[Note: The following is a transcript of the video embedded at the bottom of this article.]
I quite like the idea that we live in a computer simulation. It gives me hope that things will be better on the next level. Unfortunately, the idea is unscientific. But why do some people believe in the simulation hypothesis? And just exactly what's the problem with it? That's what we'll talk about today.
According to the simulation hypothesis, everything we experience was coded by an intelligent being, and we are part of that computer code. That we live in some kind of computation in and by itself is not unscientific. For all we currently know, the laws of nature are mathematical, so you could say the universe is really just computing those laws. You may find this terminology a little weird, and I would agree, but it's not controversial. The controversial bit about the simulation hypothesis is that it assumes there is another level of reality where someone or some thing controls what we believe are the laws of nature, or even interferes with those laws.
The belief in an omniscient being that can interfere with the laws of nature, but for some reason remains hidden from us, is a common element of monotheistic religions. But those who believe in the simulation hypothesis argue they arrived at their belief by reason. The philosopher Nick Boström, for example, claims it's likely that we live in a computer simulation based on an argument that, in a nutshell, goes like this. If there are a) many civilizations, and these civilizations b) build computers that run simulations of conscious beings, then c) there are many more simulated conscious beings than real ones, so you are likely to live in a simulation.
Elon Musk is among those who have bought into it. He too has said "it's most likely we're in a simulation." And even Neil DeGrasse Tyson gave the simulation hypothesis "better than 50-50 odds" of being correct.
Are we living in a simulation? | Bill Nye, Joscha Bach, Donald Hoffman | Big Think www.youtube.com
Maybe you're now rolling your eyes because, come on, let the nerds have some fun, right? And, sure, some part of this conversation is just intellectual entertainment. But I don't think popularizing the simulation hypothesis is entirely innocent fun. It's mixing science with religion, which is generally a bad idea, and, really, I think we have better things to worry about than that someone might pull the plug on us. I dare you!
But before I explain why the simulation hypothesis is not a scientific argument, I have a general comment about the difference between religion and science. Take an example from Christian faith, like Jesus healing the blind and lame. It's a religious story, but not because it's impossible to heal blind and lame people. One day we might well be able to do that. It's a religious story because it doesn't explain how the healing supposedly happens. The whole point is that the believers take it on faith. In science, in contrast, we require explanations for how something works.
Let us then have a look at Boström's argument. Here it is again. If there are many civilizations that run many simulations of conscious beings, then you are likely to be simulated.
First of all, it could be that one or both of the premises is wrong. Maybe there aren't any other civilizations, or they aren't interested in simulations. That wouldn't make the argument wrong of course; it would just mean that the conclusion can't be drawn. But I will leave aside the possibility that one of the premises is wrong because really I don't think we have good evidence for one side or the other.
The point I have seen people criticize most frequently about Boström's argument is that he just assumes it is possible to simulate human-like consciousness. We don't actually know that this is possible. However, in this case it would require explanation to assume that it is not possible. That's because, for all we currently know, consciousness is simply a property of certain systems that process large amounts of information. It doesn't really matter exactly what physical basis this information processing is based on. Could be neurons or could be transistors, or it could be transistors believing they are neurons. So, I don't think simulating consciousness is the problematic part.
The problematic part of Boström's argument is that he assumes it is possible to reproduce all our observations using not the natural laws that physicists have confirmed to extremely high precision, but using a different, underlying algorithm, which the programmer is running. I don't think that's what Boström meant to do, but it's what he did. He implicitly claimed that it's easy to reproduce the foundations of physics with something else.
But nobody presently knows how to reproduce General Relativity and the Standard Model of particle physics from a computer algorithm running on some sort of machine. You can approximate the laws that we know with a computer simulation – we do this all the time – but if that was how nature actually worked, we could see the difference. Indeed, physicists have looked for signs that natural laws really proceed step by step, like in a computer code, but their search has come up empty handed. It's possible to tell the difference because attempts to algorithmically reproduce natural laws are usually incompatible with the symmetries of Einstein's theories of Special and General Relativity. I'll leave you a reference in the info below the video. The bottom line is it's not easy to outdo Einstein.
It also doesn't help, by the way, if you assume that the simulation would run on a quantum computer. Quantum computers, as I have explained earlier, are special purpose machines. Nobody currently knows how to put General Relativity on a quantum computer.
IBM's quantum computerCredit: IBM Research via Flickr and licensed under CC BY-ND 2.0
A second issue with Boström's argument is that, for it to work, a civilization needs to be able to simulate a lot of conscious beings, and these conscious beings will themselves try to simulate conscious beings, and so on. This means you have to compress the information that we think the universe contains. Boström therefore has to assume that it's somehow possible to not care much about the details in some parts of the world where no one is currently looking, and just fill them in case someone looks.
