On Fine-Tuning, Responding to an Atheist YouTuber
James Fodor is a neuroscience grad student at the University of Melbourne in Australia who identifies himself as an atheist. In a recently published YouTube video, Fodor confidently presents what he thinks are a number of problems with the fine-tuning argument. After taking the time to carefully go through his 40-minute video, I believe that he has overestimated the significance of his arguments in presenting a case against theism.
Fodor begins by outlining the fine-tuning argument and then expresses his objection to a “fixation on constants” (such as the strengths of the fundamental forces, the masses of elementary particles, etc.). He declares that the constants have no meaning outside of a set of physical laws (I believe he means equations), and that we have “no idea of what the universe would be like if the laws were different.” In support of his contention that different universes could or would have different physical laws (not just physical constants), he pulls a quote from a paper by Luke Barnes, titled “The Fine-Tuning of the Universe for Intelligent Life.” Ironically, the main focus of Barnes’ paper is supporting the theistic fine-tuning argument, using physics and cosmology, as he refutes a dubious critique of fine-tuning by the late atheistic physicist Victor Stenger.
Barnes addresses the issue of whether the fine-tuning argument would be undermined by allowing different universes to have different equations for the laws of nature, but he reaches an entirely contradictory conclusion to Fodor’s.
The intuition here is that, if ours were the only universe, and if the causes that established the physics of our universe were indifferent to whether it would evolve life, then the chances of hitting upon a life-permitting universe are very small.
BARNES, P. 3
Barnes argues that allowing alternate universes to possess laws of physics contrary to our own does nothing to alleviate the curious condition that laws and constants of nature in our universe are fine-tuned to allow life. One of the fundamental truths of physics is that any attempt to describe our universe from a purely theoretical perspective is insufficient. We have to “open the window,” so to speak, and take a look at our world in order to actually know what it’s like. This means that the universe could have been different than it is. The way it is, compared to the ways it could have been, shows knife-edged fine tuning for life.
A Tautological Argument
Such fine-tuning for life cannot be dismissed with a tautological argument saying, “Of course our universe has parameters that allow intelligent life. If it didn’t, we wouldn’t be here.” I suppose a limited amount of brilliance shines through those who contend against fine-tuning with this argument, but the fine-tuning argument far out-shines this dull retort. As I state in my book, Canceled Science,
Yes, the values of the laws and constants of nature must be in a range that allows us to exist if we’re going to be around to notice our good fortune, but the surprising thing is how narrow this range of possible values turns out to be….Our being here to discover fine tuning doesn’t require that those parameters be balanced on a knife edge. Since they are, we have an additional reason to suspect, as the distinguished astronomer Fred Hoyle has famously said, that a “super-intellect has monkeyed with physics.”
CANCELED SCIENCE, P. 64
Consider Velocity
Are the equations expressing the laws of nature determined by nature or are they in fact more fundamental relations between physical concepts, such as space, time, mass, force, energy, and fields? For example, let’s look at the basic physics relation expressed as “distance equals velocity multiplied by time,” which follows from a definition of velocity as displacement per time. Is it even meaningful to postulate a hypothetical universe in which this definition doesn’t hold?
Or, take the example of Newton’s universal law of gravity, where the force between two masses, m1 and m2, separated by a distance r, is given by F=Gm1m2/r2. This relation could be found by making careful measurements, but its form could also be derived based on the geometry of three-dimensional space and symmetry considerations. However, what cannot be mathematically derived from any fundamental theory of physics is the value of the gravitational constant, G; it must be measured. The same argument for the form of the equation can be made for the fundamental force between charged particles, with the same need to observe our universe to obtain the value of the embedded constant.
Changing the exponent of the particle separation parameter, r, in the denominator of either equation implies a universe with a different number of spatial dimensions (say, two or four dimensions, instead of three). Contrary to Fodor’s statements, we know what this would imply — no life. With fewer than three dimensions, complex biochemistry cannot exist. With more than three dimensions, stable orbits, either for planets or for electrons orbiting nuclei, would not be possible
Imagining Universes
To further answer Fodor’s suggestion that fine-tuning is defeated because we can imagine universes with different laws of physics, a quote from Barnes is informative. Here he rebuts Stenger’s attempt to nullify the fine-tuning argument with a similar argument.
In reply, fine-tuning isn’t about what the parameters and laws are in a particular universe. Given some other set of laws, we ask: if a universe were chosen at random from the set of universes with those laws, what is the probability that it would support intelligent life? If that probability is suitably (and robustly) small, then we conclude that that region of possible-physics-space contributes negligibly to the total life-permitting subset. It is easy to find examples of such claims.
A universe governed by Maxwell’s Laws “all the way down” (i.e. with no quantum regime at small scales) will not have stable atoms — electrons radiate their kinetic energy and spiral rapidly into the nucleus — and hence no chemistry (Barrow & Tipler, 1986, pg. 303). We don’t need to know what the parameters are to know that life in such a universe is plausibly impossible.
If electrons were bosons, rather than fermions, then they would not obey the Pauli exclusion principle. There would be no chemistry.
If gravity were repulsive rather than attractive, then matter wouldn’t clump into complex structures.
If the strong force were a long rather than short-range force, then there would be no atoms. Any structures that formed would be uniform, spherical, undifferentiated lumps, of arbitrary size and incapable of complexity.
BARNES, P. 18
After giving a few other examples of how variations of the laws of physics would render life impossible, Barnes acknowledges that extrapolating from our present knowledge of physics to other realms with widely varying laws would stretch our understanding beyond the point of certainty.
We should be cautious, however. Whatever the problems of defining the possible range of a given parameter, we are in a significantly more nebulous realm when we try to consider the set of all possible physical laws.
BARNES, P. 19
In my opinion, our lack of God-like knowledge of the physics of all possible universes is an entirely irrelevant objection to the verity of the fine-tuning of the laws and constants of physics for this universe to support life. Barnes agrees:
The point is this: however many ways there are of producing a life-permitting universe, there are vastly many more ways of making a life-prohibiting one…. Amidst the possible universes, life-permitting ones are exceedingly rare. This is fine-tuning par excellence.
BARNES PP. 38-39
