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“Hope produces space and time?” The longer I live the more I appreciate Kurt Gödel’s proof that we can never know everything about the universe. https://www.q
by hypertexthero 2y ago
“Hope produces space and time?”
The longer I live the more I appreciate Kurt Gödel’s proof that we can never know everything about the universe.
https://www.quantamagazine.org/how-godels-proof-works-20200714/ https://www.quantamagazine.org/how-godels-proof-works-202007...
- rbanffy 2y agoYou’d need something bigger than the universe to represent everything in the universe.
- 0xdeadbeefbabe 2y agoIt would be funny to find this out empirically. Like in the tower of Babel?
- rbanffy 2y agoAccording to the legend, they didn’t find it amusing.
- bumbledraven 2y agoNot if compression is involved.
- qingcharles 2y agoThis is why I have a totally unhinged belief that it might be possible to emulate the universe inside the universe itself.
- joseph_b 2y agoEverything sounds so simple until we try to explain it. If the emulation is contained inside the universe being emulated, do you think the emulated universe includes the emulation contained within it? Does the emulation now contain another emulation? If so, now many emulations?
- TuringTourist 2y agoAnd if that is the case, the odds are basically 0 that we happen to be the first of an infinite number of universes emulating themselves
- airstrike 2y agoBut that really has no bearing on our emulated selves. For us, this is the one reality that matters
- ridgeguy 2y agoPretty sure it's emulations all the way down.
- phkahler 2y agoI don't think that's unhinged. One might think the emulation must contain a subset of the state variables of the universe. But if there are no state variables that problem goes away. I have reason to believe there are no state variables.
- bongodongobob 2y agoI don't think there's any reason you couldn't but the simulation might move so slowly that it's not useful.
- qingcharles 2y agoThere are two problems -- storing the state of your emulated universe (storage space) and the operating speed. You can undoubtably run it at less than realtime, and might even be able to find a way to scrub fwd/rev through time to the interesting bits. The bigger issue is how to store the data. If the universe is compressible we might be able to store it and operate on it. If it's not sanely compressible then we either need to use a large chunk, or all of, the universe's matter/energy to store the state of our emulator and any inhabitants of our universe would need to file written complaints in advance at Alpha Centauri if they did not consent to being subsumed into the Giant Grey Blob(tm).
- nonameiguess 2y agoIt's frankly not all that clear what this even means. When cosmologists talk about the "universe," the generally mean the observable universe, which is all events that have ever happened in the past light-cone of the observer. Since space is expanding, that is constantly changing, with the expectation being that at some point, from the perspective of anything in our current galactic supercluster, everything else will become causally disconnected when the expansion rate exceeds the speed of light and will no longer be in "our" observable universe, where even then it isn't clear what "our" means as it's also likely by then that black holes will be the only baryonic matter still in existence, and there will no longer be humans, life, planets, or even light most of the time. As those black holes degrade via Hawking radiation over however many quadrillions of quadrillions of year, without gravitationally bound superstructures of any kind, eventually all fundamental particles will be causally disconnected from all others, permanently. What then does it mean to "emulate the universe inside the universe itself?" How do you emulate a single fundamental particle with only a single fundamental particle? What is the distinction between the emulation and the real thing? The real thing has nothing else to interact with, so it can't compute. It's state can't be measured because there is nothing to measure with. In short, I hesitate to speculate about what can and can't be done with the universe because what the universe even is will change quite drastically over long enough spans of time.
- qingcharles 2y agoWell, I feel like an emulator for our universe should be able to boot off simply the initial seed value and a copy of the Total Laws of Physics(tm). If you could emulate it then you could access and see into all the parts of our universe which are currently unobservable. Of course, if you could emulate it sufficiently you should be able to scrub the timeline into the future and visit Milliways too.
- joquarky 2y agoThere's no point simulating a universe that lacks agents. When the last agent dies, the simulation should halt.
- rbanffy 2y agoWhy would you think it’s not already? What we see is the observable state, not it’s underlying representation.
- mr_toad 2y agoAs far as I understand it, the pigeonhole principle would mean that you can’t losslessly compress the entire universe.
- yreg 2y agoIs that necessarily true for all universes? I suppose an empty universe represents itself. Or you could have a universe with matter distributed in the shape of https://xkcd.com/688/ https://xkcd.com/688/
- xpl 2y agoCan there be an empty universe? I suppose there is no "self" to represent then.
- rbanffy 2y agoAn empty universe would not have any information, or state change, and wouldn’t trigger any computation, therefore, it wouldn’t exist.
- airstrike 2y agoBut if I include it as a variant in my Universe enum, then doesn't it exist anyway, at least as a concept, even if it's never constructed?
- xpl 2y agoThen it's not a real universe but a mere symbol, I'd say. "Map vs. territory" And in order for that symbol to exist (be expressed / thought of / conceived), it must be a part of some other existing universe that allows that...
- airstrike 2y agoBut in which universe does that "map" exist? Boom, you've just created an universe containing a map out of a never-constructed-universe-containing-nothing.
- titzer 2y agoWell, Quine is a thing.
- minism 2y agoRight, but isn't it a problem that a quine also requires the information contained in the language's compiler/interpreter to be fully meaningful? This would be "outside the universe" so to speak.
- akira2501 2y agoCompilers are just translators. Which is why it's not too hard to write a compiler in the language that the compiler itself implements. An assembly quine is an odd thing to even ponder.
- nonameiguess 2y agoSort of. The very first compiled binary of any new language has to first be written in a language that already has a compiler, and the very first compiler of any high-level language at all had to be written in assembler. Ultimately, if you can't write a Quine directly in logic gates, which you can't because no microprocessor can output another microprocessor, you need something external to the "universe" of the language.
- titzer 2y ago> has to first be written in a language that already has a compiler You only need an interpreter for that language.
- titzer 2y agoA minimal quine just prints itself out as "source" code. You can choose the source language to be whatever you like, such as a minimal Turing complete combinator. So all you need is an interpreter for the base level, which could be something as simple as Rule 110[1]. It really doesn't matter what Turing-complete language you choose; they can all be implemented in terms of each other, so as soon as you have your quine one language you could as well do it any other. [1] https://en.wikipedia.org/wiki/Rule_110 https://en.wikipedia.org/wiki/Rule_110
- wslh 2y agoWe don't know if the Universe is finite or infinite, and also if it works in a completely logical way.
- flatline 2y agoObligatory: https://www.smbc-comics.com/comic/real-3 https://www.smbc-comics.com/comic/real-3
- ordu 2y agoI laughed at the inscription on the blackboard (the photo in the article) "Gödel's proof -- too important to be left to mathematicians".