Physicists find we’re not living in a computer simulation

[Darth Lucifer]

Source: https://cosmosmagazine.com/physics/phys ... simulation

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The sci-fi trope might now be put to rest after scientists find the suggestion that reality is computer generated is in principle impossible, writes Andrew Masterson.

Just in case it’s been weighing on your mind, you can relax now. A team of theoretical physicists from Oxford University in the UK has shown that life and reality cannot be merely simulations generated by a massive extraterrestrial computer.

The finding – an unexpectedly definite one – arose from the discovery of a novel link between gravitational anomalies and computational complexity.

In a paper published in the journal Science Advances, Zohar Ringel and Dmitry Kovrizhi show that constructing a computer simulation of a particular quantum phenomenon that occurs in metals is impossible – not just practically, but in principle.

The pair initially set out to see whether it was possible to use a technique known as quantum Monte Carlo to study the quantum Hall effect – a phenomenon in physical systems that exhibit strong magnetic fields and very low temperatures, and manifests as an energy current that runs across the temperature gradient. The phenomenon indicates an anomaly in the underlying space-time geometry.

Quantum Monte Carlo methods use random sampling to analyse many-body quantum problems where the equations involved cannot be solved directly.

Ringel and Kovrizhi showed that attempts to use quantum Monte Carlo to model systems exhibiting anomalies, such as the quantum Hall effect, will always become unworkable.

They discovered that the complexity of the simulation increased exponentially with the number of particles being simulated.

If the complexity grew linearly with the number of particles being simulated, then doubling the number of partices would mean doubling the computing power required. If, however, the complexity grows on an exponential scale – where the amount of computing power has to double every time a single particle is added – then the task quickly becomes impossible.

The researchers calculated that just storing information about a couple of hundred electrons would require a computer memory that would physically require more atoms than exist in the universe.

The researchers note that there are a number of other known quantum interactions for which predictive algorithms have not yet been found. They suggest that for some of these they may in fact never be found.

And given the physically impossible amount of computer grunt needed to store information for just one member of this subset, fears that we might be unknowingly living in some vast version of The Matrix can now be put to rest.

[Terralthra]

"Physicists calculate that we can't be a simulation on computer technology we currently understand." What a waste of time.

[Ziggy Stardust]

Yeah, a bit silly given the obvious counter-argument that computing technology could theoretically improve to the point that it is capable of such a simulation, but to be fair, most of the people I hear spouting the whole "the universe is a simulation!!!!1" line aren't basing it off of any particular evidence or logic, anyway, so this is still useful in terms of throwing something in their faces to shut them up for a bit.

[LaCroix]

Explanations for impossible simulations:

1. It's the Universesimulation's version of a "invisible wall", making us stop wasting precious computing power. (And/Or finding out stuff that would make us even worse to simulate.)
2. There is a vastly easier way to calculate this. (But you most likely have to calculate it a couple times the hard way, first, before finding out how easy it can be done)

[B5B7]

The obvious answer to this is that in the simulated universe computers operate in a severely limited fashion programmed into the simulation, and in the "real" universe they are vastly more powerful, and/or the physical laws are different, plus the simulators have minds that are vast and cool and unsympathetic.

[Starglider]

This is a complete misunderstanding of the simulation argument. The argument is simply that sufficiently powerful computer technology could simulate a universe realistic enough that it would fool contemporary human minds into thinking it is real. It is completely unnecessary and infeasible within the known laws of physics to actually simulate a universe down to particle level. Given adequate white-box neurosimulation tools it doesn't even have to fool everyone all the time, because you can simply edit brain states and retcon any perceptions of glitches (or fix the glitch and reset the simulation to last known good state). Pretty much all quantum effects can be replaced with a bulk approximation 99.999999% of the time. This is in fact why the field of physics exists at all, if there weren't reasonably accurate highly tractable bulk approximations for most behaviour, the world would just be incomprehensible.

[Formless]

God, this thread is full of fail. Am I the only one who has kept up with recent presentations of the Simulation argument? These guy's aren't talking about The Matrix, they are arguing against the more "grounded" form of the argument.

"Physicists calculate that we can't be a simulation on computer technology we currently understand." What a waste of time.

2. There is a vastly easier way to calculate this. (But you most likely have to calculate it a couple times the hard way, first, before finding out how easy it can be done)

The obvious answer to this is that in the simulated universe computers operate in a severely limited fashion programmed into the simulation, and in the "real" universe they are vastly more powerful, and/or the physical laws are different, plus the simulators have minds that are vast and cool and unsympathetic.

Can you think of a better form of computer logic than we have now? No? Then the three of you should sit in the corner in shame. All of these are textbook Appeals to Ignorance, and shouldn't be given the time of day. This is about principles of computing, not the practical limitations of it. You can't perform the calculations because they are impossible in principle, no matter what universe you find yourself in. The fact that the calculation is an exponential function means that you run into a limit as defined by calculus. You can't calculate infinity, because you don't have infinite time to run the calculation. And if you want to say that the outside universe uses a different concept of time than ours, we have no way in principle to talk about it coherently.

Besides which, there is at least one common form of the simulation argument that the authors are referring to which requires the simulation to resemble the outside universe. But I'll get back to that when I touch on Starglider's post.

