Welcome to Tuesday Morning Apologetics (TMA). Let’s talk about the Kalam Cosmological Argument (KCA):
1. Whatever begins to exist has a cause.
2. The universe began to exist.
3. Therefore, the universe has a cause.
We’re continuing our look at a challenge to the first premise of the KCA that champions a particular model of Time.
The B-Theory of Time
In Part 1 we described what the B-Theory of Time was and a little bit about why it’s thought to be a defeater for the first premise of the KCA. This time we’re going to look at why people believe that it’s the model that does a better job at describing reality.
When I first learned about this alternate theory of Time, I hadn’t really given Time itself much thought. But, if I had to describe it, I would’ve naturally described something like A-Theory. When I was introduced to B-Theory, it initially seemed absurd to me. However, Einstein’s Theory of Relativity makes it hard to dispute. And I thought that the Relativity Theory was the only reason anyone would believe or even think of a B-Theory version of Time.
Wrong I was.
Remember when I said that on the B-Theory of Time, “what we constantly experience as the present through ‘temporal becoming’ is just an illusion”? Well, that’s kinda a fancy way of saying that Time doesn’t actually exist. That Time is “unreal”. And this is not a new idea. Time has been treated as unreal by Spinoza, Kant, Hegel and by Schopenhauer. Not to mention the fact that religions in the East often treat the unreality of Time with cardinal importance.
However, here in the West, I’m still inclined to believe that the B-Theory of Time has gained popularity mainly because of Physics. And, honestly, for good reason. It’s hard to dispute empirical evidence (1). Physics, through the general theory of relativity, now talks about the “Fabric of Spacetime”. And this Fabric is described as becoming curved by massive objects (i.e. stars, planets, you and me). This curvature is either the cause of gravity or it’s a symptom of gravity. Either way, as the name implies, the curvature of Spacetime not only impacts space, but it also impacts Time (2). And that impact can actually be measured. Additionally, Special Relativity describes Time being impacted by speeds approaching the speed of light. The faster you go the slower Time passes for you. Although, you won’t notice a difference yourself. It’s slower relative to your surroundings. Relative to things not going almost as fast as the speed of light. The following are some novel predictions, which have subsequently been experimentally verified to an exceptionally high degree of precision that supports the notion that Spacetime corresponds with reality and that seems to imply that B-Theory is true. I’m going to quote the non-Christian James Fodor, from his book, Unreasonable Faith: How William Lane Craig Overstates the Case for Christianity, because I think he does a good job of summarizing these evidences. The Hafele-Keating experiment: general relativity predicts that time passes more rapidly in weak gravitational potentials compared to strong gravitational potentials. This prediction has been verified by comparing the times measured on atomic clocks kept on the Earth’s surface to those flown on high altitude aircraft.
Shapiro time delay: signals sent to distant targets take longer to reach their destination and return to the source when they pass near a massive object (like a star) than they do in the absence of the massive object. This is another manifestation of gravitational time delay, but is an independent means of detection which further confirms the predictions of general relativity.
Gravitational redshift: electromagnetic radiation has been observed to be redshifted, or have its wavelength increased, when emitted from within a strong gravitational field. The effect is predicted by Newtonian gravity, but again the magnitude of the effect is only correctly predicted by general relativity. This phenomenon is yet another observational confirmation of gravitational time dilation.
Gravitational lensing: massive objects such as distant galaxies have been observed to bend light in a way that can produce multiple images of the same background object. This effect is predicted by Newtonian gravity but the magnitude of lensing is only correctly predicted by general relativity.
Gravitational waves: gravitational waves are waves in the curvature of spacetime that are predicted by general relativity to propagate through spacetime at the speed of light. They have recently been observed by very sensitive experimental detectors, which measure the periodic variation in distance as gravitational waves pass through the detector.
Equality of inertial and gravitational mass: gravitational mass, defined as the ability of an object to exert a gravitational force, and inertial mass, defined as the ability of an object to resist changes in its velocity, are predicted by general relativity to be identical. For decades, increasingly sophisticated tests have still failed to find any difference between inertial and gravitational mass, thereby yielding strong support for Einstein’s principle of equivalence.
Because of these evidences, I’m honestly inclined to agree with the idea that B-Theory is not only a viable theory but probably corresponds sufficiently with reality for me to believe it’s true. So, what does that mean? What does it mean to say that Time is not “real”? How can anything “begin to exist” if Time is not “real”?
Before I answer those questions, I’m going to spend some time talking about the problems I have with B-Theory. Just because I think that B-Theory is probably true doesn’t mean that there aren’t things we need to discuss. And we’ll be talking about those in Part 3.
NOTES:
I will not be attempting to give a full explanation of the Theory of Relativity here. I encourage readers to look into themselves when they have the chance.
The greater that Spacetime is curved, the slower Time progresses.
SOURCES:
McTaggart, J. Ellis, The Unreality of Time, MIND: A Quarterly Review of Psychology and Philosophy. October 1908
Fodor, James. Unreasonable Faith: How William Lane Craig Overstates the Case for Christianity (p. 45, 46-47). Hypatia Press. Kindle Edition.