By: Abigail Mullen
Quanta Magazine
On October 16, physicists from the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) announced that they have detected gravitational waves rippling through space and time. According to Science News, less than 2 seconds later the Fermi telescope spotted light in the sky corresponding to the area where the waves were detected. These gravitational waves were created by two neutron stars colliding followed by a powerful burst of light called a kilonova. The collision happened 130 million years ago and scientists have anticipated these waves for years. According to Scientific American, the previous gravitational waves detected were from merging black holes. Black holes are so dense, they do not give off light, so telescopes were not able to see it, unlike this burst.
This new detection of gravitational waves proves that they travel as fast as light, disproving many theories that exist stating the opposite. It also eradicates other theories, including theories about why the universe is expanding at the speed it is. Dark energy is an important concept in theories about the expansion of the universe. It is an unknown energy that is spread throughout space and is indicated to accelerate the expansion of the universe. This energy was observed to be weaker than it was previously calculated to be. Physicists now have to reevaluate theories and concepts that were thought to be true for decades. According to Science News, calculations of the rate in which the universe is expanding based on exploding stars do not agree with those based on the cosmic microwave background. This difference in values suggests either the measurements are wrong or the theory behind dark energy needs to be changed.
This observation gives insight into the origin of heavy elements such as gold, uranium and platinum. According to Scientific American, we have known that lighter elements, such as hydrogen and oxygen, were formed shortly after the big bang from nuclear fusion in stars. Now scientists have more data about the creation of more of the elements on the periodic table.
