> Over a sufficiently long time, random fluctuations could cause particles to spontaneously form literally any structure of any degree of complexity, including a functioning human brain
Can anyone explain this bit to me? The formation of biological brains was a multi-billion year climb against entropy. How would a brain form spontaneously without those random fluctuations tearing the constituent components apart?
I’m having trouble understanding the logic here. Random fluctuations don’t imply that any order from those fluctuations can be preserved. The higher order features like brains are path dependent on something resisting those random fluctuations to allow something stable to form, whether that’s an atomic particle, cell, organ, or organism.
The point isn't that they can be preserved; you're right that they probably wouldn't be. But all it takes is a single instant where "you" are randomly "conjured" into being: your Boltzmann brain has all your memories and everything. Even if that brain dissipates a small fraction of a second later, for that tiny amount of time, you would believe in the world as we all know it.
And the bizarre thing about this is you can't say "oh look, I've been in existence long enough to type this sentence, so I and my memories and reality must be real, and not just a random spontaneous formation of a brain", because at every single instant, you could be that brand-new Boltzmann brain, never before formed, and the bits where you thought "oh look, I've been in existence long enough..." are just the memories spontaneously implanted into that brain.
It's kinda wild. I'm not sure I buy it as a realistic possibility, but it can be fun (or terrifying) to think about.
The difference between this concept and, let's say, Descarte's evil demon, is not the philosophical skepticism but its explicit grounding in physics and thermodynamics. It basically attempts to answer the question "Where would that evil demon come from?". It materializes Descarte's thought experiment and shows that it could actually happen within the confines of our scientific knowledge, unlike malicious demons.
Descartes/Hume are saying that to even bootstrap our understanding of reality, we have a hard dependency on sensory perception. (I mention Hume because he points out that even Descartes' singular ground-truth can't lead anywhere else without linking sensory perception back into the mix.) And when I say "nearly anything" it includes our notions about the laws of physics. (Which, btw, cannot be derived from Descartes' singular ground-truth.)
At best, BB is a restatement of what I wrote with the philosophically irrelevant detail that the BB hypothesis relies on all the same laws of physics we have in common with our universe. But I imagine it's really meant commonly as a weaker claim-- one which takes the laws of physics as epistemological ground-truth to derive an ambiguity about the nature of our reality within that universe.
My speculation is that science-minded people think BB is the most potent thought experiment for the same reason non-musicians might think Pachelbel's Canon in D is the best ever-- they've heard it a lot at places filled with people they admire.
As someone familiar with both Descartes and Boltzmann, I will chime in and say that you're approaching this from an angle of contempt and defensiveness, imagining the Boltzmann brain as an inferior subset of or analogy to long-studied philosophical and metaphysical issues such as ground truth or the evil demon. Instead, I implore you to give benefit of the doubt and attempt to understand the differences.
The Boltzmann brain is not making some grand statement on ground truth or perception. It's not about intrinsics or perception at all. Boltzmann discussed how the universe, even in a state of 100% thermodynamic equilibrium, may spontaneously end up in a state of non-equilibrium, reducing entropy. The Boltzmann brain was a concept developed by others in response to this theory.
In fact, many theories are such that a Boltzmann brain actually has a higher chance of occurring than all of the billions of years of coincidences which led up to me typing this message out to you.
It's purely an argument of entropy and spontaneous symmetry breaking. The sensory and perceptive states described by the Boltzmann brain only serve to illustrate the point, and are not the main subject of the problem.
Don't forget that philosophy was the first science, and viewing people as "science-minded" (and therefore not philosophy-minded) hurts the scientific legitimacy of philosophy, and also only serves to exclude. Many scientists also have deep philosophical grounding. Many also have deep musical grounding. You yourself are exhibiting a lack of domain knowledge regarding the Boltzmann brain, filtering it through your "philosophy-minded" perspective, so maybe we can dispense with these kinds of judgements and focus on the core argument.
The world is not so black and white, and there is no false dichotomy between people who are "science-minded" and "philosophy-minded". Both follow the same exact scientific method of inquiry.
Additionally, "the same reason non-musicians might think Pachelbel's Canon in D is the best ever" comes across as a strawman. Some people might prefer that piece overall, but it's not a crime for someone to enjoy it. But relatively few probably consider it "the best ever".
But also, who cares? Why judge? I have a lot of favorite modern pieces which are technically inferior to most classical pieces. But as a musician, not just an engineer, I consider sensory evocation to be equally as important as technicality.
Sounds about right, except Pachelbel's Canon actually is the best song ever for non-musicians.
It showcases harmony and contrasting lines in the simplest, punchiest, most pleasing way. It's fundamentally "the good stuff", and untrained ears slurp it up like babies w pats of butter.
Probably no physicist thinks that Boltzman brains are a potent thought experiment. BBs are short-hand for a problem in combining cosmology and statistical mechanics in a way in which there is a hierarchy of vastly improbable configurations fluctuating into existence out of thermal equilibrium.
Discounting Brain-in-a-Vat (because it's cognitively useless), the problem in a nutshell is that we inhabit a universe which appears (a) to have had a hot dense phase in approximate thermal equilibrium, (b) a future sparse phase in approximate thermal equilibrium, and (c) a whole bunch of structure in between those. Is the structure a fluctuation in (a)? Could (a) be a fluctuation in (b)? These are reasonable questions about which one can ask: is there astrophysical or laboratory evidence available to determine the answers?
One problem is that if (a) (early conditions) is a fluctuation in (b) (late conditions), wherein (a) simply evolves into (c) (complex structure with galaxies and so on) and then (b), what mechanisms could suppress simpler configurations than (a)?
A huge huge huge number of low-entropy Boltzmann brains fluctuating into existence is vastly more likley (on Boltzmann entropy grounds) than an early very-very-very-very-very-low-entropy universe compatible with the standard model of particle physics and the cosmic microwave background and galaxies all over the sky, in which there is a nonzero chance of human brains arising via evolutionary processes.
A tiny change in a Boltzmann brain as it fluctuates into existence could lead to a significant loss of false memory; a tiny change in a maximally-hot maximally-dense phase in the early universe could lead to completely different chemical elements (or none at all).
So Boltzmann brains highlight some metaphysical ratholes one can fall into with respect to the fine-tuning of the (a) state, and have provoked work on how (a) could be so generic an outcome that the evolution of (a)->(c) is "unsurprising". The hard part is coming up with observables which usefully compare a given hypothetical solution and our own sky.
I would question the idea of bootstrapping; rather sensory perception is a QC/QA function that confirms the brain's construct of reality.
The only reason we can generally agree on the nature of any object is our common evolution and generally the same sensory ability. (but that isn't universal and differs widely across species)
Yes, and the idea of Boltzmann brains depends for its credence on those physical principles used to derive it. And those principles in turn depend on the reality (or at least reasonable reliability) of our memories and the whole history of experimental and theoretical development leading to them. So trying to use it as an arugment for philosophical scepticism, or that it's a probable scenario, would be self-defeating, denying its own evidence.
It does give a technically detailed construction for how such a scenrio might come about though, as you say, so it can be interesting to think about.
