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Epigenetics and "Intelligent Design"


Dean Pomerleau

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[Note: I really hate to put this post on the "Chit-Chat" forum, since it is science heavy. It would fit much better on a (longed-for) "Non-CR Health and Longevity" forum. But its too far from CR to justify posting it to "CR Science", so here goes...]
 
 
I'm reading philosopher Thomas Nagel's most recent book, Mind and Cosmos in which he argues that the "neo-Darwinian conception of nature is almost certainly false" - in fact, that is the subtitle of the book. Key to his argument is that it doesn't appear that the cornerstone of neo-Darwinism, namely random mutation to genes that turn out to be fitness enhancing, could ever come up with the vast variety of large scale variations in body morphology and physiological systems we see in the world, many of which are argued to be "irreducibly complex" (i.e. all-or-nothing from an evolutionary fitness perspective). The architecture of the eye, and the molecular motor that powers flagellum in bacteria are examples of these complex biological structures that would seem (to some) impossible to evolve through simple random mutation.
 
Nagel, and others (and not just  intelligent design (ID) folks, some of whom think God orchestrates evolution) see the need for some more directed form of evolution to explain the diversity and complexity of life on our planet. Nagel seems to think mind / consciousness, and not God in the traditional conception of the term, might fit the bill. But to me that seems rather extreme, and goes against "reductive materialism / naturalism" that has been so successful at explaining how the world works over the last few hundred years.
 
One wonders if a less drastic solution that tweaks the mechanism of neo-Darwinian evolution, might be invoked to save the day for materialism / naturalism.
 
As discussed elsewhere (see this post for details), I've recently been studying epigenetics, where gene expression can be modulated by methylation (among other mechanisms). In methylation, a methyl groups can attach to a particular DNA base pair, causing the gene to "wrap up" around a histone, preventing it from being transcribed into RNA, thereby suppressing expression of the protein that the gene codes for. This methylation can be driven by environmental factors, is quite localized, specific, and repeatable, and can occur not only in somatic cells, but also in germ-line cells (eggs and sperm), and thereby get passed down to several subsequent generations.
 
While the epigenetic changes can be adaptive both for the organism in which they first occur, as well as their progeny, they aren't permanent changes to the base-pair sequence of genes, so they aren't heritable variations over thousands or millions of years, like we see across species in the world. So they are "Lamarkian" to a point, but not in the true sense of the world - giraffe necks could get longer for a generation or two after (hypothetical) epigenetic changes occurred as a result of a giraffe stretching to reach the high leaves on a tree, but eventually the epigenetic changes would "wear off" and subsequent generations would go back to having short necks.
 
But what if epigenetic changes via methylation not only silences genes, but also made those silenced genes more prone to mutation? The methylation would not only be a signal that "this gene isn't worth expressing in the current environment", it would also be signaling "this gene is not very useful in is current form in the current environment, so target it for mutation". With an elevated mutation rate specific to maladaptive genes lasting several generations, new variations should more readily arise in subsequent generations, accelerating experimentation with parts of the genome where changes would be mostly likely to be beneficial in a rapidly changing environment. 
 
This sort of elevated mutation rate in parts of genes that have been methylated (silenced) is exactly what this study [1] found. To quote the abstract:
 
Our results ... provid[e] the first supporting evidence of mutation rate variation at human methylated CpG sites using the genome-wide sing-base resolution methylation data.
 
It's not clear that this targeting of random mutations to specific maladaptive genes could result in the type of big changes Nagel and others point to when criticizing neo-Darwinian evolution. But it seems like a way to facilitate a sort of "semi-Intelligent Design", without an explicit designer, by focusing "random tinkering" with the genome in places where genetic changes could do the most good in the current environment.
 
Anyway, while not (directly) related to CR, I thought it was interesting nonetheless.
 
Comments appreciated.
 
--Dean
 
----------
 
BMC Genomics. 2012;13 Suppl 8:S7. doi: 10.1186/1471-2164-13-S8-S7. Epub 2012 Dec 17.
Investigating the relationship of DNA methylation with mutation rate and allele frequency in the human genome.
Abstract
BACKGROUND:

DNA methylation, which mainly occurs at CpG dinucleotides, is a dynamic epigenetic regulation mechanism in most eukaryotic genomes. It is already known that methylated CpG dinucleotides can lead to a high rate of C to T mutation at these sites. However, less is known about whether and how the methylation level causes a different mutation rate, especially at the single-base resolution.

