Theoreticians claim to love data. Data is the thing that allows them to test their theories and prove that they are right. Unfortunately for them, the data often doesn’t support the theory. In those cases, the data has just stabbed your labor of love right in the heart, and you are expected to say “thank you, sir. May I have another?”
The recent observation of the in-spiral and merger of two neutron stars has done just that to a room full of theorists working on gravitational theories that try to get rid of dark matter.
Illuminating dark matter
Dark matter is a particle that is posited to exist in large quantities in the Universe. Physicists did not dream it up because they were bored, but because the internal gravitational structure of galaxies could not be explained by the distribution of visible matter. After the existence of dark matter was first proposed, it got some critical supporting evidence. The cosmic microwave background—the radiation emitted during the Big Bang that permeates the Universe—has features that, at the moment, we can only explain with dark matter.