It is interwoven with describing an interactive fiction game, so not every word on there represents reality, but there are sources. I found it riveting when I first read it.
Bell was inspired by Bohm's theory. Having seen that a rational theory of existence was compatible with QM, Bell wanted to know if the nonlocality could be removed. Bell's work showed that it could not be removed. Bell was a proponent of Bohm's work. Bohmian mechanics is a perfectly sound theory, proven to be consistent and in agreement with quantum mechanics results whenever QM has results.
EPR (and more relevantly, Bohm's version of it involving spin entangled particles) showed that either one has hidden variables or nonlocality. Bell's work showed that local hidden variables is not possible. Hence, nonlocality is the conclusion and the argument to demonstrate the incompleteness of quantum mechanics falls apart.
The Many Worlds interpretations kind of gets away from this by exploiting another assumption in that work: that results from experiments actually happen in the sense that the other outcomes don't. Most people at the time would have just assumed that, but MW points out that experiments need not have definitive results, instead we have multiple results of experiments correlated with multiple versions of experimenters who think they have results. Thus, the correlations we see only need to be reconciled when the two groups of experimenters get together to compare notes, a perfectly local notion. Of course, some descriptions of MW, with branching of the universe, is rather nonlocal, but a proper formulation of MW is possible without any of that.
By the way, a key feature of Bohmian mechanics is the reliance on position as the "hidden variable". The spin of a particle is not an aspect of the particle itself, but rather of the wave function guiding the particle. In the spin experiments, the correlation with the environment once measurement has happened, separates the overlapping spin parts of the wave function and the particle is then being guided by that singular spin. Hence the appearance of the particle behaving as if it had that spin, but the particle is not actually spinning, whatever that would mean for a point particle.
It reminds me of the discussion of forest fires and whether to let the smaller fires burn to avoid the big, devastating fires. And then there is the question of intentionally starting fires to do the role of the smaller ones.
Given how that debate is not even agreed upon, it is hard to believe that one could come to much of an understanding of the Festival and its need with humans.
The textblade (https://waytools.com/ ) would be the ideal form factor in my mind. Unfortunately, it has been 6 years since they said they were going to release it though there have been people (testers) using it for real for several years.
If it's not released it's pretty suspicious that they let you buy one without mentioning that.
edit: this thing looks like a total scam. Announced as being 12 weeks out in 2015, taking orders, and still not released in April 2021, yet still taking orders? That's more than a blown deadline at this point. They're lucky they haven't seen legal action.
I saw the Textblade the first day it appeared on HN and I still droll over it. It's a real shame the company has been so shady (and they were from the start). I would really love for someone to clone it and actually bring it to market.
It depends on the system as there are different levels.
1. Promote comments above code. So the syntax for comments is the default. A simple notion is a markdown file where the process to create the program is to concatenate all the code blocks in order of appearance. Everything else is irrelevant to the code generated, but relevant to the developer. The idea here is to just promote communication of the reasons why and basic philosophy that leads to the code. The what should largely be easily readable from well-written code, but the reason for this choice versus that choice is what the comments want.
2. Reorder code. So each code block has a name and can be inserted in other code blocks. Order is irrelevant. This allows one to have, say, conditional logic easily readable without the actual code in between being executed. Functions can serve this purpose too, but the advantage of this style is that one can see the woven code together and read it as a whole in addition to this separated version. It helps prevent functions from being used purely as a reordering mechanism and to have functions being used only when its features are truly needed, such as repeatedly calling the same code. This allows for an in-between of avoiding copy-and-paste and avoiding unnecessary function calls (too many can lead to bouncing all over the place to see what is actually being executed).
The first two together is what is generally taken to be the mains of literate programming. This third one, however, is what I love about it.
3. Arbitrarily changing the code bits before insertion. This allows a lot of little DSL applications, easily inserting code from one language into another (e.g., writing markdown that converts into HTML that is embedded in a JS render function). This can also be used to do copy-paste-modify on a programmatic level. I often find this step to be one just before making an actual function, but somehow it helps me step through it all more easily.
