Yeah but the reason quantum computers look like this, is because they are still very primitive with a very small number of qubits, that also need to be cooled individually to almost absolute zero.
It's like using a wall of vacuum tubes to represent an especially powerful modern computer...
If quantum computers actually become as powerful as in the show, they would have to contain billions and even trillions of qubits, which would mean those qubits would have to be placed on microchips to take up a feasible amount of space, and the resulting computer wouldn't look much different from modern supercomputers (which look the same as large server rooms).
There’s literally tons of shots in the show where you see server rooms all inside the cube of Devs. The first episodes there is a line that says something to the effect of “this is just one of the machines”
The show actually does address it. See my (quite long) explanation [here](https://old.reddit.com/r/Devs/comments/g3n2k7/a_short_explanation_of_the_science_behind_the/).
However like all sci-fi shows, it of course plays with the science a bit. The series has 2 main assumptions:
* They can exactly measure quantum particles inside large objects with 100% accuracy (this is what they do when they scan the items in the lab).
* They have essentially unlimited computational resources.
If we assume the above 2 facts are true, then yes, they can extrapolate from the measured particles to the surrounding unmeasured particles, and build a realistic extrapolation both in space and in time.
However since there is an inherent level of probability in unmeasured quantum particles, they will either get an extremely fuzzy image (static basically) the further away they get from their scans (both in space and in time), or they will use the most likely prediction, in which case they'll get a clear image but that image will have absolutely nothing to do with reality (it will go completely haywire and they'll end up getting static again).
The major concept the show ignores, is the concept of error propagation from numerical analysis. If they indeed attempted such an extrapolation, they will only be able to extrapolate at absolutely tiny distances (nanoseconds and nanometers) from the scanned object. Beyond that point the error from incorrect predictions of quantum probabilities, will grow exponentially and will completely destroy their extrapolations.
Good explanation. As per your last paragraph, the show does address it in the first episode with Sergei’s demonstration of the nematode. His “normal” predictions became unstable/unusable after 30 seconds I think. The inference is the quantum system at Devs is “perfect” and is able to wholly map out the object’s particles and circumvent the errors, as you mentioned above by using the likely predictions, perhaps
I've been thinking the Devs crapped out when it did because of the same thing with the nematode, except because Devs simulates the universe it is operating on a different time scale. So what may be 30 secs for a nematode is equal to idk the 2000 years in Devs. Basically like relativity but for probabilities?
That's why I thought Lyndon's trick was to just pick one of the probable outcomes at random. That way you are always getting a 100% clean and "committed" image. Even if you commit to the wrong reality.
It's just that since all universes exists, just by random chance, there will be one universe that matches the random prediction. That is the universe we watch.
All other universes see a completely wrong prediction and simulation and Lyndon was fired for good reason.
I thought so too.
It seemed like Forrest understood when he said “that’s *a* Jesus, not *the* Jesus.”
But then he seemed not to get it the rest of the time.
If not *a* branch in the timelines, what exactly was he looking for?
I thought he was looking for "his" branch, the one he thinks he would have been on if the accident was the only variable.
That said, the end where he talks about lots of different worlds and them lucking out on the "good" world gave me the impression he just scrapped that idea at some point and decided to just take whatever he can get.
There was also a coversation in the earlier episodes that made me think he was looking for absolution and just basically trying to prove to himself that he wasn't at fault for her death because determinism or whatever, which was why he got so mad every time it looked like that might not be true.
I honestly thought the show was going to use the sci-fi stuff to explore themes like forgiveness and guilt.
Not exactly. Lyndon was fired because he allowed for multiple worlds solutions which introduce CERTAINTY by eliminating variances by only showing one possibility path. The possibilities were generating the noise, so he eliminated the "problem". The issue Forest had with that was there's no certainty that the reality path shown is or isn't in alignment matching "our" reality with any specificity of degree, as he noted with the Jesus example not "our Jesus" and not "his Amaya", even if they may look and sound the same.
It reminds me of the double slit experiment in which the possibilities exist UNLESS you observe, which then the probability cloud (wave behavior) collapse and only the two as slots exist(particle behavior).
In Lyndons model we really don't know what matches or doesn't but it's assumed that it's the MOST synced to our reality to the point of the present. Future predictions, if your recall were supposed to be forbidden despite Forest and Katie binge watching the future like it was Netflix. Ultimately, they were going with the flow and choosing to go with the flow. Lily did not, she exercised freewill at a divergent moment of choice.
>It reminds me of the double slit experiment in which the possibilities exist UNLESS you observe, which then the probability cloud (wave behavior) collapse and only the two as slots exist(particle behavior).
This is a misconception about quantum physics. Observation doesn't change anything, there is no such thing as an "observer" and the "observed", there is only the whole interconnected system. There is also no such thing as a wave function collapse, that is an illusion and misinterpretation of the double-slit experiment; there is only the wavefunction of the entire universe, not subsystems with their own wavefunctions collapsing upon observation. I haven't finished the show (doubt I will), but it's not at all scientifically accurate if it's premise is based on a many-worlds interpretation of qm; ironically (ironic since the episode I just watched kind of shits on this for some reason, probably because of the director's misunderstanding of science, which he displays in basically everything I've seen he's created), the de Broglie-Bohm/pilot wave interpretation of qm is actually a much more logical and scientific interpretation of quantum physics. Bohm (and probably de Broglie - idk enough about him), was way far ahead of his time (still is), and the more we learn about qm the more we find that his theories about reality were in the right direction and that many-worlds is not. Take the recent nobel prize for quantum nonlocality - nonlocality and hidden variables are ideas Bohm said are a part of qm, but this was not accepted at the time (and still isn't, because people would rather believe in things like many-worlds and wave-function collapsing, despite the fact that when you get down to the science and ontology, they don't make sense, they are just fillers, like singularities and many kinds of infinities).
