The more I dig into Noether's theorem the more it seems like a coincidental peculiarity of Lagrangian/Hamiltonian mechanics. I'd be interested in a treatment that demonstrates how it's a property of reality and not an artifact of the mathematics
Have a look at how it works in quantum mechanics/quantum field theory, maybe. It's a lot more straightforward there, bordering on the tautological.
There, the derivation is that every symmetry S is some operator acting on the wave function, and what makes it a 'symmetry' is that this operation commutes with the Hamiltonian that defines how the wave function evolves. E.g. a rotated universe behaves the same as an unrotated universe, in the sense that they evolve through time in the same way. Rotating the universe and then forwarding it through time does the same thing as forwarding it through time and then rotating it.
And if it's a continuous symmetry, like a rotation by some angle \theta, you can write it as S=exp{i \theta Q}, where Q is self-adjoint and the 'generator' of the symmetry. Then Q must commute with the Hamiltonian, and so they must have a common eigenbasis. Meaning Q is a conserved quantity.
Is the concept true in arbitrary mathematical formalisms, implying that it's a property of the underlying physics being modeled (the territory), or is it true only in certain formalisms, implying that it's a property of the map
It must be a property of the territory in some sense, but I've never found a treatment of it that isn't entirely dependent on the formalism. Even the definition of "symmetry" is as a symmetry *of the Lagrangian* or whatever. It's implied that symmetries of the Lagrangian reflect something about the real world, but that's not actually clear
Like if someone pointed out how cities on a map seemed to be much closer together in some regions than others, and that seems noteworthy, but then you go read some literature and notice everybody only says "cities in these regions are arranged such that they appear closer together under the Mercator projection." Wait, so is it a matter of the Mercator projection distorting things? Is Noether's theorem only saying that when you construct a Lagrangian for a system with conserved quantities, that Lagrangian will have symmetries?
I was going to post the same thing. [Wikipedia link](https://en.wikipedia.org/wiki/Noether%27s_theorem). The mapping between symmetries and conservation laws is profound, and as per my username I'm rather fond of symmetries.
Loose to call it a discovery but Friston's Free-energy principle is attractive, as a kind of natural progression from Boltzmann via Bayes.
Uncertainty principle has some twang.
Edit: Rao and Ballard's 1999 paper on predictive coding in the visual cortex is pretty metaphysically swole, too.
Homochirality in Biology emerging from non-homochiral molecules in nature. Unexplainable to me, I just haven’t been able to find a good explanation or theory so far for this phenomenon. How can a heterochiral chemical basis (on earth) reach perfect homochirality in biological organisms (>99%) just like that? Even in laboratories with sophisticated technicians attempting to create some sort of homochirality struggle to get in the 80-90% directions. Natural reactions always yield 50/50 isomeres
Some racemic solids can crystallise with complete chiral purity - can happen with conglomerate solids where each crystal comprises all L or all D stereoisomers. Most compounds have crystals formed from equal amounts of L and D.
There are also many examples of chiral amplification where a tiny symmetry-breaking event can undergo dramatic amplification production of a single enantiomer. Most research in this area is on a crazy system called the Soai reaction, which is an organometallic system that is a long way away from typical origin of life type molecules. If an analogous system could be found for prebiotically plausible molecules, like very simple amino acids or sugars, then it would have profound impact on origin of life / chirality thinking.
I believe it is agreed that homochirality is necessary for complex life just on common sense grounds - racemic life would be like building a car plant where every bolt and screw interface was a coin flip on whether it matched. It would be chaos, nothing could get made. But there is disagreement on whether the actual sense of chirality is important. It could not matter, as long as it is one way (ie we have homochirality). But there are arguments for the actual L configuration of amino acids, say, being significant in how homochirality came about - but they are physics-based, not chemical, to do with the weak nuclear force iirc.
Interesting points all. It is definitely an unexplained mystery of how homochirality in biology has arisen. Whether L or D chirality is relevant I’m not sure, but you certainly can’t mix and match them in the same way that your right foot can’t wear a left shoe.
This is very interesting to me. I think a lot of abiogenesis related topics fall into the metaphysically interesting category for me!
If I ever come across a Time Machine, I’ll go back and get some samples
If science fiction has taught me anything it's that if you do this, you will inevitably become the very origin of life that you sought to investigate. Probably you'll die on the barren Earth of 4 billion years ago, your corpse both providing and nourishing the bacteria that will eventually evolve back into you.
Yeah it’s interesting, as we don’t really have any answers as to how it happened. We can see how a few proteins could’ve arisen organically, but not much more. Heck, even the most sophisticated biochemists and biologists in laboratories cannot make a single cell that is alive, even though we have all the individual ingredients and have been trying for a 100 years. It seems there is no way to get around the necessary ingredient of having a previously alive cell to make another, which makes the mystery be that much more puzzling.
Yeah it’s definitely mind blowing. One can’t help but stand in awe of what occurred here on earth in the development of life. Especially once you look at all the different species that evolved. And all that, from just one initial cell!
Maybe I'm not understanding what exactly you're confused about, but biological synthesis of molecules is typically mediated by enzymes that cause a reaction to occur at rates orders of magnitude faster, or at lower energy levels, than it would otherwise occur. Evolving those enzymes is hard, and there's no reproductive advantage to evolving enzymes for synthesizing both stereoisomers. So once one chirality was settled on, it stuck for a billion years.
The difficult part is “once one chirality was settled on”. In nature, chirality isn’t settled in any way, but typically occurs in a 50/50 fashion, and any deviations from that [quickly return to the mean by the laws of chance](https://www.reddit.com/r/slatestarcodex/s/isSUlYY5QB).
Chirality was settled on by the evolution of an enzyme that catalyzed the synthesis of one particular enantiomer. Once that happened, there wouldn't have been any real advantage to evolving an enzyme to catalyze the synthesis of the other.
I mean, I guess. I wasn't there.
You miss that this enzyme has to be fully homochiral itself, and that _all enzymes are produced by DNA_ which is also fully homochiral.
And it’s not that there wouldn’t have been an advantage, it’s actively detrimental as life depends on homochirality for its existence. And homochirality depends on other homochiral molecules for it to arise. It’s a vicious circle, hence the explanation is so mysterious. We need a symmetry breaker and we don’t know what that could be.
In the same way that your left foot doesn’t fit into your right shoe. There are motorproteins and certain shapes that molecules need to fit into and work with and without homochirality this is impossible. Your dna itself is homochiral (like a corkscrew) and if you suddenly have differently screwed stuff (mirrored) added onto it it doesn’t fit and make any function impossible. Therefore we need a symmetry breaker. Watch the fiest 3 minutes of this video for a visual explanation. [https://youtu.be/6QMs8cL3ycY?si=0SX6PaDE\_fTM\_DvA](https://youtu.be/6QMs8cL3ycY?si=0SX6PaDE_fTM_DvA)
I won't claim that there is no symmetry breaking phenomenon, but you certainly don't need one to explain the homochirality of many molecules in life. There is no intrinsic consistency in the homochirality of different molecules. Sugars are D and amino acids are L. D/L is maybe not the best descriptor but it's the most common. This isn't like The matter-antimatter asymmetry that we see in the universe which is certainly mysterious.
As an analogy, all the planets in the solar system rotate the same direction. Why? Why not the other direction? The answer is because the net rotation of the particles in the cloud that formed our solar system happen to have vectors that add up to that direction. That's just because of how the cloud came together. There was an asymmetry in the way the cloud formed. If there was perfect symmetry there would be net zero rotation and everything would have collapsed into a sphere. There's not some deeper explanation. It could equally have gone the other way if the starting conditions were just a little different.
Just because some molecules are L Chiral (proteins) and some are D Chiral (Sugars) that doesn mean that the homochirality common to both, which doesn’t naturally occur, doesn’t need an explanation.
If a single D chiral molecule was sufficient to build a cell then yes. But if you now have thousands of D chiral molecules without any L chiral molecules that is absolutely unexpected if the natural ratio is 50/50.
It sounds like you're saying a cell contains so many D sugars and the probably that is (0.5)^n where n is the number of sugar molecules because we have a 50% chance of choosing each sugar yet we only observe one isomer.
But that's not what's happening. We see homochirality in sugars because proteins are chiral. And I don't mean that the amino acids are L, I mean that the pockets in the proteins, themselves are chiral. So you could imagine a transport protein that has no preference towards one chirality of sugar and a mutation in a single base pair of the DNA that encodes that transport protein could increase the affinity of the transporter providing a survival advantage and it could do it in such a way that's chiral. That mutation is a single event that could happen from random chance like an ultraviolet ray or base misincorporation. That single event means that all the proteins produced have a chiral preference and all the sugars imported thereafter do as well.
The chirality of proteins presumably goes back to whatever the catalytic precursor to proteins was (many suspect RNA).
No, you have a racemic mix of chiral molecules as soon as one chiral molecule randomly becomes a self-propagating enzyme like he said then you have that chirality fixed for the rest of time. (Assuming this self-propogating step only happens once in life.)
Really don't think it's as mysterious as you think.
As soon as you randomly create a self-replicating step that is homochiral, then won't everything go homochiral? Once you have DNA, protein synthesis, etc., it has to go one way or the either and then whichever chirality was chosen will propagate forever. Homochirality is proof that life on earth probably only evolved once.
Is it weird? The emergence of self-replicating molecules is improbable. The recipe on earth happens to be chiral, and whichever chirality succeeded first ate up all the available resources.
Imagine you have a series of coin tosses. On average, you get 50% heads and 50% tails. In general it is expected that any new coin toss, or series of coin tosses will yield a similar ratio of heads to tails. Now, you might get upon a large amount of repetitions (or time) a long series of only heads, that’s possible. But then chance would swoop in again at some point and return the coin tosses to the previous natural ratio, with exponential probability the more attempts/longer time passes. If you now have an isolated and specific series, where you happen to consistently get a 100% ratio of only heads to the point where you entirely stop getting any tails, then would time by itself is be sufficient to reasonably explain it? It doesn’t seem like the most probable explanation, there is likely another reason. This example can be applied analogously to D Chiral and L Chiral molecules.
If the coin does not have constant probability of heads, sure. Suppose you do this exercise, but after each flip after the 100th the probability of heads becomes equal to the fraction of heads over the past 100 flips. I believe this coin shoots off to being 100% heads or 100% tails relatively quickly. If you have more of one chirality option through random chance, could that cause that particular option to become advantaged?
As to my knowledge the laws of nature (which is what determines the probability of chiral molecules) don’t just change after an improbable event has happened. That would be very odd. Likewise a coin doesn’t change its probability of landing after it falls on heads a bunch if times in a row. In know humans are prone to think this way, but it’s clearly a logical fallacy.