Sure. But as I said to another respondent, it's a much weaker claim than those which already exist in the philosophical literature.
That doesn't matter if BB is just a bridge for physicists to a deeper understand of philosophy. But I have a sneaking suspicion that BB is part of a basket of ideas in a kind of bubble category of "Philosophy for the Scientist." Similar to those "101 Jokes for Golfers" books-- I mean, fine, but if those are the only jokes you know you're probably insufferable at parties.
Well, the BB isn’t necessarily a serious proposal.
Rather, when you do the math on all the billion/trillion to one shots that are definitely happening, every second of every day, in physics - and look around at the universe as it appears to exist now and how many of those shots had to play out in a specific way - and then do the math on the probability of a BB spontaneously existing, then it’s really absurd that we aren’t somehow BB’s.
I don't know, I've always seen Boltzman brains like I see Schröedinger's cat. I think it was intended to show the absurdity of certain philosophical interpretations of the data available, but somehow got misapprehended as an argument defending those interpretations. Namely that randomness could somehow spontaneously lead to ordered complexity.
You seem to have it exactly backwards: we have 200 years of practical evidence in favour of modern fluctuation theory thanks to things like steam turbines. Structure does sponataneously appear in a gas in thermal equilibrium, one can show this in a classroom experiment.
Landau and Lifshitz vol 5 <https://en.wikipedia.org/wiki/Course_of_Theoretical_Physics#...> is the standard textbook. There's an older copy on the Internet Archive <https://archive.org/details/landau-and-lifshitz-physics-text...>. (Having the background of L&L vol 9 makes a classroom demonstration even easier: a small handful of electronic parts for a resistive-capactive low-voltage DC electric dipole, a decent oscilloscope or other apparatus to measure and record fluctuating voltage, and a thermometer).
The probability of an out-of-equilibrium structure spontaneously fluctuating (briefly!) into existence depends on the complexity of the structure, and Boltzmann brains are much much much less complex than the whole Earth, solar system, Milky Way, or the early universe in which these structures' precursors originated. So therefore any theory compatible with statistical physics in which the early low-entropy state of the universe is a fluctuation in a higher-entropy "gas" is imperiled.
Yes I am familiar with the physics behind what I said. Quoting a university textbook on a philosophical argument is an interesting choice.
I have studied and reflected on the subject and I really think Boltzman brains and Schröedinger cat are thought experiments that go way over the head of their pop sci/undergrad classroom interpretations.
Boltzmann brains have nothing to do with Schrödinger: statistical mechanics works fully classically, and nobody treats Boltzmann brains in a quantum mechanical way because a Boltzmann brain is an unembodied ephemeral human brain. Natural human brains have a history of being warm and electrically noisy (any quantum features decohere faster than thought), while fluctuated-out-of-equilibrium human brains aren't around long enough to have their temperature measured, nor to produce much electrical noise.
A quantum-mechanical Boltzmann brain emerging from a gas of photons in (cold) equilibrium in which fluctuations take photons out of equilibrium and into the farrrr UV is going to be on the short-lived end of Boltzmann brains: things like annihilations and complicated decay chains will dissolve them away quickly. Which is the point. Boltzmann brains, unlike the bowl of petunias in The Hitchhiker's Guide to the Galaxy, should not have time to compose poetry.
Very hot thermal radiation is what destroys classical Boltzmann brains. They sort-of are a cool spot in an extremely violently hot bubble in an otherwise cold (colder than brains!) gas of almost everywhere uniform temperature.
> Yes I am familiar with the physics ...
> Quoting a university [physics] textbook on a philosophical argument
... which is philosophizing about actual physics ...
> is an interesting choice.
Well, what textbooks or other sources do you rely upon when philosophizing about fluctuation theory? What have you read or taught from?
I understand the concepts thanks for explaining them again. They have things in common because they are both thought experiments that I think most people miss the point of.
Undergrad textbooks are not exactly cutting edge philosophy wise and you're giving me a "?" for using one in a philosophical argument and having it called pop sci/undergrad classroom interpretations, makes me doubt your reading comprehension entirely.
But this presupposes that consciousness is a mere instant. If I am conscious ‘now’ and maintain this State for Lets say 2 seconds, the chances of me being a boltzmann brain pretty quickly drop to near 0
And how could you actually determine if we’re actually in second 2, or actually in second 0 with knowledge/memories/sensory input which makes you think we’re in second 2?
At some point it does boil down to faith that we aren’t in that scenario/it isn’t what is occurring. Philosophically, it’s hard/impossible to fully logic our way out of this kind of problem.
You can’t, for a single point. My argument is that you don’t have consciousness for a single point. Thoughts take time, we have streams of consciousness.
If I can determine a current point (I argue I can), with memories, then remain conscious for let’s say 2 seconds, the chance of me being a Boltzmann brain already dropped to almost 0.
At any point you could say false memories were planted, but this assumes that I am only conscious in an instant, and merely remember previous states. Both research and my own experience seem to indicate it’s not this coherent, and we have a much longer instant of consciousness or ‘moment’.
A Boltzmann brain only makes sense for particular instants thermodynamically, coherency is as good as impossible
A mere trillion years is a tiny fraction of the time it would take for a brain to form like this spontaneously. This concept arose when people generally thought the universe was in a generally steady state and had existed forever. Even though generally say that entropy always increases if you wait long enough you might see reversals if you wait periods of time proportional to something like e^N where N is the number of particles in the system. So it's weird that we're in this low entropy solar system, but you'd expect something like that to happen every once in a while across infinite time. But since a brain has many less particles than a solar system [citation needed] you should expect brains to form from spontanious entropy reversals much more often than galaxies do. There's a principle called the "incompressability of phase space" that means that a low entropy solar system with a low entropy brain is necessarily much less likely than just the low entropy brain, because entropy reversal across an entire solar system is just so mind boggling unlikely.
Of course nowadays the cosmic redshift, etc, make us think that the universe is not eternal but began a short few billion years ago and will end in a big crunch or big rip long before we expect a single Boltzman brain to arise through the random walk of particles.
You have the analysis right (incompressibility of phase space), but maybe not the application.
Bbs are arguments against the early low-entropy state of the universe being a fluctuation out of thermal equilibrium, and of a future universe fluctuating out of the approximately de Sitter state of the far future.
Expanding steady state was an effort to capture the increasing evidence (including redshift relations) in favour of a Lemaître-style dense early universe, and to avoid several problems with ~static universes.
Since a steady-state cosmology has neither an early low-entropy configuration nor a late homogeneous equilibrium state (steady-state means homogeneity & isotropy in time as well as space: the "perfect cosmological principle"), I'm not sure how a BB argument arises in such a model. In an expanding steady-state model, is there some mechanism for making BBs other than to have them appear with the other components of new gas which under self-gravitation fragments into systems with negative heat capacity?
We should expect that there will be at some point winning lottery ticket floating in space.
I don’t think we should expect to see them, though, because they are probably very far away in time and/or space.
Also the concept of a winning lottery ticket would seem to require the existence of a lottery game, which would seem to require some sort of society to play it. We are probably not the minimal working example of a society that is able to invent a lottery, but I bet that society is closer to us in complexity than it is to a scrap of paper.
