Category: Science

“The forces of nature are phase forces.”– C. N. Yang

“The notion of local gauge invariance provides a framework of almost comical simplicity 
for the precise laws of physical interaction.”– Bruce Schumm

Physicists can describe the immense variety of the natural world by invoking only four fundamental forces. Until recently these four forces seemed to be arbitrary facts of nature but the discovery (outlined in UCSC physicist Bruce Schumm’s accessible book “Deep Down Things”) that the behavior of three of these forces can be derived from the operations of certain “symmetry groups” is one of the most exciting accomplishments in physics. Instead of accepting these forces as arbitrary facts of nature, physicists can now derive in precise detail three fundamental forces–electromagnetism, the weak and the strong nuclear forces (but not gravity)–from the transformation properties of three particular symmetry groups. Everything about the force follows from the theory (the number of “force particles”, for instance and whether these force particles self-interact or not) What needs to be supplied by experiment is one number for each force–the measured overall strength (or “charge”) of the interaction. Except for this one number every other feature of these forces is determined by the mathematical structure of its associated symmetry group–an extraordinary explanatory economy (in Schumm’s words) of “almost comical simplicity”.

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