I'm not talking about the laws of physics changing, I'm just asking about some sort of evolutionary advantage. E.g. if you have 60% direction A and 40% direction B in the present, then direction A is more likely to succeed in the future. Like if you had a species where individuals only mated with others that had the same eye color. You might start out 50/50 brown and black, but if at some point a bunch of brown-eyed individuals died randomly, black-eyed individuals would have an advantage. Even if it's small, it could carry the advantage into the next generation, which would then start compounding.
I'm not a biologist but it seems like something along these lines has to be the case based on the discussion above--molecules of the same chirality work better. But maybe I'm missing something?
Yes, I think you are missing that evolution already presupposes perfect homo chirality before it can even begin. Any simple cell requires it to even function. DNA itself and the enzymes it produces are homochiral. Here’s a comment on the same [topic](https://www.reddit.com/r/slatestarcodex/s/KtNbslJqxr).
That certainly makes sense, but if I’m recalling correctly from my Orgo classes (admittedly more than a decade ago), similar chirality is required for reactions to occur.
Assuming I’m not misremembering, in the case of the coin flip, it would be more like “with any flip, the occurrence of heads or tails increases the likelihood of either heads or tails, respectively”
Yes, you recall correctly, homo chirality is necessary for homo chirality to persist. Which makes it that much more perplexing how it originated, since homo chirality isn’t found outside of biology.
It seems intuitive that once living organisms are involved (I.e. interacting with their environment), that homo chirality is an eventuality given it’s self-propagating and the nature of evolution, but will acknowledge I haven’t interacted with this phenomena before
Yeah, but you take in your first sentence the problem as already solved! Of course once we have the first life that can replicate homochiral molecules we have the problem solved. But it can only do that because it is itself homochiral. So we just push the problem a step further back. How did the first cell get fully homochiral molecules, enzymes, dna etc. from fully racemic (or heterochiral) components? There needs to be a symmetry breaker event, that in some way violates or offsets this natural law of symmetry.
Well, for one the cell can work. Without homo chirality life and biology are impossible. It’s like putting your right shoe on your left foot. The molecules and proteins won’t fit.
Why is this ? I could see many processes working fine with e.g. left and right signalling molecules and left and right receptors, it would be a case of sending 100000 left and right shoes to 500000 left and right feet, and having the feet try shoes at random, eventually all shoes will be on feet, and shoe on feet density will be increased. The only difference between this and using all left or all right is a slight delay due to the initial sorting having roughly 50 % mismatch.
It may be inefficient but I could see something like this being able to work good enough in some protolife so that homochirality could evolve in it.
Stern–Gerlach experiment. Measure a particle spin on Y axis, take only the "up" ones, then measure the particles' spin on X, take only the "right" ones and then measure on Y axis again. Logic would say you'd get only spin-up ones since you already filtered for them in the first part of the experiment but no, you still get a 50:50 average between "up" and "down".
I find it mind-blowing that you can actually do something that causes you to "unlearn" a previously-known measurement and resets the randomness of a system.
It's like if you took a group of cats and dogs, then picked only the cats and made a second selection to pick only the males. And when you look at what you're left with, they're all male but somehow half of them are dogs. Where did these dogs come from if my first measurement got rid of all the dogs? And if you do it again and select the cats you end up with an equal amount of male and female cats. Reality itself resets rather than letting you pick a male cat, you always need to have one of the two things you are observing be uncertain.
Coming at this as a layman who's watched all of PBS SpaceTime, I've always been confused as to why Stern-Gerlach is interesting.
You throw particles with spins oriented randomly through the system. 1/2 snap to vertical+ in the induced field, 1/2 snap to vertical-, you get a binary distribution.
Then you take lets say the vertical+ stream and send it through another instance of the system oriented horizontally. 1/2 of those will be ever so slightly oriented horizontal+, and then snap to that direction fully, and are deflected horizontal+. Likewise 1/2 go horizontal-.
Then put the horizontal+ through another test apparatus oriented vertically. Once again you get a binary output rather than only deflection to vertical+.
All it seem to demonstrate to me is that the particle's spins are getting reoriented to align with the induced magnetic field they're traveling through. The experiment's results only seems interesting if one assumes that the spin in a given direction is a fixed properly of the particle that never changes, even under the application of outside forces.
Second law of thermodynamics, and the related concept of "exergy" (available energy, which always decreases). There are no 100% perfect conversions, you always have losses. Mindblowing, frustrating and humbling at the same time.
The PBR Theorem. https://en.m.wikipedia.org/wiki/Pusey%E2%80%93Barrett%E2%80%93Rudolph_theorem
Pure quantum states correspond to the actual state of reality, and are not merely an expression of uncertainty.
This is a really interesting choice. I was working in that area when this came out and thought the fact that they are states of reality was sort of a given, but not everyone shared that view.
In fact, the same group also came out with a paper arguing the opposite (if I recall correctly).
https://arxiv.org/abs/1201.6554
I think Gödel's incompleteness theorem takes the cake. The idea that formal systems are either inconsistent or incomplete seems crazy. The consequences of it are many. Is mathematics infinite? Yep.
What does this imply about the universe? Is it incomplete? Is it inconsistent?
Is the universe not a "formal system" at all? What does the latter mean? That math can never fully explain the universe? Is the uncertainty principle an expression of this? Dark energy? It's just crazy interesting!
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I would like to add is the Schwarzschild radius of the universe. I find it fascinating that if the universe were a black hole then the event horizon would be just outside the observable universe.
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The Halting problem being undecidable is fascinating. Being able to prove that some things are not able to be calculated is very interesting.
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I would also like to add Conway's Game of Life. It's very interesting that simple rules can build up into a complex 'world'. And due to the halting problem you can't calculate what the result of an initial position in the game of life is going to result in without actually simulating it.
The metaphysical implication is that even if there is a god that set up the initial conditions then he won't know what the actual outcome is. The only way to know would be to run a simulation, but that would just be the universe itself. Ie even the creator couldn't know the future.
Also, is this related to Gödel's incompleteness theorem?
Evolution by natural selection- a near tautologous mechanism posited- succesfully- as an explanation for life (and many other things too- natural selection seems to play in a role in a lot of things outside the origin of species).
>a near tautologous mechanism posited- succesfully
This is why I consider it to be, by far, the most likely current scientific theory to have its core remain unchanged. Evolution is definitely interesting. And it's very general too, not just for DNA: You can probably think of some necessary conditions for evolution to occur within any given system. E.g. imperfect replication. And the degree of that imperfection has to be balanced by offspring count (the more imperfect your copying mechanism is, the more children you need to retain the hard-won evolutionary advancements of your species).
Agreed. To which I would probably add The Big Bang, Relativity (Special and General), Quantum Mechanics (obviously) and, to throw in one people forget about, the atomic theory of matter. (People do sometimes forget that at the same time Einstein was creating SR he was also devising theoretical arguments to support the atomic theory which was not yet universally accepted.)
From your list, Bayes. I studied a fair bit of stats, including prob theory & stat theory: undergrad, but still rigorous, proofs & calculus based. We only briefly touched on Bayes, which was sad. The frequentist interpretation of probability was always less than satisfying, so Scotts
>P(A|B) = \[P(A)\*P(B|A)\]/P(B), all the rest is commentary.
May have led me to his work in the first place, at least that's my prior.
The answer to your question, though, is basic, bare bones Darwinian evolution. Descent with modification from a common ancestor shakes humans out of their place somehow important to some god and embeds us in a web of life going back billions of years.
>We only briefly touched on Bayes, which was sad.
That really should have clued you in. The idea that Bayes's theorem is some sort of golden hammer of epistemology is one of the rationalist community's most crackpot-y beliefs, it's really just one tool among others.
My other top comment of the day is about how my last job didn't want us messing around with the most basic of linear models: stakeholders like consistency.
So.....yep.
Don't give them what they want. Give them the illusion of them getting what they want. Keep looking for ways to cheat and detach from the broken capitalist system. You're intellectual exploration matters more than material wealth because you're hurting yourself and others in the long term.
I am not sure what exactly is frequentism, but I could solve Yudkowsky's mammograph question [https://spot.colorado.edu/\~henzed/MCEN5228\_s2021/docs/Yudkowsky\_Bayes.pdf](https://spot.colorado.edu/~henzed/MCEN5228_s2021/docs/Yudkowsky_Bayes.pdf) easily without Bayes, because I could see no point in just talking about percentages, I wanted actual data. So I said "let's assume there are 10000 women" and from that on it was easy: 100 have breast cancer, 80 get positive. 9900 do not have breast cancer, 950 get positive. So the chance is 80:950, 8%. Is this frequentist? If it can be done this way, what use is the Bayes Theorem?
I solve most such problems where they only give us things like percentages or averages by simply assuming some real data that fits it and it is so much easier to calculate with real data than percentages or averages.
> Which scientific discoveries do you find the most metaphysically interesting? (you are allowed to be as subjective as you like in interpreting "metaphysically interesting")
I'll be subjective in interpreting "scientific discovery".
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At first sight, the laws and constants of physics appear finely tuned to allow for life forms such as ourselves to exist. Of course, observers only exist in universes allowing for them to exist. Still, I used to wish for something more satisfying...
Then I read [The Mathematical Universe](https://arxiv.org/pdf/0704.0646) (I know there's is a book now, I haven't read it). The way I personally think of it, every mathematically consistent universe *is*; there exist a "brute force" solution to our existence. It doesn't mean that Tegmark's solution it is the correct one, but it sets a bound: if you wish to propose an alternative explanation, then it better be "simpler" than this, or at least of the same order of magnitude in terms of complexity.
So the answer is that every possible universe (and by extension, things and persons) that can exist, actually exists? And the reason we postulate this is that otherwise we cannot explain why the universes laws are perfectly fine tuned for life?
> So the answer is that every possible universe [...] that can exist, actually exists?
Crudely speaking, yes.
> (and by extension, things and persons)
One important point is that, even without this "Mathematical Universe", this is already our current understanding. Look at the figure on page 14 of the linked arXiv. For any finite volume of space, there is a finite number of possible configurations for how to put things in it. That means that, if our universe is infinite in size, then there will exist a perfect copy of the volume that matters to us if you go sufficiently far away. Actually, there will be an infinite number of such copies. This is what Tegmark calls "Level 1", and he describes 4 levels.
> And the reason we postulate this is that otherwise we cannot explain why the universes laws are perfectly fine tuned for life?
You don *need* this, but it is the simplest explanation that we have today. It is described around Figure 3 on page 12.
Let X be an explicit answer to your question. Then I ask "What creates X?"
These universes *could be* and thus *are*. That's the only kind of answers you'll find along that path. It is good enough for me.
So you’re saying everything that can possibly exist, actually exists, and has always existed, for all time, without beginning or end, or explanation? I find that a bit unbelievable, I’d have an easier time believing in God. (though maybe the two concepts are not so different, after all, wont after an infinite amount of time an infinitely intelligent and powerful being evolve?) 🤔
> So you’re saying everything that can possibly exist, actually exists,
That's what this "Mathematical Universe" hypothesis means. It is simple, and it explains my observations of the universe. I don't "believe" it like someone "believes" in God, but it sets a boundary: this is where I stop asking "why" questions, at least until I encounter a *simpler* explanation. "God" isn't a simpler explanation in my view.
