"If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn't turn out very well for the Native Americans."

"I believe that human beings have a duty to explore the universe."

"So next time someone complains that you made a mistake, tell him that may be a good thing. Because without imperfection, neither you nor I would exist."

"The universe is a big place, and we are a small part of it. But we are an important part of it."

"There are no black holes, only gray holes."