How fast is gravity?

Gravity is the most familiar of the known forces, but it seems to be eternal and unchanging. However, scientists believe that gravity moves with a specific speed. In this video, Fermilab’s Dr. Don Lincoln describes a fascinating observation that definitively measures the speed of gravity. Fermilab physics 101: https://www.fnal.gov/pub/science/particle-physics-101/index.html Fermilab home page: https://fnal.gov