Gravitational waves are theorized to be actual ripples in the fabric of space-time that manifest as low frequency waves detectable (hopefully) by human instruments. Theories state that these gravitational waves would be the result of extremely energetic or large cosmic events such as a pair of massive black holes orbiting each other as two galaxies collide, phase transitions in the very early universe, or even as relics from the time just after the big bang (a theory recently brought into question) when all of the universe burst into existence and expanded rapidly from an infinitesimally small volume in a fraction of a second.

The National Science Foundation (NSF) has awarded the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) $14.5 million over 5 years to create and operate a Physics Frontiers Center (PFC). What mission is the NANOGrav looking to undertake? Scientists there will be detecting for themselves these elusive gravitational waves.

According to Einstein’s theories about all this, gravitational waves, being at such a low frequency, would have extremely long waves, much longer than our solar system. Therefore, a single machine large enough to detect these wavelengths itself would be impossible to construct. Fortunately though, by detecting the millisecond pulsars – the rapidly spinning, superdense remains of massive stars that have exploded as supernovas – we can use the intensely stable celestial clock to detect variations in its pulsing caused by passing gravitational waves.

“For pulsar astronomers to be able to detect these gravitational waves, we really need the best and most sensitive radio telescopes in the world,” said Scott Ransom, an astronomer with the National Radio Astronomy Observatory (NRAO) in Charlottesville, Va., and one of the founding members of NANOGrav. “In the United States, we have the two best — the Green Bank Telescope in West Virginia with its fantastic sky coverage and the Arecibo Observatory in Puerto Rico with its unmatched sensitivity. These instruments have given us a huge edge in this research.”