RESULTS:

In this study, we used genome-wide single-base resolution methylation data to perform a comprehensive analysis of the mutation rate of methylated cytosines from human embryonic stem cell. Through the analysis of the density of single nucleotide polymorphisms, we first confirmed that the mutation rate in methylated CpG sites is greater than that in unmethylated CpG sites. Then, we showed that among methylated CpG sites, the mutation rate is markedly increased in low-intermediately (20-40% methylation level) to intermediately methylated CpG sites (40-60% methylation level) of the human genome. This mutation pattern was observed regardless of DNA strand direction and the sequence coverage over the site on which the methylation level was calculated. Moreover, this highly non-random mutation pattern was found more apparent in intergenic and intronic regions than in promoter regions and CpG islands. Our investigation suggested this pattern appears primarily in autosomes rather than sex chromosomes. Further analysis based on human-chimpanzee divergence confirmed these observations. Finally, we observed a significant correlation between the methylation level and cytosine allele frequency.

CONCLUSIONS:
Our results showed a high mutation rate in low-intermediately to intermediately methylated CpG sites at different scales, from the categorized genomic region, whole chromosome, to the whole genome level, thereby providing the first supporting evidence of mutation rate variation at human methylated CpG sites using the genome-wide sing-base resolution methylation data.
PMID: 23281708
 
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Yes that is interesting.  Thank you Dean.  Not sure if I have posted about this before, but the most (only?) interesting contribution I have seen from the 'intelligent design' people is Barrow and Tipler in 'The Anthropic Cosmological Principle'.  It is enormously technical but the gist of their argument comes through clearly.

 

http://www.amazon.com/Anthropic-Cosmological-Principle-Oxford-Paperbacks/dp/0192821474

 

In essence their position is that the values of all the cosmological constants - Plank's constant; the energy thresholds necessary to produce the elements within the stars; the angles in which hydrogen and oxygen atoms are positioned when combined to form water to give it its astonishingly helpful properties; along with lots of others - are so 'fine tuned'* to produce life that they must have been planned that way from the outset. 

 

* By fine tuned, the authors claim that if the values of any of these constants had been either a little smaller or a little greater than they are then it would have been impossible for life (and intelligence and understanding) ever to develop. 

 

I am not saying I think the authors are right.  Rather that they have provided the only argument for intellgent design that I have come across that I consider may be worth considering.  Both authors are serious scientists.  (And serious christians too!)  I rather think they started with their conclusion and then looked for as much evidence as they could lay their hands on which might support it.

--------------------------

And I am going to take your comments, Dean, about the need for an additional forum as an excuse to suggest yet another forum that might serve a useful purpose.  I think it would be helpful to have a forum where posts would be restricted to those where members brag about how healthy they are.  I would personally be interested to see what others have been able to achieve through their CR efforts.  And those completely new to CRSociety and caloric restriction might be very interested to read the contents of such a forum, and help them make their minds up as to whether they should get involved.  

  

Without the existence of a forum specifically for this purpose, I think many of us (not me though!) might be too modest to post such information.  In addition to posting such information on such a forum members would be encouraged to explain the type of CR they have pursued, which may be responsible for their excellent health (Paleo CR?  Low fat CR? High protein CR?  Atkins CR??? .......  ). 

 

I imagine the first post to such forum might be made by Saul bragging about his absolutely astonishingly good ratio of total cholesterol/HDL.  Next, and only shortly thereafter, I would expect Al to be bragging about his unbelievably good PSA test results.   ..........  And yes, I have to admit that I do have a post of mine in mind as I write this  : ^ )))))

 

Rodney.

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Hi Rodney,

 

I too think fine-tuning of the cosmological constants is the best argument to support the idea that our universe was created by some sort of intelligent super-being, although not necessarily the God of the Abrahamic religions. But I must say I can't take Tipler too seriously after reading his hair-brained ideas on the Omega Point. As you said, he seems to have a theological perspective and tries to bend science to support it - well past the point of breaking it, if you ask me.

