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In an Infinity of Universes, Countless Ones Are Run by Cats…

Daniel Díaz notes that most of the talk about the multiverse started to appear once it was realized that there was fine-tuning in nature

Walter Bradley Center director Robert J. Marks has been doing a series of podcasts with Swedish mathematician Ola Hössjer, and Colombian biostatistician Daniel Díaz in connection with a recent co-authored paper on the fine-tuning of the universe for life in the Journal of Cosmology and Astroparticle Physics. In the first portion of this episode, podcast 153, “Why is there fine-tuning everywhere?” they look at whether life was seeded in our universe by advanced life forms (directed panspermia), as advocated by some prominent scientists. In the second portion, they discuss the view — again, held by prominent science figures — that our universe is an advanced computer sim. In the third segment, they tackle the idea that there is nothing to know from a science perspective — we’re here because we’re here (the Weak Anthropic Principle). We are merely biased in thinking any reason is required.

But now they discuss the most daring hypothesis — which is, surprisingly perhaps, one of the most common: There is an infinity of universes out there. Perhaps most are lifeless but ours just happens to work: Here’s Marks, Hössjer, and Díaz’s take on it.

This portion begins at 18:53 min. A partial transcript, Show Notes, and Additional Resources follow.

Robert J. Marks: Okay. Well, Daniel, I’m hoping you will comment on the multiverse. That’s another explanation for why we are experiencing fine-tuning.

Daniel Díaz: The multiverse is this idea that there is not only one single universe, but that there are multiple universes. The theory, again, is highly controversial, because nobody can measure what is happening outside our universe.

Robert J. Marks: That’s a good question. I don’t think, and correct me if I’m wrong, that there’s any evidence at all for the existence of a multiverse.

Daniel Díaz

Daniel Díaz: No, it is only some theoretical developments that are based on the assumption. It’s basically assuming that there must be other universes, so we have a multiverse that produces that outcome [occasionally fine tuned universes]. It is not a conclusion of physics.

Most of the talk about multiverses started to appear once it was realized that there was fine-tuning in nature. Of course, as a metaphysical possibility… Well, it is a possibility. But it is highly biased by the assumptions that people are making with respect to the cause of the fine-tuning that we are observing.

We cannot know that there are universes beyond ours. We cannot even look at our whole universe. We can only see our universe to the point where light hasn’t traveled yet. That is what is called in physics, the observable universe.

There is theoretically a portion of our universe that we cannot observe. My point is that we cannot even look at our whole universe, let alone looking outside the universe. There’s no way to do that. We could even know how to measure that thing.

Note: Prominent proponents of the multiverse have included well-known cosmologists such as Max Tegmark and Alexander Vilenkin, Brian Greene and Neil Turok, Alan Guth and Stephen Hawking, as discussed in online science magazines. Opponents include theoretical physicist Sabine Hossenfelder( “Why the multiverse is religion, not science”) and cosmologist George Ellis(“beyond the domain of science”) In the absence of evidence, the issue appears to be a philosophical one.

Robert J. Marks: I have to brag about one of my publications, one of my pieces of analysis about the multiverse. Some people say that in some parallel universe, this podcast would end right now. And in another universe, it would say that Daniel was in Miami as opposed to Columbia.

They use the multiverse to say that anything can happen. Now, there’s different versions of the multiverse. One is from quantum theory, which says every time there’s a quantum collapse, that the universe is split. There are other theories where these multiverses literally exist. And I visualize them as being side by side.

Ola Hössjer

One of the most common one has about 101000 universes in the multiverse. And that sounds like a lot. It does sound like there might be some place that this podcast ends right now. And there might be one where it doesn’t end right now. But if you look at the simple math behind it, it can’t happen.

Following on that, there’s a universe where I am bald. I still am not totally bald. It’s getting thin up there, but I’m not totally bald. How many universes would it require for me to be bald in one and not bald in the other? It would take two universes, right? Now, we talk about Ola. No offense, Ola, but in some universe you might be bald too.

Ola Hössjer: Yes, certainly.

Robert J. Marks: And so, what happens? How many universes do we need for that? We need four. Right?

Ola Hössjer: Yes.

Robert J. Marks: We need bald, bald. Bald, not bald. Not bald, bald. And then, the fourth one. We have four. Now, let’s put Daniel, who has a rich crop of beautiful hair. But in some universe, Daniel, you’re bald. How many universes would we need then?

Robert J. Marks

Daniel Díaz: Eight.

Robert J. Marks: We would need eight. Every time we add a different contingency, we double the number of universes that are required.

Daniel Díaz: At least.

Robert J. Marks: At least. Yes. We’re only using binary counter distinctions here also. We could have one where you’re bald, not bald, and then maybe partially bald. We could do three or four or five. We would multiply it, instead of by two, we would multiply it by five. But let’s just stick with two. You take each added counter distinction, and it doubles the number of universes.

You can work backwards by taking… If you’re a nerd, you take the log base two of the number of universes to get the number of counterdistinctions. Anyway, if you go up to 101000, which is a common model … how many counter distinctions can you have? Well, if you take the log base two of that, you find out less than 4,000. There can only be 4,000 different things in these universes. Even though 101000 sounds like a heck of a lot, there’s not a lot of things you can do with only 101000, parallel universes.

And then, there’s people that say, “Well, maybe we have an infinite number of universes?” That is pure speculative metaphysics. There’s nothing in our universe that is infinite. Everything is finite. Everything.

Daniel Díaz: Your point is that, as we are adding contingencies, the number of multiverses is exponentially increasing?