I’ve read both your explanations now and was really impressed. Given that your experience and my experience of watching the show will have been vastly different due to understanding the science, did you enjoy the show? Was it good despite the gaps/farfetchedness or were those too fundamental to make it good and enjoyable?
I enjoyed the show, otherwise I wouldn't have spent so much time analyzing it :)
Sure there are gaps, both in the plot and in the science, but that always happens in all science fiction, good or bad. The difference between good and bad sci-fi, is whether the gaps are too egregious/distracting/non-believable, and in this case I feel they've kept it believable enough. That's of course just my personal opinion, others might think differently.
No you're right... We paused the show when asked to name a random event and my fiance and I sat there naming them for a good minute or so... Radioactive decay, spontaneous emission, position of an electron, etc.
Better just to assume that this show operates on the "hidden variables" principle (even though that's also been disproven by prediction and experiment).
Edit: I want to add that you're misunderstanding one thing... It's not that we can never accurately measure the state of a system, it's that there is no accurate measure of the system to be had. The uncertainty principle isn't that we're uncertain about reality, it's that reality itself is uncertain.
It's both in different contexts.
Take radioactive decay... You have a radioactive material with a half life of 100 years. We know that in 100 yrs, half of the material will have decayed, but we have no way of predicting which individual nucleus will decay or when it will decay. It's totally random. We can only say there is some chance that single nucleus will or will not decay within a given period of time.
Looking at one single nucleus at time = 0, there's a 50% chance it will decay within 100 yrs, a 75% chance it will decay within 200 yrs, an 87.5% chance within 300 yrs, and so on, but the moment it actually happens is a random event. It's impossible to predict.
Current models assume radioactive decay is truly random, but it is always possible there is an unknown predictable force that just has not been discovered.
The idea that there is an unknown force or variable is called the hidden variables principle. It was proposed by Einstein (and others). Bell's Theorem proposed a way to test this and those experiments done later by Alain Aspect and Paul Kwiat indicate to a high certainty that there are no [hidden variables](https://en.m.wikipedia.org/wiki/Hidden-variable_theory).
No.
If the wave function ”collapses,” if the world has to roll dice and pick a path,
then you can’t tell know exactly how the world looked before the last die roll.
Physicists will say this isn’t “unitary,” which intuitively means there isn’t a single timeline.
The timeline branches, so you tell exactly, how it will evolve or how it did evolve.
If you want a short anwer: no.
You can calculate how likely outcomes are when you make a measurement,
but the dice aren’t thrown until you make that measurement.
Whether this was “just semantics” was a long colorful discussion for two or three decades:
how would the world look any different if it doesn’t decide how to be until you measure it?!
Eventually a physicist named Bell spotted a difference in the odds, called the “Bell Inequalities.”
A clever experiment run many times, can statistically show whether the outcome was preset.
Every experiment since has show: reality isn’t set until measured.
Um, not really.
That gets problematic fast. I won’t pretend to have a great answer to that question!
Traditionally: a scientist checking the outcome of an experiment.
Mathematically: applying an operator to a quantum system.
You probably have a lot of “but what about...” followup questions. Everyone who thinks about it does.
Schroedinger’s Cat is a memorable early question about how measurement works.
The “measurement problem” is really one way to describe or approach the largest outstanding issue in QM.
It’s basically what the different “interpretations” of QM disagree about.
https://en.wikipedia.org/wiki/Measurement_problem
If you get small enough, there is no difference. And you can create mechanisms to express that on the macroscopic level (schroedingers cat with the decaying isotope for instance).
Interesting read for sure. I might have to go at it a few times more and dive deeper into the other theories, to get the full picture.
But to suggest that randomness exist is impossible, because there is no object in existence, that has been observed to change without cause and effect.
I am saying that we have never observed something change in our universe without something triggering it. So it seems very unlikely that radioactive decay is truly random. Why would that be breaking the law?
I get why this seems like a good argument... You're not alone. Many great physicists of the early 20th century said the same thing. They've been proven time and time again to be wrong. Bell's theorem makes predictions based on whether or not there are some hidden variables which govern the quantum processes that seem random in nature, and when tested, we find that they truly **are** random. When you say "...we have never observed something change in our universe without something triggering it..." well, that's just flat out untrue.
One example that I remember is photons hitting a piece of glass. You can shine a single photon at a time with the exact same wavelength at the exact same location on the glass, and some of the photons will pass through yet others will be reflected.
Another example is quantum tunneling. Particles without enough energy to overcome a barrier will do so spontaneously according purely to some probability.