The point of the Boltzmann brain is that it's spontaneous (which is also what makes it impossible). If a billion years of slowly ratcheting up complexity counts as a "random fluctuation", then every brain is a Boltzmann brain.
If time is infinite then the argument from exponential complexity doesn't really work as a counterargument to Boltzmann brains. It might take Rayo's number of years plus five for a good measure but it is still bound to happen with absolute certainty.
The point is not that it's likely (or practically possible) that such a brain would come into being spontaneously. The point is that it is (mathematically) still more likely than some other theories about the formation of the universe (namely those that give it the order we see, low entropy, by "miraculous" happy accident), thus showing that those theories are most likely nonsense, by reductio ad absurdum. (Those other theories can't be true, otherwise we might as well find brains in space.)
It's about quantum mechanics and the fact that "empty space" is not really empty. Particles do pop into existence (from nothing), according to QM, so there's a non-zero probability for any "pattern" to pop into existence. Sort of like if you have an infinite number of coin flips then at some place and time you'll land on heads a million times in a row, no matter how unlikely. And for any million-bit sequence you're guaranteed to hit it too. So a human "brain" is just a pattern that's likewise guaranteed to be "encountered".
A similar concept is how the first replicator RNA/DNA got created as the beginning of life. If RNA can exist in large numbers of random sequences, then a sequence that can replicate itself only has to "happen" once and then life is started and will never slow down but will grow in complexity, as long as the environment can support it.
I get the part about popping into existence but how would even so much as a bilipid layer around a single cell form, let alone a whole brain? Where are all the antiparticles in this, except shooting around? Even if all the particles pop into existence perfectly placed for a single quanta of Plank time, aren’t the antiparticles destructively interfering with all the other particles even before they begin to annihilate? I imagine they would prevent any chemical reaction happening at all at that density. What about all the force carriers? Can they even pop into existence in the quantum foam coupled?
It wouldn’t really resemble a brain in biological sense of the world because the only stimuli it can and will react to is its own disintegration. It’s hard to justify it even “existing” at all. A “virtual” brain in the sense of virtual particles perhaps, except it seems quantitatively useless.
The probability of even a Hydrogen atom popping into existence is astronomically low, but the point is that one could. And if one can, then many can, and on and on. The point is that it's not impossible, just improbable. But by definition of one did pop into existence, it's a stable state and would therefore not just simply vanish after forming.
I think the time-energy uncertainty relation limits their distance and it is very small, closer to a Planck length than any precision we can measure. They have to be close enough to annihilate within a specific time limit related to the energy of the particles (ΔE·Δt ≥ ℏ/2) and the higher energy the particles like a full proton, the less time they have.
I think maybe the original Boltzmann brain may have been about pre-existing matter particles having the ability to just "jump" to a new location (similar to how they can tunnel thru a barrier), and so you can have them all just "jump" into the shape of a perfect square, perfect crystal, or even perfectly formed cat.
So it's not necessarily about the "from pure empty space" version of it. This is all just a thought experiment and not intended to be taken literally.
Honestly, you have a series of good questions and unfortunately I don't think your other interlocutor is helping.
I'll give it a try. This is very much a hand-wave.
tl;dr: Boltzman brains (Bb) from energy gradients: a "formless" high-energy fluctuation in a cold gas returns to thermal equilibrium through a Bb state.
The classical cartoon for a Standard Model of Particle Physics human Boltzmann brain (SMBb) is a cold (too cold for metabolism) Maxwell-Boltzmann gas or soup of atoms which in principle could condense into biological molecules via chains of endothermic and exothermic reactions. The gas is on average too cold for the endothermic parts, though, which essentially means no products comparable to those from anabolism.
From fluctuation theory randomly there will be high-temperature regions which allow for endothermy. In a hot bubble, which quickly cools by dissipation, complex molecules are (briefly) energetically favourable as their formation also lowers, locally, the temperature of the hot spot in which it's embedded.
The Boltzmann brain formed in this way is liable to be cooked apart by the heat of the hot spot outside the small region that cooled as the Bb condensed in it.
You've been wondering about how an SMBb might form. The starting point is a cold gas of photons. In that gas regions with vast amounts of gammas can fluctuate out of equilibrium: this is the hot spot. Particle pair productions and complicated decay chains serve to cool the hot spot (inelastically scattering gammas, among other processes), and consequently forming complex bound states embedded within the super-hot-but-rapidly-cooling spot is energetically favourable. Yes one has to have some luck (or some extra constraint or mechanism) in matter/antimatter asymmetry, which should be encoded in the grand canonical ensemble for interacting particles.
The SMBb will be torn apart by gammas and other radiation in the hot spot in which it is momentarily a cold spot.
One might compare this with a different extremely hot "hot spot" in which complicated states can form briefly. High-entropy pulsional pair-instability supernovae (PPISN) <https://online.kitp.ucsb.edu/online/stars-c17/woosley/pdf/Wo...> (see especially the graph on slide 5) are massive stars whose core rises to pair production temperatures. The pair-production cools the core of the very hot (~ 0.3 GK), very massive star; the cooling means less radiation supporting the star's bulk above the core. Gravitation from the sheer mass of the star itself drives a thermal runaway. However, during the runaway, there will be further cooling via nuclear processes that tend to generate a large neutrino flux. Soon however the star and all the heavy daughter products which condense during the pair-producing phase tend to be violently explosively disassembled.
The "hot spot" for a Standard Model Boltzmann brain might be several terakelvins hotter than a PPISN's core (the SMBb bubble ought to be gamma gas reaching QCD or even GUT temperatures), but won't be massive enough to self-gravitate. Animatter is the least of the SMBb's worries, given all the hotter radiation surrounding the cold spot formed by condensing into the brain itself.
> Sort of like if you have an infinite number of coin flips then at some place and time you'll land on heads a million times in a row, no matter how unlikely.
If random event result is any real (i.e. not limited integers and fractions) number from interval 0-1, then no number will appear twice even after infinite number of throws.
Open question surely follows: Time and space, are they integer or real?
That's kind of like asking if spacetime is quantized or not. We have bits of evidence in both directions. For example, the entropy of a 2D (conventional) Event Horizon, is identical to the number of planc-length (square) units of area on the EH sphere, and so that's a definitely quantity/number, for any given Black Hole mass. You could interpret that as saying the EH is broken up into "pixels" sort of, which a kind of quantized view of spacetime if our universe is indeed a big Event Horizon.
I'm with you. There are forces that would prevent random particles from being in any configuration "at random".
Example: At random, 2x2x2cm ice cube in center of sun sized star. You can't get from here to their because an ice cube will never form next to heat.
In some alternate reality where atoms materialize in random configurations out of nothing maybe, but that's not our reality where atoms interact with other atoms and that interaction prevents the vast majority of combinations. It doesn't matter if time is infinite.
I just don’t understand how it would be possible over any time period, doesn’t matter if it’s a billion years or even 10^10^10^10… years. There are conservation laws governing how particles can pop into existence and them all popping into existence in just the right place is only even remotely plausible if you ignore the antiparticles that are formed in the same space.
