"The main point is to be honest with yourself, and to admit when you are wrong."

"I am an optimist, because I believe that man is capable of solving his problems."

"It is not enough to invent. One must also know how to sell."

"The world is full of magic things, patiently waiting for our senses to grow sharper."

"It is not possible that such a small difference in the atomic weights of hydrogen and helium could have such tremendous consequences."