Where is the replicator? Evolution doesn’t happen just because. Copies are made, not all identical, some get to the next iteration, and if what makes them different gives them better chances to get to the next stage, then that difference may remain.

Where that plays with universes?

I get that if they are infinite amounts of universes, the ones with conditions of evolving intelligence hace more chances to be observed from within, but more or less that’s it.

The universe is the replicator. This comes directly from John Wheeler's old idea, which he came up with back in the 1970s to solve the two mysteries in our universe that involve singularities: black holes, and the Big Bang. I've written about this a lot, so I'm happy to go into more detail:

As an elegant way to solve the two problems, Wheeler proposed that mass/energy in a parent universe collapsed to form a black hole (thus leaving the bubble of space-time that was the parent universe). It then “bounced” at the singularity, and expanded in a Big Bang, to form a new universe – budding off a new bubble of space-time, outside of, and separate from, its parent universe.

That is, parent universes reproduced through black holes, which “bounced” to form Big Bangs. Each Big Bang was therefore the birth of a new child universe, which grew up to produce more black holes; more child universes.

In the 1990s, another brilliant American theoretical physicist, Lee Smolin, saw a marvellous implication of Wheeler’s idea that had been completely missed by everybody (because theoretical physicists don’t usually read much evolutionary biology; Smolin had been reading some, for fun). Smolin realised that if there was slight variation in the basic parameters of matter in the child universe (rather than the large and random variation assumed by Wheeler), you would automatically get Darwinian evolution of universes. That’s because slight variation allows for inheritance; and some of those slight variations would lead to more black hole production; more reproductive success; more offspring. Those successful variations would therefore be inherited more widely than less successful variations. The successful variations would vary again (slightly) in the next generation, with some variants being even more reproductively successful (and some less); and off we go – Darwinian evolution of universes, with the evolutionary ratchet optimizing for reproductive success. Over time, the majority of universes will come to be fine-tuned for very high levels of black hole production (compared to the evolutionary starting point, where the numbers could be as low as one or two). This seems plausible: our universe has already produced over forty quintillion black holes, just from stellar collapse. (That’s 4×10¹⁹; a four and 19 zeros! For how they worked that out, see Sicilia, Lapi, et al, 2022.) Smolin’s simple and straightforward evolutionary theory of universes became known as Cosmological Natural Selection (CNS), laid out in his paper Did the Universe Evolve?, and his book The Life of the Cosmos.

So, Smolin had uncovered a powerful evolutionary implication, hidden inside Wheeler’s simple model of the reproduction of universes.

Again, I've written about the reproduction of universes at length here...

The key implication of cosmological natural selection: https://theeggandtherock.com/p/the-key-implication-of-cosmol...

And here...

A history of cosmological natural selection: https://theeggandtherock.com/i/158515951/background-lee-smol...

And if you prefer Youtube, I've talked about it here on the Infinite Loops podcast: https://www.youtube.com/watch?v=rZ5inYnDWWA&t=2341s (the link skips the biographical stuff and goes straight to the theory)

And if you prefer Substack, I've talked about it on The Weekly Anthropocene: https://sammatey.substack.com/p/interview-julian-gough-on-co...

Explore! Enjoy!

So you more or less have a copy mechanism, assuming that that information is carried somehow passing through the black hole process, with some structure to be replayed just because, and, what is the selection process? How many universes you spawn from a single one? How make ones more fit? It is nice to speculate, but it should go through the falsability test.

It's an interesting idea, but I feel like this is taking a lot of speculative (not observable) ideas for granted. What is a "variation in the basic parameters of matter"? Has anyone observed such a thing taking place? Also where would the universe birthing take place? I'm assuming you want me to believe the expansion of a brand new universe isn't occuring within the space of our own? I don't know how we would study new bubbles of space time, whatever those are.

>... proposed that mass/energy in a parent universe collapsed to form a black hole (thus leaving the bubble of space-time that was the parent universe). It then “bounced” at the singularity, and expanded in a Big Bang, to form a new universe...

