Parable of Alien Chess • Hacker News Board

Re: Parable of Alien Chess

#71

Post by [deleted] » Tue, Jan 05, 2021, 10:14 AM UTC

slx26 wrote: post #52

subroutine wrote: post #24

The statement, "A machine that allows his alien eyes to see the first move." seems too information-rich for what the author then describes as the alternative model. Perhaps not the point of this thought experiment, but let's assume the aliens can only crudely see the first move: they know how many pieces there are on each side of the board, their color, but otherwise all the pieces look the same. They cannot see the…

Observing the movement of pieces quickly reveals that the board is divided in 64 squares. Squares being black and white or any other set of colors is actually irrelevant. They can basically fully understand the game from this, no need to make things complicated.

[deleted]

Re: Parable of Alien Chess

#72

Post by TeMPOraL » Tue, Jan 05, 2021, 10:14 AM UTC

dusted wrote: post #32

tikej wrote: post #8

This text mainly shows that author either misunderstands chess, probability and science, likely at the same time, or just wants to critique for critique’s sake. Of course while it’s good to search for alternative models/theories/explanations, unless you can provide something with better with more predictive power than the existing/widely accepted ones, it’s a good idea to hold the critique. EDIT: To clarify: by less…

I don't think it's entirely right to discard comparatively less developed theories based on their relatively weaker predictive power. That does sound like how one reaches a local maximum, to use the term from the article. Think on it in a different way, most of the very revolutionary theories, those that changed how we see the world, were relatively more simple, they were generally simple enough that one fringe could…

> Think on it in a different way, most of the very revolutionary theories, those that changed how we see the world, were relatively more simple, they were generally simple enough that one fringe could develop them to a point where they shined so brightly as to be next to irrefutable. Things like how the earth might be round, and circle the sun.

Intresting trivia: heliocentrism didn't show "shining brightly as to be next to irrefutable" - it was a fringe idea that could not be confirmed through observation at the time, required some pretty wild (for the time) assumptions - such as stars being very, very far away, to explain why there's no visible parallax from Earth's movements - and went against existing understanding of physics in general (such as, Earth is very big and heavy and bulky, so it's not obvious how could it be moving in circles very fast). Also, IIRC, the predictions made by heliocentric model were less accurate than geocentric ones.

It took astronomical observations with early telescopes to provide data points favoring a mixed geo/heliocentric model, and then further observations, work of Kepler and Newton's theory of gravity for heliocentric model to finally start making sense.

This does serve as an example backing TFA's thesis: some accepted theories, like (then) geocentric model, may be just local maxima - theoretical dead ends. A potential better theory will initially look bad in comparison, it needs work to develop past the accepted one.

Re: Parable of Alien Chess

#73

Post by ibab » Tue, Jan 05, 2021, 10:15 AM UTC

Jweb_Guru wrote: post #63

ibab wrote: post #59

Earlier quoted context omitted.

In the Everett/Many Worlds interpretation the appearance of randomness can be explained as an emergent phenomenon resulting from not being able to predict which part of the wave function we will end up in before running an experiment.

The Everett/Many Worlds interpretation cannot reproduce the predictions of quantum mechanics without extra assumptions (e.g. the Born rule) that don't have any physical basis within the context of MWI.

Yes, you are right to point this out. There are some important details that are still being debated. Personally my impression is that the debate has advanced enough to the point where MWI can’t be outright dismissed based on this argument. There are multiple plausible explanations and the remaining difficulties have more to do with philosophy than physics.

Edit: To give one example of an approach that I think is promising: We start by describing the observer and environment through a density matrix (a probability distribution over possible wave functions) and introduce an interaction with a quantum system (e.g. a spin). Given a reasonable interaction, you can show that the entanglement in the combined state (observer, environment and spin) leads to the system approaching a state that is a probability distribution of entangled states where each probability corresponds to the Born rule. Interestingly in this case the probabilities emerge from our lack of knowledge about the microstate of the observer/environment, so it’s actually thermodynamic uncertainty.

