“If gravity were somewhat stronger or weaker, stars wouldn't exist, and neither would you. And the same can be said of other constants of physics. Several have to be 'just right.'”

American astronomer and author

G. Seth Shostak is an American astronomer and author, best known as the senior astronomer for the SETI Institute. He has spent his career working in astronomy and public discussion of the search for life beyond Earth. His work at SETI places him at the center of research and outreach on extraterrestrial intelligence. As an author and scientist, he often writes and speaks about astronomy, the search for signals from other civilizations, and related questions about the universe.