🧵 An objection to many worlds from anthropics
Anonymous at Thu, 3 Apr 2025 15:48:17 UTC No. 16636135
Before I begin this article, let me say: I am not an expert on the many worlds interpretation of quantum physics. You shouldn't really trust what I have to say on this subject. The extent of my expertise is having gotten an A in high school physics and read some Eliezer Yudkowsky articles about many worlds. I could tell you almost nothing about the physics behind many worlds. Fortunately, my argument doesn't hinge on highly precise facts about physics.
The basic idea of many worlds is that each time a quantum mechanical event happens, the universe splits so that there's a world where it turns out each of the ways it could have. So, for instance, if a particle can either go left or right, the world splits and there's one world where it goes left and another where it goes right. This may sound ridiculous and gerrymandered, but it allegedly falls straightforwardly out of existing physical equations rather than requiring an epicycle.
Anonymous at Thu, 3 Apr 2025 15:51:00 UTC No. 16636137
What do you think about the concept of alternate timelines?
Anonymous at Thu, 3 Apr 2025 16:03:36 UTC No. 16636149
>>16636135
How much splitting happens? A lot! Likely an infinite amount of splitting happens per second. If the amount is finite, it's likely on the order of 2^10^18 new universes per person per second, and obviously much more caused by all the rest of the universe https://substack.com/redirect/cdd0a
To introduce my objection, let me give an analogy. Let's imagine that the human population is increasing massively. The first generation has just 100 people. The next has 100^100 people. The one after that has 100^100^100 people. And so on. Given the massive expansion in the number of people, you should expect-with near certainty-to be born right before the end of the world. Given the massive growth in numbers of people, nearly everyone who ever lived will be born at that time. So given that you exist, you should think probably you would be born at that time.
This is analogous to how if you know that almost no one lives in Antarctica, you should think probably you don't live in Antarctica. If you woke up in Antarctica, unsure of how you got there, this would be a bit of evidence that a larger percentage of people are in Antarctica than you thought. If you woke up in Asia, and were considering between the theories that Asia has the most people and that Antarctica does, your evidence would favor the theory that Asia does.
🗑️ Anonymous at Thu, 3 Apr 2025 16:04:59 UTC No. 16636150
>>16636149
The core idea is that if almost everyone has some property X then you should expect to have property X.
But now let's apply that to many worlds. On many worlds, the number of worlds is constantly increasing at extreme rates. Nearly everyone who has ever lived will live right before the end of civilization. Conditional on many worlds, therefore, it's overwhelmingly likely that you currently live at the end of the world.
Counterpoint: you don't. So because many worlds gives you reason to expect that you would live at the end of the world, this is strong evidence against many worlds. Just like in the earlier case, if you find that you're not at the end of the world, you get extremely strong evidence that the theory is false.
Now, you might object that there could be multiple ends of the world. To simplify, let's say that there is one world A. A branches into B and C. Then C ends but B branches into D and E. There might be no single end of the world but just ends of individual branches. This is correct, but you should expect to be at the end of whichever branch is yours. That's where most people are. At the very least, you should expect to find yourself quite late in the universe, which we do not.
In fact, because in the distant future there are likely to be many more Boltzmann brains, by this logic, you should suspect that you're a Boltzmann brain on many worlds. A Boltzmann brain is a brain that randomly fizzes into existence in the recesses of outer space, rather than evolving on a planet. It forms randomly as a result of chemicals coming together. During heat death, after the last black hole has burned out, Boltzmann brains will still be able to form but there won't be any complex structures. Thus, it seems like if many worlds is true, you should suspect you're almost definitely a Boltzmann brain. Almost everyone who lives will do so after heat death.
🗑️ Anonymous at Thu, 3 Apr 2025 16:06:24 UTC No. 16636151
>>16636150
Another reply: on many worlds, it looks like the number of worlds will be infinite in any case. At every time, there will be infinite people of the same cardinality. A cardinality, for those who don't know, is a measure of the number of elements of a set. Two sets have the same cardinality if you can pair their members one to one: a set of two apples and two bananas have the same cardinality because you can pair their members one to one. Infinities are usually measured by cardinality; the number of natural numbers ( -2, -1, 0, 1, 2, 3, 4) has the same cardinality as the number of prime numbers as you can pair them off one to one.
Thus, a defender of many worlds could reply that at every single time, the cardinality of worlds will be the same-aleph null perhaps. Thus, it's not really increasing and you shouldn't expect to find yourself in a later world.
This has several problems. The first one is that it's probably the wrong analysis of infinity. Imagine there are aleph null people. They each have ten kids. You're created but don't know if you're part of the first generation or a later generation. It seems obvious that you should think at 10:1 odds that you're in the later generation. Even if the cardinalities don't change, you should probably still think that you're in the later generation. If you deny that, then you should think that in the actual world, so long as it's infinite, you're no likelier to be born after the first generation of humans than to be the first generation of humans.
Similarly, with many worlds, if aleph null universes repeatedly split, you should expect to be in one of the later universes, rather than one of the originals.