Robert J. Marks: Exactly. It increases exponentially, and 101000 isn’t enough to do anything. And I think multiverse, in terms of probability, has been added for those that don’t want to look to a creator as saying, “Well, if we have a multiverse. Then, anything could happen.”

And careful analysis says that isn’t true.

Note: Dr. Marks’s paper is “Diversity Inadequacies of Parallel Universes: When the Multiverse Becomes Insufficient to Account for Conflicting Contradistinctions,” PSCF, Volume 71, Number 3, September 2019: “Abstract: The diversity of conflicting contradistinctions available from parallel universes is commonly exaggerated. The number of required universes is shown to increase exponentially with respect to the number of desired contradistinctions. For the commonly cited upper bound of 101000 universes in the multiverse, only 3,322 binary contradistinctions are possible. What about a countably infinite number of universes? Any finite number of contradistinctions are possible in such a multiverse. If, though, there are a countably infinite number of contradistinctions, all possible cases are not realizable in a multiverse with a countably infinite number of universes.”

Next: If extraterrestrials didn’t fine tune Earth, maybe there is a God. Traditional philosophers, not committed strongly to a religion, have thought so. Let’s follow the reasoning.

Here are all of the instalments, in order, of the discussion between Robert J. Marks, Ola Hössjer, and Daniel Díaz on the fine tuning of the universe for life:

The first episode:

Ours is a finely tuned — and No Free Lunch — universe. Mathematician Ola Hössjer and biostatistician Daniel Díaz explain to Walter Bradley Center director Robert J. Marks why nature works so seamlessly. A “life-permitting interval” makes it all possible — but is that really an accident?


Fine-tuning? How Bayesian statistics could help break a deadlock: Bayesian statistics are used, for example, in spam filter technology, identifying probable spam by examining vast masses of previous messages. The frequentist approach assesses the probability of future events but the Bayesian approach assesses the probability of events that have already occurred.

The second episode:

Life is so wonderfully finely tuned that it’s frightening. A mathematician who uses statistical methods to model the fine tuning of molecular machines and systems in cells reflects… Every single cell is like a city that cannot function without a complex network of services that must all work together to maintain life.

Can there be a general theory for fine-tuning? If you make a bowl of alphabet soup and the letters arrange themselves and say, good morning, that is specified. What are the probabilities? Ola Hössjer sees the beauty of mathematics in the fact that seemingly unrelated features in cosmology and biology can be modeled using similar concepts.

The third episode

Was the universe created for life forms to live in? How would we know? We can begin by looking at the fundamental constants that underlie the universe. The constants of the universe — gravitational constant, entropy, and cosmological constant — must be finely tuned for life to exist.

Why did Stephen Hawking give up on a Theory of Everything? Daniel Díaz and Ola Hössjer continue their discussion of the fine tuning of the universal constants of nature with Robert J. Marks. The probability, they calculate, that the fine tuning of our universe is simply random is down to 10 to the minus sixty — a very small number.

The fourth and final episode

Is life from outer space a viable science hypothesis? Currently, panspermia has been rated as “plausible but not convincing.” Marks, Hössjer, and Diaz discuss the issues. Famous atheist scientists have favored panspermia because there is no plausible purely natural explanation for life on Earth that would make it unnecessary.

Could advanced aliens have fine-tuned Earth for life? That’s a surprisingly popular thesis, considering how hard it is to account for life without assuming a creator. As Robert Marks, Ola Hössjer, and Daniel Díaz discuss, some prominent atheists/agnostics have chosen to substitute advanced extraterrestrials for God.

Our universe survived a firing squad and it’s just an accident? According to the Weak Anthropic Principle, if things weren’t the way they are, we wouldn’t be here and that’s all there is to it. Given the odds, a philosopher likens the Weak Anthropic Principle to surviving a firing squad and concluding, incuriously, well… that’s just the way things are.

In an infinity of universes, countless ones are run by cats… Daniel Díaz notes that most of the talk about the multiverse started to appear once it was realized that there was fine-tuning in nature. Robert J. Marks points out that even 10 to the 1000th power of universes would only permit 3,322 different paths. Infinity is required but unprovable.


If extraterrestrials didn’t fine tune Earth, maybe there is a God. In the face of a grab bag of ideas like creation by ETs or countless universes (some run by cats), why does the idea of a Creator seem far out? Traditional philosophers, not committed to a religion, have thought that deism (and theism) are rational, science-based conclusions, based on fine tuning.

You may also wish to read:

Weak Anthropic Principle? Not an explanation but a tautology!
Compared to the Strong Anthropic Principle — the universe is objectively fine-tuned for life — the Weak Anthropic Principle aims to avoid evidence and subvert discussion. “If the universe were not fine-tuned, we wouldn’t be here to know it” is a tautology because the subject and the predicate mean the same thing.


No Free Lunches: Robert J. Marks: What the Big Bang teaches us about nothing. Bernoulli is right and Keynes is Wrong. Critics of Bernoulli don’t appreciate the definition of “knowing nothing.” The concept of “knowing nothing” can be tricky.

Show Notes

  • 00:33 | Introducing Dr. Daniel Díaz and Dr. Ola Hössjer
  • 01:53 | Panspermia
  • 04:59 | The Sims Theory
  • 10:40 | Anthropic Principle
  • 18:53 | Multiverse
  • 26:03 | The Creator Interpretation
  • 29:11 | Personal Beliefs
  • 36:24 | Final Words

Additional Resources

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In an Infinity of Universes, Countless Ones Are Run by Cats…