Forget about the particles for a second. This is about fundamental quantum fields. The fields can randomly fluctuate from the vacuum state into a more ordered state where virtual particles are created.
The conjecture here is that a given volume of space must, at some point, randomly evolve into the quantum state you're interested. When the quantum fields align into the same state that a bunch of particles would represent, those particles appear out of the vacuum.
The trick that makes this work is that conservation laws don't apply on very small time scales. That's how virtual particles work after all. The energy can only be temporarily borrowed from the vacuum, unless you pay the energy cost to make that particle 'real' by destroying its virtual pair (see Hawking radiation).
You might imagine TV static, just random visual noise. There's no real reason the randomness can't line up to produce one single coherent frame before decohering. Just imagine that in 3 (or 11) dimensions.
I don't think an antiparticle pair is a strict requirement for virtual particles either. As long as energy is conserved on macro timescales, the universe doesn't really care what state the quantum fields are in.
Conservation of energy is only considered true "locally", but not globally.
There are many examples of this in nature, believe it or not.
If you wanted to have a system that perfectly conserved energy, how would you expect to measure its existence, or changes in state, anyway?
Besides, even if you assume conservation of particle number, it only has to be eventual conservation.
Suppose I borrow some energy from "over here" temporarily and accidentally assemble them into a perfect brain for a second, then they can disperse again, if they like.
A bigger question is, if energy were conserved globally, where exactly did those handy particles come from in the first place anyway?
Among the de Sitter invariant states for massive fields is the Euclidean or Bunch-Davies vacuum, which allows for pair production with separations greater than the horizon distance. Since our universe seems to be marching towards a state highly similar to the Euclidean vacuum, such pairs seem (a) physically plausible (b) and with some low probability could arise in groups which (c) because they are interacting particles, might nucleate.
Nucleated objects could be long-lasting, which blunts the Boltzmann brain (Bb) picture, as under fluctuation theory the Bb is ephemeral and time-reversible. On the other hand, it's historically been attractive to think of the nucleation of a inflating patch of spacetime (with low enough entropy that structure like galaxies might form as it expands and fragments gravitationally).
Think of it this way: you've probably heard about the million monkeys on a million typewriters will eventually produce Shakespeare? Ultimately something deeply meaningful like that is just a sequence of symbols and you generate enough randomo sequences of symbols, one or more of them will be literature.
A Boltzman Brain is basically that but for a quantum system. In the far future, it's suspected the Universe will undergo heat death and eventaully reach thermodynamic equilibrium but that doesn't mean nothing happens on a quantum level. A chaotic system as otherwise thermodynamic equilibrium is still capable of having temporary, localized order without violating entropy.
So over any sufficiently long period of time (we're talking 10^100000+ years here), you'll get all sorts of interesting arranagements of matter. One of these is a localized reality where it or being in it are capable of sentience.. They won't have any conception of the Universe outside of this but, for a time, they will be able to contemplate their reality.
Think of it another way: take a bucket filled with random elements, mix it and tip it on the floor. Do this enough times and one of those bucket pours will be sentient life.
Adding to the million monkeys on a million typewriters: There is Project Babel, an algorithm that strives to produce every combination of letters (and then also words) possible.
It's "books" are filled mostly with gibberish but theoretically, if running long enough, it will generate books that have not been written yet.
The problem with the Boltzmann brain, and the reason you’re almost certainly not one, is that if you are one then your senses have no relation to reality - including the part of reality where you read about the Boltzmann brain concept, or any measurements you can make about the underlying reality that makes you think you could be one.
This is the same with all solipsistic arguments, like simulation hypothesis. If the universe is, in fact, an illusion, then how do you truly know anything about the real world? Sure it could be a computer simulation, but there’s no way to know for sure. The parent universe could actually follow different laws entirely. It could be creating a ”simulation” through entirely different methods. Hell, for all you know it could be an evil demon using magic to trick us, because magic could be real in the parent universe. It’s all unfalsifiable.
I agree with your initial argument about why we aren't Boltzmann brains, but I don't think that the same argument follows regarding the simulation hypothesis. A simulation would imply a set of rules being set up, of which your senses, and the reality they experience, are an emergent property. That is, there are rules, and your senses are generally consistent with whatever they are.
With a Boltzmann brain, there's no reason whatsoever to think that any senses are consistent from one moment to the next or that any action can predictably yield any reaction. It would all just be random.
What OP is saying, I think, is that the argument that led us to believe that Boltzmann Brains are more likely than normal brains is itself product of the physics of the world we experience.
But then, if we conclude that we must be a BB, there is no reason for the physics of the universe in which this BB exists to be the same as the physics of the universe we experience. Hence, the argument breaks down, because BB are only very likely in the 'simulated universe', but have no reason to be in the 'real universe' (which has no reason to abide by the same laws of physics).
In other words, the assumption that we are a BB, because they are so much more likely, invalidates the argument that BBs are much more likely.
Whatever the physics of the parent universe are, they either prohibit BBs (and then that universe would be ours, which it presumably isn’t) or are unlikely to affect BBs in a way that disallows creating BBs that observe a similar universe. It’s akin to “why tf I’m a human on Earth 2024 of all planets and things” argument. Well, four reasons: you’re, a human, here, now.
Even if we assume that this universe we observe as BBs is as well the parent universe, it can produce not only human BBs obviously and not only coherent experiences. Complete nonsense is normal here too.
So if a universe allows for BBs (iow, spontaneous temporary observers with state that somehow produces the me-is-observing effect), it allows for all sorts of experiences, and given enough iterations could reconstruct itself and everything imaginable and unimaginable in a sequence of arbitrary length. “You’re certainly not”doesn’t follow here. It may be or it may be not. You’re a human, here, now.
But if you can have a Boltzmann brain, then you can also have stable environment pop into existence. In a simulation, there's no guarantee the simulation follows the parent universe's rules. It could be a simulation with made-up rules. Maybe exploring alternate kinds of universes.
Yet, I observe what appears to be consistency and rules. Randomness happening to manifest in a way that mimics consistency and rules is very very unlikely, probably more unlikely than there actually being consistency and rules.
The falsifiable part of something like the simulation hypothesis has to do with nested sets. If the reality we exist in is capable of producing everything that would be necessary for a conscious being to experience a convincing reality within its available resources and computational power, then the fact of consciousness is not sufficient to conclude that the reality in which we operate does not exist inside another reality with the same capability to produce an internal model of reality sufficient for supporting consciousness.
As you said, it does not definitively tell us anything about the reality in which that simulation exists other than that it has the same property that we experience of being capable of hosting a nested reality sufficient for supporting consciousness.
Although we can't specify particular aspects of that reality, we are capable of mathematically representing potential properties of universes that have the capability to host a nested simulation. None of this provides certainty, but it provides a basis of exploring possibilities, and actual understanding requires methods beyond the hypothesis of a larger reality.
Physics provides us a lot of ideas about the potential for the nature of reality and methods for testing and falsifying them but is not in itself sufficient. We don't need to find all the answers in one line of inquiry. The holographic principle of string theory is one example of a type of simulation existing inside a larger reality but far from the only one.