 

Regarding the implications of the fine-tuning argument, I'm more partial to the multiverse hypothesis than the "God did it" hypothesis for explaining fine-tuning of all the cosmological constants. In fact I recently wrote about how fine-tuning in the multiverse might in fact explain Fermi's Paradox - why we don't see any aliens. If you're interested, here is my argument:

 

https://thoughtfulcog.wordpress.com/2015/07/13/can-the-inflationary-multiverse-explain-the-fermi-paradox/

 

--Dean

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".....  although not necessarily the God of the Abrahamic religions".  In my judgment it would be near infinitely unlikely the intelligent super-being (should there be one) would be associated with any currently-practised religion, any more than with any of the myriad religions/gods now long-since extinct.  (Among the ones we are aware of, including those of the romans, ancient greeks or egyptians, mayans, papuans, etc.  .........)  I expect almost all the current ones to be extinct 100 years from now.

 

When a scientist (or AI) eventually figures out how it is possible for a universe to come into existence apparently out of nothing, and if it turns out a sentient entity was indeed involved, perhaps a religion (not a word I would want to use however) based on the evidence will arise.  But I very much doubt he will want us all to gather together and sing once a week.

 

Rodney.

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Earlier I wrote: 

 

I too think fine-tuning of the cosmological constants is the best argument to support the idea that our universe was created by some sort of intelligent super-being, although not necessarily the God of the Abrahamic religions.

 

I take back what I said.

 

I actually think the best argument to support the idea that there is something "bigger" going on (perhaps as a result of an intelligent creation event) is the unreasonable effectiveness of mathematics at allowing us to explain the universe we observe. Physicist Eugene Wigner put it this way:

 

The miracle of the appropriateness of the language of mathematics for the formulation of the laws of physics is a wonderful gift which we neither understand nor deserve.

 

As Albert Einstein said: 

 

The most incomprehensible thing about the universe is that it is comprehensible.

 

I think the two most reasonable explanations for this mystery, given what we know and where we are headed, is that we are the equivalent of a giant simulation, per Nick Bostrom's simulation argument, or (perhaps equivalently) we are a mathematical structure, per Max Tegmark's mathematical universe hypothesis.

 

--Dean

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  • 2 weeks later...

Hi Rodney,

 

I too think fine-tuning of the cosmological constants is the best argument to support the idea that our universe was created by some sort of intelligent super-being, although not necessarily the God of the Abrahamic religions. But I must say I can't take Tipler too seriously after reading his hair-brained ideas on the Omega Point. As you said, he seems to have a theological perspective and tries to bend science to support it - well past the point of breaking it, if you ask me.

 

Regarding the implications of the fine-tuning argument, I'm more partial to the multiverse hypothesis than the "God did it" hypothesis for explaining fine-tuning of all the cosmological constants. In fact I recently wrote about how fine-tuning in the multiverse might in fact explain Fermi's Paradox - why we don't see any aliens. If you're interested, here is my argument:

 

https://thoughtfulcog.wordpress.com/2015/07/13/can-the-inflationary-multiverse-explain-the-fermi-paradox/

 

--Dean

 

The fine-tuning idea sounds like a set up for a tautology and self-bias to me. E.g. "humans/life/consciousness/this-particular-universe is so special, therefore there must be some special reason behind/explaining its origins."

 

But why assume that humans/life/consciousness/this-particular-universe is somehow inherently "special" in the first place? Why would a universe without humans/life/consciousness be any less inherently special?

 

 

 

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Hi Brett:

 

Well if there are in fact quintillions of universes (more specifically: quintillions of Big Bangs, now evolving) and if the physical constants among them are randomly distributed, then according to Barrow and Tipler (B&T) life would evolve in an incredibly small proportion of them. 

 

In that case our Big Bang - and its physical constants - would certainly qualify as 'different' (special?) if, as B&T would claim, it is very unusual in being able to evolve life.  I suspect B&T might argue that if there indeed is a *very* large number of universes, and the physical constants *are* randomly distributed, then ours might be the only one able to support life and understanding.  But in that case why would a hypothesized Super-Being bother to create all those other sterile universes? 

 

I recall that the ratio of the mass of the electron to the proton is another critically important number, small variations in which would make (IIRC) the evolution of atoms impossible.

