Our theme of the universe being weird and expressing its weirdness through pulsars now continues. 

A different group of researchers, members of the NANO Grav collaboration, which stands for Nanohertz Observatory for Gravitational Waves, is looking for the ripples that pass through space-time when gravitational waves run through the universe. The kinds of gravitational waves they’re looking for have a much longer wavelength than what can be detected by LIGO and Virgo. 

Instead of looking for the distances inside massive Earth-bound detectors to contract, NANO Grav looks for the spaces between us and distant pulsars to contract. If everything works as theorized, distances between us and distant pulsars will contract an amount that is directly related to their distance from us and the direction the waves are traveling. This research was done using a combination of the high accuracy Arecibo Observatory and the large field-of-view Green Bank Telescope. 

Unfortunately, while the survey has now published a wealth of preliminary detections, nothing they’re seeing is definitive, and more observations are needed. And Arecibo has collapsed and can’t provide more observations. This research showed us what can be done. It is a hint at the future, but we have to mourn lost potential as we realize what science won’t be possible unless there is an investment in a replacement for Arecibo.

More Information

CU Boulder press release 

“The NANOGrav 12.5 yr Data Set: Search for an Isotropic Stochastic Gravitational-wave Background,” Zaven Arzoumanian et al., 2020 December 24, The Astrophysical Journal Letters