So any universe expanding within a black hole of ours has to exist with only the mass that fell into it? How would it produce black holes itself with so little mass?

Yes, this is a very common, and understandable, question; I get asked it a lot. But in fact new (child) universes aren't constrained in size by the initial energy/mass entering the parent black hole. Actually, that's one of the most attractive aspects of the theory. Universes have a huge reproductive advantage over, say, animals.

We know that in our own universe, the (positive) mass energy of matter and its (negative) gravitational energy net out to zero. But that means the amount of energy required to build a universe like ours is essentially… well, none. (See Laurence Krauss’s book, A Universe from Nothing; or Stephen Hawking and James Hartle’s 1983 paper, The Wave Function of the Universe, and Hawking’s later book with Leonard Mlodinow, The Grand Design, etc.)

Child universes are therefore effectively free to produce. Thus, over time, evolution will favor making more (and smaller) black holes from the same amount of matter. Yes, the black holes will get smaller – but the universes they give birth to, through Big Bangs, will still be full sized.

And universes aren’t constrained by a shared environment with limited resources – newborn universes aren’t all competing in a valley with a limited amount of grass. Indeed, each new universe is entirely self-contained and self-sufficient, being both organism and environment – it supplies its own energy for its own development, efficiently and frugally, through stellar fusion, gravitational collapse, et cetera.

This means evolution should ultimately favour runaway black hole production. (And that checks out: in the most recent estimate, in 2022, by a team from the International School of Advanced Studies in Trieste, our universe was estimated to have already generated up to a trillion supermassive black holes – and 40 quintillion stellar-collapse black holes.)

Not convinced you've got evolution there. You've got adaptive radiation, but where's the natural selection?

The low-black-hole universes aren't going to stop "procreating" because high-black-hole universes exist. At most, all you can say is that if you select a universe at random, it's likely to be a high-black-hole universe.

And I think you can use that fact to argue the theory's wrong: because surely our own universe is an LBH universe? A trillion is rookie numbers. There must be universes that produce vastly more black holes than ours, so the chances of us ending up in such an LBH universe at random are vanishingly small.

> And universes aren’t constrained by a shared environment with limited resources – newborn universes aren’t all competing in a valley with a limited amount of grass.

Yeah, that's what I'm trying to say. Without competition, it's not evolution.

But since the mass that entered the black hole continues to produce gravitational pull in our universe, the child universe must still be anchored within ours, at least gravitationally, and we should feel the pull from all the additional mass the new universe generates?

So where did the original universe come from?

I think this cuts through that Gordian knot. "Nothingness" is just an idea in our heads: we have never encountered "nothing". There's no such thing, it's an idea. There is always something; there was always something. And sure enough, in this model, there was always something, some original universe. (Back when it was actually "uni"!) Some unbelievably primitive always-existent universe, made of the original ur-matter, long before the modern periodic table evolved, long before even electrons, protons, and neutrons. All you need is that always-existent universe, time, and change.

How primitive can it be and still reproduce? Because to kick-start an evolutionary process, the only thing that it needs to do is reproduce.

How does a universe reproduce, in this model? VERY VERY SIMPLY. Mass-energy collapses to a point, bounces to form a new universe. All it has to do is collapse. So you have some primitive matter that collapses. It doesn’t have to collapse millions of times and produce millions of offspring (like our universe). Not yet. It just has to do it once. Flip/flop, a collapse and an expansion. A black hole/big bang cycle. And then eventually (and it has infinite time in which for this to happen!), it has to do it twice.

It produces two new universes. There’s two direct collapses that bounce to form new big bangs, new universes, right? And there’s no structure. There’s no complexity. But that’s a direct collapse, forming supermassive black holes. (Which is how, I argue, the supermassive black holes we find today in our universe must still form; evolution conserves successful reproductive strategies, she isn't going to invent a far more complicated way to do it, when a simple way is already available.)