Again though, he doesn't explain how this is supposed to work. What kind of computer code can actually do that? What algorithm can identify conscious subsystems and their intention and then quickly fill in the required information without ever producing an observable inconsistency? That's a much more difficult issue than Boström seems to appreciate. You cannot in general just throw away physical processes on short distances and still get the long distances right.
Climate models are an excellent example. We don't currently have the computational capacity to resolve distances below something like 10 kilometers or so. But you can't just throw away all the physics below this scale. This is a non-linear system, so the information from the short scales propagates up into large scales. If you can't compute the short-distance physics, you have to suitably replace it with something. Getting this right even approximately is a big headache. And the only reason climate scientists do get it approximately right is that they have observations which they can use to check whether their approximations work. If you only have a simulation, like the programmer in the simulation hypothesis, you can't do that.
And that's my issue with the simulation hypothesis. Those who believe it make, maybe unknowingly, really big assumptions about what natural laws can be reproduced with computer simulations, and they don't explain how this is supposed to work. But finding alternative explanations that match all our observations to high precision is really difficult. The simulation hypothesis, therefore, just isn't a serious scientific argument. This doesn't mean it's wrong, but it means you'd have to believe it because you have faith, not because you have logic on your side.
The Simulation Hypothesis is Pseudoscience
Republished with permission of Dr. Sabine Hossenfelder. The original article is here.
Are you living in a computer simulation?
If you've spent enough time online, you've probably encountered this question. Maybe it was in one of the countless articles on simulation theory. Maybe it was during the chaos of 2020, when Twitter users grew fond of saying things like "we're living in the worst simulation" or "what a strange timeline we're living in." Or maybe you saw that clip of Elon Musk telling an audience at a tech conference that the probability of us not living in a simulation is "one in billions."
It might sound ludicrous. But Twitter memes and quotes from "The Matrix" aside, simulation theory has some lucid arguments to back it up. The most cited explanation came in 2003, when Oxford University philosopher Nick Bostrom published a paper claiming at least one of the following statements is true:
- The human species is very likely to go extinct before reaching a "posthuman" stage
- Any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof)
- We are almost certainly living in a computer simulation
The basic idea: Considering that computers are growing exponentially powerful, it's reasonable to think that future civilizations might someday be able to use supercomputers to create simulated worlds. These worlds would probably be populated by simulated beings. And those beings might be us.
In the new documentary "A Glitch in the Matrix", filmmaker Rodney Ascher sends viewers down the rabbit hole of simulation theory, exploring the philosophical ideas behind it, and the stories of a handful of people for whom the theory has become a worldview.
The film features, for example, a man called Brother Laeo Mystwood, who describes how a series of strange coincidences and events — a.k.a "glitches in the matrix" — led him to believe the world is a simulation. Another interviewee, a man named Paul Gude, said the turning point for him came in childhood when he was watching people sing at a church service; the "absurdity of the situation" caused him to realize "none of this is real."
But others have darker reactions after coming to believe the world is a simulation. For example, if you believe you're in a simulation, you might also think that some people in the simulation are less real than you. A few of the film's subjects describe the idea of other people being "chemical robots" or "non-player characters," a video-game term used to describe characters who behave according to code.
The documentary's most troubling sequences features the story of Joshua Cooke. In 2003, Cooke was 19 years old and suffering from an undiagnosed mental illness when he became obsessed with "The Matrix." He believed he was living in a simulation. On a February night, he shot and killed his adoptive parents with a shotgun. The murder trial spawned what's now known as the "Matrix defense," a version of the insanity defense in which a defendant claims to have been unable to distinguish reality from simulation when they committed a crime.
Of course, Cooke's case lies on the extreme side of the simulation theory world, and there's nothing inherently nihilistic about simulation theory or people who believe in it. After all, there are many ways to think about simulation theory and its implications, just as there are many different ways to think about religion.
And as with religion, a key question in simulation theory is: Who created the simulation and why?
In his 2003 paper, Bostrom argued that future human civilizations might be interested in creating "ancestor simulations," meaning that our world might be a simulation of a human civilization that once existed in base reality; it'd be a way for future humans to study their past. Other explanations range from the simulation being some form of entertainment for future humans, to the simulation being the creation of aliens.
"If this is a simulation, there's sort of a half dozen different explanations for what this is for," Ascher told Big Think. "And some of them are completely opposite from one another."
To learn more about simulation theory and those who believe in it, we spoke to Ascher about "A Glitch in the Matrix", which premiered at the 2021 Sundance Film Festival and is now available to stream online. (This interview has been lightly edited for concision and clarity.)
Rodney Ascher / "A Glitch in the Matrix"
Throughout 2020, many people seemed to talk about the world being a simulation, especially on Twitter. What do you make of that?
