I might have been just as happy to have been a practicing primary-care doctor. But as a medical student, I had interacted with patients suffering from neurodegeneration or acute clinical schizophrenia. It left an indelible mark on my memory.

One of the major lessons in all of biochemistry, cell biology and molecular medicine is that when proteins operate at the sub cellular level, they behave in a certain way as if they're mechanical machinery.

I started taking a basic biology course, and I really loved it. I started asking research questions incessantly. I was drawn very quickly to biology.

The truth is that anyone, almost anyone, who receives the Nobel Prize has some indirect knowledge of one sort or another that they may be a candidate.

On the other hand, the waging of peace as a science, as an art, is in its infancy. But we can trace its growth, its steady progress, and the time will come when there will be particular individuals designated to assume responsibility for and leadership of this movement.

The whole Hubble program has just been a fabulous testament to the NASA science community and the NASA astronaut community.

Photosynthetic organisms in the sea yield most of the oxygen in the atmosphere, take up and store vast amounts of carbon dioxide, shape planetary chemistry, and hold the planet steady.

The art of teaching is the art of assisting discovery.