It's possible to run an experiment to see if a conscious entity could be convinced that a simulated reality was real. Hard to do ethically since consent would invalidate the illusion, but possible to demonstrate convincing virtual reality with computer generated sensory experiences.
Models like the holographic principle can be tested both mathematically and through experiment. Full tests are beyond our current capabilities but not unfalsifiable in theory.
This is a great example. You can prove that a VM can be just as capable as a bare metal OS. Then you connect to a random networked machine. Without any further information, would you guess that you chose bare metal or a VM (or container)? Knowing that virtualized OSs are both possible and heavily distributed, you would guess that any random machine you chose was probably virtualized.
The simulation hypothesis follows a similar logic with one less data point. Knowing that experienced reality could in theory be nested inside a superstructure but not knowing the actual deployment of such nested experiences, we would guess that our experienced laws of physics probably exist inside a superstructure.
What the properties of that superstructure are beyond the hypothesis itself because we don’t have the same knowledge of virtualization of physics as we do of OSs.
String theory is one attempt to describe that structure based on mathematical reasoning. The simulation hypothesis just states that physics is likely to be virtualized inside another system and that it’s worth exploring physics at its limits to understand the properties of that virtualization.
It’s falsifiable through the development of analytical methods that don’t fully exist yet but not theoretically unfalsifiable.
I think that's a misapplication of Occam's Razor. I'm not sure how exactly you're using contrived here, but the idea that complicated interactions like the ones we experience are likely to exist inside simpler systems is seeking the less contrived reason for existence. I'm saying that it's likely in the same way that virtual machines are likely to exist inside networks. Virtual machines might be more complicated than operating systems running on bare metal, but it's simpler and easier to create a thousand virtualized environments than one additional bare metal computer by orders of magnitude. In the same way, if it's possible to create nested experiencable universes, the total number of virtualized environments experienced is likely to be much greater than the number environments operating on the most bare, fundamental principles of existence alone.
This simulator's world is less likely, because it consumes more resources: needs to run thousand nested worlds, so their probabilities are reduced proportionally and further reduced by the virtual machine itself. Also bare metal is more efficient if virtual machine properly interprets instructions and doesn't merely forward them to processor.
Consuming more resources is a matter of perspective, not efficiency, because the scale of total phenomena would be much larger than what is experienced. Always bet against the comprehensiveness of your comprehension.
Also, any line of inquiry that applies probabilistic arguments to evolution-based questions is already off in the weeds. The brains in our bodies didn't arise as a result of pure random organization, but developed incrementally in a direction that maximized reproductive fitness. There is no reason to think that brains appearing in isolated space at random, complete with memories, would ever be a thing.
So it's simply not meaningful to ask about the relative odds of these two positions.
> There is no reason to think that brains appearing in isolated space at random, complete with memories, would ever be a thing.
There are only a limited amount of physical states possible in a given volume and given an infinite amount of time and space, all of them will happen an infinite amount of times.
That logic doesn't exactly hold. Consider Gardens of Eden in Game of Life [0]. We can suspect that reality is similar to GoL where there is an infinite space and time that evolves according to some ruleset. In that case it is plausible that there are conceivable states that will, nonetheless, not be assumed even if there are an infinite set of possible states that reality will assume and infinite time to explore them all.
I disagree. I once had someone say that if you were to smash an iphone into tiny tiny pieces and put it into a plastic bag and shake it, given enough time, it would reassemble itself into a working iphone, the pieces randomly ending up where they need to be in order to operate like it did originally.
While it is technically possible for that to happen, the probability of the intricacies that make up the iphone's circuits and screen, the chemicals that make up the battery, etc, assembling themselves into a complete and working phone, even on an infinite timeline, is not that high. And it could, in theory, never actually happen, since if there is still time that you can move forward into, there's still the chance that the moment the iphone assembles itself into a working phone lies somewhere in the future, and always will. It could just never happen before the heat death of the universe.
> While it is technically possible for that to happen, the probability of the intricacies that make up the iphone's circuits and screen, the chemicals that make up the battery, etc, assembling themselves into a complete and working phone, even on an infinite timeline, is not that high.
"Infinity" is not the same thing as a "really long time". You can't use ordinary conceptions of probabilities on infinite time scales. If you wait a Graham's number of years, you still haven't even started a small fraction on the way to infinity.
I'm not sure. Quantum tunneling is a thing. Given the possibility of particles deciding to spontaneously just up and teleport to a nearby location, the available options increase significantly.
My chief complaint is that it’s functionally equivalent to belief in God. It strikes me as fundamentally the same instinct but reinterpreted in a manner palatable to the “i’m very logical and rational” crowd.
Belief in God implies some effect on one's behavior, unless you believe in a completely impersonal Prime Mover that retires thereafter.
The notion that one is a Boltzmann brain doesn't really change anything. If you are, there's absolutely nothing you can do about it. So the only sensible thing is to assume that you aren't, regardless of probabilities.
I've seen a paper (probably by Bostrom) deducing normative statements ("oughts") from the simulation hypothesis (purely descriptive, "is"). Namely: the grad students running these simulations are more likely to switch off boring simulations. Thus, if we want to keep living in this world, we should strive to make it interesting.
I must say, with Trump, Brexit, war, and more Trump: Well done, folks!
Our world is boring though, cf Boötes Void. Those transcendental extrauniversal aliens invented quantum physics, what do you expect them to believe? If their world can create such immense simulations, maybe it's because their world is too fabulous and they look for serenity.
I don't agree. A belief in a god/gods generally also includes beliefs about what that god(s) wants or does. A Boltzmann brain would have no special powers apart from what a (very) specific arrangement of particles would have. There's no hint of them operating outside physics at all.
Also, there is at least a connection to experimental physics in that we can measure "virtual" particles (e.g. Casimir effect) and can calculate their probabilities etc. There's no such underlying experiment for God(s) that I'm aware of.
It really depends what is meant by "the same instinct".
The reason I don't agree with the parent comment is because to truly believe in a Boltzmann brain would seem maximally nihilistic.
Many people truly believe in God/gods at their deepest level. While the Boltzmann brain is an interesting thought experiment, I don't think anyone really takes it to heart the same way a Christian believes in Jesus.
Even while I would probably give the Boltzman brain a far greater probability than most, people don't go around telling other people this is all just a momentary, random fluctuation.
I think BB is bigger than God. God still has specific ways, while BB can simulate all experiences given infinite time, in parallel. So the universe where God exists and he will burn us in hell for atheism and mastrubation is just a tiny subset of what BBs can do. Cause if BBs are possible, they can do things a human cannot imagine about any God. Imagine a cubic meter randomly enumerating all quantum states within it, forever, ignoring consciousless ones.
Well, a BB may well be bigger than our conception/imagining of God(s), but there's a fundamental difference - BBs are constrained by physics etc whereas God(s) are supernatural and not constrained by physics.
That’s an interesting idea I’m not sure I agree with, it’s hard to formulate why, but I’ll try.