 

It might be an interesting exercise for someone with enough knowledge of the issues to imagine how other universes would evolve with different sets of physical constants.  It might be a productive source of ideas for science fiction - an earthling traveling to and investigating different universes! 

 

Rodney.

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But why assume that humans/life/consciousness/this-particular-universe is somehow inherently "special" in the first place? Why would a universe without humans/life/consciousness be any less inherently special?

 

Brett,

 

I agree that we tend to have a strong anthropocentric bias. While I think humans are a (local?) maximum in "interesting complexity" in our universe, even if we weren't here I think the universe would be "special" (i.e. in need of explaining) because of the amazing complexity that has arisen from such (apparently) homogeneous and "boring" beginnings. The best cosmological theory at the moment (the Big Bang theory), says our universe started out as a (nearly) uniform soup of subatomic particles. The laws of physics appear to be tuned to enable (at least very occasionally) extremely intricate and complex structures to evolve from this very humble beginning.

 

This tendency alone (whether humans emerged or not) would seem to require some sort of explanation, rather than just being a brute fact. Perhaps it was a super-being who tuned it, or perhaps it's a result of anthropic bias - there are a huge number of universes with different laws of physics, and we (naturally) find ourselves in one of the very few that are tuned to support the emergence of complex structure, and eventually life and intelligence.

 

I suspect B&T might argue that if there indeed is a *very* large number of universes, and the physical constants *are* randomly distributed, then ours might be the only one able to support life and understanding.  But in that case why would a hypothesized Super-Being bother to create all those other sterile universes? 

 

Rodney,

 

It isn't hard to come up with at least one potential answer to your question. Perhaps it was "easier" for the super-being to create diverse life by creating many universes and letting life evolve in those conducive to life, rather than figuring out how to manually tune the physical constants to support life.

 

This is easy to imagine by analogy. When biochemists are trying to find a mutation that can make a bacteria do something useful (e.g. metabolize some sort of toxin, like oil, to help clean up an oil spill), rather than trying to tinker with the bacteria's DNA directly, they set up a bunch of petri dishes containing the bacteria, dump a bunch of toxin into each, and then simply wait and watch to see which petri dish(es) evolve bacteria that flourishes in the presence of the toxin, and in which the concentration of the toxin drops over time. In other words, they let blind mutation and evolution find the answer for them, because it's easier and more effective than manual tinkering.

 

--Dean

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But why assume that humans/life/consciousness/this-particular-universe is somehow inherently "special" in the first place? Why would a universe without humans/life/consciousness be any less inherently special?

 

Brett,

 

I agree that we tend to have a strong anthropocentric bias. While I think humans are a (local?) maximum in "interesting complexity" in our universe, even if we weren't here I think the universe would be "special" (i.e. in need of explaining) because of the amazing complexity that has arisen from such (apparently) homogeneous and "boring" beginnings. The best cosmological theory at the moment (the Big Bang theory), says our universe started out as a (nearly) uniform soup of subatomic particles. The laws of physics appear to be tuned to enable (at least very occasionally) extremely intricate and complex structures to evolve from this very humble beginning.

 

This tendency alone (whether humans emerged or not) would seem to require some sort of explanation, rather than just being a brute fact. Perhaps it was a super-being who tuned it, or perhaps it's a result of anthropic bias - there are a huge number of universes with different laws of physics, and we (naturally) find ourselves in one of the very few that are tuned to support the emergence of complex structure, and eventually life and intelligence.

 

Attributing inherent significance to complexity just seems like yet more anthropocentric bias to me. Why the bias against attributing significance to homogeneity?

 

Furthermore, an inability or unwillingness to entertain alternative universes which function in bizarrely different ways to the known universe(not just, for example, merely extrapolating known physics with tweaks to various constants etc) may, again, be a reflection and limitation and bias of the human(s) involved. 

 

Just generally, doesn't attempting to explain the perceived specialness of the universe with a special intelligent creative being/force, just move the question from what created the special universe, to what created the special creator of the universe?

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Brett,

Placing special value on complexity may be a bias of humans, but I wouldn't say that it is anthropocentric (human-centered or human-focused). There are many types of interesting complexity that could exist in the absence of humans.

 

And maybe I wouldn't even call it "valuing" complexity. The change from homogeneity to complexity is an interesting transformation that bears explaining, regardless of what form the complexity takes, and regardless of whether you consider complexity "better" than homogeneity or not.