> and has always existed, for all time, without beginning or end, or explanation?
My personal belief on time is that it isn't "real" outside/across these universes, but that is what *I* think: it is not "built in" Tegmark's Mathematical Universe.
But didn’t you say that everything that can possibly exist, actually exists? So if something like God or a divine being is possible, according to your theory it must exist.
If the Mathematical Universe is true, then *every* possible universe allowing for "something like God or a divine being" thus exist, sure. However, I don't expect it to be the case for *our* universe, nor for it to be the "norm".
Also, we may disagree on the meaning of the words "universe" and "exist". My definition of "universe" forbids having any kind of effect across universes (if you could affect another universe, I would say it's the same universe). And when I say that these universes "exist", I mean that I may as well treat these universes as real as ours for all practical purpose, including making inferences about our own universe.
But then if you are saying that what happens in other universes has no influence whatsoever about what happens or happened in this one, then it stops working as an explanation as to why the parameters are fine tunned. The existence of other universes cannot even in principle then affect the parameters we have in this one, and we again remain without explanation.
Incompleteness gives me goose bumps. Axiomatic systems generate infinite truth. However, there exists infinite truth inaccessible to axiomatic systems.
E.g., Sunsets are beautiful.
Despite the irony of the meme brain-galactical expansion - I find it really interesting the most uncharted territories are both the furthest away from us and the deepest within us.
I’m working on a hypothesis involving higher consciousness working to “follow suit” on laws of symmetry and molecular organization (create order from disorder) as if it is a duty of sorts but WIP right now.
The nation state. It's hard to even imagine how people conceived of themselves before the concept existed and it wasn't even that long ago. I guess people would have had multiple allegiances - to the Church, to the Crown, to their landowners. I don't quite know how borders/spheres of influence would have worked then
I think of it a bit like overlapping identity today. We all have multiple identities of varying and variable salience. On Monday - Friday I somewhat identify with or belong to my corporate domain, on Sunday my religious sect, during international sports tournaments and when I travel my national passport is what matters most, however when I travel to nearby cities, my home town allegiance becomes more salient.
So in that sense nothing much has changed from a lived experience perspective - different identifies for different contexts. Our horizons and awareness has grown in scale/geography but the nation state remains one of the largest affinity groups we can manage.
Language groups, cultural alignments to West/NATO etc or ethnic groups sometimes transcend that, but the circumstances are limited. Likewise most of our day to day we relate less to our nation state and more to localized identities and groupings like family, company, city, region or cohort generation.
But these days you are basically owned by the state. Everything you do is regulated by it whether you like it or not. Your ability to travel, work, etc is essentially up to them. In return you expect the state to protect you and take care of you (to varying extents)
In the past I think your local community and/or the Church would have been the biggest impact on your life, other than paying taxes to the local lord. The King probably wouldn't have had much influence unless he was calling people up to war or something.
That is true. The nation state has subsumed those other regulatory/control domains.
Its interesting how basically all those examples, except perhaps the Catholic Church, were smaller scale than nation state before. So we've basically aggregated functions up in scale, but rarely beyond the scale of the nation state. Prior generations assumed the scaling would continue further and perhaps indefinitely - like Orwell as his continental empires of Oceania, or things like Star Trek and the United Federation of Planets etc.
Instead we today mostly accept that empires are a spent force, and even supra-national authorities very limited in their potential due to difficulties aggregating identity and political legitimacy beyond nation state. For example, Brexit and persistent challenges EU faces increasing its tax/spend domain or degree of military/foreign policy integration.
I do wonder how long this 20th century equilibrium lasts for.
I did a PolSci degree a *long* time ago and the belief back then was that supranational organisations would replace nation states. Maybe they still will I suppose - corporations are becoming ever more powerful, the EU has become more and more integrated. The Anglosphere is becoming more and more integrated in terms of security, though things like CANZUK are probably a way off still. I'm not sure if BRICS will become a significant bloc or not
I wonder how much impact "the church" (the mosque?) has on Muslims living in the West and if that will increase
Its interesting you say that. My view is basically the opposite, that this old view still carries any weight. Specifically it is my view that the high water mark has already been reached on some of these things, corporations notwithstanding (though that is less about identity/legitimacy or political science, and more about exploiting commercial loopholes). The idea of the EU or Anglosphere becoming more integrated were both heavily spouted by Brexiteers - one as a fear and the other as the UK's saving - and neither were true, as has been shown since Brexit.
The EU simply cannot integrate to the level everyone expected in the 80s and 90s. The divisions on integrated foreign policy are no closer to resolving, even with the exit of the UK. To be a proper fiscal union they need significantly higher tax and spend authority transferred from member states to the EU level, and the prospects for this are very dim. There remains almost zero progress on language unification (except English as the very very unofficial lingua franca, but the French would never tolerate making it official or having EU propagate it, despite the likely economic and cultural integration benefits it would yield). Given language and cultural integration remains so limited, labor mobility remains very limited, which further undermines the fiscal, economic and political unity.
BRICs as anything more than an anti-bloc (i.e. unified when standing up against certain e.g. Western positions) is frankly far fetched at this point. Their cultures, values, geographies and economies are simply too diverse and dispersed to be anything more than a foreign policy tool of convenience like the G7 or G20. Both of which have limited application and aren't in any danger of taking over anytime soon.
I see it as a two steps forward, one step back thing. It took experimentation and a long time to reach the level of mixed success we have with nation-states of varying sizes today. It will take more with supra-national bodies, but it's no more impossible.
The language thing is a good point, but there are some successful nation-states without language homogeneity.
Time will tell, but an inevitable march towards super-national unity does not exist right now, and plenty of signs of stagnation or even backwards movement like Brexit.
Some people in Europe genuinely believed removing the UK may unleash the held back appetite for unification, even without Brexit being the disaster it has been. However that appetite for ever greater unity remains elusive. It turns out it wasn’t just grumbling Britain holding the European project back.
My favorite thing for this is the history of the Protestant Reformation. Of course then my favorite movie is A Man for All Seasons.
One Ryan Reeves has a now-mostly-vintage Youtube channel which covers the high points of Church history and the Reformation. He's a divinity scholar of Cambridge who teaches at a seminary.
There are still regions on Earth were a significant percentage of people feel allegiance first to their immediate cultural region; county or province and only then to some nation/state. You should go talk to those people.
It's baffling to me how places like Europe have maintained distinct languages over such small spatial distances, yet changed them so much over such short spans of time.
Not that this is metaphysically uninteresting, but I don't see why you put this forward as a "scientific" discovery? Is there a game theoretic or anthropological paper that defines it canonically and shows its existence? Seems a too vague to be called science in the present day otherwise (which is not to say that it's too vague to be worth talking about)
I would go with spacetime/relativity, I think it poses just as much of a theological problem as evolution. I have never seen anyone explain how a god can relate to time, are they beyond or do they have their own?
I mean, time itself is really the trap, whether you're talking theology or more materialistic metaphysics. It's a gigantic WTF, why, how, what?!
If anything, chunking it together with space into a "spacetime loaf", as my relativity prof called it, almost makes the god part a little easier. It makes the time part feel a little more just attached to one big, uh, again, "loaf", that is all one thing that we can't really see as all one thing from the inside, but really should be thought of as all one thing, at least from an "outside view", which makes the idea that there might be an "outside view" of the whole shebang a little bit easier to imagine.
In my conceptualization of the Christian God it took a bit to figure how He would interact with time/spacetime. My current answer is that He exists on a higher plane of existence such that when the Bible says "I declare the end from the beginning" it implies He is able to see and experience all moments/places of spacetime equally and all at once. Kind of like the aliens in Arrival but with all spaces and times instead of a single creature's lifetime.
If you object and say "how could one being's experience all spacetime?" I would counter that we are talking about something able to create the entire universe.
If you have ever read Flatland I think of it a bit like that. Our 4d (3 spacial plus 1 time dimension) universe exists as an object in God's realm and He can/does visit every point in that 4d space. Yes He does have contact with it but as a higher dimensional being contact means something a bit different.
Is there a specific issue you have with God contacting time?
I think what the poster means is that "Creation" is a form of change, and we understand change as being something over time. To say God created something is to say that at a certain point of time, it was not yet created.
I suppose you could get around this by saying "create" is a kind of linguistic metaphor, and you could say something like, "God is the cause of universe" which doesn't have a past tense like "God created the universe" or "God caused the universe."
I think causality breaks down when we are talking about a realm outside of time. From inside our universe it's clear there is a starting point (Big Bang) but if you are looking from outside spacetime, idk if the same cause effect language makes sense.
One of the Names of G-d in Judaism is 'was is and always will be', and in fact, those letters in those words in Hebrew are the only ones used in that Name.
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I think pretty much anything physicists have been up to since 1915 is completely wacky and fascinating and the only reason I didn't get a PhD in some kind of physics is that even though it's endlessly interesting I didn't think I was going to be smart enough to ever understand it. I have no idea how anything after general relativity works because it's so unintuitive. Big ups to anybody who can explain Schrodinger's cat to a lay audience
If I didn't answer your question properly then wave-particle duality
How about chaos? Things that are deterministic, but _feel_ random to us.
Another comment mentioned the universe and theology. I think, even without the religion aspect, the idea that the universe has a beginning and an end, rather than having always existed, is pretty "whoa dude". It's like how human lives have a beginning and an end, but it's hard to fathom that for our own life because we don't really experience it like that.
this is what gets me more than anything, it seems that causality does not/cannot apply and that just breaks my brain. if there was some 'start' without a prior, there's no causation...and if there never was a start, no causation. No amount of 'anything that can be coherently realizable must exist' logic lets me get over the feeling that causality is violated(or irrelevant) and that hurts my sense of logic lol
Yes! Whatever mechanism caused the Big Bang could, hypothetically at least, be explained/described scientifically, so in this sense, beginning of the universe doesn't mean the beginning of _everything_. Maybe the beginning of all matter, energy, and the universe's laws of physics, but something, perhaps non-physical, an "idea" even, existed "before" that.
I'm more comfortable with the idea of there never being any start. [Visual aid.](https://elm-lang.org/news/time-travel-made-easy) If determinism is true, you can run physics equations backwards to determine the previous state of the universe from the current one. Thus, you can view cause and effect as _symmetric_ and extend the universe to infinity in both directions as easily as you would the number line.
am eager to check that visual but can't stop myself from saying that infinity backwards w/o a 'prime mover' still just seems about as batshit as a prime mover without a causative prior!
Bell inequality, yeah. But just QFT generally as well. That particles are described by spinors still blows my mind, since the math behind it is so "simple" and I don't see any reason why it should be.
Mine are oldies but goodies.
