"The universe is a cruel and unforgiving place."

"It is a matter of common sense to take a method and try it. If it fails, admit it frankly and try another. But above all, try something."

"We are very, very small, but we are also very, very smart."

"The universe is a grand design, but it's not designed by a grand designer."

"Look up at the stars and not down at your feet. Try to make sense of what you see, and wonder about what makes the universe exist. Be curious."