> Doesn't attempting to explain the perceived specialness of the
> universe with a special intelligent creative being/force, just
> move the question from what created the special universe, to what
> created the special creator of the universe?

Not necessarily. Not if it is turtles all the way down [1] ;-)

To think that we are at the "top level" of whatever exists in the universe / multiverse, and that we could ever comprehend it all, seems like the ultimate in hubris. I often think of the bacteria in our gut, forever isolated and therefore oblivious to the larger framework within which they are embedded and for which they play a small but nonetheless integral role.

In the end, the fact that there is something rather than nothing at all seems to afford no ultimate explanation.

Dean

[1] https://en.m.wikipedia.org/wiki/Turtles_all_the_way_down

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Thanks Dean.  So in that case then, the Super-Being (tSB) is not omnicient.  Makes sense.  Next: how do we set up a test to figure out if that is what is happening?  (!)

 

Of course, another possibility is that, having done his original petri dish experiments trillions of years ago, he now knows which combinations of constants do enable life to evolve after, say, twenty billion years, and now only creates new universes with the constants that have previously been proven 'successful', recycling the resources from the unsuccessful universes for use in others.  Probably Brett would argue (?) that the idea there has only been one set of petri dishes is a 'special' self-centred bias of the kind he suggests.  Perhaps we are part of the zillionth set of petri dishes, each set containing zillions of petri dishes of which we happen to be just one dish in a comparatively recent experiment, and maybe all the petri dishes in this experiment have constants capable to permitting life to evolve, although not necessarily all of them the same as ours.

 

And I see that I likely suffered from self-centred bias by supposing that it is only 'life' that is the tSB's hoped-for end product.  Perhaps there are phenomena we could not possibly imagine which are considerably more interesting (to tSB, and to us if only we were aware of it) than life, which may be able to evolve in universes with particular sets of constants?  And the tSB isn't really especially interested in life, but more so these other phenomena.  Or perhaps some of these other phenomena are already happening in our dish but we are just not capable of detecting them?

 

I imagine the person who figures this out might get a Nobel Prize!

 

Rodney.

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Of course, another possibility is that, having done his original petri dish experiments trillions of years ago, he now knows which combinations of constants do enable life to evolve after, say, twenty billion years, and now only creates new universes with the constants that have previously been proven 'successful', recycling the resources from the unsuccessful universes for use in others.

 

<snip>

 

And the tSB isn't really especially interested in life, but more so these other phenomena.  Or perhaps some of these other phenomena are already happening in our dish but we are just not capable of detecting them?

 

There is a fascinating non-fiction book along these lines by physicist Lee Smolin that I highly recommend, called The Life of the Cosmos. Smolin develops a speculative theory, along with predictions that he claims haven't been falsified in the 16 years since its publication, in which there is no "Super-Being". Instead there is an entirely natural, unguided evolution of baby universes (equivalent to the 'petri dishes' we're talking about) that naturally develop "interesting complexity" within them as a fortunate byproduct. Here is a rough sketch of how Smolin's theory works (perhaps with a few embellishments...):

 

  • New baby universes are formed inside black holes (or black holes of a sufficient mass). 
  • Each baby universe inherits the properties of its 'parent' universe (laws of physics, universal constants), with some mutation which adds variation.
  • Over time in such a system, the laws of physics will evolve so that new baby universes become more and more prolific at generating black holes, with baby universes inside them possessing properties similar to (but slightly different from) their own.
  • As a result of this process, over time the population of baby universes will become dominated by those which are optimized to produce a maximal number of black holes, i.e. have more babies.
  • We live in one of these baby universes, with a very high probability of being highly tuned for producing a (nearly) maximal number of black holes.
  • Black holes (optionally, of a sufficient mass) can only be produced in maximal numbers in baby universes that persist for a long time, perhaps in fact are "open" (eternally expanding), like ours now appears to be.
  • But universes that are "too open" (i.e. expanding too rapidly) will blow all matter far apart, preventing the formation of any black holes.
  • So the cosmological constant, the balance between the forces of expansion and contraction of the baby universe, should be highly tuned - "on a knife's edge" between expansion and gravitational collapse, as our universe appears to be, in order to maximize the formation of black holes.
  • Universes that are large, long-lived, and subject to "localized clumping" of matter due to gravity, facilitate both the formation of black holes, and as a fortuitous byproduct, the clumping of matter into structures exhibiting interesting complexity.
  • The complex lifecycle of galaxies, where waves of supernova in the spiral arms form black holes and cause gravitational collapse of gas clouds into new stars that will generate still more supernova and more black holes, drive the process of both continuous black hole formation, and the formation of localized energy sources (stars) around which pockets of complexity can emerge, much like the parasitic complex ecosystems that form around smoker vents along mid-ocean rifts.  
  • Our planet, and the life that has emerged on it, is one such pocket of complexity - the lucky (for us) byproduct of a process that was tuned by a form of natural selection to maximize black holes, and which had no intention of creating life or the complexity we see.

