From start to finish, the kalam cosmological argument is predicated upon the A-Theory of time. On a B-Theory of time, the universe does not in fact come into being or become actual at the Big Bang; it just exists tenselessly as a four-dimensional space-time block that is finitely extended in the earlier than direction. If time is tenseless, then the universe never really comes into being, and, therefore, the quest for a cause of its coming into being is misconceived.1
This is a big problem for the KCA, since every cosmologist I’ve ever spoke with or read on the issue of time rejects the A-Theory of time. In fact, the standard concept of spacetime we’ve had since Einstein rejects the A-Theory of time. (There are many defenders of the A-Theory, but they seem to be mostly philosophers, not physicists.)
So, about a century after Einstein’s seminal work on relativity, how does Craig argue in favor of an A-Theory of time?
Craig’s major work here is found in two very expensive books, The Tensed Theory of Time: A Critical Examination and The Tenseless Theory of Time: A Critical Examination.
A quick aside: I chuckle whenever I hear atheists complain that “Craig is ignorant of cosmology.” Really? Have they read his 50-page discussion of contemporary cosmological models in The Blackwell Companion to Natural Theology? Looks pretty freakin’ not-ignorant to me. And how many cosmologists have spent more than 600 pages examining the arguments for and against the various models of time? Not many. So stop kiddin’ around: Craig knows more cosmology than nearly all his published critics.
Anyway, I haven’t read Craig’s professional books on the subject, but his two-chapter summary of the material in Time and Eternity should be adequate to at least begin a conversation about the nature of time. But before I come back to Craig, I need to explain why most physicists reject the A Theory of time in the first place.
Our Everyday Experience of Time
Most people believe that time is dynamic. Only the present moment is real: past states of the universe no longer exist, and future states do not yet exist. Our language reflects this common belief, for we have different verb tenses for talking about the past, present, and future. We can say Bob walked, or Bob is walking, or Bob will walk.
Most people also believe that time flows continuously from the past into the future. We remember the past, because it existed before, but we cannot remember the future because it hasn’t happened yet. The “present moment” flows ever forward so that what was in the future is now in the present, and a bit later has fallen into the past.
That is, most people are “presentists” because they think only the present moment exists. Or, they might be “possibilists” because they think the past and present exist, but not the future:
Presentism is how we all experience time. It is how I experience time. So why have most physicists rejected this view ever since Einstein?
Einstein and Time
A few decades after publishing his theories of Special Relativity and General Relativity, Einstein concluded:
It appears therefore more natural to think of physical reality as a four-dimensional existence, instead of, as hitherto, the evolution of a three-dimensional existence.2
As it turns out, it is actually impossible to find any objective and universally acceptable definition of “all of space, taken at this instant.” This follows … from Einstein’s special theory of relativity. The idea of the block universe is, thus, more than an attractive metaphysical theory. It is a well-established scientific fact.3
Or, here is philosopher Vesslin Petkov:
…special relativity [by itself] appears to provide a definite proof of the block universe view.
However, acceptance of the block universe view may not be as universal as I had recently thought. Physicist Hrvoje Nikolic ought to know, and he wrote a paper called “Block time: Why many physicists still don’t accept it?” (He suggests that some physicists cling to the old notions of time not because of the physics, but because of our everyday language and our intuitive sense of the flow of time.)
So let’s look at the arguments. But first, we need to be reminded of what Einstein taught us about space and time. Stay tuned.
- The Blackwell Companion to Natural Theology, pp. 183-184. [↩]
- Relativity: The Special and the General Theory, 15th ed. pp. 150. [↩]
- The Fourth Dimension, p. 149. [↩]
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