Google Bard hallucinates a solar sail that travels "100 times the speed of light"
(media.kbin.social)
https://en.wikipedia.org/wiki/Breakthrough_Starshot
A flyby mission has been proposed to Proxima Centauri b, an Earth-sized exoplanet in the habitable zone of its host star, Proxima Centauri, in the Alpha Centauri system. At a speed between 15% and 20% of the speed of light, it would take between 20 and 30 years to complete the journey, and approximately 4 years for a return message from the starship to Earth.