That has to be how the earliest universes reproduced, without complex structures. All they have to do is just be a cloud of totally unstructured ultra-primitive matter, just collapsing. A directly collapsing cloud. No fancy nuclear fusion or stellar masses. And all that more complex stuff – stars, stellar collapse black holes, life, technology, technologically manufactured small black holes – comes later. They are later evolutionary breakthroughs. But they build on that earlier foundation, of direct collapse supermassive black holes.

And people give Platonists a hard time …

>There is always something;...

I am sorry, but I can't help feel like this is a cop out. Much like "Its tortoises all the way down". Or "God created the universe and God always existed".

Making this original universe very simple does not help much, and it is just kicking the can down the road a bit. The fundamental questions still remains.

Why does there need to be an original?

What is there to "reproduce" if there is no "original" version to get the ball rolling?

We know how living things reproduce, but we still ask how life originated. Same thing.

Indeed! You're right, there doesn't. See my reply above.

(Whoops, I was replying to "Why does there need to be an original?"; not sure why the reply ended up elsewhere.)

Which one?

> Some futurist philosophers had extended the idea to explain the emergence of complex life from hot gas and stars. Humans exploit increasingly powerful energy sources, a progression they argued could culminate in artificial black holes. If those black holes spawned new universes, then a cosmos capable of producing technologically advanced life might produce more offspring. The progression from hot gas to stars, life and technology could, they proposed, be a product of cosmic natural selection.

So the meaning of life is to make as many black holes as possible?

In a crude way, you could say so. Certainly, looked at through a purely evolutionary lens, the meaning of life for universes is (in one respect) to make as many black holes as possible. That maximises reproductive success for the unit of selection that is the universe. But of course, once consciousness enters the picture, things get more complicated. If conscious beings are generating most of the black holes in a universe for energy production (that are, as a side effect, generating child universes elsewhere, outside that parent universe), then the intelligent lifeforms making those black holes are going to feel some moral obligation to the child universes they're generating at the other side of those black holes. And if they have any control over the basic parameters of matter in the child universes, then perhaps they optimise for universes of a particular kind. They might not go for sheer numbers of offspring in the child universes. They might instead try to minimise unnecessary suffering in the child universe. They might not want the universes to generate life at all, because that's quite a moral weight to bear. Or they might want them to be maximally life producing, because life is intrinsically a good thing, from their point of view. It could go a number of ways. But it would certainly be true that a blind evolutionary search of the possibility space, in order to maximise black hole production, is no longer the case.

Last year's thread (mentioned in OP's text above):

The Blowtorch Theory: A new model for structure formation in the universe - https://news.ycombinator.com/item?id=44115973 - May 2025 (170 comments)

Thank you!

I think it was in the book Pale Blue Dot by Carl Sagan where I read that why the planets orbit in circular motion is because they are the planets that survived what must have been a chaotic early universe.

In the early universe, those planetary bodies must have been moving in different ways and colliding into one another, and the rate of collisions must have been very high.

Ultimately, the constant collisions led to eventual clearing off of bodies that did not move in circular motion, and that's what we see today. A natural selection of objects of the cosmos.

I might be misremembering Carl Sagan's description. But I'm almost certain I read this in Pale Blue Dot. I keep meaning to re-read that book.

A more physical way to think through this may be: imagine many many bits of rock all with their own semi random velocity. The overall system has an angular momentum that must be preserved. So as these bits of rock accrete you end up with orbits of large bodies that all must add up to the initial angular momentum of the system. Since every planet is a conglomeration of many bits it is extremely likely that all orbits are in the same rotational direction, though not guaranteed.

Sagan is terrific. And it's true that the planets and moons that survive have made it through a pretty brutal era of orbit-clearance. But the evolutionary cosmology model I and others have been exploring is at the level of universes, and is genuinely Darwinian; it gives an evolutionary explanation for why our universe has parameters of matter that allow for the generation of long-term stable planets, and the development of lifeforms on those planets, and the development of technologies by those lifeforms. I would love you to read the Smithsonian Magazine piece and come back to me; it's a beautiful explanation of why universes contain little blue dots at all! I think Sagan would have loved it. Maybe not been convinced by it (it's still a speculative theory, though it is currently having predictive successes), but he would certainly have thought it worth exploring.