God itself can be supernatural, but feels like it can only affect a limited part of any universe due to the limitations in observer’s mind. If we could expand BB size indefinitely up to the size where it stays coherent (light milliseconds?) then that would basically cover everything that a consciousness itself could experience. This makes God infiniteness sort of redundant and unclear why it would be needed to generate a universe.
This echoes with my vague idea that hypothetical FGH-sized beings are indistinguishable from God(s) whose infinite part could actually create more issues than it might solve.
Iow, we have to define some Continuum of reality for God of omega+ size to operate on, not to mention Proper Class sized God. Our ancestors really overkilled this idea, but little did they know. So maybe we should take its infiniteness as “anything imaginable by an arbitrarily-sized BB” rather than its naive infinite meaning.
I'm thinking that there's a difference between God(s) and the conception of God(s). Any BB will be limited by e.g. speed of light which will limit how big they can get and still have coherent thoughts. I suppose we could get a super-massive Borg type of BB collective, but they're still limited by location/speed etc. God(s) would presumably not be bound by such limitations. (Not that I happen to believe in God(s)).
I think there's an even more interesting implication of Boltzmann brains. The non-local universe is infinite in both time and space and when you're dealing with infinities of time and space two axioms become true. Everything that can occur has to occur and nothing can occur only once. So if intelligent life was able to form in our local universe we would have to assume higher intelligence spontaneously arose, AKA Boltzmann brains, in the non-local universe and exists infinitely.
That's not true. The expansion of Pi is infinite, but that doesn't mean you can find every string of numbers in it, I believe that's still an open question. Just because you have an infinity, doesn't mean it contains everything an infinite amount of times. The Cantor set is a good example.
That's a good argument for why it's not worth spending a lot of time being concerned about your own ontological status, but it's not really an argument against the concept or the math behind it. It's a conclusion one could derive from some fairly non-controversial assumptions, and if we're agreeing that the conclusion is wrong, the problem with the chain of logic and math needs to be found.
The conclusion only holds if you assume that you yourself are not a BB. Yes, in our universe, the laws of physics predict that BBs are much more likely than normal brains, given you wait long enough.
However, the moment you assume that then it must mean that you yourself are a BB, the argument breaks down. Because the huge probability of BB applies only to the laws of physics of the universe you live in; if you are a BB, the laws of physics of your universe have no reason to be the same as the laws of physics in the actual universe, where the BB exists. Thus, you can make no prediction on the likelihood of a BB arising, since you don't know the physics of the actual universe.
I'm confused. We make predictions about things we don't fully understand all the time. And about things we cannot possibly perceive. We do so by recognizing patterns across things we can see, and probing the relationship to the things we cannot. (See could mean any perception).
It's not guaranteed we could do that, even in our universe it's not guaranteed, but it's also not ruled out.
I don't think that's actually a problem with the Boltzmann brain concept; I think it's just a reason why we don't want it to be the actual representation of reality.
I've chosen not to care; if I'm a BB, or even just a character in a simulation, my life and choices still have meaning to me -- whatever I actually am -- and that's what I've decided is important.
I mean the more interesting part to me is that probability comes into play: consider the age you live in. If you get to a historically conventional age for dying of old age, but then boom clinical immortality comes along, well that would feel technologically appropriate and yet be awfully convenient timing.
I'll be happy if it happens, but squint-eyes a little that it did.
Well no, that's not the reason why we're not Boltzmann Brains. A Boltzmann Brain is perfectly capable of believing that it is sensing reality in exactly the same way that your brain believes so.
It is worth reading the section "Modern reactions to the Boltzmann brain problem" in the article to understand why the Boltzmann Brain is a useful thought experiment.
A lot of religions can be interpreted in such a way as to essentially say "the entire real world is just a very complex simulation being played out by the Divine"; there there is no real world to know about, just thoughts in the Mind of God.
The point of descarte is that you dont know anything about anything, and in my opinion, all of his bad arguments begin when he starts stating his certainties, except for his first one.
There is a widely circulated (amongst philosophers) argument against the Boltzmann brain hypothesis made on bayesian grounds. Technical, but very interesting. It's being published next year in what's generally regarded as the top academic journal for philosophy: https://philpapers.org/archive/DOGWIA-6.pdf
> As unlikely as it is for a BB to form at all, it’s drastically more unlikely for additional things to simultaneously form around it. And even if additional things did form around the BB, it is not especially likely they will be the kind of stable and sensible objects a brain could even perceive. Therefore, the evidence we have is more likely supposing we are OOs than supposing we are BBs.
which doesn't ring true to me. Assuming that universe is indeed dominated by BBs, it's not at all clear to me that any observations we could possibly make "is more likely supposing that we are OOs". While the number of BBs "with decorations" would be dwarfed by the number of BBs without, it is still entirely feasible that there are many more such BBs than there are OOs.
I also found their argument as to why all observations shouldn't be considered hallucinations (including "over time", "history of" etc) as a matter of probability to be incomprehensible.
It's philosophically gauche but I often like to criticize arguments based on “what if they were right?”...
So for example the ontological argument putatively argues for the existence of a Perfect Being but it would seem to work even if you restricted the domain somewhat to something smaller than “all beings”, and so presumably also argues for the existence of a perfect Toaster.
Similarly here, the claim is that in a BB universe, even though countlessly more brains see the exact same stuff as you, there is something about the Bayesian update factor that you all have where you all still should conclude you are not the Boltzmann Brains and the evidence is never enough.
How do you look at that description, and not conclude that according to that argument, Bayesian reasoning is just strictly wrong? Like everyone (more or less) is “it” and everyone (more or less) says “it’s not me!” and everyone (more or less) is wrong and here is our philosopher dusting their hands saying ‘yep! sounds good, solved the problem!’
> How do you look at that description, and not conclude that according to that argument, Bayesian reasoning is just strictly wrong?
I believe you're conflating epistemics with decision theory. Sure, the measure of all minds experiencing your current mind-state may be dominated by Boltzmann Brains, with observations that do not correspond to any local state of the world, and which will dissipate momentarily.
But, since your decisions as one of those BB's have no effect, you should make decisions based on the fraction of minds-like-you which are living in a persistent world where those decisions have effects which can, in principle, be predicted.
I love that this addresses that probabilistic confirmation is fundamentally intransitive in Bayesian epistemology, and bumps in probability don’t necessarily propagate through multiple probabilistic links (Evidence -> BBU and BBU -> BB doesn’t mean Evidence -> BB).
Really well put-together and careful main line of argumentation IMO
Ludwig Eduard Boltzmann; 20 February 1844 – 5 September 1906) was an Austrian physicist and philosopher.
Boltzmann wrote treatises on philosophy such as "On the question of the objective existence of processes in inanimate nature" (1897). He was a realist. In his work "On Thesis of Schopenhauer's", Boltzmann refers to his philosophy as materialism and says further: "Idealism asserts that only the ego exists, the various ideas, and seeks to explain matter from them. Materialism starts from the existence of matter and seeks to explain sensations from it."
The reasonable things that continue happening each day in our universe would be extremely unlikely if we are just Boltzman brains. Every bit of sensible reality would be coincidental. The very continuance of that reality is an experiment constant proving the falsehood of Boltzman brains, at a rate of oh maybe millions of sigmas of confidence per second.