🗑️ Anonymous at Thu, 3 Apr 2025 16:08:21 UTC No. 16636152
>>16636151
The second big problem is that if this is right then credences turn out undefined. If there are aleph null people with each of several properties, generally your credence in having any of the properties will be undefined. If this is right, then before learning your birth rank, you should have undefined credence in each of the times you could be born at. But then, because later periods have mostly Boltzmann brains, you'll have undefined credence in your being a Boltzmann brain. https://substack.com/redirect/e551b
This objection strikes me as pretty strong. But I could easily be missing stuff. As I've said before, I don't really get the physics of many worlds. So proponents of many worlds tell me: why am I wrong?
🗑️ Anonymous at Thu, 3 Apr 2025 16:34:14 UTC No. 16636167
https://benthams.substack.com/p/an-
🗑️ Anonymous at Thu, 3 Apr 2025 17:03:32 UTC No. 16636190
>>16636137
I have no idea Anon
Anonymous at Thu, 3 Apr 2025 17:23:08 UTC No. 16636213
>>16636149
>infinite per second
Tell me how I know you didn't do the math without telling me how I know you didn't do the math.
Anonymous at Thu, 3 Apr 2025 17:31:27 UTC No. 16636221
>>16636135
The many worlds view of quantum mechanics includes probability mass attached to those worlds, not just possibility. If the anthropic effects you describe scale with probability mass, which it is generally understood to do, the contradiction disappears.
Anonymous at Thu, 3 Apr 2025 17:35:02 UTC No. 16636227
>>16636152
You're not wrong. The epistemic filter to use when someone puts forward random scenario garbage under the pretense of equal chance, is which one comes up as easier to test. Oh, you have to put me asleep 50 times to wake me up 46 times? Sounds much more difficult to test than just having me fall asleep 12 times and not give a fuck how the experiment was supposed to go
🗑️ Anonymous at Thu, 3 Apr 2025 17:38:45 UTC No. 16636237
>>16636221
Can you post that on his article linked itt? I'm not the author and I'd be interested in seeing his response to your comment and your response to his response etc etc
Anonymous at Thu, 3 Apr 2025 17:41:09 UTC No. 16636241
>>16636237
The first two comments the article page loads for me already make this objection in a slightly different form. Me repeating it in different words would be redundant.
Anonymous at Thu, 3 Apr 2025 18:54:52 UTC No. 16636331
>>16636237
Can you prove this lack of identity without making a statistical deference?
Anonymous at Thu, 3 Apr 2025 22:16:14 UTC No. 16636646
>>16636150
That's pretty cool, so I'm just a randomly generated brain in a given state at any moment, but I also have memories of the past. Shouldn't it be extremely likely that my memory is incoherent with my present? Like I should remember skydiving just a moment ago, but now I'm suddenly posting on 4chan.
Anonymous at Thu, 3 Apr 2025 22:18:57 UTC No. 16636651
Isn't it likely thar during heat death, many universes spontaneously reassemble into stable universes full of planets and galaxies again?
Things get weird when you introduce infinite possibilities.
Anonymous at Thu, 3 Apr 2025 22:21:35 UTC No. 16636655
>>16636646
The actual reason people don't bring this up is they're afraid of the idea anyone else is also from this same random aphasia.
Anonymous at Thu, 3 Apr 2025 22:22:35 UTC No. 16636656
>>16636651
Not at all
Anonymous at Thu, 3 Apr 2025 22:59:10 UTC No. 16636727
>>16636656
Why not? If Boltzmann brains can randomly exist than so can Boltzmann cars, Boltzmann planets, and Boltzmann universes.
Anonymous at Thu, 3 Apr 2025 23:01:23 UTC No. 16636731
>>16636135
>read some Eliezer Yudkowsky articles
This was your first mistake
Anonymous at Thu, 3 Apr 2025 23:01:53 UTC No. 16636734
>>16636727
Nope.
Anonymous at Thu, 3 Apr 2025 23:02:23 UTC No. 16636736
>>16636727
>If Boltzmann brains can randomly exist
They can't.
Anonymous at Thu, 3 Apr 2025 23:04:08 UTC No. 16636739
>>16636736
Yep, do teh math
Anonymous at Thu, 3 Apr 2025 23:08:20 UTC No. 16636745
>>16636736
Well no kidding, it's an argument against infinite possibilities, against suppositions like this
> 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.
Anonymous at Thu, 3 Apr 2025 23:26:17 UTC No. 16636772
>>16636135
all so-called "interpretations" of quantum mechanics are nonsense.
It's a model that works to predict phenomena, with all sorts of "strange" model properties emerging from the mathematical desciption of the model. But this is far from strange, with many of the theoretical prerequisites to develop quantum mechanics also displaying similar "unintuitive" properties.
The only valid "intepretation" of quantum mechanics is "shut up, calculate and experimentally verify". Everything else is fast food trash for the people.
>Eliezer Yudkowsky
Oh no no no...
Anonymous at Thu, 3 Apr 2025 23:32:24 UTC No. 16636780
>>16636745
I can control this future to every atom of specificity using the protocol which renders for the idiots who posted on /x/ claiming to have achieved a quantum chronometer.
