Recent Progress in Theoretical Physics

Abstract

WHEN an army is making a rapid advance over fresh ground it is not the time to make an elaborate survey of the territory conquered, but on the other hand sketch maps, however provisional and imperfect, of the main lines of advance and the chief points of attack, are all the more useful to the soldier in the field and interesting to the newspaper reader at home. What follows is an attempt to draw such a sketch map for some important recent work in physics.