Youth is not a time of life; it is a state of mind; it is not a matter of rosy cheeks, red lips and supple knees; it is a matter of the will, a quality of the imagination, a vigor of the emotions; it is the freshness of the deep springs of life.

You can't just sit there and wait for people to give you that golden dream. You've got to get out there and make it happen for yourself.

The thrill of discovery never gets old.

Mathematics is the music of reason.

科学的每一次伟大进步都源于新的想象的大胆。