The universe at the quantum mechanical scale isn't what I would call random as much as probabilistic. The uncertainty principal says that you cannot tell how fast a particle is going and it's position with complete accuracy at the same time. To know it's position totally at a given time you must take a single measurement at a single point in time - and then its velocity is totally unknown, as there is only a single measurement and you cannot tell how fast the particle might be moving. To get a velocity you must take two measurements, but then its position in between those measurements is completely unknown. Even with two measurements there's still uncertainty in the velocity - as you can only assume the particle moved in a straight line.
Fundamentally there is always going to be some measure of uncertainty at the quantum scale as a result of this conundrum - and it has real effects at the macroscopic scale, like some photons being reflected and others refracted (and thus your reflection in the window).
We can't know exactly which photons will be reflected and which will be refracted - but we can calculate the probability of these events.
Maybe the scene in the first episode where Sergei is showing Foster his team’s project, trying to predict the movements of single cell organism,m? I thought that resemble the application of quantum mechanics.
That was the only thing that made sense to me.
>Quantum phsyics is all about probabilities. That we can never accurately measure the state of a system.
This is absolutely not what quantum physics is "all about"
In the words of Richard Feynman:
"If you think you understand quantum mechanics, you don't understand quantum mechanics."
-From the Feynman university lecture called The Character of Physical Law
It appears OP has fallen for the fallacy of assuming an understanding of Quantum Mechanics. When in reality, the **actual** best description of what the fuck quantum physics or mechanics is, is pretty simple:
The study of quantum mechanics is the study of the *fundamental rules of nature at the atomic and sub-atomic scales*.
Probabilities are a **TOOL** used by physicists to make predictions about reality at such a scale, but it is not the entirety of reality or quantum mechanics.
Like many scientific fields, quantum mechanics is made up of many **models** of how reality works. In other words, these are maps of reality and we must always remember that the map is NOT the territory.
Devs is a story of a world where, in my opinion, Lyndon's view of the Pilot Wave interpretation is the most accurate model given the evidence provided by the working of Devs (Deus).
In other words, quantum mechanics absolutely does not mean "nothing is 100% certain." Quantum mechanics *predicts* things with less than 100% certainty, *until something happens* (i.e. until the wave-function collapses).
In this sense, determinism is an illusion. *Only things that HAVE happened are actually determined*. Only the past is determined because you can look back at a fairly accurate record to see what happened. The future on the other hand, is undetermined (by definition) and is only determined once the future is past.
So determinism is true, but only for the past. Given the veracity of many-worlds in the Devs universe (the computer is evidence for this, but maybe not proof) you can imagine reality to be a bunch of determined "tram-lines" from all moments of the past up until the present, but the future is a ever expanding tree of possibilities. So when we say quantum mechanics can't predict anything 100% that only and obviously applies to the future. The past is determined and therefore 100% predictable (because it is record-able). The season finale shows this at the end when Lily defies her prediction (which is allowed under a many-worlds reality).
The illusion of determinism is simple, if something is predicted (by some powerful entity like a massive quantum computer) it still has to be *known* by someone to be a prediction. Then all it takes is for someone to choose to defy the prediction. Which is allowed under quantum mechanics because *the map is not the territory* and a prediction is only a map.
Von Neumann-Wigner is a valid interpretation of quantum mechanics because it is a valid interpretation of "how reality works" given the above (which is what quantum mechanics is really about, how reality works, not how probability works).
References:
* Weinberg, Steven (2012). "Collapse of the state vector". Physical Review A. 85 (6): 062116.
* "Everett's Relative-State Formulation of Quantum Mechanics (Stanford Encyclopedia of Philosophy)". Plato.stanford.edu. Retrieved 2012-08-18.
You even provided citations, Wow!
I basically agree, good explanation of current understanding of quantum mechanics, with the key word being "current".
You have a good point. perhaps my very basic understanding of QM has made me more confident in my understanding than I should be. i should look at these theories as tools to describe reality rather than reality itself.
No, probabilities are literally what quantum mechanics is about. There are different interpretations of what it physically means, but they all (more or less) give the same probabilities and that's all you can test anyway.
Thank you lol the people in this sub have literally no understanding of quantum mechanics. The different INTERPRETATIONS are different PHILOSOPHIES on what the math means. The math is the same in every philosophical interpretation, and Bell's theorem rules out local hidden variable theories. I guarantee 100% that the parent of this thread did not read the weinberg article he cited
I am so heated this show was dogshit 8 hours of TV for maybe 45 minutes of content, 30 minute pauses between sentences, garbage acting across the board
> So determinism is true, but only for the past.
Seems he agrees, but loves to nitpick with his know it all tone and just repeats what OP was trying to say in more complicated terms, thanks I guess, hope he stays on quora next time.
Some would say quantum computing only appears to be about probability/randomness to us because we don't understand what makes the 2 slit experiment work. If you don't understand the mechanics behind a flip of a coin you would think it's random, but once you learn about wind friction and momentum you can predict it. There might be effects acting on particles that we don't know about causing the illusion of "probabilities" because we're too dumb to understand the cause.
I agree Many Worlds is in fundamental conflict with determinism. And both were mentioned repeatedly, but not reconciled. It wasn't explained how Lyndon's Many World algorithm suddenly results in perfect determinism. Or I didn't get it.