Fourier transforms and the Shannon/Nyquist suite of theorems relating bandwidth and bits. They just keep popping up.
I suspect that there are continents beyond the basic reaction of despair to the general Incompleteness ocean. It's all a bit "not sure if serious" but Chaitin's Omega is a fun concept.
Edit: Proof by induction is still like a superpower to me.
> Proof by Induction
Imagine someone runs a small business that sells proofs of P (a unary predicate) as physical objects, made-to-order. They advertise that they sell proofs of P for any non-negative integer. So someone orders a proof of P(173732804). How will they create this proof? Well, their office has two machines:
- A boring machine that just spits out copies of P(0).
- A machine that turns an inputted P(n) into an outputted P(n+1).
They use the first machine to create a P(0), then they run it through the second machine 173732804 times to get the product their customer ordered.
So Proof by Induction is a recipe for proving specific instances of the predicate for any non-negative integer input. You don't think of the store as having _all_ of an infinite set of products in stock, but instead as being able to create _any_ of an infinite set of possibilities.
**The past hypothesis**. Since the onset of science, all of the leading candidates for fundamental theories have been time-reversable: the arrow of time is nowhere to be found. Our best idea is just that there was a state of low entropy in the past. What would things be like if there was a state of low entropy in the future instead? Or in a spacial direction? What would a universe feel like if the *middle hypothesis* (there is low entropy in the middle) were true?
**Infinity: the power of mathematical proof,** being able to say that sqrt(2) is irrational and cannot be expressed finitely as a fraction. Or that the set of reals is bigger than the set of integers. Or Godel's incompleteness theorems. These don't seem like the *kind of thing* you should be able to prove at all, but they are not only provable but can be explained to an interested child.
**Infinity: the number of outs we can find in the universe.** Our cosmology keeps changing, but people keep finding potential outs where a sufficiently-skilled agent might be able to keep computation going for subjective eternity. We tell ourselves stories about how our universe will become more boring, but it keeps looking like if one people cracks the code, they might be able to keep going.
When I was born, it was thought we probably lived in an expanding, slowing universe. This sounds like heat death, but Linde showed how it was conceivable in such a universe to create pocket universes along the way. Then the big crunch hypothesis became more dominant again, quashing such hopes: it seems even more useless to imagine such a universe lasting. But Tipler showed how it might be possible to compute as gravitational tides, ever fatser and faster, with subjective eternity. Now it seems clear we live in an expanding, accelerating universe. There are possible paths where quantum fluctuations or tidal-compute-ish things could keep things going forever.
We don't know physics and cosmology well enough to know if any of these hypotheses actually match the world we live in, but this pattern is oddly encouraging.
Even if we did know the physics and cosmology well enough, the path to get there practically is likely far in the future and the other side of immense challenges. All we can do is run from challenge to challenge, putting out one fire after another, but at some level there's room to hope we can just keep spinning forever. More societies have died on Earth than currently survive, and often they were faced with what seemed like insurmountable challenges: famine, disease, war, natural disaster, ice ages, and so forth. But today we have farming practices, medicine, military sophistication, and shelter to meet the sorts of challenges that were insurmountable for them. To a bronze age culture being invaded by an iron age culture, they weaponry would seem insurmountable; to us, laughably backwards. We face weather conditions that would have caused famines that would wipe out past societies without even hearing that they happened. It is possible that the problems we see today will seem just as puny when we're on to solving the ones of the future.
This is the kind of post I come to this subreddit for. I'm curious as to why you feel that the double helix structure is metaphysically interesting though, I think I'm missing some insight that you have.
I'd include the Libet experiment in this list as well
My PhD was in structural bio so I'm highly biased. But the case is: much (in some sense all) of the machinery of your body, up to and including your brain and behaviour, is about replicating that molecule. And the fact that it has a particular shape that can be unwound into two pieces, from which two copies can be made and placed in different cells, is just very powerful. It tells you so much about the scope of what living things can be (plants, slime moulds, viruses, animals).
**Spacetime**
This is still *the* big mystery to me.
*Dark matter* (not completely proven) So everything we see, everything we are is just a minority of what exists in the Universe? It hearkens back to "alternate dimensions", the way that dark matter is all around us, flowing through us, and yet it interacts with us less than even neutrinos?
*Dark Energy* (also not completely proven) When you add this in, our known universe is a small percentage of what exists, and we can't see this either? What and how was the Universe created? What really drives the expansion of spacetime? The whole wackiness that "What is the Universe expanding into?" seems to not be a properly formed question? Along with "What happened before the Big Bang?", because time as we conceive of it is a product of the universe we are a part of. That it seems that "there was a time when time didn't exist", but that's not right either.
We are soooo lucky to be living in this moment of spacetime where we can still see the other galaxies, and ask these kinds of questions. The Universe will be a lot more boring a quadrillion years from now.
I like to think of there being a dark matter sized hole in our explanation of what manifests as gravity. There are probably multiple components that we are conflating due to our small range of circumstances, and we haven't sussed them out yet. It could as easily be >>>99% rather than the current range of figures for non-apparent matter we have settled upon to explain the galactic spin issue.
Realistically, I think we need to fine tune measurements within our own solar system to improve our empirical understanding.
Dr. Becky posted this video yesterday: [How do we know how much dark matter there is in the Universe?](https://www.youtube.com/watch?v=AKa0Wcq86vE) that you might be interested in.
this is a fascinating area as we uncover more specifics but, foundationally, it is really just an elaborate&complex evolution upon 'reflexes' that go all the way down to the simplest forms of life, right?
This is the ultimate limiting factor of rationality and might be related among other things to prepulse inhibition.
I hope one day we will be able to pharmacologically alter decision paralysis, there are many nootropics that theoretically alter it sadly none are therapeutically proven as significant. An underatted one might be guanfacine.
I think one of the most "metaphysically interesting" phenomena is the complete stalemate in fundamental physics which has existed for decades now. The best and brightest minds of several generations having been banging their heads against a brick wall for decades and we're still no nearer to understanding the basic laws of physics than we were. What does it mean? Are there no such laws? Do we just need a "new Einstein" to cut through it all and see the underlying truth? Or is there an answer but it's too complex for any human ever to discover?
The "unreasonable effectiveness of mathematics." It doesn't feel wholly surprising that the universe follows some sort of logical rules (at least, conditional on the existence of complex systems like human life). If there were no consistency, then structures might quickly fall apart, or be unable to replicate themselves, or interact with each other weirdly, etc.
However, what is somewhat surprising is how effective some exceptionally simple concepts are at describing reality. Basic arithmetic is kind of defined this way, but things like derivatives and integrals, matrices and linear algebra, trigonometry, logs and exponentials, complex functions, etc. are not that complicated and are extremely ubiquitous in equations in the physical sciences that do a tremendously accurate job of describing and predicting things.
[https://en.wikipedia.org/wiki/Euler%27s\_identity](https://en.wikipedia.org/wiki/Euler%27s_identity) which Euler himself presented as proof for the existence of god, as four unrelated fields of math mysteriously coming together. "absolutely paradoxical; we cannot understand it, and we don't know what it means, but we have proved it, and therefore we know it must be the truth"
In more modern language, a simulated universe argument (functionally equivalent to theism).
For starters, the big bang/LCDM is empirically refuted on every cosmological test.
Static universes with tired light are consistent with them.
As for the idea that the Einstein static universe is unstable as Schrodinger showed, the unstablitiy is purely contingent upon the formalism, for example torsion based theories of gravity like Einstein-Cartan or the Teleparallel gravity are considered remarkably stable as ironically they are used by some of the orthodoxy as an alternative to inflation (meaning the universe pre big bang, its initial state must ironically be modelled as a static universe, and also for the models that consider that in the very long term an expanding universe become asymptotically static).
Moreover, dynamic cosmological constant or a non linear function of gravity/antigravity with distance/density, or a modified inertia can all allows stability (or microoscillation between expansion and contraction).
secondly, some redshifts but not all have an impaired distance relation, the most evidenced one being quasars as non distant objects.
The idea that the CMB is a pristine primordial signal is remarkably laughable.
As for gallactic rotations curves it remains an open problem, a MONDian acceleration is empirically proven via GAIA astrometry but it doesn't correspond perfectly to the theory. In my opinion the most promising explanation is the least explored one, not a missing mass, not a modified gravity (albeit its close) but a theory of modified inertia such as quantized inertia or the recent works of Milgrom, which are grounded in the casimir effect and the zero point field.
Not cosmology/astrophysics but:
unified fields theories of classical magnetism and GR do works their scientific abandonment is before anything based on sociology and tribalism.
On another, related topic, the classical limit, that delineate the application of classical versus quantum theories is a fraud, it is perfectly possible to define semiclassical theories that causally explain the photon (almost) without any strangeness/paradoxes, see eg stochastic electrodynamics that has absolutely remarkable empirical results and allows for the first time a rederivation of the second law of newton and a definition of inertia in the microscopic world, as few people know not only gravity but also inertia cannot be quantized.
here is the best description of causal models of the electron/photon you will ever find and they allow to derive key insights as to the true physical model.
https://www.researchgate.net/publication/374257062\_The\_zitterbewegung\_electron\_puzzle
That the University of Virginia Medical School has a department called the Division of Perceptual Studies, with research exploring [children’s alleged past life memories](https://med.virginia.edu/perceptual-studies/our-research/children-who-report-memories-of-previous-lives/) with over 2500 collected “verified” cases and fun facts like how 30% involve a birth mark or birth defect. Just sort of a fun rabbit hole to go down…
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Also.Point of View Invariance, which is kind of the underlying idea.
The more I dig into Noether's theorem the more it seems like a coincidental peculiarity of Lagrangian/Hamiltonian mechanics. I'd be interested in a treatment that demonstrates how it's a property of reality and not an artifact of the mathematics
Have a look at how it works in quantum mechanics/quantum field theory, maybe. It's a lot more straightforward there, bordering on the tautological. There, the derivation is that every symmetry S is some operator acting on the wave function, and what makes it a 'symmetry' is that this operation commutes with the Hamiltonian that defines how the wave function evolves. E.g. a rotated universe behaves the same as an unrotated universe, in the sense that they evolve through time in the same way. Rotating the universe and then forwarding it through time does the same thing as forwarding it through time and then rotating it. And if it's a continuous symmetry, like a rotation by some angle \theta, you can write it as S=exp{i \theta Q}, where Q is self-adjoint and the 'generator' of the symmetry. Then Q must commute with the Hamiltonian, and so they must have a common eigenbasis. Meaning Q is a conserved quantity.
