Knowledge only progresses by making mistakes as fast as possible. - Kenneth W. Ford

the past has no existence except as it is recorded in the present. (...) we would seem forced to say that no phenomenon is a phenomenon until it is an observed phenomenon. The universe does not 'exist, out there' independent of all acts of observation. Instead, it is in some strange sense a participatory universe

Yes, there is happiness to be found in the mere contemplation of the deepest mysteries.

Never make a calculation until you know the answer.