It is certainly true that principles cannot be more securely founded than on experience and consciously clear thinking.

It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing...

We can't solve today's problems with the mentality that created them.

Conscious man, to be sure, has at all times been keenly aware that life is an adventure, that life must, forever, be wrested from death.

You teach me baseball and I'll teach you relativity...No we must not. You will learn about relativity faster than I learn baseball.

Don't second guess the mistakes you've made, others will do that for you. Make things as simple as possible, but not simpler.

Time flies when you are having fun.