tachyon eddies

Caption: Sisko on a solar sailing ship

Star Trek: Deep Space Nine

Episode: DS9 468 - Explorers

The known currents of the naturally faster-than-light particles between Bajor and the Denorius Belt are discovered by Commander Sisko and son Jake to have a warp-drive effect on their ancient Bajoran lightsail craft with its high surface-area-to-mass ratio, proving that the ancients could have reached Cardassia.