4. Arbitrarily arranging inputs and outputs. Basically, write code entirely the way you (or your team, but probably just you) want to write it. If you want HTML, JS, and CSS all located together in functional units but put into separate files, no problem. If you want them coded in separate files but them brought into one HTML file, no problem. You want to manage configuration, installation, compiling, ..., no problem. You can write these files all separately, together, in pieces of relevance, etc. The danger is of course that your preferred style will not match others, but the hope of the original comment before code will allow people to follow. Essentially, you can read a top-level project management file that tells you where to look for all the other bits and it is faithful because this is how the system is being created.
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A system that I created that does all of that is https://github.com/jostylr/literate-programming It does work and I tweak every now and then, but it certainly is not in an ideal state. It is a npm installable command line program and there is a 10% written book linked to from the README (free to read on Leanpub in HTML style). Almost every command is documented in there, but just barely.
It is a markdown-based tool. I had experimented with creating a different tool called pieceful-programming which would allow for changing the basic literate style (say instead of markdown, using asciidoc). But I did not complete it (yet?).
I used my tool for web programming, allowing me to freely arrange backend and frontend code as I see fit.
The Bohmian model is that particle positions are an intrinsic part of the evolution of the theory. This is in contrast to, say, the Copenhagen interpretation in which the particle position is not a part of the evolution of the system. In the CI, wave functions are real (I guess) and we need something external to the model, called measurements, which mathematically do some complicated operation to the wave function of putting it in an approximate eigenstate (it can't do it exactly nor is the approximate nature specified and the timing of this is generally specified but not really clear about time of arrival measurements in scattering experiments).
In the Bohmian model world, particle positions would be real. They may not be measurable to the inhabitants to infinite precision (assuming quantum equilibrium, i.e., the particles are distributed according to psi-squared), but the particles have definite postions in this world. It has in it no need to postulate anything about measurement. Observables and all that are deduced from the theory.
It is important to ask what in a model has a fundamental existence, what has an implied existence, and what is just a useful term for something secondary to all that. In Bohmian mechanics, particles (things with position) have a fundamental existence, the wave function has an implied existence because that is how the particles move about, and spin has a secondary existence since it does not have a separate existence from either of those two objects, being solely deduced from the motion of the particles.
The Bohmian model is well-defined and has an easy correspondence between the entities that are real and our experience (stuff has position). It does not require observers to be complete. A Bohmian world could happily exist without PhDs, humans, mammals, life forms, etc.
What's real in CI? Not really sure, but I guess the wave function and measuring devices? It does require something that corresponds to measurements and the evolution of that classical world is distinct and separate.
This is the context of calling BM a realist theory. I would just call it an actual theory.
Bohmian mechanics illuminates the quantum randomness, allowing it to be analyzed. The theory happens to be deterministic (ignoring creation/annihilation), but it derives the apparent randomness from all that and it clarifies the meaning of psi-square.
> What's real in CI? Not really sure, but I guess the wave function and measuring devices? It does require something that corresponds to measurements and the evolution of that classical world is distinct and separate.
The wave function and any of its behaviors are not considered Real in CI, quite the opposite. CI posits that the wave function / schrodinger equation is just a mathematical tool that can be used to model the behavior of quantum phenomena - it is merely a tool that we can use, together with the Born rule, to predict the outcome of measurements. The measurements are the only things that are real. That's why CI is also sometimes summarized as "shut up and calculate" :).
> Whether pilot wave theory can be made consistent with at least special relativity is still open as far as I know
It can be made consistent, namely, adding a foliation (a notion of a canonical present moment) makes it work out fine. The foliation is not detectable, it gives the right predictions, it is mathematically sound, etc.
But it does feel philosophically sketchy and not fundamentally relativistic. However, there is a paper https://arxiv.org/abs/1307.1714 which explores how to derive foliations from the wave function itself and thus would be as relativistic as in theory involving the wave function.
The article also points to other articles with a variety of ideas how to deal with nonlocality in Bohmian mechanics.
For those who enjoy historical and game-play review of text-based games and similar games, there is the digital antiquarian: https://www.filfre.net/ If you go to the ebooks page, you can get (free) ebooks of game coverage from years spanning from 1966 to 1993. I believe every infocom text game is covered.
It is interwoven with describing an interactive fiction game, so not every word on there represents reality, but there are sources. I found it riveting when I first read it.