Dutch Physicist Quotes
It was a little over fifty years ago that George Uhlenbeck and I introduced the concept of spin. It is therefore not surprising that most young physicists do not know that spin had to be introduced. They think that it was revealed in Genesis or perhaps postulated by Sir Isaac Newton, which most young physicists consider to be about simultaneous.
Above all, it's creative thinking that lies at the basis of discoveries. You must dare to think differently, see things from different sides, in order to come across fortuitous new ideas frequently. You should develop even the most stupid ideas and when you do this systematically, there will always come something useful out of it.
The solution of the measurement problem is twofold. First, any observation or measurement requires a macroscopic measuring apparatus. A macroscopic object is also governed by quantum mechanics, but has a large number of constituents, so that each macroscopic state is a combination of an enormous number of quantum mechanical eigenstates. As a consequence the quantum mechanical interference terms between two macroscopic states virtually cancel and only probabilities survive. That is the explanation why our familiar macroscopic physics, concerned with billiard balls, deals with probabilities rather than probability amplitudes.
According to my views, aiming at quantitative investigations, that is at establishing relations between measurements of phenomena, should take first place in the experimental practice of physics. By measurement to knowledge [door meten tot weten] I should like to write as a motto above the entrance to every physics laboratory.
I ndeed, one of the most important of our fundamental assumptions must be that the ether not only occupies all space between molecules, atoms, or electrons, but that it pervades all these particles. We shall add the hypothesis that, though the particles may move, the ether always remains at rest.
What counts, I found, is not what you cover, but what you uncover. Covering subjects in a class can be a boring exercise, and students feel it. Uncovering the laws of physics and making them see through the equations, on the other hand, demonstrates the process of discovery, with all its newness and excitement, and students love being part of it.