I see that just as sort of evidence of how deep the idea [of simulation theory] is penetrating our culture. You know, I'm addicted to Twitter, and everyday something strange happens in the news, and people make some jokes about, "This simulation is misfiring," or, "What am I doing in the dumbest possible timeline?"
I enjoy those conversations. But two things about them: On the one hand, they're using simulation theory as a way to let off steam, right? "Well, this world is so absurd, perhaps that's an explanation for it," or, "Maybe at the end of the day it doesn't matter that much because this isn't the real world."
But also, when you talk about the strange or horrifying, or bizarre unlikely things that happen as evidence [for the simulation], then that begs the question, well what is the simulation for, and why would these things happen? They could be an error or glitch in the matrix. [...] Or those strange things that happen might be the whole point [of the simulation].
How do you view the connections between religious ideas and simulation theory?
I kind of went in [to making the film] thinking that this was, in large part, going to be a discussion of the science. And people very quickly went to, you know, religious and sort of ethical places.
I think that connection made itself clearest when I talked to Erik Davis, who wrote a book called "Techgnosis", which is specifically about the convergence of religion and technology. He wanted to make it clear that, from his point of view, simulation theory was sort of a 21st-century spin on earlier ideas, some of them quite ancient.
To say that [religion and simulation theory] are exactly the same thing is sort of pushing it. [...] You could say that if simulation theory is correct, and that we are genuinely in some sort of digitally created world, that earlier traditions wouldn't have had the vocabulary for that.
So, they would have talked about it in terms of magic. But by the same token, if those are two alternative, if similar, explanations for how the world works, I think one of the interesting things that it does is that either one suggests something different about the creator itself.
In a religious tradition, the creator is this omnipotent, supernatural being. But in simulation theory, it could be a fifth-grader who just happens to have access to an incredibly powerful computer [laughs].
Rodney Ascher / "A Glitch in the Matrix"
How did your views on simulation theory change since you started working on this documentary?
I think what's changed my mind the most in the course of working on the film is how powerful it is as a metaphor for understanding the here-and-now world, without necessarily having to believe in [simulation theory] literally.
Emily Pothast brought up the idea of Plato's cave as sort of an early thought experiment that is kind of resonant of simulation theory. And she expands upon it, talking about how, in 21st-century America, the shadows that we're seeing of the real world are much more vivid. You know, the media diets that we all absorb, that are all reflections of the real world.
But the danger that the ones you're seeing aren't accurate—whether that's just signal loss from mistakes made by journalists working in good faith, or whether it's intentional distortion by somebody with an agenda—that leads to a really provocative idea about the artificial world, the simulated world, that each of us create, and then live in, based on our upbringing, our biases, and our media diet. That makes me stop and pause from time to time.
Do you see any connections between mental illness, or an inability to empathize with others, and some peoples' obsession with simulation theory?
It can certainly lead to strange, obsessive thinking. [Laughs] For some reason, I feel like I have to defend [people who believe in simulation theory], or qualify it. But you can get into the same sort of non-adaptive behavior obsessing on, you know, the Beatles or the Bible, or anything. [Charles] Manson was all obsessed on "The White Album." He didn't need simulation theory to send him down some very dark paths.
Credit: K_e_n via AdobeStock
Why do you think people are attracted to simulation theory?
You might be attracted to it because your peer group is attracted to it, or people that you admire are attracted to it, which lends it credibility. But also like, just the way you and I are talking about it now, it's a juicy topic that extends in a thousand different ways.
And despite the cautionary tales that come up in the film, I've had a huge amount of fascinating social conversations with people because of my interest in simulation theory, and I imagine it's true about a lot of people who spend a lot of time thinking about it. I don't know if they all think about it alone, right? Or if it's something that they enjoy talking about with other people.
If technology became sufficiently advanced, would you create a simulated world?
It'd be very tempting, especially if I could add the power of flight or something like that [laughs]. I think the biggest reason not to, and I just saw this on a comment on Twitter yesterday, and I don't know if it had occurred to me, but what might stop me is all the responsibility I'd feel to all the people within it, right? If this were an accurate simulation of planet Earth, the amounts of suffering that occurs there for all the creatures and what they went through, that might be what stops me from doing it.
If you discovered you were living in a simulation, would it change the way you behave in the world?
I think I would need more information about what the nature of the purpose of the simulation is. If I found out that I was the only person in a very elaborate virtual-reality game, and I had forgotten who I really was, well then I would act very differently then I would if I learned this is an accurate simulation of 21st-century America as conceived by aliens or people in the far future, in which case I think things would stay more or less the same — you know, my closest personal relationships, and my responsibility to my family and friends.
