At first gravitational waves were theoretical. As astronomical instruments improved physicists were able to model gravitational waves based on the discovery of pulsars that orbit around a neutron star. In 2015 the first gravitational wave was detected, opening an entirely new field of astrophysics. But there was still a limited amount of data regarding gravitational waves and how they form. Now scientists are excited by the discovery of another gravitational wave, one of the oldest found yet. This brings the total number of known gravitational waves to three. Scientists believe it will take a total of ten gravitational waves to yield enough data upon which to base any conclusion regarding the development of black holes, the entities that create gravitational waves.
This is what scientists have discovered so far. Black holes emit energy that transforms into gravitational waves. These waves cause ripples in space time. But the gravitational waves that are coming from distant black holes are not acting in the same manner as the black holes that exist in this galaxy.
All black holes spin and the alignment of their spins helps scientists determine how they were formed. Scientists are finding that distant black holes do not have similarly aligned spins, which means that those black holes came into being in ways that are unfamiliar to us. This has led to the speculation that powerful gravitational waves can form a kind of black hole nursery which is not possible in our Milky Way.
Will Farr of the Birmingham Institute for Gravitational Wave Astronomy is the author of the latest paper in Nature that discusses the third gravitational wave and its implications. He told Gizmodo that future discoveries will be “weird and exciting.”
Stein Sigurðsson of Pennsylvania State University’s Department of Astronomy and Astrophysics wrote the paper’s commentary. In his view more data could lead to even stranger discoveries and theories such as black holes getting their start from supernova explosions or the existence of three black holes rather than a typical pair. Other astronomers believe that swarms of black holes could exist in galactic centers. But all of this is still theoretical.
Although scientists are attempting to better understand the strange relationships between gravitational waves and black holes, new data is uncovering more possibilities than had been previously imagined.