Now, if you believe the universe came to an initial state due to pure thermodynamic coincidence, millions of sigmas per second is laughably small compared to the chance that a whole universe outside your brain popped into existence, so Boltzman brains are the most believable thing and you should believe in them.
This completes a pretty direct argument: Believing the initial state of the universe was a thermodynamic coincidence forces you to believe in Boltzman brains, Boltzman brains force you to believe reality should collapse immediately, and reality does not collapse immediately. Therefore you simply can't believe the first assumption, that initial state of the universe was a thermodynamic coincidence.
Accepting this is often called the "Past Hypothesis". It's spoken of in deferential terms and said that it can't ever be proven... But to me this is rock-solid proof, with more sigmas of evidence than any other scientific discovery and increasing by the second! Can't we just call it the Past Theorem already?
How do you know that reality does not collapse immediately? At any given instant you could be a fresh brain that just came into existence, all your previous memories which imply a life lived up to this point also formed in that same instant.
Indeed the bigger issue as I see it is that the only "sensible reality" that can exist is the one you subjectively experience. Since that one is the only sensible one, it's the only one you perceptually would be able to hang around for - even if it's actually a conincidental series of flickers of sapience across trillions and trillions of years.
i.e. a time stepped simulation, absent external reference, doesn't know how long it's been between the actual steps - could be seconds, could be hours, could be years.
EDIT: Like the real issue with "death" is that it's not "eons on darkness" - which is why I think people get afraid of it (or one of the reasons) - but that actual, literal non-existence is inconceivable even though we all did it - 13 billion years of not-existing in the universe, then suddenly you.
So after you die the same problem re-emerges: the conscious experience of "you" ends...but then from the subjective blink of an eye if something happens to restart that information process just right, suddenly again, you - and it has to be you, and no one else, because if it wasn't then well, it would be someone else - i.e. why am I me, and not my wife or son for example?
What if it was someone who just happened to be extremely similar to you? There's a decent probability that someone extremely similar to you will come into existence during the finite lifespan of the universe. Would that person be likely to be "you"? By comparison, would they be more "you" than a version of yourself that woke up with brain damage?
The point is that you, dear reader, could be the Boltzmann Brain, and that would mean that all your memories spontaneously came into being, giving you the illusion of a past history, and it would also mean that you will dissipate again shortly after; there is no continuity, and we're not all BBs. 'We' are all just figments of your imaginary imagination, conjured momentarily into memory and then lost again.
For a Boltzmann brain there is no real past or future - your reality does indeed collapse immediately and you'll never know it; the idea that 'reality doesn't collapse immediately' is not a verifiable fact, because the only evidence you have to the contrary is encoded in and perceived by your brain...
If you are a Boltzman brain then you are born with memories you have (that haven't really happened) and you have no future (because the next moment you'll collapse).
You could even live kind of a "life" by randomly popping into existence once every million years in some differrent galaxy, experiencing one planck time and collapsing (and the only thing that connects the instances to each other is that the next instance by random chance has memories consistent with the previous instance).
They could even appear in non-chronological order.
I don't think it's likely, but it's more likely than having the one randomly generated brain experience stuff "in real time".
The problem with this is that the vast majority of such brains would be a mess. Their experience, cognition, etc would be completely incoherent. Only a teeny, tiny, minuscule fraction of them would have coherent experiences that make sense.
So if the argument is we're most likely to be such brains, then we are most likely to exist in a haze of incoherence. We don't. Right now I have an experience of a coherent historic memory, intentionality, sensory experiences, all of which make sense in the instant. If I am a random Bolzmann brain none of that should be true.
So we'd have to have a reason to suppose that the minuscule fraction of coherent, consistent random Bolzmann brains are more likely than the occurrence of environments that generate 'actual' brains, each of which may generate many, many such brains.
Extreme solipsism is a navel gazing Boltzmann brain.
The runners up are brains in jars and simulation theory.
I feel like a Boltzmann brain knowing that it’s a Boltzmann brain is too good to be true. Might as well make the god of Abraham out of entropy - if you can get a regular Boltzmann brain, why not get the most powerful Boltzmann? Maybe it will take trillions of attempts over trillions of universe births and deaths. But you only need it to work the once.
I find the idea of a Boltzmman brain ridiculous.
It is impossible for a random interactions of particles form such complexity.
I find Lee Cronin's assembly index a great argument against this.
Complex things such as living organisms, and brains, contain as integral part of themselves time. Not just time, as in infinite time, but evolutionary time.
No it is not. A bunch of pixels that form an image has nothing to do with stuff that was generated by evolution. Brains don't get assembled just by pushing together atoms or molecules at random, the evolved over eons going through a lot of intermediate stages.
See also this fantastic podcast (if I remember the episode correctly, although it doesn't matter much as they're all good and he talks about the subject frequently because it's tightly related to his day job)
I find it weird that they consider "particles which fluctuate", but these particles are a part of the universe already. There's nothing to fluctuate when the universe doesn't exist.
However, if something fluctuates somewhere eternally, then I'd say that it's possible that this random fluctuation causes a very simple computer to form which is able to update it's state based on some simple rules, which results in complexity, i.e. our universe. This way you wouldn't need complexity to pop up spontaneously, but just a simple thing which is able to simulate a complex thing.
A snapshot of an instance of you is just a really large number. A unique transition between two instances of you (@ t and t+1) is also a large number. A slideshow of your entire life's instances is just a really really large number.
All these numbers are somewhere on the number line. In fact, the slideshow of every creature is on the number line.
Is anything real? Because being instantiated in matter is just another way of animating the slideshow where physics takes care of the transition function.
There are unfortunately no insights to be had in this endeavor.
I just want to point out that the time for one to randomly appear is somewhere between 10^10^50 and 10^10^69, which is is a pretty large gap. Like the difference between the two is just 10^10^69, mostly. I'll point out here that I'm not using units. The article does, but it's not like they really mean anything at these time scales. A plank time (10^-43 s) to the age of the current universe (10^9 yr) to the lower bound for the estimated time until the heat death of the universe (10^109 yr), all of those time units just end up as rounding errors compared to the lower limit of 10^10^50.
The article does not go over here the time that such a brain could last for, but given that it's quantum mumbo jumbo, we can again assume something in the times of 10^-43s to 10^109 yr. Which, again, means that such a brain can hardly be said to have ever have existed in the first place compared to the time of it's formation probability. And yes, that means our current universe is in the same 'meh, just round it off' bucket.
Like, we get caught up in the minutiae of this thing's mind, it's perceptions, it's sanity, it's soul (?). But if anything the absurdist thought experiment ends as just a mirror aimed at ourselves, with the void now creeping in behind our hats. What am I? What is perception? What is time? Can any of this ever possibly matter compared to these might-as-well-be infinities? Oh God!
I've put numbers up here, they are very poor estimates mostly. And then I tell you that these numbers are so huge that, very literally, nothing that will ever exist in our universe can be made to understand that far future in which this absurd quantum brain comes out of. That time ceases to have any meaning at all in this not quite so empty quantum vacuum.