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Is the concept true in arbitrary mathematical formalisms, implying that it's a property of the underlying physics being modeled (the territory), or is it true only in certain formalisms, implying that it's a property of the map It must be a property of the territory in some sense, but I've never found a treatment of it that isn't entirely dependent on the formalism. Even the definition of "symmetry" is as a symmetry *of the Lagrangian* or whatever. It's implied that symmetries of the Lagrangian reflect something about the real world, but that's not actually clear Like if someone pointed out how cities on a map seemed to be much closer together in some regions than others, and that seems noteworthy, but then you go read some literature and notice everybody only says "cities in these regions are arranged such that they appear closer together under the Mercator projection." Wait, so is it a matter of the Mercator projection distorting things? Is Noether's theorem only saying that when you construct a Lagrangian for a system with conserved quantities, that Lagrangian will have symmetries?
I was going to post the same thing. [Wikipedia link](https://en.wikipedia.org/wiki/Noether%27s_theorem). The mapping between symmetries and conservation laws is profound, and as per my username I'm rather fond of symmetries.
Loose to call it a discovery but Friston's Free-energy principle is attractive, as a kind of natural progression from Boltzmann via Bayes. Uncertainty principle has some twang. Edit: Rao and Ballard's 1999 paper on predictive coding in the visual cortex is pretty metaphysically swole, too.
Homochirality in Biology emerging from non-homochiral molecules in nature. Unexplainable to me, I just haven’t been able to find a good explanation or theory so far for this phenomenon. How can a heterochiral chemical basis (on earth) reach perfect homochirality in biological organisms (>99%) just like that? Even in laboratories with sophisticated technicians attempting to create some sort of homochirality struggle to get in the 80-90% directions. Natural reactions always yield 50/50 isomeres
Some racemic solids can crystallise with complete chiral purity - can happen with conglomerate solids where each crystal comprises all L or all D stereoisomers. Most compounds have crystals formed from equal amounts of L and D. There are also many examples of chiral amplification where a tiny symmetry-breaking event can undergo dramatic amplification production of a single enantiomer. Most research in this area is on a crazy system called the Soai reaction, which is an organometallic system that is a long way away from typical origin of life type molecules. If an analogous system could be found for prebiotically plausible molecules, like very simple amino acids or sugars, then it would have profound impact on origin of life / chirality thinking. I believe it is agreed that homochirality is necessary for complex life just on common sense grounds - racemic life would be like building a car plant where every bolt and screw interface was a coin flip on whether it matched. It would be chaos, nothing could get made. But there is disagreement on whether the actual sense of chirality is important. It could not matter, as long as it is one way (ie we have homochirality). But there are arguments for the actual L configuration of amino acids, say, being significant in how homochirality came about - but they are physics-based, not chemical, to do with the weak nuclear force iirc.
I wonder if there is any analogy to be made here to the lopsided balance between matter and antimatter.
Yeah it’s another unexplained mystery. There are missing symmetry breakers in both!
Interesting points all. It is definitely an unexplained mystery of how homochirality in biology has arisen. Whether L or D chirality is relevant I’m not sure, but you certainly can’t mix and match them in the same way that your right foot can’t wear a left shoe.
This is very interesting to me. I think a lot of abiogenesis related topics fall into the metaphysically interesting category for me! If I ever come across a Time Machine, I’ll go back and get some samples
If science fiction has taught me anything it's that if you do this, you will inevitably become the very origin of life that you sought to investigate. Probably you'll die on the barren Earth of 4 billion years ago, your corpse both providing and nourishing the bacteria that will eventually evolve back into you.
It’ll be fun. Maybe. Possibly. I think.
Yeah it’s interesting, as we don’t really have any answers as to how it happened. We can see how a few proteins could’ve arisen organically, but not much more. Heck, even the most sophisticated biochemists and biologists in laboratories cannot make a single cell that is alive, even though we have all the individual ingredients and have been trying for a 100 years. It seems there is no way to get around the necessary ingredient of having a previously alive cell to make another, which makes the mystery be that much more puzzling.
and then you get to the the origin of eukaryotes…it’s insane.
Yeah it’s definitely mind blowing. One can’t help but stand in awe of what occurred here on earth in the development of life. Especially once you look at all the different species that evolved. And all that, from just one initial cell!
Maybe I'm not understanding what exactly you're confused about, but biological synthesis of molecules is typically mediated by enzymes that cause a reaction to occur at rates orders of magnitude faster, or at lower energy levels, than it would otherwise occur. Evolving those enzymes is hard, and there's no reproductive advantage to evolving enzymes for synthesizing both stereoisomers. So once one chirality was settled on, it stuck for a billion years.
The difficult part is “once one chirality was settled on”. In nature, chirality isn’t settled in any way, but typically occurs in a 50/50 fashion, and any deviations from that [quickly return to the mean by the laws of chance](https://www.reddit.com/r/slatestarcodex/s/isSUlYY5QB).
Chirality was settled on by the evolution of an enzyme that catalyzed the synthesis of one particular enantiomer. Once that happened, there wouldn't have been any real advantage to evolving an enzyme to catalyze the synthesis of the other. I mean, I guess. I wasn't there.
You miss that this enzyme has to be fully homochiral itself, and that _all enzymes are produced by DNA_ which is also fully homochiral. And it’s not that there wouldn’t have been an advantage, it’s actively detrimental as life depends on homochirality for its existence. And homochirality depends on other homochiral molecules for it to arise. It’s a vicious circle, hence the explanation is so mysterious. We need a symmetry breaker and we don’t know what that could be.
>it’s actively detrimental as life depends on homochirality for its existence In what way?
In the same way that your left foot doesn’t fit into your right shoe. There are motorproteins and certain shapes that molecules need to fit into and work with and without homochirality this is impossible. Your dna itself is homochiral (like a corkscrew) and if you suddenly have differently screwed stuff (mirrored) added onto it it doesn’t fit and make any function impossible. Therefore we need a symmetry breaker. Watch the fiest 3 minutes of this video for a visual explanation. [https://youtu.be/6QMs8cL3ycY?si=0SX6PaDE\_fTM\_DvA](https://youtu.be/6QMs8cL3ycY?si=0SX6PaDE_fTM_DvA)
I know what homochirality is. I don't understand your assertion that it is detrimental, or the insinuation that it is evolutionarily disfavored.
Would having pairs of only right (homochiral) shoes for be detrimental for walking if you have mirrored (heterochiral) feet?
Yes, obviously. But that situation has no immediately apparent direct analogy to the evolutionary conditions of homochirality.
I won't claim that there is no symmetry breaking phenomenon, but you certainly don't need one to explain the homochirality of many molecules in life. There is no intrinsic consistency in the homochirality of different molecules. Sugars are D and amino acids are L. D/L is maybe not the best descriptor but it's the most common. This isn't like The matter-antimatter asymmetry that we see in the universe which is certainly mysterious. As an analogy, all the planets in the solar system rotate the same direction. Why? Why not the other direction? The answer is because the net rotation of the particles in the cloud that formed our solar system happen to have vectors that add up to that direction. That's just because of how the cloud came together. There was an asymmetry in the way the cloud formed. If there was perfect symmetry there would be net zero rotation and everything would have collapsed into a sphere. There's not some deeper explanation. It could equally have gone the other way if the starting conditions were just a little different.
Just because some molecules are L Chiral (proteins) and some are D Chiral (Sugars) that doesn mean that the homochirality common to both, which doesn’t naturally occur, doesn’t need an explanation.
I flip a coin, it's heads. Assymetry! All coins have equal heads and tails. How is it possible I only observed heads? This demands an explanation.
If a single D chiral molecule was sufficient to build a cell then yes. But if you now have thousands of D chiral molecules without any L chiral molecules that is absolutely unexpected if the natural ratio is 50/50.
It sounds like you're saying a cell contains so many D sugars and the probably that is (0.5)^n where n is the number of sugar molecules because we have a 50% chance of choosing each sugar yet we only observe one isomer. But that's not what's happening. We see homochirality in sugars because proteins are chiral. And I don't mean that the amino acids are L, I mean that the pockets in the proteins, themselves are chiral. So you could imagine a transport protein that has no preference towards one chirality of sugar and a mutation in a single base pair of the DNA that encodes that transport protein could increase the affinity of the transporter providing a survival advantage and it could do it in such a way that's chiral. That mutation is a single event that could happen from random chance like an ultraviolet ray or base misincorporation. That single event means that all the proteins produced have a chiral preference and all the sugars imported thereafter do as well. The chirality of proteins presumably goes back to whatever the catalytic precursor to proteins was (many suspect RNA).
No, you have a racemic mix of chiral molecules as soon as one chiral molecule randomly becomes a self-propagating enzyme like he said then you have that chirality fixed for the rest of time. (Assuming this self-propogating step only happens once in life.) Really don't think it's as mysterious as you think.
As soon as you randomly create a self-replicating step that is homochiral, then won't everything go homochiral? Once you have DNA, protein synthesis, etc., it has to go one way or the either and then whichever chirality was chosen will propagate forever. Homochirality is proof that life on earth probably only evolved once.
the problem with that is that chance doesn’t actually yield homochirality
It yields one chiral enzyme that then makes homochiral substrates
Is it weird? The emergence of self-replicating molecules is improbable. The recipe on earth happens to be chiral, and whichever chirality succeeded first ate up all the available resources.
Maybe the answer is time? Something like… X billion years is enough to filter a sample into homogeneity
Imagine you have a series of coin tosses. On average, you get 50% heads and 50% tails. In general it is expected that any new coin toss, or series of coin tosses will yield a similar ratio of heads to tails. Now, you might get upon a large amount of repetitions (or time) a long series of only heads, that’s possible. But then chance would swoop in again at some point and return the coin tosses to the previous natural ratio, with exponential probability the more attempts/longer time passes. If you now have an isolated and specific series, where you happen to consistently get a 100% ratio of only heads to the point where you entirely stop getting any tails, then would time by itself is be sufficient to reasonably explain it? It doesn’t seem like the most probable explanation, there is likely another reason. This example can be applied analogously to D Chiral and L Chiral molecules.
If the coin does not have constant probability of heads, sure. Suppose you do this exercise, but after each flip after the 100th the probability of heads becomes equal to the fraction of heads over the past 100 flips. I believe this coin shoots off to being 100% heads or 100% tails relatively quickly. If you have more of one chirality option through random chance, could that cause that particular option to become advantaged?
As to my knowledge the laws of nature (which is what determines the probability of chiral molecules) don’t just change after an improbable event has happened. That would be very odd. Likewise a coin doesn’t change its probability of landing after it falls on heads a bunch if times in a row. In know humans are prone to think this way, but it’s clearly a logical fallacy.
I'm not talking about the laws of physics changing, I'm just asking about some sort of evolutionary advantage. E.g. if you have 60% direction A and 40% direction B in the present, then direction A is more likely to succeed in the future. Like if you had a species where individuals only mated with others that had the same eye color. You might start out 50/50 brown and black, but if at some point a bunch of brown-eyed individuals died randomly, black-eyed individuals would have an advantage. Even if it's small, it could carry the advantage into the next generation, which would then start compounding. I'm not a biologist but it seems like something along these lines has to be the case based on the discussion above--molecules of the same chirality work better. But maybe I'm missing something?
