I was doing some research on the multiverse theory to prepare myself for an episode of the Knight and Rose Show podcast. I thought it might be a good idea to put the list of objections to the multiverse theory into a blog post, explain them all as simply as I could, and then link to an expert for the details on one more that you can take with you on your apologetics adventures.

So, the first thing is to explain what caused the development of the multiverse theory: the fine-tuning argument. The fine-tuning argument has to do with the constants, quantities and ratios that are simply “given” as parameters to the universe, at the beginning of the universe. The parameters are fine-tuned to allow complex, embodied life to exist. Change the parameters slightly, and you have no life. It’s an argument for design. And the multiverse is supposed to counter it.

Let’s link to something by Dr. Stephen C. Meyer, for a quick version of what that argument is all about:

Beginning in the 1960s, physicists unveiled a universe apparently fine-tuned for the possibility of human life. They discovered that the existence of life in the universe depends upon a highly improbable but precise balance of physical factors.⁴ The constants of physics, the initial conditions of the universe, and many other of its features appear delicately balanced to allow for the possibility of life. Even very slight alterations in the values of many factors, such as the expansion rate of the universe, the strength of gravitational or electromagnetic attraction, or the value of Planck’s constant, would render life impossible. Physicists now refer to these factors as “anthropic coincidences” (because they make life possible for man) and to the fortunate convergence of all these coincidences as the “fine tuning of the universe”. Given the improbability of the precise ensemble of values represented by these constants, and their specificity relative to the requirements of a life-sustaining universe, many physicists have noted that the fine tuning strongly suggests design by a preexistent intelligence. As well-known British physicist Paul Davies has put it, “the impression of design is overwhelming.”⁵

To see why, consider the following illustration. Imagine that you are a cosmic explorer who has just stumbled into the control room of the whole universe. There you discover an elaborate “universe-creating machine”, with rows and rows of dials, each with many possible settings. As you investigate, you learn that each dial represents some particular parameter that has to be calibrated with a precise value in order to create a universe in which life can exist. One dial represents the possible settings for the strong nuclear force, one for the gravitational constant, one for Planck’s constant, one for the ratio of the neutron mass to the proton mass, one for the strength of electromagnetic attraction, and so on. As you, the cosmic explorer, examine the dials, you find that they could easily have been tuned to different settings. Moreover, you determine by careful calculation that if any of the dial settings were even slightly altered, life would cease to exist. Yet for some reason each dial is set at just the exact value necessary to keep the universe running. What do you infer about the origin of these finely tuned dial settings?

And in a previous post, I wrote about the three examples of fine-tuning that I personally have ready to go in a discussion, the ones that are the simplest for me.

Anyway, atheists were not very happy about what the progress of science had revealed, so decided to invent a new theory to get them out of the evidence. And that theory is the multiverse theory. The multiverse theory simply states that we shouldn’t be surprised to find evidence for design in our universe, because there are billions and billions of other universes where there is no design, and so, we just got lucky.

So, here is my quick list of objections (and brief explanations) to this multiverse theory:

1. Boltzmann Brains: In an infinite multiverse, random chaos should create lone brains with fake memories way more often than real people with bodies like us. So why do we see a universe with embodied intelligences?
2. Inverse Gambler Fallacy: The multiverse says, “Our universe is rare, so there must be tons of others.” But seeing one rare thing doesn’t prove that billions of hidden common things exist.
3. Universe generating factory still needs fine-tuning: Even if a “multiverse factory” spits out universes with different random quantities and constants, it still needs super-precise settings to make any life-friendly ones. The problem just moves up a level.
4. No direct evidence for multiverse: We can’t see, touch, or detect other universes. So far, it’s a story, not science.
5. Infinite universes means anything can happen, making science impossible: If there is an infinite number of actual universes, then anything can happen, and we can’t do science any more.
6. Multiverse can’t explain independent local fine-tuning: The multiverse might explain one dial being right, but not why we find fine-tuning for habitability (and fine-tuning that is correlated with discoverability) at lower levels.
7. The measure problem: Even if universes exist, physicists can’t agree on how to measure probability. Without that, the multiverse can’t explain anything.

So, people really find #4 to be the easiest to remember. By definition, we can’t ever get out of our universe to be able to observe these other universes that supposedly exist. So definitely remember that one. And then #3, because Stephen C. Meyer makes a big deal out of the universe generator needing fine-tuning itself, in his book “The Return of the God Hypothesis”. You can read an essay that mentions it here, written by Robin Collins. And #6 is good too, here is an article by Guillermo Gonzalez about the local fine-tuning (habitability – discoverability link).

But here are some details on #1 in this article from Science and Culture by physicist Dr. Brian C. Miller. Basically, the multiverse theory makes a prediction about what we should see if it were true, but sadly for the design-deniers, our experience contradicts the prediction.

Boltzmann Brains

Standard multiverse models, such as those based on eternal inflation and string theory, predict that the odds are far smaller for a brain emerging from a gradual process in an ancient universe than for a brain emerging from atoms suddenly coalescing in a young universe. In other words, we are far less likely to possess a brain with memories of a real life history than possess what is termed a Boltzmann brain that emerged from quantum fluctuations in the recent past with fictitious memories.

Since no one desires to believe in such freaky observers as Boltzmann brains, physicists have grappled with our being such seemingly improbable normal observers. In addition, our universe is highly atypical in its old age and its high level of order. Mathematical physicist Roger Penrose calculated that the odds of a universe appearing as orderly as ours to be 1 chance in 10 to the power of 10 to the power of 123 — a number that includes more zeros than the number of atoms in the visible universe.

So, I hope that’s enough to equip you to discuss this theory. Now you have everything you need. Three easy examples of fine-tuning, and four easy refutations of the the counter to the fine-tuning. This is a solid argument, so have fun with it.