 

Smolin says his theory predicts that (among other things) the laws of physics and the constants of nature should be finely tuned to maximize the formation of black holes, along the lines of the cosmological constant tuning I allude to above. For example, he says if the so-called "fine structure constant," a combination of the speed of light, the charge of the electron, and Planck's constant (which governs quantum mechanics) were even slightly different, helium would not be able to fuse into carbon in the cores of stars, and without carbon, heavier elements couldn't form which eventually lead to supernova collapse and black hole formation. In that case, the universe would consist solely of hydrogen and helium, elements too simple to support any kind of complex chemistry, or life.  According to Smolin, tweaking with any of these constants of nature should reduce the number of black holes that are formed.

 

This (admittedly very speculative) theory, which Smolin calls "Cosmic Natural Selection (CNS)", holds a lot of appeal for me. First, it brings the beautiful theory of evolution into the one branch of science where it hasn't previously played a role in our theories - physics. Second, it extends the concept of "the appearance of design without a conscious designer" to a whole new level - the level of universes. Third, while it postulates an incredible number of universes, it does not require quite as many as the standard anthropic multiverse theory for how life arose, and how the laws of physics became so finely tuned for life, since there is significant selection pressure in favor of focusing new universes on the part(s) of the "multidimensional space of the laws of physics" where black holes, and therefore interesting complexity, most easily arise. 

 

Perhaps the most interesting thing is that the CNS theory makes scientifically-testable predictions about the values for the constants of nature and their impact on black hole formation. So unlike the traditional anthropic argument for the multiverse (or the argument that "God did it"  :)xyz ), CNS is a theory that could be tested and refuted, which makes it a true scientific theory in the Karl Popper sense of the term.

 

For the record (in case any of them are proven true!), my three favorite theories for "the big picture" of life, the universe and everything are (in no particular order):

  • The Cosmic Petri Dish theory with one or more levels of Super-Beings above us who set things in motion, discussed in previous posts.
  • Smolin's Cosmic Natural Selection theory, without a conscious designer, discussed here.
  • Bostrum's Simulation Argument that postulates we live inside a hyperrealistic computer simulation created by our descendents.

But note - none of these provides an answer to the ultimate (to me unanswerable) question of why there is something rather than nothing...

 

--Dean

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Gosh.  Thank you!  The 'something rather than nothing' issue certainly does appear insoluble.  We humans have this hang up in our belief that if we see an effect then, necessarily, it must have had a cause.  Perhaps we are mistaken about that, and the mistake arises from a problem with our brain wiring?  Maybe AI could get around this silly little difficulty?

 

Rodney.

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Addendum:

 

Since Smolin developed his Cosmic Natural Selection theory in the late 90's, there has emerged a fascinating connection between black holes and cosmology called the holographic principle.

 

I don't entirely understand it, but the consensus among physicists seems to be that the information that falls into the 3D sphere that is the interior of a black hole is somehow smeared across the spherical 2D surface of its event horizon, so that information isn't lost.

 

At the same time, the holographic principle also seems to suggest that all the information about the "interior" of our 3D universe (i.e. reality as we perceive it) can be equivalently represented, or considered to be smeared across a 2D surface surrounding our universe. In other words, we are a 3D projection of a distant 2D hologram (or 4D and 3D if you want to include time as a dimension).

