In this illustration, a hot, dense and expanding debris cloud is removed from neutron stars just prior to collision.
Credit: Goddard NASA / CI Lab Space Flight Center
Gravity is great and strange and difficult to study. It moves in space like a wave, much like light does. But these waves are subtle and difficult to detect. They occur in measurable quantities only after massive events, such as the collision of black holes. Humankind has not spotted its first gravitational wave before 2015. Then, in 2017, astronomers detected for the first time the gravitational waves and light coming from a single event: a collision. Neutron stars. Today, researchers are using data from this event to confirm some basic facts about the universe.
In a document that was downloaded for the first time on November 1 on the arXiv pre-print server (which Live Science saw for the first time in ScienceAlert), the researchers announced that they had found no evidence of "gravitational leak". Scientists had thought that it was possible for gravity to enter the higher dimensions (those beyond the four that humans experience – up / down, side by side, forward / backward, time) even though light do not do it. If this happens, the force of gravity would lose more of its energy than light while crossing the space. But the comparison of the light and gravitational waves resulting from this collision between neutron stars showed that this did not happen.
The gravity of our entire dimension seems to remain where it is, as Albert Einstein had predicted in his theory of general relativity.
The researchers in the new study also analyzed gravitational waves to determine whether graviton – the theoretical particle that carries gravity – could have a mass, unlike other particles. If there was a "massive graviton", the gravitational waves would also have a mass, and if these waves had a mass, they would show signs of momentum, unlike the light particles, which are massless. It would also be a violation of general relativity. But again, that did not happen.
Overall, the researchers found that Einstein's theories of gravity remain fundamentally intact. One day it could change. But this is not yet the case, even after two neutron stars have collided.
Originally published on Science live.