Adam Frank, an astrophysicist, argues that if UFOs are alien spaceships, the challenge is reconciling interstellar travel with unimaginably vast distances and the universal speed limit, since a light-year is about six trillion miles, Alpha Centauri lies a … #aliens #bigthink #ovni #uap #ufo #ufosky https://bigthink.com/13-8/ufo-light-speed