Not truth, nor certainty. These I forswore
In my novitiate, as young men called
To holy orders must abjure the world.

“If …, then,” this only I assert;
And my successes are but pretty chains
Linking twin doubts, for it is vain to ask
If what I postulate be justified,
Or what I prove possess the stamp of fact.

Yet bridges stand, and men no longer crawl
In two dimensions. And such triumphs stem
In no small measure from the power this game,
Played with the thrice attenuated shades
Of things, has over their originals.

How frail the wand, but how profound the spell.

– Clarence Wylie, Jr.

Comments on time by Einstein and Feynman


Since the laws of quantum physics are reversible in time, we shall have to consider computing engines which obey such reversible laws. Feynman RP. Foundations of Physics, Volume 16, Number 6, 507-531, DOI: 10.1007/Dec.

Now he has departed from this strange world a little ahead of me. That means nothing. People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion. — Albert Einstein on the occasion of his friend Michele Besso’s death…and three weeks before Einstein’s death.