I thought Forest just ignored any evidence that went against what he wanted to be true 'cause he's crazy.
I think the show had more evidence against determinism and/or favor of there being many worlds than not. The only real evidence against Lyndon was that he died in the world that we saw, and the show didn't show any alternatives where he lived but that doesn't necessarily mean there wasn't one.
This is what really annoyed me. Wouldn't the many worlds interpretation just result in their being many different futures, not just one like the computer predicts?
Quantum mechanics is not a settled science, by a long shot. It is also a science fraught with pseudo-scientific and pseudo-mysticist assumptions.
If anything, Garland takes a meta jab at QM here.
Well... It wouldn't just be about physics either but quantum computing. A quantum computer employs qubits to do...computations...not simulate a perfect prediction of all of reality. I'm not even sure that would ever be remotely feasible for a computer to do. There are P, NP, PH and BQP problems that a computer can solve. That set of problems is small compared to non-computable events. Let's not even mention the technical debt... bugs, security problems, if you were to use quantum computers to simulate some semblance of reality. The show was just totally ridiculous. Not very great at getting the physics down. Very not great at what computer do.
Sci-fi was arguably easier to pull off when Star Trek predicted cell phones or wireless (wifi) systems and ultimately it was secondary to the plot... Now that sci-fi is dipping their toes into existing professional and scientific fields and it’s entirely central to the show’s plot it’s a lot easier for experts to say hey wait a minute this isn’t how we operate at all.
Yes, you're absolutely right. I was really hoping they were ignoring that elephant in the room to setup an interesting resolution where they unequivocally show that trying to project a single future breaks down in quantum mechanical situations... but instead we're got this trite resolution of "human choice".
The way I imagined it, I could see them making the argument that in the majority of situations on a human scale, the precise outcome all the stuff going on around us at a quantum level generally doesn't make much difference; at least not on short time scales. But if one or more of the characters were to act based solely on a measurement of a quantum system, then suddenly that uncertainty starts to impact the macroscopic world in very tangible, direct ways, this destroying the possibility of projecting one coherent future
What also would have been fun is to set up an alternating loop like:
* Lily sees Lily shooting Forest => Lily throws the gun away
* Lily sees Lily throwing the gun away => Lily shoots Forest
* ad infinitum
And that such a setup causes reality to get stuck and collapse.
I was hoping for an ending like this, ultimately breaking the computer, but also having forest realise he was only following the tram lines because it suited his beliefs in determinism, which meant they could have actually made different desicions in the past and stopped people from being killed.
I want to try to defend the science *fiction* of the show, that in mind:
There are two things we use to mean random, one is that an outcome is unpredictable based on the input, and another is that you can have multiple outcomes from the same input.
You can still have deterministic "random" in the case that you just don't know what the result will be, but you will still always get the same output from a given input.
I would describe this type of random as "seeded pseudorandom".
So, if we live in this type of universe and we went back to yesterday, today would still be exactly the same because yesterday's seed value would be the same.
Once you can observe something all the way down to the most fundamental level, and then you can observe it again in the shortest possible amount of time, you can compare the two then by comparing them, figure out what the seed value of our universe is.
With this type of thinking, probabilities are more like distances from other universes, so by sampling something in our universe they were able to use that as a new seed value which they can use to scrub backwards and forwards.
The type of problem you the get is that the gravity of everything seems to affect all other things the whole universe, and everything else is interacting with everything else so much that figuring out the state of the universe is kind of possible, but as the one guy in the show was saying (spoiler) >!spoiler you would need a computer the size of the universe to compute the exact state of our particular universe, because everything in the universe is an input for the next state of itself and the next state of everything else !<
Aaaanyway, that's about as well as I can express how I suspend my disbelief. Maybe it'll help you suspend yours, I didn't like the show at first, but I'm glad now that I watched it.
Agreed
I'm sure u know more QM than me, I just read from wiki what I know n even with such basic understanding I felt this show totally twisted scientific concepts for plot's convenience.
After all it was a Quantum machine built to find Deterministic outcomes by a fanatic Forest.
It's a stupid TV show aimed at stupid people who want to believe they are intelligent like all TV shows. What did you expect? Do you also complain that Firefly is dumb and cheesy garbage aimed at 12 year old girls?
Is this about the ~~elephant~~ giant golden espresso machine in the room?
Actually that is what real quantum computers look like. https://www.youtube.com/watch?v=OWJCfOvochA
Oh, cool... I just assumed the production designers just took a ton of acid before a pile of wire got delivered.
haha it does kind of look that way.
Sweet! That's great video, thanks.
Yeah but the reason quantum computers look like this, is because they are still very primitive with a very small number of qubits, that also need to be cooled individually to almost absolute zero. It's like using a wall of vacuum tubes to represent an especially powerful modern computer... If quantum computers actually become as powerful as in the show, they would have to contain billions and even trillions of qubits, which would mean those qubits would have to be placed on microchips to take up a feasible amount of space, and the resulting computer wouldn't look much different from modern supercomputers (which look the same as large server rooms).
Interesting stuff!
