And anyone who thinks they can talk about quantum theory without feeling dizzy hasn't yet understood the first thing about it.
Niels BohrThose who are not shocked when they first come across quantum theory cannot possibly have understood it.
Niels BohrThe present state of atomic theory is characterized by the fact that we not only believe the existence of atoms to be proved beyond a doubt, but also we even believe that we have an intimate knowledge of the constituents of the individual atoms.
Niels BohrIn physics we deal with states of affairs much simpler than those of psychology and yet we again and again learn that our task is not to investigate the essence of things-we do not at all know what this would mean&mash;but to develop those concepts that allow us to speak with each other about the events of nature in a fruitful manner.
Niels Bohr