Primary alternative to dark matter can't deal with gravitational waves' speed.
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. Read more...