It is seen as the application of a systematic “scientific method” involving wearing a white coat and being dull. I feel that too many young people co… - Philip W. Anderson

By symmetry we mean the existence of different viewpoints from which the system appears the same. It is only slightly overstating the case to say that physics is the study of symmetry. The first demonstration of the power of this idea may have been by Newton, who may have asked himself the question: What if the matter here in my hand obeys the same laws as that up in the sky—that is, what if space and matter are homogeneous and isotropic?

Surely there are more levels of organization between human ethology and DNA than there are between DNA and quantum electrodynamics, and each level can require a whole new conceptual structure.

My Harvard classmate, Thomas S. Kuhn wrote, some years ago, an influential book about scientific revolutions. Fortunately, many scientific revolutions do not follow his scenario, but the one he focused on, the discovery of quantum mechanics, is well described by his model, which is most valid for a revolution occurring in the central core of a mature science.