Comments on Unruh's Paper

Abstract

Unruh has commented upon my recent proof that certain predictions of quantum theory are incompatible with the assertion that no influence of any kind acts backward in time in any Lorentz frame. Unruh fails to make a necessary distinction between statements that assert the existence of values, and statements that assert the existence merely of correlations between possible values. Consequently his argument fails to show that my proof involves a tacit or hidden reality assumption that is alien to quantum theory.