provide us with additional insights on this background gravitational map of the universe. Scientists had to gather data from several radio telescopes and dig through 15 years of pulsar data to paint this picture. Joel Achenbach and Victoria Jaggard writing for The Washington Post:
The claim that telescopes across the planet have seen signs of a “gravitational wave background” has sent a thrill through the astrophysics community, which has been buzzing for days in anticipation of the papers that were unveiled late Wednesday. The discovery seems to affirm an astounding implication of Albert Einstein’s general theory of relativity that until now has been far too subtle to detect.
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NANOGrav gathered data from 68 pulsars using the Green Bank Telescope in rural West Virginia, the 27 telescopes of the Karl G. Jansky Very Large Array in New Mexico, and the now-defunct Arecibo Observatory in Puerto Rico.
Teams in other countries also observed the same measurable background gravitational waves from these pulsars as predicted. These independent detections affirm Einstein’s general theory of relatively. Huge convergence. This is a historical moment of consilience!