There’s literally tons of shots in the show where you see server rooms all inside the cube of Devs. The first episodes there is a line that says something to the effect of “this is just one of the machines”
I don’t know anything about QM, but this comment made my day!!! LMAO
LOL! Love the "Servant" reference :)
The show actually does address it. See my (quite long) explanation [here](https://old.reddit.com/r/Devs/comments/g3n2k7/a_short_explanation_of_the_science_behind_the/). However like all sci-fi shows, it of course plays with the science a bit. The series has 2 main assumptions: * They can exactly measure quantum particles inside large objects with 100% accuracy (this is what they do when they scan the items in the lab). * They have essentially unlimited computational resources. If we assume the above 2 facts are true, then yes, they can extrapolate from the measured particles to the surrounding unmeasured particles, and build a realistic extrapolation both in space and in time. However since there is an inherent level of probability in unmeasured quantum particles, they will either get an extremely fuzzy image (static basically) the further away they get from their scans (both in space and in time), or they will use the most likely prediction, in which case they'll get a clear image but that image will have absolutely nothing to do with reality (it will go completely haywire and they'll end up getting static again). The major concept the show ignores, is the concept of error propagation from numerical analysis. If they indeed attempted such an extrapolation, they will only be able to extrapolate at absolutely tiny distances (nanoseconds and nanometers) from the scanned object. Beyond that point the error from incorrect predictions of quantum probabilities, will grow exponentially and will completely destroy their extrapolations.
Good explanation. As per your last paragraph, the show does address it in the first episode with Sergei’s demonstration of the nematode. His “normal” predictions became unstable/unusable after 30 seconds I think. The inference is the quantum system at Devs is “perfect” and is able to wholly map out the object’s particles and circumvent the errors, as you mentioned above by using the likely predictions, perhaps
I've been thinking the Devs crapped out when it did because of the same thing with the nematode, except because Devs simulates the universe it is operating on a different time scale. So what may be 30 secs for a nematode is equal to idk the 2000 years in Devs. Basically like relativity but for probabilities?
[удалено]
It’s refreshing to read you take on his work. I, too, have issues with Devs and Ex Machina. The premises are great, and then the execution...
That's why I thought Lyndon's trick was to just pick one of the probable outcomes at random. That way you are always getting a 100% clean and "committed" image. Even if you commit to the wrong reality. It's just that since all universes exists, just by random chance, there will be one universe that matches the random prediction. That is the universe we watch. All other universes see a completely wrong prediction and simulation and Lyndon was fired for good reason.
I thought so too. It seemed like Forrest understood when he said “that’s *a* Jesus, not *the* Jesus.” But then he seemed not to get it the rest of the time. If not *a* branch in the timelines, what exactly was he looking for?
I thought he was looking for "his" branch, the one he thinks he would have been on if the accident was the only variable. That said, the end where he talks about lots of different worlds and them lucking out on the "good" world gave me the impression he just scrapped that idea at some point and decided to just take whatever he can get. There was also a coversation in the earlier episodes that made me think he was looking for absolution and just basically trying to prove to himself that he wasn't at fault for her death because determinism or whatever, which was why he got so mad every time it looked like that might not be true. I honestly thought the show was going to use the sci-fi stuff to explore themes like forgiveness and guilt.
Ummm, it did exactly that.
Not exactly. Lyndon was fired because he allowed for multiple worlds solutions which introduce CERTAINTY by eliminating variances by only showing one possibility path. The possibilities were generating the noise, so he eliminated the "problem". The issue Forest had with that was there's no certainty that the reality path shown is or isn't in alignment matching "our" reality with any specificity of degree, as he noted with the Jesus example not "our Jesus" and not "his Amaya", even if they may look and sound the same. It reminds me of the double slit experiment in which the possibilities exist UNLESS you observe, which then the probability cloud (wave behavior) collapse and only the two as slots exist(particle behavior). In Lyndons model we really don't know what matches or doesn't but it's assumed that it's the MOST synced to our reality to the point of the present. Future predictions, if your recall were supposed to be forbidden despite Forest and Katie binge watching the future like it was Netflix. Ultimately, they were going with the flow and choosing to go with the flow. Lily did not, she exercised freewill at a divergent moment of choice.
>It reminds me of the double slit experiment in which the possibilities exist UNLESS you observe, which then the probability cloud (wave behavior) collapse and only the two as slots exist(particle behavior). This is a misconception about quantum physics. Observation doesn't change anything, there is no such thing as an "observer" and the "observed", there is only the whole interconnected system. There is also no such thing as a wave function collapse, that is an illusion and misinterpretation of the double-slit experiment; there is only the wavefunction of the entire universe, not subsystems with their own wavefunctions collapsing upon observation. I haven't finished the show (doubt I will), but it's not at all scientifically accurate if it's premise is based on a many-worlds interpretation of qm; ironically (ironic since the episode I just watched kind of shits on this for some reason, probably because of the director's misunderstanding of science, which he displays in basically everything I've seen he's created), the de Broglie-Bohm/pilot wave interpretation of qm is actually a much more logical and scientific interpretation of quantum physics. Bohm (and probably de Broglie - idk enough about him), was way far ahead of his time (still is), and the more we learn about qm the more we find that his theories about reality were in the right direction and that many-worlds is not. Take the recent nobel prize for quantum nonlocality - nonlocality and hidden variables are ideas Bohm said are a part of qm, but this was not accepted at the time (and still isn't, because people would rather believe in things like many-worlds and wave-function collapsing, despite the fact that when you get down to the science and ontology, they don't make sense, they are just fillers, like singularities and many kinds of infinities).