Yeah, a bit silly given the obvious counter-argument that computing technology could theoretically improve to the point that it is capable of such a simulation, but to be fair, most of the people I hear spouting the whole "the universe is a simulation!!!!1" line aren't basing it off of any particular evidence or logic, anyway, so this is still useful in terms of throwing something in their faces to shut them up for a bit.

Exactly. The Simulation argument is just repackaged Cartesian Skepticism, and the numerous problems with it were pointed out long ago by the Pragmatist and Instrumentalist philosophers of yesteryear. Its not only without evidence, it doubles down by denying that evidence is a valid basis of reasoning. Its like the Boltzmann Brain hypothesis: it is cognitively unstable, meaning that a Boltzmann Brain can never admit to being a Boltzmann Brain without admitting that you lack the cognitive capacity to trust your own judgement... including the judgement that you are a Boltzmann Brain. Similarly, a simulated brain cannot ever conclude that it is simulated without admitting, as some here have admitted, that it lacks the ability to trust its own judgement that it is a simulated brain. That brings us back to the pragmatic point that the exercise is a waste of time if it rejects the use of evidence. A schizophrenic can only trust others to tell them they are insane. And even then, they have no reference point for what that means because delusion is their normal state of being.

It also incorrectly confuses statistical calculations with parsimony: parsimony governs the number of variables and assumptions one ought to include in an equation, and since statistical equations cannot distinguish between a "good" or "bad" number of inputs those arguments are confused about the relationship between philosophy and math. The Boltzmann Brain and Simulation arguments always contain a larger number of assumptions than a theory of physics where there is only one universe, because you are creating a whole bunch of variables that govern the simulation in order to trick the brains inside it (as Starglider suggests). It inherently contains more assumptions about the world without explaining any useful feature of it which wouldn't be explained by a one-world hypothesis.

1. It's the Universesimulation's version of a "invisible wall", making us stop wasting precious computing power. (And/Or finding out stuff that would make us even worse to simulate.)

One variation of the simulation argument, advanced by Neil DeGrass Tyson (and I have no idea why such a man would bother, but whatever), is a statistical argument that simulations can contain simulations, therefore if you select at random from a bunch of worlds you could exist in it is more likely to be a simulated world than a non-simulated world. However, if we accept that emulations within emulations cause computational slowdown, as it does in the observable world and as you are assuming with this point, then Dr Tyson's argument either falls apart completely, or at least could be falsified by simply trying to create an advanced simulation of our own and seeing if it works or causes glitches in our own reality. At a certain point in complexity, the simulation should not only be impossible, but if we were inside a computer we have potentially identified a way to crash the computer. It sounds dangerous, of course, but at least we would know something was wrong when the owners rebooted the simulation and our embedded simulation was mysteriously rendered non-functional.

Besides that, if a feature of our universe cannot be computed within our universe, then any simulation we can actually verify to be a simulation (by creating it) would not look like the universe we live in. It is therefore likely that there are variables of the universe we are embedded within which could not be implemented in our universe; however, their existence in the outer universe violates parsimony and makes the argument an impossible fractal. The people in the larger universe would also have to question the validity of their existence, and the people one level up from that would have to question the validity of their universe, until its impossible to know if there even is a such thing as a non-simulated universe!

Parsimony exists because infinite inexplicable variables is impervious to reason. This paper at minimum gives us soft or statistical evidence that we are not living in a simulation.

This is a complete misunderstanding of the simulation argument.

[Formless]

Goddamnit, the computer ate up my post and now I can't fix the quote tags or re-create what I wrote the first time around. My reply to Starglider was this:

The finding may not argue against all forms of the Simulation Argument, but it does not have to. Most forms are philosophically unsound anyway. What you talk mostly about is just Descarte's Demon, but modernized. As with the Boltzmann Brain scenario, in order to accept the idea that your brain can be tampered with at the whims of some other being, you have to reject literally everything you know-- including the very knowledge of logic that lead you to that conclusion. After all, what if the simulation was specifically intended to simulate a crazy person? Someone who is incapable of using logic correctly? You cannot follow that train of thought without contradiction. But you must consider the possibility if you are going to follow the simulation argument to its logical conclusion.

But back to my point that you are only considering one form of the simulation argument. What this finding shows is that we certainly aren't living in one popular conception of the argument. Namely, we can't be living in an Ancestor Simulation. This form of the argument differs from others by speculating on the motive for why the simulation exists: we are being simulated by humanity's descendants as a form of living history for them. Problem is that this form of the argument requires A Priori that the physics of our world closely approximates the physics of the higher level universe. Why? Because any glitch could lead to exploits. What if, for instance, the nuclear bomb was caused by an exploit? The fine tuning of the fundamental constants make this quite plausible. If it were an exploit, though, which we as AI discovered and used against each other, then the simulation is fucked and we are representatives of the wrong history. However, if the physics of our universe must look closely like the physics of the parent universe, then this finding poses a problem: our computers must have the same limitations as the contemporary computers of the ancestors of the humans who are running this simulation. Which were the forerunners of the computer actually running the simulation. They have to be accurate as well, or else the internet won't work correctly, which would also be a huge hit to the historical accuracy of the simulation. So proof by contradiction: we cannot be living in an ancestor simulation, which for many is the most plausible simulation argument currently around.