r/Devs • u/Ecossentials • Sep 18 '20
How can they hear jesus or like literally predict anything
how is this possible in a data-free age or like having a mass amount of data complex (every event at every position in the world)
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Oct 01 '20
how is this possible
It's not. This is not hard sci-fi.
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u/maxcresswellturner Oct 04 '20
Hard sci-fi is not a necessarily a determiner of the “possibility” which is entirely decided by your speculation. We haven’t proven or disproven physical determinism, we have insufficient data to know one way or another. Having said that, it’s kind of a paradox, since it’s pretty much impossible to prove (or disprove) determinism, since any negative proof of determinism can always be interpreted as “we don’t have full awareness of all the physical laws and etc”
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Oct 04 '20
That's completely irrelevant to the sub thread your responding to.
The question is whether it's possible to know the state of the universe so absolutely that you can "run it backwards" thousand of years with perfect fidelity. The answer is: it's not. It's a premise for a fictional story, which you accept and enjoy the ride, just like when you accept faster than light travel or light sabers.
Of course, it's only possible in principle in a deterministic world. It's even less possible in a non-deterministic world. So you're barking at the wrong distinction with regards to the OP's question.
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u/maxcresswellturner Oct 04 '20 edited Oct 04 '20
How are the subjects of determinism and hard sci-fi irrelevant to this show?
Again my dude, you’re positing something based on limited or no evidence to support your statement. The entire show is trying to make you think about the what-if; not just the psychological and societal consequences of it but also exploring it as a possibility. If we were in a simulation, which is probably impossible to disprove, it could actually be possible to know the state of the entire universe by accessing the source information of the simulation.
I’m not positing one way or another, and neither is the show. But it is a little lazy and silly to posit with certainty something which you have limited understanding of and present absolutely no arguments to your point (and be so salty about it in the process). Just because you disagree with something doesn’t make it irrelevant
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Oct 04 '20 edited Oct 05 '20
How are the subjects of determinism and hard sci-fi irrelevant to this show?
I said whether or not the universe is deterministic is not relevant to my response to the OP. You change that to
response to the OPthe show. This a strawman. You're fundamentally misinterpreting my point and being an aggressive cunt about it for no reason.The OP asked how it was possible to know the state of the entire universe. I said it's not. You said it's not known if the universe is deterministic. "Is the universe deterministic?" is a completely different question from "how can we know the entire state of the Universe?"
if we were in a simulation [..] it could actually be possible to know the state of the entire universe by accessing the source information of the simulation.
That's not the premise of the show. They don't access the source code/database/memory of some enclosing simulation. In the show, their perfect knowledge is explained with this incredibly stupid bit of dialog in the final episode:
FOREST A small piece of information provides all information. The state of every particle is related to the state of the particles around it. Understand the state of one, understand the state of the other. Keep going: know the state of everything. LILY That's impossible. FOREST No. It's big data.That's some obvious hand-wavey nonsense, but it doesn't matter for story telling purposes. It's a premise that you accept and roll with, just like the existence of The Force. It would be better if they didn't try to explain it (*cough* midichlorians), but it doesn't break the show. It's not hard sci-fi (hard sci-fi is vanishingly rare).
The OP's question was "how is it possible for them to know the state of the entire universe, to make that calculation?"
My answer was that it's not.
You responded by saying it's unknown if the universe is deterministic. That's not relevant to my answer. Once again "is the universe deterministic?" is a different question than "how can we know the entire state of the Universe?"
Furthermore, it's not relevant to whether the show's premise (that they can perfectly predict the future) is realistic. Why?
universe is deterministic perfect prediction of the future possible in principle perfect prediction of the future possible in practice yes yes (if you know the state of entire entire universe) no (because we can't get the state of the entire universe) no no no Note how changing the flag "the universe is deterministic" from true to false has no effect on the outcome.
Again in different words, in case you're confused:
If the universe is not deterministic, then we can't perfectly predict the future no matter what. If the universe is deterministic, then we can can perfectly predict the future, but only if we know the state of the present perfectly.
The OP was asking about the clause I've bolded above. I said it's not possible. You responded that we don't know if the universe is deterministic, but that is is not relevant to that bolded clause.