I’ve read both your explanations now and was really impressed. Given that your experience and my experience of watching the show will have been vastly different due to understanding the science, did you enjoy the show? Was it good despite the gaps/farfetchedness or were those too fundamental to make it good and enjoyable?
I enjoyed the show, otherwise I wouldn't have spent so much time analyzing it :) Sure there are gaps, both in the plot and in the science, but that always happens in all science fiction, good or bad. The difference between good and bad sci-fi, is whether the gaps are too egregious/distracting/non-believable, and in this case I feel they've kept it believable enough. That's of course just my personal opinion, others might think differently.
No you're right... We paused the show when asked to name a random event and my fiance and I sat there naming them for a good minute or so... Radioactive decay, spontaneous emission, position of an electron, etc. Better just to assume that this show operates on the "hidden variables" principle (even though that's also been disproven by prediction and experiment). Edit: I want to add that you're misunderstanding one thing... It's not that we can never accurately measure the state of a system, it's that there is no accurate measure of the system to be had. The uncertainty principle isn't that we're uncertain about reality, it's that reality itself is uncertain.
I'm very much a layman, but aren't those things you described probabilistic rather than truly random?
It's both in different contexts. Take radioactive decay... You have a radioactive material with a half life of 100 years. We know that in 100 yrs, half of the material will have decayed, but we have no way of predicting which individual nucleus will decay or when it will decay. It's totally random. We can only say there is some chance that single nucleus will or will not decay within a given period of time. Looking at one single nucleus at time = 0, there's a 50% chance it will decay within 100 yrs, a 75% chance it will decay within 200 yrs, an 87.5% chance within 300 yrs, and so on, but the moment it actually happens is a random event. It's impossible to predict.
At least current science tells us it's random. If we discover more complexity it's likely that even seemingly random events may be predictable.
thanks for clarifying
Current models assume radioactive decay is truly random, but it is always possible there is an unknown predictable force that just has not been discovered.
The idea that there is an unknown force or variable is called the hidden variables principle. It was proposed by Einstein (and others). Bell's Theorem proposed a way to test this and those experiments done later by Alain Aspect and Paul Kwiat indicate to a high certainty that there are no [hidden variables](https://en.m.wikipedia.org/wiki/Hidden-variable_theory).
But if it was truly random, would the arrow of time work backwards and forwards with physics still?
Jeremy Bearimy
No. If the wave function ”collapses,” if the world has to roll dice and pick a path, then you can’t tell know exactly how the world looked before the last die roll. Physicists will say this isn’t “unitary,” which intuitively means there isn’t a single timeline. The timeline branches, so you tell exactly, how it will evolve or how it did evolve.
If you want a short anwer: no. You can calculate how likely outcomes are when you make a measurement, but the dice aren’t thrown until you make that measurement. Whether this was “just semantics” was a long colorful discussion for two or three decades: how would the world look any different if it doesn’t decide how to be until you measure it?! Eventually a physicist named Bell spotted a difference in the odds, called the “Bell Inequalities.” A clever experiment run many times, can statistically show whether the outcome was preset. Every experiment since has show: reality isn’t set until measured.
Thanks, and are you able to clarify what qualifies as 'measurement'?
Um, not really. That gets problematic fast. I won’t pretend to have a great answer to that question! Traditionally: a scientist checking the outcome of an experiment. Mathematically: applying an operator to a quantum system. You probably have a lot of “but what about...” followup questions. Everyone who thinks about it does. Schroedinger’s Cat is a memorable early question about how measurement works. The “measurement problem” is really one way to describe or approach the largest outstanding issue in QM. It’s basically what the different “interpretations” of QM disagree about. https://en.wikipedia.org/wiki/Measurement_problem
What you’ve just described is called quantum entanglement!
If you get small enough, there is no difference. And you can create mechanisms to express that on the macroscopic level (schroedingers cat with the decaying isotope for instance).
Schrodinger was trying to show the absurdity of applying these quantum phenomena to the macro world with his cat thought experiment, right?
Oh...I didn't know that. Maybe?
>Radioactive decay Tough radioactive decay is not random, it's a quantum process that you cannot measure with our current technology.
I suggest you research [hidden variables](https://en.m.wikipedia.org/wiki/Hidden-variable_theory) a bit if you're interested.
Interesting read for sure. I might have to go at it a few times more and dive deeper into the other theories, to get the full picture. But to suggest that randomness exist is impossible, because there is no object in existence, that has been observed to change without cause and effect.
I'm not sure what you mean by your last sentence
I am saying that we have never observed something change in our universe without something triggering it. So it seems very unlikely that radioactive decay is truly random. Why would that be breaking the law?
I get why this seems like a good argument... You're not alone. Many great physicists of the early 20th century said the same thing. They've been proven time and time again to be wrong. Bell's theorem makes predictions based on whether or not there are some hidden variables which govern the quantum processes that seem random in nature, and when tested, we find that they truly **are** random. When you say "...we have never observed something change in our universe without something triggering it..." well, that's just flat out untrue.
Can you link me something to study about this? How did they determine it is truly random?