I just finished reading the article. Thanks for sharing.

Yes, I'm familiar with the multiverse idea, and I think I was first introduced to it in The God Delusion by Richard Dawkins.

I think the idea is plausible because if we have multitudes of planets, and multitudes of stars and galaxies, it might be reasonable to expect multiple universes as well.

Another idea which I've read about, and I think still in the God Delusion (but it might have been a Carl Sagan book, I don't quite remember), is that perhaps there aren't multiple universes currently existing. That is, there is no multiverse, but the universe, following the Big Bang, expands up to a point and then eventually collapses in a Big Crunch, and then explodes again in yet another Big Bang with different variations in its laws of physics.

In some of these new iterations of the universe, life as we know it cannot emerge; but in certain configurations, just as we have in this current universe, life has the necessary physical constants and environment to emerge and eventually be able to contemplate the universe that gave rise to it.

The strong Anthropic Principle is an interesting concept, but it's unfortunate that we have insufficient or even no evidence for any of these postulations.

I don't know if you were already familiar with the idea of an infinite series of Big Bangs and Big Crunches instead of the existence of parallel universes (a.k.a. multiverse), but if you weren't, it's the reason you sometimes see the Big Bang defined as something as -

"the cosmic explosion that marked the beginning of the universe or its current iteration."

The "current iteration" stated in those definitions refer to the idea just expounded.

Thanks again for sharing, I love reading about the universe, even though I'm not a physicist.

Yes, I'm familiar with the idea of a Big Bang/Big Crunch cycle. It's intriguing. But, though it too gives you a sequence of universes, its automatic 1-to-1-to-1-to-1 sequential structure doesn't really give you an evolutionary mechanism. I think connecting collapsing mass/energy in a parent universe (a black hole) to expanding mass/energy in a child universe (a Big Bang) makes a lot of sense; even more than a Big Bang/Big Crunch. As the great physicist John Wheeler pointed out in the 1970s, it solves the two otherwise bewildering mysteries involving singularities in our universe! (Black holes, and the Big Bang.) And, because any small variation in the basic parameters of matter means the child universe will generate either more or less black holes (offspring), there is a Darwinian evolutionary ratchet; a reason why universes might get more complex over time, as the ratchet of evolution fine-tunes universes to produce more offspring by whatever means works. (Down three different black hole formation channels, in my model; each more complex than the last, and each emerging from the one before. Strong circumstantial evidence for an evolutionary history!)

> And, because any small variation in the basic parameters of matter

Does this mean variations in laws of physics, or just the configuration of matter? Is there any evidence that physics might vary between black holes? Is that necessary for cosmic evolution?

Where does the distinction lie between infinite parallel universes and infinite universes in a cycle? Does time pass through the cycle unbroken? Wouldn’t it also require a “superuniverse” with its own laws such that any universe it contains must be constructed so that a big crunch has to happen?

one random thought I have that is probably wrong is that at some point a black hole has to end. If a black hole is "stuff goes in but does not come out" then if that continued forever, at some point the whole universe would be in one super giant black hole. Since we are not in one super giant black hole, something has to happen to reverse that process. A black hole has to die somehow, just like stars die eventually.

A "big crunch" sounds awfully like all the matter in the universe ends up in one gigantic black hole. And maybe when all the matter in the universe is inside one black hole, then gravity gets weird because there is no "outside" matter to maintain the integrity of the black hole. So the black hole then can just "explode" in a "big bang" from the pressure inside. Just a random theory from a non physics person.

Hawking radiation and expansion.

Fun fact: this really only works in three dimensions.

In three, angular momentum in one axis is maintained. Everything else cancels out. More, and you get clouds.

Yes! Fascinating, that you can only get stable planetary systems in universes with three spatial dimensions. More, and it all goes to hell.

