For humans to exist as we do on planet earth requires “in multiple ways that the structure of the universe be precisely set” — so says Robin Collins in his essay “The Fine Tuning Evidence is Convincing” in Debating Christian Theism (eds. J.P. Moreland, C. Meister, K.A. Sweis). Sometimes this is called the “teleological” argument for God while the entire discussion is also called the “anthropic [human] principle” at work in the universe as we know it.
This discussion quickly gets beyond my expertise so I want to call to our attention just a few observations:
1. Consider, Collins says, “the requirements of constructing atoms, the building blocks of life.” We would need to think of the law of energy and momentum conservation as well as the second law of thermodynamics and then we’d need three particles with masses corresponding to that of the electron, proton, and neutron. For all this to work into life for humans, we’d need also the conservation of electric charge and the conservation of the baryon number, and we’d need the electric force and the strong nuclear force.
2. “… the building blocks for highly complex, self-replicating structures require the right set of laws and principles.” And this one has always been a stunner for me, I don’t know about you: “If, for instance, one of the above laws/principles were removed (while keeping the others in place), ECAs [embodied conscious agents] would be impossible” (37). What has always impressed me, then, is how many laws and principles and factors — in minute details — have to be in place for humans to exist on this planet — and for the planet to survive in fact.
4. One alternative is called the “multiverse hypothesis” — namely, that there are millions or more (perhaps) universes and it just so happens that this is the one where the right constants arose to support humans (ECAs).
5. “the cases of fine-tuning are multiple and diverse, so even if one cannot be certain of any given case, together they provide a compelling case for an extraordinarily fine-tuned universe” (44).