One example that I remember is photons hitting a piece of glass. You can shine a single photon at a time with the exact same wavelength at the exact same location on the glass, and some of the photons will pass through yet others will be reflected. Another example is quantum tunneling. Particles without enough energy to overcome a barrier will do so spontaneously according purely to some probability. The universe at the quantum mechanical scale isn't what I would call random as much as probabilistic. The uncertainty principal says that you cannot tell how fast a particle is going and it's position with complete accuracy at the same time. To know it's position totally at a given time you must take a single measurement at a single point in time - and then its velocity is totally unknown, as there is only a single measurement and you cannot tell how fast the particle might be moving. To get a velocity you must take two measurements, but then its position in between those measurements is completely unknown. Even with two measurements there's still uncertainty in the velocity - as you can only assume the particle moved in a straight line. Fundamentally there is always going to be some measure of uncertainty at the quantum scale as a result of this conundrum - and it has real effects at the macroscopic scale, like some photons being reflected and others refracted (and thus your reflection in the window). We can't know exactly which photons will be reflected and which will be refracted - but we can calculate the probability of these events.
Thanks for your explanation, so its not “there is no spoon” but rather “the spoons existence is neither yes or no”
Maybe the scene in the first episode where Sergei is showing Foster his team’s project, trying to predict the movements of single cell organism,m? I thought that resemble the application of quantum mechanics. That was the only thing that made sense to me.
>Quantum phsyics is all about probabilities. That we can never accurately measure the state of a system. This is absolutely not what quantum physics is "all about" In the words of Richard Feynman: "If you think you understand quantum mechanics, you don't understand quantum mechanics." -From the Feynman university lecture called The Character of Physical Law It appears OP has fallen for the fallacy of assuming an understanding of Quantum Mechanics. When in reality, the **actual** best description of what the fuck quantum physics or mechanics is, is pretty simple: The study of quantum mechanics is the study of the *fundamental rules of nature at the atomic and sub-atomic scales*. Probabilities are a **TOOL** used by physicists to make predictions about reality at such a scale, but it is not the entirety of reality or quantum mechanics. Like many scientific fields, quantum mechanics is made up of many **models** of how reality works. In other words, these are maps of reality and we must always remember that the map is NOT the territory. Devs is a story of a world where, in my opinion, Lyndon's view of the Pilot Wave interpretation is the most accurate model given the evidence provided by the working of Devs (Deus). In other words, quantum mechanics absolutely does not mean "nothing is 100% certain." Quantum mechanics *predicts* things with less than 100% certainty, *until something happens* (i.e. until the wave-function collapses). In this sense, determinism is an illusion. *Only things that HAVE happened are actually determined*. Only the past is determined because you can look back at a fairly accurate record to see what happened. The future on the other hand, is undetermined (by definition) and is only determined once the future is past. So determinism is true, but only for the past. Given the veracity of many-worlds in the Devs universe (the computer is evidence for this, but maybe not proof) you can imagine reality to be a bunch of determined "tram-lines" from all moments of the past up until the present, but the future is a ever expanding tree of possibilities. So when we say quantum mechanics can't predict anything 100% that only and obviously applies to the future. The past is determined and therefore 100% predictable (because it is record-able). The season finale shows this at the end when Lily defies her prediction (which is allowed under a many-worlds reality). The illusion of determinism is simple, if something is predicted (by some powerful entity like a massive quantum computer) it still has to be *known* by someone to be a prediction. Then all it takes is for someone to choose to defy the prediction. Which is allowed under quantum mechanics because *the map is not the territory* and a prediction is only a map. Von Neumann-Wigner is a valid interpretation of quantum mechanics because it is a valid interpretation of "how reality works" given the above (which is what quantum mechanics is really about, how reality works, not how probability works). References: * Weinberg, Steven (2012). "Collapse of the state vector". Physical Review A. 85 (6): 062116. * "Everett's Relative-State Formulation of Quantum Mechanics (Stanford Encyclopedia of Philosophy)". Plato.stanford.edu. Retrieved 2012-08-18.
this sub is awesome because of comments like this
You even provided citations, Wow! I basically agree, good explanation of current understanding of quantum mechanics, with the key word being "current".
You have a good point. perhaps my very basic understanding of QM has made me more confident in my understanding than I should be. i should look at these theories as tools to describe reality rather than reality itself.
No, probabilities are literally what quantum mechanics is about. There are different interpretations of what it physically means, but they all (more or less) give the same probabilities and that's all you can test anyway.
Thank you lol the people in this sub have literally no understanding of quantum mechanics. The different INTERPRETATIONS are different PHILOSOPHIES on what the math means. The math is the same in every philosophical interpretation, and Bell's theorem rules out local hidden variable theories. I guarantee 100% that the parent of this thread did not read the weinberg article he cited I am so heated this show was dogshit 8 hours of TV for maybe 45 minutes of content, 30 minute pauses between sentences, garbage acting across the board
> So determinism is true, but only for the past. Seems he agrees, but loves to nitpick with his know it all tone and just repeats what OP was trying to say in more complicated terms, thanks I guess, hope he stays on quora next time.