So, having looked into this mirror, I don't know what tell you. I'm going for a walk, enjoy the season here, hug the fam, have a coffee, laugh, run, play. The universe has spared us this moment.
Hmm. Is a Boltzmann brain incompatible with quantum immortality? I guess it is possible, just unlikely, that you’ll end up as a Boltzmann brain that just happens to not dissipate, right?
I dont need to logically disprove theories like this, because I experience myself in a way that you can't argue against. Trying to convince me my experience of myself is an illusion is, in my view, a horrible case of trying to fit reality to your model. Yet it's one that a surprising number of scientifically minded people enjoy doing, for some reason. Beats me.
Here's a different way of thinking about it. There are two things that are both very plausible: One - based on your direct personal experience - is that you are a non-boltzmann-brain-human living a normal life on earth. Two - based on well-accepted science - is that it is MUCH more likely for you to be a boltzmann brain than not.
Great; these two things are seemingly inconsistent. Which means one must be false. But if either of these is false, it's surprising! Because one is based on our direct experience of ourselves, as you have pointed out, and the other is based on well-established science. So what's interesting about Boltzmann brain (and similar) is that it shows that one part of our body of knowledge must be false. And this ought to motivate us to investigate exactly what it is that we have wrong.
None of these are even the interesting points. Arguing about whether you or I are a BB is meaningless.
What I want to know is this: will BBs exist in the immeasurably far future? If they will exist, how fast could they possibly think, how long could they last, and what is the limit on their intelligence? Could they comprehend their own existence from first principles? In the short instants that they exist, would they realize how short their life expectancy is?
>Two - based on well-accepted science - is that it is MUCH more likely for you to be a boltzmann brain than not.
We're not each individual BBs (and you're not a lonely BB imagining the rest of us). It's closer to the truth that our entire universe is one big BB that just blipped into existence one moment billions of years ago. If we accept the concept of a Boltzmann Brain at all, then it must be that some configurations of one where parts of the brain are disconnected from each other and each spawns and intelligence... or even just unintelligent matter/machinery. Scale that up to a few billion light years wide, and that's us.
If a BB could exist, it could also represent a type of intelligence that is so foreign to our experience that we wouldn't even recognize it as such, even if it could last long enough for us to encounter and study it.
Very likely BBs can't exist in our current high-stability regime, and only in the post-matter universe where vacuum-decay-style events occur more often would they manifest. I think they're incredibly far future only. As for the type of intelligence, it seems probably that they'd be completely alien to us, yes, as there must be modes of intelligence other than that evolved my social monkeys. Don't expect any of them to be friendly (though, what sort of violence they could hope to commit is beyond me).
I don't think anyone wants to convince you that you're a Boltzmann brain. This is more a thought experiment. The fun is to try to explain on logical grounds why this isn't a viable option.
Not sure why you're so hostile toward this. No one is saying that you're a BB; it's a thought experiment on the nature of reality.
And if you were a BB, you probably wouldn't know it, and how you experience yourself is irrelevant. That's kinda the point. The problem with the BB thought experiment is that it isn't falsifiable, at least not with techniques we have now.
It's impossible to logically disprove a theory like this, because the entirety of your thought process would itself be a random fluctuation, never mind the inputs on which it is based.
The problem is that if you start with the reasonable assumption that you objectively exist and that your observations are valid, the model of the universe derived from those observations (or at least some otherwise viable models) includes prevalence of Boltzmann brains.
The "Big Bang" theory (BBT) is equally as absurd as the Boltzmann brain conjecture, and recent evidence from the James Webb Space Telescope provides even more evidence against the BBT, by showing there are too many mature universes near the theorized "beginning of time" and also the Hubble expansion is off by 8%.
I think there's more and more evidence that we're instead in a 3D reality that's the manifold (surface) of an Event Horizon. We're neither inside nor outside a black hole, but on the boundary of one.
All Black Holes form from matter "falling in" rather than stuff "exploding out", and that's how our universe formed (as a Black Hole, one dimension higher up than normal 2D black holes we see). The general rule is that any N-dimensional reality is on an Event Horizon and will have contained/embedded within it (N-1)-dimensional other black holes (it's a hierarchy).
The JWT also just showed our universe is expanding at a rate that's also inconsistent with our current Big Bang theory, and is off by a whopping 8%. I think the reason we see the expansion is not because of Dark Energy (which likely doesn't even exist), but is because the surface of all Event Horizons only expands over time, or in the case of a 3D (excluding time dimension) Universe we see more and more of volumetric space forming, because it's a volumetric expansion for us, rather than the "area" (2d) expansion on conventional 2D Black Holes.
I also think the surface normal vector (perpendicular) vector, at any point on such a manifold (Event Horizon) will be experienced as a "time" dimension. That's why time is a "special" variable. Thus time only moves forward whenever the event horizon "grows" (due to matter falling in from outside it)
I've been convinced of this theory for about 10 years. I don't know why people can't wrap their heads around a 3D version of the Holographic Principle (as opposed to the standard 2D version of it, per Susskind, etc.), or indeed an N-dimensional-manifold version of it.
This guy did tho... (he gets into the good part right at about halfway thru)
It might very well be internally consistent but it's not a theory of where the universe came from. It's easy to add complexity, but the goal is always to remove it.
That's right. It doesn't try to say that everything magically popped into existence like the Big Bang does. It doesn't try to stipulate that there was a "beginning to time" (yes I know that's paradoxical, but you know what I mean). It says things didn't explode outward, but are collapsing inward, which is proven by gravity. There's nothing "magical" in it, that contradicts known science. However the Big Bang Theory is entirely 100% "magical", and contradicts every law of physics that exists!
That's fun. Where did the universe that is collapsing inwards come from, and what is the CMB? Do you have a mathematical treatment of this?
I think the main issue is that the event horizon of a black hole only exists relative to an observer. They're not physically 'real' objects but just theoretical mathematical limits we can calculate. They're 'where the escape velocity becomes c'. As an observer approaches a black hole the apparent event horizon shrinks away from them, in a way directly analogous to a geographical horizon.
If Big Bang advocates can claim the Big Bang created a whole universe of matter in a single instant as if by magic, then we can likewise make the simpler more scientifically justifiable claim that emptiness spawns tiny bits of matter everywhere, all the time.
The fact that CMB lines up with an explosion theory may simply be that Black Holes are mathematically similar to explosions (i.e. starting small, and growing spherically)
Regarding Event Horizon surface, I say there's something like wave-particle duality going on with this observer v.s. observed paradox. The EH is both a 'surface' and 'not-a-surface' depending on your perspective. Physics is odd enough for these kinds of paradoxes, when there's equal evidence for both viewpoints.
Can anyone explain this bit to me? The formation of biological brains was a multi-billion year climb against entropy. How would a brain form spontaneously without those random fluctuations tearing the constituent components apart?
I’m having trouble understanding the logic here. Random fluctuations don’t imply that any order from those fluctuations can be preserved. The higher order features like brains are path dependent on something resisting those random fluctuations to allow something stable to form, whether that’s an atomic particle, cell, organ, or organism.
IANAP and I don’t know what I’m talking about