Ask Ethan: Why Do Gravitational Waves Travel Exactly At The Speed Of Light? General Relativity has nothing to do with light or electromagnetism at all. So how do gravitational waves know to travel at the speed of light? September 30, 2021sciencehistoryscoper https://medium.com/starts-with-a-bang/ask-ethan-why-do-gravitational-waves-travel-exactly-at-the-speed-of-light-c60ae2656e32