Re: Parable of Alien Chess

#74

Post by subroutine » Tue, Jan 05, 2021, 10:18 AM UTC

slx26 wrote: post #52

subroutine wrote: post #24

The statement, "A machine that allows his alien eyes to see the first move." seems too information-rich for what the author then describes as the alternative model. Perhaps not the point of this thought experiment, but let's assume the aliens can only crudely see the first move: they know how many pieces there are on each side of the board, their color, but otherwise all the pieces look the same. They cannot see the…

Observing the movement of pieces quickly reveals that the board is divided in 64 squares. Squares being black and white or any other set of colors is actually irrelevant. They can basically fully understand the game from this, no need to make things complicated.

I'm not sure they would be able to infer the board has 64 squares. They can't see the board, and can only see the locations of the starting pieces and location of the first move. The center of the board could be anything - 300 hexagons, a spin-wheel, series of mouse traps, etc.

Here's my interpretation of what they see pre- and post- opening move...

PRE: https://i.ibb.co/s6WnPNV/Chess.png

POST: https://i.ibb.co/7pg7GHW/Chess1.png

Re: Parable of Alien Chess

#75

Post by TeMPOraL » Tue, Jan 05, 2021, 10:19 AM UTC

the8472 wrote: post #68

H8crilA wrote: post #51

Earlier quoted context omitted.

> QM is the only physical theory that has randomness as an inherent part It's either inherent randomness or just a deep hole in the whole thing (similar to the alien chess thought experiment problem). Personally I choose to believe that the theory is just incomplete because nobody can even define what a "measurement" really is, meaning in which cases what we do is a "measurement" and in which cases it is not a "measu…

> nobody can even define what a "measurement" really is Isn't that the observer becoming entangled with the measured system?

It is, but that's in interpretations that also don't have the concept of "wave function collapse" in them. WFC is a feature of interpretations that considers measurement as something ontologically special.

Re: Parable of Alien Chess

#76

Post by Jweb_Guru » Tue, Jan 05, 2021, 10:20 AM UTC

ibab wrote: post #73

Jweb_Guru wrote: post #63

Earlier quoted context omitted.

The Everett/Many Worlds interpretation cannot reproduce the predictions of quantum mechanics without extra assumptions (e.g. the Born rule) that don't have any physical basis within the context of MWI.

Yes, you are right to point this out. There are some important details that are still being debated. Personally my impression is that the debate has advanced enough to the point where MWI can’t be outright dismissed based on this argument. There are multiple plausible explanations and the remaining difficulties have more to do with philosophy than physics. Edit: To give one example of an approach that I think is prom…

I'm not dismissing MWI, I'm just saying that current formulations either don't reproduce quantum mechanics or don't really address the existence of randomness within quantum mechanics.

Re: Parable of Alien Chess

#77

Post by FeepingCreature » Tue, Jan 05, 2021, 10:21 AM UTC

keiferski wrote: post #22

jackhalford wrote: post #14

> In Against Method, Paul Feyerabend, in what an unreflective mind might misinterpret as a "troll," says that it is important for science that people have biases, financial interests, interfering religious and political doctrines and the like in science. Also dying, and new generations coming along is in the interest of science. quite ironically the development of eternal life would kill scientific progress, which mi…

Eternal life would also almost certainly kill any class mobility.

On the other hand, we may develop a society where advancement does not depend on death.

Re: Parable of Alien Chess

#78

Post by Jweb_Guru » Tue, Jan 05, 2021, 10:23 AM UTC

TeMPOraL wrote: post #75

the8472 wrote: post #68

Earlier quoted context omitted.

> nobody can even define what a "measurement" really is Isn't that the observer becoming entangled with the measured system?

It is, but that's in interpretations that also don't have the concept of "wave function collapse" in them. WFC is a feature of interpretations that considers measurement as something ontologically special.

