“Whenever I bring up the fine tuning argument and the constants of the universe in a conversation with my husband, he asks if the constants could have been different. I never fully understood what he really wanted to know. But I googled a bit to try and figure out what he really wants to know, and it seems as if it has something to do with “top-down cosmology”. According to Stephen Hawking: ” it is inevitable that we find our Universe’s “fine-tuned” physical constants, as the current Universe “selects” only those past histories that led to the present conditions”. He seems to be saying that the constants aren’t fine tuned because it could not have been different. Therefore, no fine tuning argument. I don’t know how to answer him to this. I hope this makes sense :)” – Jana B.
Thanks for the great question! I should say, I’m so glad to see you’re engaging your husband with substantive dialogue on God’s existence. We’ll keep praying for you and him! Jana, I think your question could be boiled down to this: In light of Stephen Hawking’s “top down cosmology”, are the physical constants the way they are necessarily, and thus not fine-tuned after all? The short answer is no, and I’ll explain.
In the book The Grand Design (which is currently holding up an uneven coffee table leg in my living room) Hawking argues against the typical way of trying to understand the universe. That is the “usual assumption in cosmology is that the universe has a single definite history.” This is what Hawking and co-author Leonard Mlodinow describe as the “bottom-up” approach to cosmology. The “bottom-up” approach trades on our everyday experience of cause and effect: A causes B causes C and so on. For example, both sets of your grandparents fall in love and give birth to your parents who fall in love and give birth to you. But what Hawking and Mlodinow are suggesting flips causality and ends up with the absurd claim, “We create history by our observation, rather than history creating us.” This isn’t just the anthropic principle, this is some kind of silly, anthropic divinity principle.
Much of this trades on a novel interpretation of quantum mechanics that says a subatomic particle takes all possible paths as it travels from one point to another. But this theory of simultaneous particle paths (posited by Richard Feynman) doesn’t suggest that the particle is actually everywhere at once. It’s just a way of making the math work at the quantum level. So, when Hawking and Mlodinow try to suggest that history is like the subatomic particle, they’re taking a leap that could clear the Sears Tower.
All of this is really to show that Hawking’s “top down cosmology” is an assertion that is lacking serious evidence to support it. Not only that but you have to deny your everyday experience of causality in order to affirm it! So, when Hawking argues that the constants are inevitable because the universe selects past histories that lead to the present, he shouldn’t be taken seriously. By the way, this is the same Hawking that once marveled at the precise fine-tuning of the universe in A Brief History of Time.
If I were in a conversation with your husband I’d ask him, “If you agree with Hawking’s “top down” approach then you must deny causality. Are you ready to do that?” And then let him wrestle with that.
Once we realize that Hawking’s theory is absurd and return to the so-called “bottom up” approach, we see that the constants certainly could have been different and, thus, not life permitting. For example, if the force of gravity had been slightly stronger in the universe’s initial conditions, there would have been a Big Crunch following the Big Bang and life would never have formed. Or if the force of gravity had been slightly weaker, then the atoms in the universe would never have come together to form stars and galaxies. No stars, no sun, no life on Earth. The fact that the constants are not necessary have been so widely acknowledged by folks like John Barrow, Frank Tipler, Paul Davies, Michael Turner, even Carl Sagan, I would argue that it’s controversial to claim that they are necessary.
 Stephen Hawking and Leonard Mlodinow, The Grand Design (New York: Bantam Books, 2010), 139.