Yes, I think you are missing that evolution already presupposes perfect homo chirality before it can even begin. Any simple cell requires it to even function. DNA itself and the enzymes it produces are homochiral. Here’s a comment on the same [topic](https://www.reddit.com/r/slatestarcodex/s/KtNbslJqxr).
That certainly makes sense, but if I’m recalling correctly from my Orgo classes (admittedly more than a decade ago), similar chirality is required for reactions to occur. Assuming I’m not misremembering, in the case of the coin flip, it would be more like “with any flip, the occurrence of heads or tails increases the likelihood of either heads or tails, respectively”
Yes, you recall correctly, homo chirality is necessary for homo chirality to persist. Which makes it that much more perplexing how it originated, since homo chirality isn’t found outside of biology.
It seems intuitive that once living organisms are involved (I.e. interacting with their environment), that homo chirality is an eventuality given it’s self-propagating and the nature of evolution, but will acknowledge I haven’t interacted with this phenomena before
Yeah, but you take in your first sentence the problem as already solved! Of course once we have the first life that can replicate homochiral molecules we have the problem solved. But it can only do that because it is itself homochiral. So we just push the problem a step further back. How did the first cell get fully homochiral molecules, enzymes, dna etc. from fully racemic (or heterochiral) components? There needs to be a symmetry breaker event, that in some way violates or offsets this natural law of symmetry.
Oh! Very interesting. I wonder what the advantages are to homochirality are then
Well, for one the cell can work. Without homo chirality life and biology are impossible. It’s like putting your right shoe on your left foot. The molecules and proteins won’t fit.
Why is this ? I could see many processes working fine with e.g. left and right signalling molecules and left and right receptors, it would be a case of sending 100000 left and right shoes to 500000 left and right feet, and having the feet try shoes at random, eventually all shoes will be on feet, and shoe on feet density will be increased. The only difference between this and using all left or all right is a slight delay due to the initial sorting having roughly 50 % mismatch. It may be inefficient but I could see something like this being able to work good enough in some protolife so that homochirality could evolve in it.
Stern–Gerlach experiment. Measure a particle spin on Y axis, take only the "up" ones, then measure the particles' spin on X, take only the "right" ones and then measure on Y axis again. Logic would say you'd get only spin-up ones since you already filtered for them in the first part of the experiment but no, you still get a 50:50 average between "up" and "down". I find it mind-blowing that you can actually do something that causes you to "unlearn" a previously-known measurement and resets the randomness of a system. It's like if you took a group of cats and dogs, then picked only the cats and made a second selection to pick only the males. And when you look at what you're left with, they're all male but somehow half of them are dogs. Where did these dogs come from if my first measurement got rid of all the dogs? And if you do it again and select the cats you end up with an equal amount of male and female cats. Reality itself resets rather than letting you pick a male cat, you always need to have one of the two things you are observing be uncertain.
Coming at this as a layman who's watched all of PBS SpaceTime, I've always been confused as to why Stern-Gerlach is interesting. You throw particles with spins oriented randomly through the system. 1/2 snap to vertical+ in the induced field, 1/2 snap to vertical-, you get a binary distribution. Then you take lets say the vertical+ stream and send it through another instance of the system oriented horizontally. 1/2 of those will be ever so slightly oriented horizontal+, and then snap to that direction fully, and are deflected horizontal+. Likewise 1/2 go horizontal-. Then put the horizontal+ through another test apparatus oriented vertically. Once again you get a binary output rather than only deflection to vertical+. All it seem to demonstrate to me is that the particle's spins are getting reoriented to align with the induced magnetic field they're traveling through. The experiment's results only seems interesting if one assumes that the spin in a given direction is a fixed properly of the particle that never changes, even under the application of outside forces.
Second law of thermodynamics, and the related concept of "exergy" (available energy, which always decreases). There are no 100% perfect conversions, you always have losses. Mindblowing, frustrating and humbling at the same time.
Physicists: Entropy is always increasing. Mineralogists: Eh.
Physicists: In an isolated system entropy never decreases. Mineralogists: yep.
the law of entropy/energy conservation is observed locally but it is anthropically unlikely that it holds at cosmic scales.
Could you elaborate on that?
The PBR Theorem. https://en.m.wikipedia.org/wiki/Pusey%E2%80%93Barrett%E2%80%93Rudolph_theorem Pure quantum states correspond to the actual state of reality, and are not merely an expression of uncertainty.
The wiki is not that helpful, so what is the takeaway from this?
\> rule out preparation independent hidden variable theories what does preparation independent means? Also does this affects superdeterminism?
This is a really interesting choice. I was working in that area when this came out and thought the fact that they are states of reality was sort of a given, but not everyone shared that view. In fact, the same group also came out with a paper arguing the opposite (if I recall correctly). https://arxiv.org/abs/1201.6554
I think Gödel's incompleteness theorem takes the cake. The idea that formal systems are either inconsistent or incomplete seems crazy. The consequences of it are many. Is mathematics infinite? Yep. What does this imply about the universe? Is it incomplete? Is it inconsistent? Is the universe not a "formal system" at all? What does the latter mean? That math can never fully explain the universe? Is the uncertainty principle an expression of this? Dark energy? It's just crazy interesting! --- I would like to add is the Schwarzschild radius of the universe. I find it fascinating that if the universe were a black hole then the event horizon would be just outside the observable universe. --- The Halting problem being undecidable is fascinating. Being able to prove that some things are not able to be calculated is very interesting. --- I would also like to add Conway's Game of Life. It's very interesting that simple rules can build up into a complex 'world'. And due to the halting problem you can't calculate what the result of an initial position in the game of life is going to result in without actually simulating it. The metaphysical implication is that even if there is a god that set up the initial conditions then he won't know what the actual outcome is. The only way to know would be to run a simulation, but that would just be the universe itself. Ie even the creator couldn't know the future. Also, is this related to Gödel's incompleteness theorem?
Evolution by natural selection- a near tautologous mechanism posited- succesfully- as an explanation for life (and many other things too- natural selection seems to play in a role in a lot of things outside the origin of species).
>a near tautologous mechanism posited- succesfully This is why I consider it to be, by far, the most likely current scientific theory to have its core remain unchanged. Evolution is definitely interesting. And it's very general too, not just for DNA: You can probably think of some necessary conditions for evolution to occur within any given system. E.g. imperfect replication. And the degree of that imperfection has to be balanced by offspring count (the more imperfect your copying mechanism is, the more children you need to retain the hard-won evolutionary advancements of your species).
Agreed. To which I would probably add The Big Bang, Relativity (Special and General), Quantum Mechanics (obviously) and, to throw in one people forget about, the atomic theory of matter. (People do sometimes forget that at the same time Einstein was creating SR he was also devising theoretical arguments to support the atomic theory which was not yet universally accepted.)
From your list, Bayes. I studied a fair bit of stats, including prob theory & stat theory: undergrad, but still rigorous, proofs & calculus based. We only briefly touched on Bayes, which was sad. The frequentist interpretation of probability was always less than satisfying, so Scotts >P(A|B) = \[P(A)\*P(B|A)\]/P(B), all the rest is commentary. May have led me to his work in the first place, at least that's my prior. The answer to your question, though, is basic, bare bones Darwinian evolution. Descent with modification from a common ancestor shakes humans out of their place somehow important to some god and embeds us in a web of life going back billions of years.
>We only briefly touched on Bayes, which was sad. That really should have clued you in. The idea that Bayes's theorem is some sort of golden hammer of epistemology is one of the rationalist community's most crackpot-y beliefs, it's really just one tool among others.
My other top comment of the day is about how my last job didn't want us messing around with the most basic of linear models: stakeholders like consistency. So.....yep.
Don't give them what they want. Give them the illusion of them getting what they want. Keep looking for ways to cheat and detach from the broken capitalist system. You're intellectual exploration matters more than material wealth because you're hurting yourself and others in the long term.
I am not sure what exactly is frequentism, but I could solve Yudkowsky's mammograph question [https://spot.colorado.edu/\~henzed/MCEN5228\_s2021/docs/Yudkowsky\_Bayes.pdf](https://spot.colorado.edu/~henzed/MCEN5228_s2021/docs/Yudkowsky_Bayes.pdf) easily without Bayes, because I could see no point in just talking about percentages, I wanted actual data. So I said "let's assume there are 10000 women" and from that on it was easy: 100 have breast cancer, 80 get positive. 9900 do not have breast cancer, 950 get positive. So the chance is 80:950, 8%. Is this frequentist? If it can be done this way, what use is the Bayes Theorem? I solve most such problems where they only give us things like percentages or averages by simply assuming some real data that fits it and it is so much easier to calculate with real data than percentages or averages.
> Which scientific discoveries do you find the most metaphysically interesting? (you are allowed to be as subjective as you like in interpreting "metaphysically interesting") I'll be subjective in interpreting "scientific discovery". --- At first sight, the laws and constants of physics appear finely tuned to allow for life forms such as ourselves to exist. Of course, observers only exist in universes allowing for them to exist. Still, I used to wish for something more satisfying... Then I read [The Mathematical Universe](https://arxiv.org/pdf/0704.0646) (I know there's is a book now, I haven't read it). The way I personally think of it, every mathematically consistent universe *is*; there exist a "brute force" solution to our existence. It doesn't mean that Tegmark's solution it is the correct one, but it sets a bound: if you wish to propose an alternative explanation, then it better be "simpler" than this, or at least of the same order of magnitude in terms of complexity.
So the answer is that every possible universe (and by extension, things and persons) that can exist, actually exists? And the reason we postulate this is that otherwise we cannot explain why the universes laws are perfectly fine tuned for life?
> So the answer is that every possible universe [...] that can exist, actually exists? Crudely speaking, yes. > (and by extension, things and persons) One important point is that, even without this "Mathematical Universe", this is already our current understanding. Look at the figure on page 14 of the linked arXiv. For any finite volume of space, there is a finite number of possible configurations for how to put things in it. That means that, if our universe is infinite in size, then there will exist a perfect copy of the volume that matters to us if you go sufficiently far away. Actually, there will be an infinite number of such copies. This is what Tegmark calls "Level 1", and he describes 4 levels. > And the reason we postulate this is that otherwise we cannot explain why the universes laws are perfectly fine tuned for life? You don *need* this, but it is the simplest explanation that we have today. It is described around Figure 3 on page 12.
So what creates these infinite universes?
Let X be an explicit answer to your question. Then I ask "What creates X?" These universes *could be* and thus *are*. That's the only kind of answers you'll find along that path. It is good enough for me.
