Life

Life would be tragic if it weren’t funny.
Mankind’s greatest achievements have come about by talking, and its greatest failures by not talking. It doesn’t have to be like this. Our greatest hopes could become reality in the future. With the technology at our disposal, the possibilities are unbounded. All we need to do is make sure we keep talking.
Science is beautiful when it makes simple explanations of phenomena or connections between different observations. Examples include the double helix in biology and the fundamental equations of physics.
We are in danger of destroying ourselves by our greed and stupidity. We cannot remain looking inwards at ourselves on a small and increasingly polluted and overcrowded planet.
The past, like the future, is indefinite and exists only as a spectrum of possibilities.
Work gives you meaning and purpose and life is empty without it.
Intelligence is the ability to adapt to change.
We are all now connected by the Internet, like neurons in a giant brain.
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.
I believe alien life is quite common in the universe, although intelligent life is less so.
Science is not only a disciple of reason but, also, one of romance and passion.
My advice to other disabled people would be, concentrate on things your disability doesn't prevent you doing well, and don't regret the things it interferes with. Don't be disabled in spirit as well as physically.
There is more to life than increasing its speed.
You must be the change you wish to see in the world
Strength does not come from physical capacity. It comes from an indomitable will.
One needs to be slow to form convictions, but once formed they must be defended against the heaviest odds.
Live as if you were to die tomorrow. Learn as if you were to live forever. 
Power is of two kinds. One is obtained by the fear of punishment and the other by acts of love. Power based on love is a thousand times more effective and permanent then the one derived from fear of punishment.
The best way to find yourself is to lose yourself in the service of others.