 

These two models from black hole physics and cosmology suggest to me we're looking at the same type of phenomena from the "inside" and from the "outside" when we look at the cosmic microwave background and the event horizon of a black hole, respectively. As if, as Smolin suggests, our universe is the interior of a black hole.

 

Obviously highly speculative...

 

For anyone interested, here is a great video lecture by physicist Leonard Susskin on the holographic principle and how it relates to both black holes and our universe as a whole.

 

--Dean

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Not that simple addition and subtraction (or conservation laws) would necessarily be expected to be valid inside a black hole:  but would it not seem to follow that if we (our 'universe') are the progeny of an earlier black hole in another universe, then each succeeding universe must be much smaller than the preceding one, since it is the product of the black hole from which it arose, which possessed only a tiny fraction of the mass of the previous universe, which presumably contained billions of black holes?

 

Rodney.

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Rodney,

Not that simple addition and subtraction (or conservation laws) would necessarily be expected to be valid inside a black hole:  but would it not seem to follow that if we (our 'universe') are the progeny of an earlier black hole in another universe, then each succeeding universe must be much smaller than the preceding one, since it is the product of the black hole from which it arose, which possessed only a tiny fraction of the mass of the previous universe, which presumably contained billions of black holes?

 

Yes, you'd think that - sort of like nested Russian dolls - each new universe must be smaller than the last if all its matter (= energy via E=MC^2), is "borrowed" so to speak from its parent universe. Of the three theories I mentioned:

  1. The Cosmic Petri Dish theory with one or more levels of Super-Beings above us who set things in motion, discussed in previous posts.
  2. Smolin's Cosmic Natural Selection theory, with baby universes for making black holes without a conscious designer, fortuitously promoting complexity and life too.
  3. Bostrum's Simulation Argument that postulates we live inside a hyperrealistic computer simulation created by our descendents.

the first two, and even the third to some extent (if simulated universes inside simulated universes are allowed), would seem to be seriously hampered in their plausibility by this objection about resource limitations.

 

But fortunately, and quite amazingly, it appears there is a loophole to this sort of resource limitation built into the laws of physics. Physicist Lawrence Krauss has an entire book on the subject (A Universe from Nothing). The subtitle of the book ("Why There Is Something Rather than Nothing") is entirely specious - The "nothing" Krauss is starting with is really quite a lot - a vacuum "pre-loaded" with laws of quantum physics.

 

But give that starting point, and enough time (perhaps a VERY long time, although it's not clear even what time means in such a primordial state), he walks the reader through how something quite remarkable can happen. In a nutshell, as a result of random fluctuations in the "quantum foam" that we know are occurring all the time at very small scales, a small patch of the vacuum can nucleate into a form of "matter" (a very strange form of matter, not matter as we normally know it), with very high negative pressure, and which (unlike matter as we know it), doesn't dilute as the baby universe gets bigger. Due to its very high negative pressure, this baby universe expands enormously both in size and in mass from much smaller than microscopic to something about the size of a beachball which is packed with all the matter/energy that will ever exist in the full-sized universe via the process of "inflation" that scientists are pretty convinced happens, based on the remnants from the Big Bang.

 

In the process of inflation, the "positive" energy that gets generated and locked up in all the stuff (matter & energy) being created within this non-diluting inflaton field is exactly balanced by the "negative" gravitational potential energy locked up in the gravitational expansion of all that stuff, so that they exactly balance. You end up with huge universe with lots of stuff in it, but with net zero energy - what physicists have called the "ultimate free lunch". 

 

This free lunch, the fact that in theory a universe of the proportion we live in can pop into existence without any net input of energy from the "outside", is what makes theories #1 and #2 plausible - otherwise universes begatting other universes, or scientists creating "petri dish" universes in a lab, would quickly peter out (or never get off the ground) due to lack of enough matter and/or energy to keep generating them.

 

Here is a terrific short video by physicist Alan Guth, the discoverer/inventor of the theory of inflation, talking about the possibility of exactly this - future scientists creating a baby universe in a lab by generating a tiny black hole from only one gram of highly compressed matter and inducing it to undergo inflation, without destroying their own universe in the process. At the end he speculates that it's not inconceivable that we could be living in one such lab-grown baby universe.

 

So these speculations may be wild, but they're not entirely implausible, and I'm not the only one making them.  :)xyz

 

--Dean

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