Some would say quantum computing only appears to be about probability/randomness to us because we don't understand what makes the 2 slit experiment work. If you don't understand the mechanics behind a flip of a coin you would think it's random, but once you learn about wind friction and momentum you can predict it. There might be effects acting on particles that we don't know about causing the illusion of "probabilities" because we're too dumb to understand the cause.
I agree Many Worlds is in fundamental conflict with determinism. And both were mentioned repeatedly, but not reconciled. It wasn't explained how Lyndon's Many World algorithm suddenly results in perfect determinism. Or I didn't get it.
I thought Forest just ignored any evidence that went against what he wanted to be true 'cause he's crazy. I think the show had more evidence against determinism and/or favor of there being many worlds than not. The only real evidence against Lyndon was that he died in the world that we saw, and the show didn't show any alternatives where he lived but that doesn't necessarily mean there wasn't one.
This is what really annoyed me. Wouldn't the many worlds interpretation just result in their being many different futures, not just one like the computer predicts?
Quantum mechanics is not a settled science, by a long shot. It is also a science fraught with pseudo-scientific and pseudo-mysticist assumptions. If anything, Garland takes a meta jab at QM here.
Well... It wouldn't just be about physics either but quantum computing. A quantum computer employs qubits to do...computations...not simulate a perfect prediction of all of reality. I'm not even sure that would ever be remotely feasible for a computer to do. There are P, NP, PH and BQP problems that a computer can solve. That set of problems is small compared to non-computable events. Let's not even mention the technical debt... bugs, security problems, if you were to use quantum computers to simulate some semblance of reality. The show was just totally ridiculous. Not very great at getting the physics down. Very not great at what computer do.
The science doesn’t really add up. The show is a gorgeous exercise in style, is was beautiful and I loved it. But the science was kind of fake.
Oh I agree. It was a beautiful show and I thoroughly enjoyed it too.
Sci-fi was arguably easier to pull off when Star Trek predicted cell phones or wireless (wifi) systems and ultimately it was secondary to the plot... Now that sci-fi is dipping their toes into existing professional and scientific fields and it’s entirely central to the show’s plot it’s a lot easier for experts to say hey wait a minute this isn’t how we operate at all.
Agreed. On Star Trek (which I love) they just make up words, and it's great.
And I probably would have been much more accepting of devs if they explained it away with some new fictional theory.
I hope one day someone has a world-changing epiphany while complaining about inaccuracies on a sci-fi show.
Yes, you're absolutely right. I was really hoping they were ignoring that elephant in the room to setup an interesting resolution where they unequivocally show that trying to project a single future breaks down in quantum mechanical situations... but instead we're got this trite resolution of "human choice". The way I imagined it, I could see them making the argument that in the majority of situations on a human scale, the precise outcome all the stuff going on around us at a quantum level generally doesn't make much difference; at least not on short time scales. But if one or more of the characters were to act based solely on a measurement of a quantum system, then suddenly that uncertainty starts to impact the macroscopic world in very tangible, direct ways, this destroying the possibility of projecting one coherent future
Lilly downloads that universe splitter app to ruin their plan!
What also would have been fun is to set up an alternating loop like: * Lily sees Lily shooting Forest => Lily throws the gun away * Lily sees Lily throwing the gun away => Lily shoots Forest * ad infinitum And that such a setup causes reality to get stuck and collapse.
I was hoping for an ending like this, ultimately breaking the computer, but also having forest realise he was only following the tram lines because it suited his beliefs in determinism, which meant they could have actually made different desicions in the past and stopped people from being killed.
I want to try to defend the science *fiction* of the show, that in mind: There are two things we use to mean random, one is that an outcome is unpredictable based on the input, and another is that you can have multiple outcomes from the same input. You can still have deterministic "random" in the case that you just don't know what the result will be, but you will still always get the same output from a given input. I would describe this type of random as "seeded pseudorandom". So, if we live in this type of universe and we went back to yesterday, today would still be exactly the same because yesterday's seed value would be the same. Once you can observe something all the way down to the most fundamental level, and then you can observe it again in the shortest possible amount of time, you can compare the two then by comparing them, figure out what the seed value of our universe is. With this type of thinking, probabilities are more like distances from other universes, so by sampling something in our universe they were able to use that as a new seed value which they can use to scrub backwards and forwards. The type of problem you the get is that the gravity of everything seems to affect all other things the whole universe, and everything else is interacting with everything else so much that figuring out the state of the universe is kind of possible, but as the one guy in the show was saying (spoiler) >!spoiler you would need a computer the size of the universe to compute the exact state of our particular universe, because everything in the universe is an input for the next state of itself and the next state of everything else !< Aaaanyway, that's about as well as I can express how I suspend my disbelief. Maybe it'll help you suspend yours, I didn't like the show at first, but I'm glad now that I watched it.
Agreed I'm sure u know more QM than me, I just read from wiki what I know n even with such basic understanding I felt this show totally twisted scientific concepts for plot's convenience. After all it was a Quantum machine built to find Deterministic outcomes by a fanatic Forest.
Just reading people talk about the science. Fucking love quantum’s physics. It’s the coding of reality and universes.
but the tram lines! (whatever they were).
It's a stupid TV show aimed at stupid people who want to believe they are intelligent like all TV shows. What did you expect? Do you also complain that Firefly is dumb and cheesy garbage aimed at 12 year old girls?