Colloquium

The Physics of Theoretical Computation

Edward Fredkin
Distinguished Career Professor
Carnegie Mellon University

Wednesday, September 10, 2008   4:00 p.m.  NSH 118

(Refreshments at 3:30 p.m. NSH 202)

 

There are many different theoretical models of computation, ranging from the Turing Machine to structures designed out of interconnected Boolean Logic.  The basic laws of Physics have little application to such systems where symmetries and conservation laws are absent.  Further, computers are not normally what might be called “...closed systems” as our models usually involve inputs and outputs.  Finally, the microscopic internal operations of computers are dominated by friction.  The manifestation of that friction is the heat produced by active computer circuits.  While unusual, it is fortunate that theoretical computation can also be intellectually plastic; there are a great many possible models of computation!   We choose to follow Galileo by constructing and examining models of computation as closed systems in the absence of friction.  The experience yields insights into fundamental aspects of information and computation.