Over at the other blog, my coverage of William Lane Craig’s cosmological arguments has attracted the attention of a commenter whose URL is biblicalscholarship.wordpress.com. He has at least one comment on each of my posts starting with the one I published three weeks ago, and part of his first comment is this:
I see no reason to believe that the cause must occur before the effect. For example, if I throw a brick through a window, the brick does not pass through the window before the window breaks. At the precise moment the window breaks the brick is acting upon the window. Cause and effect are simultaneous.
He’s responding to my argument that time (and thus the material universe of space-time) must exist before cause and effect is possible, because cause and effect exist in a chronological order, and the cause has to happen before the effect. I know what I want to say in response, but perhaps some of you who know subatomic physics could comment on whether or not I’m on the right track.
I’ve done some thinking about this and I’ve wavered back and forth on the point of whether or not a cause can indeed be simultaneous with its effect. Currently, I’m still inclined to say that it can’t, at least in terms of what I’d call real cause and effect (as opposed to mere apparent cause and effect). In the specific example of the brick through the window, I’d say that the motion of the brick and the breaking of the glass appear to be simultaneous, but that’s merely an artifact of our perceptual limitations. If we could pick just the instant where the brick first makes contact with the glass, and could zero in to a near-atomic scale physically, with a corresponding slowdown in the passage of time, we would observe that the electron shells in the atoms of the brick do not actually touch the electron shells of the atoms in the glass, but rather the fields interact with each other, such that the kinetic energy in the brick’s atoms is transferred to the atoms in the glass. At a certain level, this transfer of energy is not instantaneous, but is subject to the limitations of the speed of light (i.e. the influence of the cause cannot propagate to the target object at a rate that exceeds the speed of light). Since there is a non-zero interval of time between the generation of the cause and the propagation of its influence to the effect, the cause still comes first.
Is that legit? Is it sound physics to say that the influence of the cause cannot propagate to the effect at a rate faster than the speed of light? And on an even more esoteric note, is it possible or even meaningful to speak of two events as occurring simultaneously? Technical answers welcome, technically-correct answers in layman’s terms even more welcome.