Anonymous at Thu, 3 Apr 2025 23:42:32 UTC No. 16636787
>>16636772
David Deutsch says he's as sure of the many worlds theory as he is of evolution.
Anonymous at Thu, 3 Apr 2025 23:44:01 UTC No. 16636789
>>16636787
Then his reasoning is multiversally half wrong at each point.
Anonymous at Thu, 3 Apr 2025 23:51:08 UTC No. 16636795
>>16636135
you are a retard
>Likely an infinite amount of splitting happens
No, it must be countably finite. It is a big number, but it must be a countably finite number, becaue quantization implies that there is a finite number of states each particle can possibly take and there is a finite number of particles.
As a gross simplification, consider the 1-dimensional particle in a box: There is a finite number of positions it can take, as distance is quantized. Therefore in accordance with many worlds, this one particle will "create", a countably finite number of worlds after each planck time (time is also quantized as it is defined in terms of distanced, which is quantized) passes. It's a lot, but it is not infinite, it is always countably finite. After any number of planck times, you can in principle determine the exact number of worlds the particle has created. This generalizes to the more complex cases.
>let me give an analogy
This has nothing to do with quantum mechanics, but I'll humor you on the sillier things:
>>16636150
>Counterpoint: you don't.
Counterpoint: how do you know?
>because in the distant future there are likely to be many more Boltzmann brains
Why is that? How do you know there CAN be any at all? You're making a strong claim with no evidence.
>>16636152
>why am I wrong?
Because fundamentally this argument mixes
a wrong analogy with physical theory. You are trying to say that worlds formed by the minute movements of particles are people, when they are are not in fact people.
It's not science fiction, it's not even fictional science. It's scientific fanfiction.
Anonymous at Thu, 3 Apr 2025 23:52:34 UTC No. 16636796
>>16636787
>some guy says a thing
okay, cool.
How about you read a physics textbook or 10.
Anonymous at Thu, 3 Apr 2025 23:53:09 UTC No. 16636797
>>16636795
>there is a finite number of
Wrong, particles slip.
Anonymous at Thu, 3 Apr 2025 23:55:02 UTC No. 16636798
>>16636797
no they don't, I think you might need to revisit your understanding of what a particle is.
Anonymous at Fri, 4 Apr 2025 00:00:00 UTC No. 16636803
>>16636798
You solved fusion?
King Android at Fri, 4 Apr 2025 00:08:58 UTC No. 16636813
lie detected:
>vacuum density
Anonymous at Fri, 4 Apr 2025 00:10:54 UTC No. 16636816
>>16636803
I think you are confused what a particle is, especially if you start considering many worlds.
Particles appear to "slip", because a particle, despite being point-shaped has a volume in space. This volume is a consequence of the positional wave function model, however the model accounts for multiple particles, they cannot occupy the exact same space. Recall the one dimensional two particles in a box model.
Therefore we can make the assertion that no, particles do not in fact slip.
Please just go to the library and borrow a physics textbook.
🗑️ Anonymous at Fri, 4 Apr 2025 00:12:15 UTC No. 16636821
>>16636816
Same lie, your soul is dead and you with not have a future with viable mind uploading.
Anonymous at Fri, 4 Apr 2025 00:13:01 UTC No. 16636822
>>16636821
Enjoy your doomsday cult.
Anonymous at Fri, 4 Apr 2025 00:13:30 UTC No. 16636823
>>16636816
Same lie, your soul is dead and you will not have a future with viable mind uploading.
Anonymous at Fri, 4 Apr 2025 00:14:15 UTC No. 16636827
>>16636823
My soul is the only thing holding this wretched world together. You exist, because I allow it.
Anonymous at Fri, 4 Apr 2025 00:16:23 UTC No. 16636831
>>16636827
Wrong, lying to the public, and shadows this time are invited WITH weapons to torture you and everything in existence which tries to claim or implicate loyalty in your direction to death, whether a sophon gets in my way or not.
You are locked in nature, I run it.
Anonymous at Fri, 4 Apr 2025 00:19:11 UTC No. 16636835
>>16636831
stop consuming so much chinky scifi garbage and read something of actual value
Anonymous at Fri, 4 Apr 2025 00:35:25 UTC No. 16636860
Madplatypus can act as a weapon.
Anonymous at Fri, 4 Apr 2025 07:35:01 UTC No. 16637050
What about many interacting worlds theory?
Anonymous at Fri, 4 Apr 2025 08:13:24 UTC No. 16637068
>>16636813
vacuum density is a macroscopic consequence of wave mechanics.
Anonymous at Fri, 4 Apr 2025 10:05:40 UTC No. 16637123
>>16636135
the Relational Interpretation is many-worlds without the many worlds. all apparent contradictions and idiosyncracies of QM disappear when you simply let go of the notion of one (or more) canonical realities.
Anonymous at Fri, 4 Apr 2025 14:47:22 UTC No. 16637281
Well, it's bullshit, and hidden variable seems to be better explanation. Also if multiverses exist, you'd probably need a device to do such thing.