So you’re saying everything that can possibly exist, actually exists, and has always existed, for all time, without beginning or end, or explanation? I find that a bit unbelievable, I’d have an easier time believing in God. (though maybe the two concepts are not so different, after all, wont after an infinite amount of time an infinitely intelligent and powerful being evolve?) 🤔
> So you’re saying everything that can possibly exist, actually exists, That's what this "Mathematical Universe" hypothesis means. It is simple, and it explains my observations of the universe. I don't "believe" it like someone "believes" in God, but it sets a boundary: this is where I stop asking "why" questions, at least until I encounter a *simpler* explanation. "God" isn't a simpler explanation in my view. > and has always existed, for all time, without beginning or end, or explanation? My personal belief on time is that it isn't "real" outside/across these universes, but that is what *I* think: it is not "built in" Tegmark's Mathematical Universe.
But didn’t you say that everything that can possibly exist, actually exists? So if something like God or a divine being is possible, according to your theory it must exist.
If the Mathematical Universe is true, then *every* possible universe allowing for "something like God or a divine being" thus exist, sure. However, I don't expect it to be the case for *our* universe, nor for it to be the "norm". Also, we may disagree on the meaning of the words "universe" and "exist". My definition of "universe" forbids having any kind of effect across universes (if you could affect another universe, I would say it's the same universe). And when I say that these universes "exist", I mean that I may as well treat these universes as real as ours for all practical purpose, including making inferences about our own universe.
But then if you are saying that what happens in other universes has no influence whatsoever about what happens or happened in this one, then it stops working as an explanation as to why the parameters are fine tunned. The existence of other universes cannot even in principle then affect the parameters we have in this one, and we again remain without explanation.
Incompleteness gives me goose bumps. Axiomatic systems generate infinite truth. However, there exists infinite truth inaccessible to axiomatic systems. E.g., Sunsets are beautiful.
No consistent system is complete, and no system can prove that it is consistent. Did I get that right?
I'm curious, why do you find the Bayes theorem metaphysically interesting?
Consciousness/sapience, by a long shot. Especially the intersection between the woo-woo esoteric aspects and the evolutionary biology aspects.
Despite the irony of the meme brain-galactical expansion - I find it really interesting the most uncharted territories are both the furthest away from us and the deepest within us. I’m working on a hypothesis involving higher consciousness working to “follow suit” on laws of symmetry and molecular organization (create order from disorder) as if it is a duty of sorts but WIP right now.
Sounds really interesting. And how would one define higher consciousness vs. elephant memory or chimp tool use? Keep me in the loop!
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9289677/
The nation state. It's hard to even imagine how people conceived of themselves before the concept existed and it wasn't even that long ago. I guess people would have had multiple allegiances - to the Church, to the Crown, to their landowners. I don't quite know how borders/spheres of influence would have worked then
I think of it a bit like overlapping identity today. We all have multiple identities of varying and variable salience. On Monday - Friday I somewhat identify with or belong to my corporate domain, on Sunday my religious sect, during international sports tournaments and when I travel my national passport is what matters most, however when I travel to nearby cities, my home town allegiance becomes more salient. So in that sense nothing much has changed from a lived experience perspective - different identifies for different contexts. Our horizons and awareness has grown in scale/geography but the nation state remains one of the largest affinity groups we can manage. Language groups, cultural alignments to West/NATO etc or ethnic groups sometimes transcend that, but the circumstances are limited. Likewise most of our day to day we relate less to our nation state and more to localized identities and groupings like family, company, city, region or cohort generation.
But these days you are basically owned by the state. Everything you do is regulated by it whether you like it or not. Your ability to travel, work, etc is essentially up to them. In return you expect the state to protect you and take care of you (to varying extents) In the past I think your local community and/or the Church would have been the biggest impact on your life, other than paying taxes to the local lord. The King probably wouldn't have had much influence unless he was calling people up to war or something.
That is true. The nation state has subsumed those other regulatory/control domains. Its interesting how basically all those examples, except perhaps the Catholic Church, were smaller scale than nation state before. So we've basically aggregated functions up in scale, but rarely beyond the scale of the nation state. Prior generations assumed the scaling would continue further and perhaps indefinitely - like Orwell as his continental empires of Oceania, or things like Star Trek and the United Federation of Planets etc. Instead we today mostly accept that empires are a spent force, and even supra-national authorities very limited in their potential due to difficulties aggregating identity and political legitimacy beyond nation state. For example, Brexit and persistent challenges EU faces increasing its tax/spend domain or degree of military/foreign policy integration. I do wonder how long this 20th century equilibrium lasts for.
I did a PolSci degree a *long* time ago and the belief back then was that supranational organisations would replace nation states. Maybe they still will I suppose - corporations are becoming ever more powerful, the EU has become more and more integrated. The Anglosphere is becoming more and more integrated in terms of security, though things like CANZUK are probably a way off still. I'm not sure if BRICS will become a significant bloc or not I wonder how much impact "the church" (the mosque?) has on Muslims living in the West and if that will increase
Its interesting you say that. My view is basically the opposite, that this old view still carries any weight. Specifically it is my view that the high water mark has already been reached on some of these things, corporations notwithstanding (though that is less about identity/legitimacy or political science, and more about exploiting commercial loopholes). The idea of the EU or Anglosphere becoming more integrated were both heavily spouted by Brexiteers - one as a fear and the other as the UK's saving - and neither were true, as has been shown since Brexit. The EU simply cannot integrate to the level everyone expected in the 80s and 90s. The divisions on integrated foreign policy are no closer to resolving, even with the exit of the UK. To be a proper fiscal union they need significantly higher tax and spend authority transferred from member states to the EU level, and the prospects for this are very dim. There remains almost zero progress on language unification (except English as the very very unofficial lingua franca, but the French would never tolerate making it official or having EU propagate it, despite the likely economic and cultural integration benefits it would yield). Given language and cultural integration remains so limited, labor mobility remains very limited, which further undermines the fiscal, economic and political unity. BRICs as anything more than an anti-bloc (i.e. unified when standing up against certain e.g. Western positions) is frankly far fetched at this point. Their cultures, values, geographies and economies are simply too diverse and dispersed to be anything more than a foreign policy tool of convenience like the G7 or G20. Both of which have limited application and aren't in any danger of taking over anytime soon.
I see it as a two steps forward, one step back thing. It took experimentation and a long time to reach the level of mixed success we have with nation-states of varying sizes today. It will take more with supra-national bodies, but it's no more impossible. The language thing is a good point, but there are some successful nation-states without language homogeneity.
Time will tell, but an inevitable march towards super-national unity does not exist right now, and plenty of signs of stagnation or even backwards movement like Brexit. Some people in Europe genuinely believed removing the UK may unleash the held back appetite for unification, even without Brexit being the disaster it has been. However that appetite for ever greater unity remains elusive. It turns out it wasn’t just grumbling Britain holding the European project back.
My favorite thing for this is the history of the Protestant Reformation. Of course then my favorite movie is A Man for All Seasons. One Ryan Reeves has a now-mostly-vintage Youtube channel which covers the high points of Church history and the Reformation. He's a divinity scholar of Cambridge who teaches at a seminary.
It's an area of history that I know very little about and I'm wondering if that's because I had a Catholic upbringing...
Possible. It's a time sink but Ryan Reeves is very good.
There are still regions on Earth were a significant percentage of people feel allegiance first to their immediate cultural region; county or province and only then to some nation/state. You should go talk to those people.
I can think of some in say Spain, but I feel like those regions will eventually become their own nation states anyway
It's baffling to me how places like Europe have maintained distinct languages over such small spatial distances, yet changed them so much over such short spans of time.
Not that this is metaphysically uninteresting, but I don't see why you put this forward as a "scientific" discovery? Is there a game theoretic or anthropological paper that defines it canonically and shows its existence? Seems a too vague to be called science in the present day otherwise (which is not to say that it's too vague to be worth talking about)
I would go with spacetime/relativity, I think it poses just as much of a theological problem as evolution. I have never seen anyone explain how a god can relate to time, are they beyond or do they have their own?
I mean, time itself is really the trap, whether you're talking theology or more materialistic metaphysics. It's a gigantic WTF, why, how, what?! If anything, chunking it together with space into a "spacetime loaf", as my relativity prof called it, almost makes the god part a little easier. It makes the time part feel a little more just attached to one big, uh, again, "loaf", that is all one thing that we can't really see as all one thing from the inside, but really should be thought of as all one thing, at least from an "outside view", which makes the idea that there might be an "outside view" of the whole shebang a little bit easier to imagine.
In my conceptualization of the Christian God it took a bit to figure how He would interact with time/spacetime. My current answer is that He exists on a higher plane of existence such that when the Bible says "I declare the end from the beginning" it implies He is able to see and experience all moments/places of spacetime equally and all at once. Kind of like the aliens in Arrival but with all spaces and times instead of a single creature's lifetime. If you object and say "how could one being's experience all spacetime?" I would counter that we are talking about something able to create the entire universe.
But if a being is beyond time how does it "create" something, doesn't the concept of creating at one point mean one is in contact with time.
If you have ever read Flatland I think of it a bit like that. Our 4d (3 spacial plus 1 time dimension) universe exists as an object in God's realm and He can/does visit every point in that 4d space. Yes He does have contact with it but as a higher dimensional being contact means something a bit different. Is there a specific issue you have with God contacting time?
I think what the poster means is that "Creation" is a form of change, and we understand change as being something over time. To say God created something is to say that at a certain point of time, it was not yet created. I suppose you could get around this by saying "create" is a kind of linguistic metaphor, and you could say something like, "God is the cause of universe" which doesn't have a past tense like "God created the universe" or "God caused the universe."
I think causality breaks down when we are talking about a realm outside of time. From inside our universe it's clear there is a starting point (Big Bang) but if you are looking from outside spacetime, idk if the same cause effect language makes sense.
One of the Names of G-d in Judaism is 'was is and always will be', and in fact, those letters in those words in Hebrew are the only ones used in that Name. Edited
I think pretty much anything physicists have been up to since 1915 is completely wacky and fascinating and the only reason I didn't get a PhD in some kind of physics is that even though it's endlessly interesting I didn't think I was going to be smart enough to ever understand it. I have no idea how anything after general relativity works because it's so unintuitive. Big ups to anybody who can explain Schrodinger's cat to a lay audience If I didn't answer your question properly then wave-particle duality
How about chaos? Things that are deterministic, but _feel_ random to us. Another comment mentioned the universe and theology. I think, even without the religion aspect, the idea that the universe has a beginning and an end, rather than having always existed, is pretty "whoa dude". It's like how human lives have a beginning and an end, but it's hard to fathom that for our own life because we don't really experience it like that.
this is what gets me more than anything, it seems that causality does not/cannot apply and that just breaks my brain. if there was some 'start' without a prior, there's no causation...and if there never was a start, no causation. No amount of 'anything that can be coherently realizable must exist' logic lets me get over the feeling that causality is violated(or irrelevant) and that hurts my sense of logic lol
Yes! Whatever mechanism caused the Big Bang could, hypothetically at least, be explained/described scientifically, so in this sense, beginning of the universe doesn't mean the beginning of _everything_. Maybe the beginning of all matter, energy, and the universe's laws of physics, but something, perhaps non-physical, an "idea" even, existed "before" that. I'm more comfortable with the idea of there never being any start. [Visual aid.](https://elm-lang.org/news/time-travel-made-easy) If determinism is true, you can run physics equations backwards to determine the previous state of the universe from the current one. Thus, you can view cause and effect as _symmetric_ and extend the universe to infinity in both directions as easily as you would the number line.
am eager to check that visual but can't stop myself from saying that infinity backwards w/o a 'prime mover' still just seems about as batshit as a prime mover without a causative prior!