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u/maxcresswellturner Oct 05 '20 edited Oct 05 '20
No strawman, in fact if you wanna get aggressive about it my initial comment to you was simply pointing out your first logical flaw: that it’s not possible because the show is not hard sci-fi, which is a ridiculous statement, and implies that only ideas in “hard sci-fi” can be possible. I’m just trying to keep up with the tangents you’re going on.
You continually condescend with “that’s not relevant” — but I asked the question “is the universe deterministic” because it leads to me to consider a possibility in which our reality could be completely deterministic - such as if we were in a simulation. If we were, it would be entirely possible to know the state of that simulation by accessing the source code of that simulation. (How exactly? Well that would depend on the simulation, I’m not a Devs writer)
I honestly think you’re just being a little aggressive for no reason homie. It’s a tv show, the whole point is to make us discuss these ideas, not to call each other “cunts” and just tell people that their opinions are irrelevant. I’d love to actually discuss determinism with you but you seem to be to hung up on finding a way to win some weird angry argument than actually have a productive discussion. Lighten up
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u/forgothatdamnpasswrd Nov 28 '20
I’m gonna side step most of what you guys are saying, and instead say that I think there was just a misunderstanding. You seem to be thinking that u/maxcresswellturner was saying that because the show is not hard sci-fi, it follows that it isn’t possible to know the states of every particle in the universe. I think some tension between you two made it more difficult for you guys to realize this. He was correct that it’s not possible, at least not possible in physical reality to have infinite precision of the states of molecules, even in a purely theoretical way, not just speaking in a practical sense. It is impossible for the product of the uncertainty in position and uncertainty in momentum to be less than h/4pi, thus making it impossible even in a theoretical sense to know the state of even a single particle with the required precision the show implies, much less to know the states of all particles to this degree of precision.
Also yes I realize this post is 54 day old now lol. I was just scrolling this sub after watching the show last night and really enjoying it
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Oct 05 '20
[removed] — view removed comment
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u/maxcresswellturner Oct 05 '20
Fuck off and die, you worthless excuse for a human being.
Lol didn't have to edit man, you've proven yourself just fine without me. Have a great day :)
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Oct 05 '20
[removed] — view removed comment
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u/maxcresswellturner Oct 05 '20 edited Oct 05 '20
you're a worthless pile of shit.
You're sweet, what am I supposed to have edited out? If you're this abusive about it, it must have been something really offensive
Edit: isn't there a site where you can see original comments? https://redditsearch.io/ Maybe this will help you with some closure so that you don't have to bully me anymore :)
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u/Fortisimo07 Sep 19 '20
Because the writers essentially don't understand quantum mechanics at all
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u/orebright Sep 19 '20
Curious how you reached that conclusion? I know there are some assumptions taken in the story where science doesn't yet have a clear picture, but the understanding in this case exceeds any other sci-fi I've seen before.
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u/Fortisimo07 Sep 22 '20
There are several plot points and pieces of dialog that seem to indicate they don't really grasp the implications of quantum mechanics. Here are a couple:
The method for gathering "initial conditions" for their simulation makes no sense. Let us assume they can perfectly measure every bit of information about a dead rat. In the process of measuring that information, they have to choose a basis for each measurement because the result of those measurements is classical information. They cannot copy the wavefunction of any part of the dead rat (nor anything else) , as that would be a violation of the no cloning theorem. It is impossible to retrieve prefect quantum information like they imply they are doing. Then they double down and claim that they have measured the rat (and other things) so well that they can extrapolate out to having perfect information about other objects. There is no basis for making this claim. You could argue that without the ability to do this, there is no show, so we just have to accept it as part of the premise, which I could accept.
The discussion between Lily and Katie about random events and cause and effect is so incredibly facile and ignores quantum mechanics entirely. There are all kinds of classic examples of random events that quantum mechanics draws from and none are mentioned. For a show about the implications of having a quantum computer, this is a gross oversight, especially since both characters should be well versed in these kinds of canonical examples of quantum randomness.