Read it recently and that sounds right.

It's strangely tautological to me but I only have my lifetime to consider, not the age of the solar system.

I think it's worth noting that the universe-selection theory outlined in this article is a lot more conservative than the full Blowtorch Theory about cosmic structure formation.

That's a fair point. I suspect that any journalist trying to write about this subject for a respectable mainstream publication (like the Smithsonian Magazine) has to negotiate pretty hard with his or her editor to get the piece to run at all. So a carefully edited secondary piece of journalism like this will tend to be a lot more conservative than the raw primary work it is based on (such as my posts). But that's fine, that's just how the ecosystem works. I'm free to push these ideas as hard as I can, and the mainstream can then sift through them, filter them, and run the ones that seem most solid. That's good, that's healthy! Some of my wilder ideas are very likely to be wrong! In fact, I was surprised to see so many mainstream scientists prepared to be quoted in this piece, even offering cautious support. It feels as though a paradigm shift might be starting to happen.

I can't find the reference, but there are many integer or near-integer relationships among the planets of our solar system. Such a preponderance that it seems improbable.

Yes, they slip into resonances. This is even more pronounced in the case of the moons of Jupiter and Saturn. The resonances give them stability. As I've written before, elsewhere; Ganymede, Europa, and Io, for example, are in 1:2:4 resonance with each other: that is, for every single orbit of Jupiter that Ganymede makes, Europa makes two, and Io makes four. That keeps all three orbits stable, longterm: if one were to drift slightly, the others would gravitationally nudge it back into resonance.

So what we are seeing here is a strong, simple, robust, self-stabilising system that should automatically build out large numbers of potentially habitable worlds in every solar system. Order automatically emerges from randomness, and is automatically maintained. There’s no delicate single-point-of-failure to worry about. No precise, narrow Goldilocks zone you have to stay in. But of course, the question then is WHY are the basic parameters of matter, and the laws of physics, tuned so that this is the natural result! What tuned them? I would argue, evolution is the answer.

For those interested, I've written further about this here: https://theeggandtherock.com/p/life-without-stars-stanets-an...

Maybe you mean Orbital resonance: https://en.wikipedia.org/wiki/Orbital_resonance

Maybe thinking of Titius-Bode laws? Or perhaps the notion of Musica universalis? These are not taken too seriously since they do not hold to close observation.

https://en.wikipedia.org/wiki/Titius%E2%80%93Bode_law

https://en.wikipedia.org/wiki/Musica_universalis

I was deeply influenced by encountering your work at the time I did, thank you and keep it up :) great to see you on HN

Hey, thanks. Fun to be here! I love these ideas, I'm delighted people are interested in debating them.

If black holes contain universes (idk, maybe dimensionally reduced ones), this strikes me as more likely than bullshit. Not likely. But real enough to be worth toying with.

Definitely worth toying with. Lee Smolin's original idea of cosmological natural selection, of the Darwinian evolution of universes, is about the same age as string theory, and it's just as powerful and interesting a speculative idea. Yet it has received far less attention, I think because it fell between the disciplines, so no field felt qualified to explore it, and thus no field took responsibility for it. I think it's possibly the most neglected major idea in science, and it's almost purely for those sociological reasons, not scientific.

> Yet it has received far less attention, I think because it fell between the disciplines

It’s unfalsifiable with known methods. Until we can experimentally manipulate black holes, this is all philosophy. Not science.

Well, that's a purely physics argument. You need to think instead about the information about an evolutionary history that can be extracted from an evolved organism (and the implications thereof), even if you only have one example. There's a surprising amount. As an evolutionary theory, it therefore makes predictions about the order of structure formation in the early universe. Which are working out pretty well so far.

Implications: https://theeggandtherock.com/p/the-key-implication-of-cosmol...

Predictions thereof: https://theeggandtherock.substack.com/p/predictions-what-the...

https://theeggandtherock.substack.com/p/predictions-what-the...