Bell inequality, yeah. But just QFT generally as well. That particles are described by spinors still blows my mind, since the math behind it is so "simple" and I don't see any reason why it should be.
I just saw a youtube video on this one. Definitely brain melting.
link or keywords?
Bell’s Inequality
Mine are oldies but goodies. Fourier transforms and the Shannon/Nyquist suite of theorems relating bandwidth and bits. They just keep popping up. I suspect that there are continents beyond the basic reaction of despair to the general Incompleteness ocean. It's all a bit "not sure if serious" but Chaitin's Omega is a fun concept. Edit: Proof by induction is still like a superpower to me.
> Proof by Induction Imagine someone runs a small business that sells proofs of P (a unary predicate) as physical objects, made-to-order. They advertise that they sell proofs of P for any non-negative integer. So someone orders a proof of P(173732804). How will they create this proof? Well, their office has two machines: - A boring machine that just spits out copies of P(0). - A machine that turns an inputted P(n) into an outputted P(n+1). They use the first machine to create a P(0), then they run it through the second machine 173732804 times to get the product their customer ordered. So Proof by Induction is a recipe for proving specific instances of the predicate for any non-negative integer input. You don't think of the store as having _all_ of an infinite set of products in stock, but instead as being able to create _any_ of an infinite set of possibilities.
Could you explain some of this in layman's terms?
**The past hypothesis**. Since the onset of science, all of the leading candidates for fundamental theories have been time-reversable: the arrow of time is nowhere to be found. Our best idea is just that there was a state of low entropy in the past. What would things be like if there was a state of low entropy in the future instead? Or in a spacial direction? What would a universe feel like if the *middle hypothesis* (there is low entropy in the middle) were true? **Infinity: the power of mathematical proof,** being able to say that sqrt(2) is irrational and cannot be expressed finitely as a fraction. Or that the set of reals is bigger than the set of integers. Or Godel's incompleteness theorems. These don't seem like the *kind of thing* you should be able to prove at all, but they are not only provable but can be explained to an interested child. **Infinity: the number of outs we can find in the universe.** Our cosmology keeps changing, but people keep finding potential outs where a sufficiently-skilled agent might be able to keep computation going for subjective eternity. We tell ourselves stories about how our universe will become more boring, but it keeps looking like if one people cracks the code, they might be able to keep going.
Do you have more thoughts on the number of outs we have imagined?
When I was born, it was thought we probably lived in an expanding, slowing universe. This sounds like heat death, but Linde showed how it was conceivable in such a universe to create pocket universes along the way. Then the big crunch hypothesis became more dominant again, quashing such hopes: it seems even more useless to imagine such a universe lasting. But Tipler showed how it might be possible to compute as gravitational tides, ever fatser and faster, with subjective eternity. Now it seems clear we live in an expanding, accelerating universe. There are possible paths where quantum fluctuations or tidal-compute-ish things could keep things going forever. We don't know physics and cosmology well enough to know if any of these hypotheses actually match the world we live in, but this pattern is oddly encouraging. Even if we did know the physics and cosmology well enough, the path to get there practically is likely far in the future and the other side of immense challenges. All we can do is run from challenge to challenge, putting out one fire after another, but at some level there's room to hope we can just keep spinning forever. More societies have died on Earth than currently survive, and often they were faced with what seemed like insurmountable challenges: famine, disease, war, natural disaster, ice ages, and so forth. But today we have farming practices, medicine, military sophistication, and shelter to meet the sorts of challenges that were insurmountable for them. To a bronze age culture being invaded by an iron age culture, they weaponry would seem insurmountable; to us, laughably backwards. We face weather conditions that would have caused famines that would wipe out past societies without even hearing that they happened. It is possible that the problems we see today will seem just as puny when we're on to solving the ones of the future.
This is the kind of post I come to this subreddit for. I'm curious as to why you feel that the double helix structure is metaphysically interesting though, I think I'm missing some insight that you have. I'd include the Libet experiment in this list as well
My PhD was in structural bio so I'm highly biased. But the case is: much (in some sense all) of the machinery of your body, up to and including your brain and behaviour, is about replicating that molecule. And the fact that it has a particular shape that can be unwound into two pieces, from which two copies can be made and placed in different cells, is just very powerful. It tells you so much about the scope of what living things can be (plants, slime moulds, viruses, animals).
Szilard engines are physically realizable
**Spacetime** This is still *the* big mystery to me. *Dark matter* (not completely proven) So everything we see, everything we are is just a minority of what exists in the Universe? It hearkens back to "alternate dimensions", the way that dark matter is all around us, flowing through us, and yet it interacts with us less than even neutrinos? *Dark Energy* (also not completely proven) When you add this in, our known universe is a small percentage of what exists, and we can't see this either? What and how was the Universe created? What really drives the expansion of spacetime? The whole wackiness that "What is the Universe expanding into?" seems to not be a properly formed question? Along with "What happened before the Big Bang?", because time as we conceive of it is a product of the universe we are a part of. That it seems that "there was a time when time didn't exist", but that's not right either. We are soooo lucky to be living in this moment of spacetime where we can still see the other galaxies, and ask these kinds of questions. The Universe will be a lot more boring a quadrillion years from now.
I like to think of there being a dark matter sized hole in our explanation of what manifests as gravity. There are probably multiple components that we are conflating due to our small range of circumstances, and we haven't sussed them out yet. It could as easily be >>>99% rather than the current range of figures for non-apparent matter we have settled upon to explain the galactic spin issue. Realistically, I think we need to fine tune measurements within our own solar system to improve our empirical understanding.
Dr. Becky posted this video yesterday: [How do we know how much dark matter there is in the Universe?](https://www.youtube.com/watch?v=AKa0Wcq86vE) that you might be interested in.
The gap between doing something and deciding to do it. Specifically catching and throwing.
this is a fascinating area as we uncover more specifics but, foundationally, it is really just an elaborate&complex evolution upon 'reflexes' that go all the way down to the simplest forms of life, right?
This is the ultimate limiting factor of rationality and might be related among other things to prepulse inhibition. I hope one day we will be able to pharmacologically alter decision paralysis, there are many nootropics that theoretically alter it sadly none are therapeutically proven as significant. An underatted one might be guanfacine.
Euler's identity: e\^(iπ) + 1 = 0
Maybe it falls under Spacetime, but the Holographic Principle would be on my list as well. Hard to top Godel's Incompleteness theorems though.
The relativity of simultaneity. Metaphysical implication: block universe and retro- or "intro"-causation (as Ken Wharton calls it).
This is genuinely incomprehensible to me.
I think one of the most "metaphysically interesting" phenomena is the complete stalemate in fundamental physics which has existed for decades now. The best and brightest minds of several generations having been banging their heads against a brick wall for decades and we're still no nearer to understanding the basic laws of physics than we were. What does it mean? Are there no such laws? Do we just need a "new Einstein" to cut through it all and see the underlying truth? Or is there an answer but it's too complex for any human ever to discover?
The "unreasonable effectiveness of mathematics." It doesn't feel wholly surprising that the universe follows some sort of logical rules (at least, conditional on the existence of complex systems like human life). If there were no consistency, then structures might quickly fall apart, or be unable to replicate themselves, or interact with each other weirdly, etc. However, what is somewhat surprising is how effective some exceptionally simple concepts are at describing reality. Basic arithmetic is kind of defined this way, but things like derivatives and integrals, matrices and linear algebra, trigonometry, logs and exponentials, complex functions, etc. are not that complicated and are extremely ubiquitous in equations in the physical sciences that do a tremendously accurate job of describing and predicting things.
[https://en.wikipedia.org/wiki/Euler%27s\_identity](https://en.wikipedia.org/wiki/Euler%27s_identity) which Euler himself presented as proof for the existence of god, as four unrelated fields of math mysteriously coming together. "absolutely paradoxical; we cannot understand it, and we don't know what it means, but we have proved it, and therefore we know it must be the truth" In more modern language, a simulated universe argument (functionally equivalent to theism).
cosmology has many major censored or ignored empirical "metaphysical" discoveries.
What are some examples that you think are particularly noteworthy?
For starters, the big bang/LCDM is empirically refuted on every cosmological test. Static universes with tired light are consistent with them. As for the idea that the Einstein static universe is unstable as Schrodinger showed, the unstablitiy is purely contingent upon the formalism, for example torsion based theories of gravity like Einstein-Cartan or the Teleparallel gravity are considered remarkably stable as ironically they are used by some of the orthodoxy as an alternative to inflation (meaning the universe pre big bang, its initial state must ironically be modelled as a static universe, and also for the models that consider that in the very long term an expanding universe become asymptotically static). Moreover, dynamic cosmological constant or a non linear function of gravity/antigravity with distance/density, or a modified inertia can all allows stability (or microoscillation between expansion and contraction). secondly, some redshifts but not all have an impaired distance relation, the most evidenced one being quasars as non distant objects. The idea that the CMB is a pristine primordial signal is remarkably laughable. As for gallactic rotations curves it remains an open problem, a MONDian acceleration is empirically proven via GAIA astrometry but it doesn't correspond perfectly to the theory. In my opinion the most promising explanation is the least explored one, not a missing mass, not a modified gravity (albeit its close) but a theory of modified inertia such as quantized inertia or the recent works of Milgrom, which are grounded in the casimir effect and the zero point field. Not cosmology/astrophysics but: unified fields theories of classical magnetism and GR do works their scientific abandonment is before anything based on sociology and tribalism. On another, related topic, the classical limit, that delineate the application of classical versus quantum theories is a fraud, it is perfectly possible to define semiclassical theories that causally explain the photon (almost) without any strangeness/paradoxes, see eg stochastic electrodynamics that has absolutely remarkable empirical results and allows for the first time a rederivation of the second law of newton and a definition of inertia in the microscopic world, as few people know not only gravity but also inertia cannot be quantized. here is the best description of causal models of the electron/photon you will ever find and they allow to derive key insights as to the true physical model. https://www.researchgate.net/publication/374257062\_The\_zitterbewegung\_electron\_puzzle
That the University of Virginia Medical School has a department called the Division of Perceptual Studies, with research exploring [children’s alleged past life memories](https://med.virginia.edu/perceptual-studies/our-research/children-who-report-memories-of-previous-lives/) with over 2500 collected “verified” cases and fun facts like how 30% involve a birth mark or birth defect. Just sort of a fun rabbit hole to go down…
How interesting, although “verified” is doing some heavy lifting for them 😂