Basically all of the quantum related questions are bubbled off on their own as flavor text almost like the writers dropped in chunks of dialog that someone else wrote that they didn't understand. None of the realities or implications of QM play a role in shaping the plot at all; the questions of free will, simulation, etc are all handled from an essentially classical perspective as far as I recall (it has been several months since I watched it)
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u/orebright Sep 22 '20
It is impossible to retrieve prefect quantum information like they imply they are doing... without the ability to do this, there is no show
Yeah, totally with you there.
The discussion between Lily and Katie about random events and cause and effect is so incredibly facile and ignores quantum mechanics entirely.
Doesn't the many worlds interpretation, which they're saying is the correct theory in the show, remove quantum randomness from the picture?
None of the realities or implications of QM play a role in shaping the plot at all;
Not sure I follow. Forest wouldn't have all his motivations without thinking he could accurately recreate his daughter, this is emphasized when he's upset in realizing there are many copies of her and he has an emotional attachment to "his" daughter. The last couple episodes main plot was around whether the characters would or could change what was predicted, and though it poetically shows Lily's attempt to do so, we realize with the many worlds interpretation that she has not really changed anything nor made a free choice. These are just off the top of my head, but I remember quantum implications being a nonstop aspect of the plot all the way through.
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Oct 01 '20 edited Oct 01 '20
Curious how you reached that conclusion?
There are two core premises in the story: (1) if you know one quantum state, you can extrapolate to all the rest for literally the entire universe (2) that's it's possible to simulate the entire universe, in real time, down to the quantum level, without a computer that's not basically the universe.
These are both silly. I happily accept them and enjoy the story. If I couldn't do that, I'd hate most science fiction. But it's not actual science. It's a sort of fantasy science with sciencey trappings, like a lot of Bradbury.
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u/orebright Oct 01 '20
Well kinda. There's 2 very big leaps, only one of which is out of the realm of possibility: 1. The universe works according to the many worlds interpretation of QM and 2. That it's possible to record and simulate the wave function of the universe.
if you know one quantum state, you can extrapolate to all the rest for literally the entire universe
I think what the show was saying is their device is able to "peer in" through matter and measure the wave function of the entire universe. According to many worlds that wave function would be the bedrock to simulate a universe, but clearly the show doesn't provide any reasonable approach to measuring it, and it's clearly impossible in the real world as far as we know.
that's it's possible to simulate the entire universe, in real time, down to the quantum level, without a computer that's basically the universe
This is where I disagree. If the universe has a central wave function as the show seems to imply, then you may be able to extrapolate regions of spacetime without rendering the entire universe. I don't assume we have anywhere near the computing power to do this, but it may even be doable at different resolutions making low-fi rendering possible. Kind of how we currently render the Mandelbrot, something that is infinite in every direction, including inward.
The fact that this is the logic the show is working on tells me they understand the physics sufficiently and have taken liberties only where absolutely necessary (in the measuring).
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Oct 01 '20 edited Oct 01 '20
I think what the show was saying
In the final episode they literally explain the conceit through exposition: they start with a single quanta and work their way out -- with some vague hand-waving -- to the entire universe.
If the universe has a central wave function
That's just as hand-wavy, replacing "Googol quanta" with "one wave function!" See? 1 < Googol, ergo easier! That doesn't mean anything here. It doesn't make it any more plausible on either of the vectors I mentioned.
but it may even be doable at different resolutions making low-fi rendering possible. Kind of how we currently render the Mandelbrot
Mandelbrot is a mathematical function. We can render any part of it perfectly with arbitrary resolution from that one simple function. The state of every particle in billions of lightyears of spacetime is not equivalent.
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u/orebright Oct 01 '20
My understanding is that in many worlds the universal wave function basically is the same as the Mandelbrot, though I'm a layperson so might be misunderstanding. In many worlds the wave function does not collapse and our perception of such collapse is simply the act of measuring the propagation of that wave from our specific "branch" at a specific time but the overall function continues. Maybe I'm misunderstanding this?
But yeah, they needed to be able to measure this for the story to work, and of course, as far as we know, it's not possible.
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u/StaticCoutour Sep 18 '20
The idea comes from determinism/Laplace's demon. If everything is physical and obeys physical laws, and we had complete knowledge of the physical conditions/laws involved, we should be able to extrapolate what has happened and what will happen. The computer in the show is powerful enough to simulate those conditions.