That's the question of Patreon supporter Darren Redfern, who asks:Are gravitational waves themselves subject to gravity? One side of me says gravitational waves are a form of energy so therefore must be affected by gravity. Like light, gravitational waves have a wavelength. We have observed a number of different gravitational waves thanks to LIGO: 11 at last count. Although it might seem counterintuitive that gravitation would affect gravitational waves, this is one of those wonderful times where theory and observation line up perfectly.

Source: Forbes December 15, 2018 15:00 UTC