Comment by gmuslera
4 days ago
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!
>... 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.)
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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.
It's actually not taking a lot of speculative ideas at all. It's taking one hypothesis (universal reproduction) and noticing that if it has one interesting feature (slight variation in parameters), you automatically and essentially unavoidably get Darwinian evolution which could very cleanly and succinctly explain a lot of the weird fine-tuning that seems to be present in our universe.
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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.
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.
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Why does there need to be an original?
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Which one?