If you don't consider measurement ontologically special, then you need to somehow derive a physically meaningful Born rule without reference to measurement, which so far is something that AFAIK has only been accomplished in theories with large amounts of nonlocality and extra assumptions. The idea that people cling to the obviously false projection postulate out of obstinance is really strange to me, there just aren't very good alternatives available (at least not with the math fully worked out).

Re: Parable of Alien Chess

#79

Post by a-nikolaev » Tue, Jan 05, 2021, 10:26 AM UTC

boldslogan wrote: post #50

Lewton wrote: post #47

The author unironically uses a parable about aliens predicting chess outcomes with a coin flip and how wrong that is, to promote the idea that random fringe ideas without predictive power have value. I severely doubt anyone who isn't already primed to agree with the conclusions would read this and find it convincing (I don't find the idea that science needs ways to escape local maxima particularly controversial, but…

I think the issue arises, when a player who is not good at chess would lose, literally 100% of the time against anyone even close to a top regional level. In other words, chess is not a 50% chance game, it is a variable chance game depending on who you play, so the analogy is hard to follow because the aliens would not come up with this 50% outcome idea.

Chess must be a "beauty contest" then.

Seriously, a model that can predict things better than a coin flip will be more scientific. Even if it utilizes something that is somewhat hypothetical / not immediately observable. Say, Newtonian mechanics talks about forces - but forces is a totally made up concept, their nature is (for the most part) not explained within the Newtonian mechanics framework at all, but it's a good model.

Also, many models of reality that are "inferior" to the "real models" are still very helpful and useful in science. Many numerical methods scientists are happy to use, say finite differences, discretize continuous equations. This transformation makes the model strictly speaking worse. But this is fine, since it allows to produce calculations that match and predict experiments. Even in Physics, people start using ML / neural networks to approximate complex calculations. Not because a neural network is a better more descriptive model of the reality (of course it's not), but because it calculates the answer close enough to the real one.

Crank ideas are crank not because they use use some made up concepts that cannot be experimentally seen. They are crank, because they ignore mainstream development, staying blissfully unaware of the subtleties and details the mainstream theories have already considered and resolved.

So the main fault of crank theories is the ignorance of their creators, who are either not willing or not able to correctly contextualize their work within the previously existing knowledge. If you want to do science, you have to do your homework: 1) explore and learn what is known already, 2) develop it further or propose an alternative, 3) contextualize your work within the existing knowledge about the subject. Skipping steps 1 and 3 is dishonest.

Re: Parable of Alien Chess

#80

Post by TeMPOraL » Tue, Jan 05, 2021, 10:26 AM UTC

H8crilA wrote: post #51

jackhalford wrote: post #45

Earlier quoted context omitted.

you have it wrong, QM is the only physical theory that has randomness as an inherent part, as compared to e.g thermodynamics where randomness is due to lack of information. It is proven (see Bell inequalities) that randomness in QM isn't due to lack of information. You can't just wave away the collapse mechanism, what do you make of the double alit experiment? isn't the target "real" enough?

> QM is the only physical theory that has randomness as an inherent part It's either inherent randomness or just a deep hole in the whole thing (similar to the alien chess thought experiment problem). Personally I choose to believe that the theory is just incomplete because nobody can even define what a "measurement" really is, meaning in which cases what we do is a "measurement" and in which cases it is not a "measu…

I'm voting for a deep hole.

My layman feeling wrt. QM, and Copenhagen school in particular, is that we're searching for too computationally simple mental models. Most other areas of physics - like GR, SR, thermodynamics - can get away with aggregating matter into points, perfect spheres, etc. because they're working in macro scale, but QM is trying to deal with the smallest bits of our reality. Now the boundary between QM and "classical physics" is one where your quantum system will interact with 10^{double digit} amount of other quantum-relevant bits. I have a feeling that searching for what constitutes "a measurement" in such scenario is missing the point, and even talking about the macro system being entangled with the test system is pretty much skipping over all the interesting bits.