UCI-UCSD Logic & Philosophy of Science

Two putative consequences of relativistic quantum field theory are: (i) in the non-exotic setting of Minkowski spacetime, an observer moving with constant acceleration, through what a non-accelerating observer considers a vacuum or no-particle state, is pelted with particles (the Unruh effect); and (ii) in the more exotic setting of a spacetime containing a black hole, an observer outside the black hole is pelted with particles apparently emanating from the (evidently not so) black hole (the Hawking effect). In each case, the pelted observer attributes the quantum field a thermal state, a state whose statistical character is claimed to reflect, in the case of the Unruh effect, the acceleration of the pelted observer or, in the case of the Hawking effect, the initial mass of the evaporating black hole. I hope in this non-technical talk to use the Hawking and Unruh effects to illustrate what's at stake in some of the interpretive questions that arise in connection with RQFT, interpretive questions that are distinctive of RQFT, in the sense that they don't arise for more mundane quantum theories.