THE ATTACK ON TENSE: THE PHYSICISTS

While only a minority of physicists would like to do away with time completely, many, perhaps the majority, are content to dispense with tensed time. The shortest of the numerous arguments for maintaining that “the distinction between past, present and future is only a stubbornly persistent illusion” derives from special relativity and goes like this. The observed time relations between events will depend on the viewpoint (more accurately, the inertial frame of reference) of the observer. One observer will see that A is past with respect to B, another will see them in reverse order with A future with respect to B, and a third may judge them as being simultaneous with A and B co-present. All three are equally valid. There is no referee, occupying a privileged viewpoint, who can adjudicate because, to the democratic eye of physical science all observers are equal. To put this in relativistic terms, there is no privileged foliation of the manifold – a slicing of space–time into spaces at different times – no “now” acting as a universal reference point, underwriting the present.

In the absence of a privileged viewpoint, there is nothing corresponding to the “real” temporal location of an event in relation to another event. “At a given time” is not a relativistic invariant notion. Anyone setting himself up as a referee is in the same boat as the others: he is just another individual at another viewpoint and not privy to locations in an absolute time in which events “really” take place and their “real” temporal order determined.