Just that we're in a simulation isn't enough. If all we know is that it's a simulation, kind of the weirdness is that that word "simulation" starts to mean less. Because whatever qualities the real world has and ours doesn't is inconceivable to us. This is still as real as real gets.
A scientist devised a computer algorithm which may lead to transformative discoveries in energy and whose very existence raises the likelihood that our reality could actually be a simulation.
The algorithm was created by the physicist Hong Qin, from the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL).
The algorithm employs an AI process called machine learning, which improves its knowledge in an automated way, through experience.
Qin developed this algorithm to predict the orbits of planets in the solar system, training it on data of Mercury, Venus, Earth, Mars, Ceres, and Jupiter orbits. The data is "similar to what Kepler inherited from Tycho Brahe in 1601," as Qin writes in his newly-published paper on the subject. From this data, a "serving algorithm" can correctly predict other planetary orbits in the solar system, including parabolic and hyperbolic escaping orbits. What's remarkable, it can do so without having to be told about Newton's laws of motion and universal gravitation. It can figure those laws out for itself from the numbers.
Qin is now adapting the algorithm to predict and even control other behaviors, with a current focus on particles of plasma in facilities built for harvesting fusion energy powering the Sun and stars. Along with Eric Palmerduca, a Ph.D. graduate student at PPPL, Qin is using his technique "to learning an effective structure-preserving algorithm with long-term stability to simulate the gyrocenter dynamics in magnetic fusion plasmas," as he elaborated. He also plans to utilize the algorithm to study quantum physics.
Physicist Hong Qin with images of planetary orbits and computer code.
Credit: Elle Starkman
Qin explained the unusual approach taken by his work:
"Usually in physics, you make observations, create a theory based on those observations, and then use that theory to predict new observations, " said Qin. "What I'm doing is replacing this process with a type of black box that can produce accurate predictions without using a traditional theory or law. Essentially, I bypassed all the fundamental ingredients of physics. I go directly from data to data (…) There is no law of physics in the middle."
Qin was partially inspired by the work of Swedish philosopher Nick Bostrom, whose 2003 paper famously argued that the world we are living in may be an artificial simulation. What Qin believes he has accomplished with his algorithm is provide a working example of an underlying technology that could support the simulation in Bostrom's philosophical argument.
In an email exchange with Big Think, Qin remarked: "What is the algorithm running on the laptop of the Universe? If such an algorithm exists, I would argue that it should be a simple one defined on the discrete spacetime lattice. The complexity and richness of the Universe come from the enormous memory size and CPU power of the laptop, but the algorithm itself could be simple."
Certainly, the existence of an algorithm that derives meaningful predictions of natural events from data does not yet mean that we ourselves have the capabilities to simulate existence. Qin believes we are likely "many generations" away from being able to carry out such feats.
Qin's work takes the approach of using "discrete field theory," which he thinks is particularly well suited for machine learning, while somewhat difficult for "a current human" to understand. He explained that "a discrete field theory can be viewed as an algorithmic framework with adjustable parameters that can be trained using observational data." He added that "once trained, the discrete field theory becomes an algorithm of nature that computers can run to predict new observations."
Are we living in a simulation? | Bill Nye, Joscha Bach, Donald Hoffman | Big Think
According to Qin, discrete field theories go against the most popular method of studying physics today, which looks at spacetime as continuous. This approach was started with Isaac Newton, who invented three approaches to describing continuous spacetime, including Newton's law of motion, Newton's law of gravitation, and calculus.
Qin believes there are serious issues in modern research that stem from the laws of physics in continuous spacetime being expressed through differential equations and continuous field theories. If laws of physics were based on discrete spacetime, as Qin proposes, "many of the difficulties can be overcome."
If the world works according to discrete field theory, it would look like something out "The Matrix," made of pixels and data points.
Qin's work also coincides with the logic of Bostrom's simulation hypothesis and would mean that "the discrete field theories are more fundamental than our current laws of physics in continuous space." In fact, writes Qin, "our offspring must find the discrete field theories more natural than the laws in continuous space used by their ancestors during the 17th-21st centuries."
Check out Hong Qin's paper on the subject in Scientific Reports.
A number of massive geo-engineering schemes have been proposed for dealing with climate change. These range from brightening the sun by pumping seawater spray up through ship masts, to dimming it by injecting calcium carbonate dust into the atmosphere. These ideas may or may not work, but they also may or may not backfire.
We can hardly afford to make things worse, and Earth is a big, interwoven set of complex systems. Wouldn't it be great if we had a sort of practice Earth on which we could try out such potentially high-impact solutions without risking additional harm to our planet?
We may soon have one, thanks to the European Union's new Destination Earth project. Climate scientists and computer experts are attempting to create Earth's digital twin: A virtual Earth that mirrors the real one closely enough that policymakers can audition planet-changing geo-engineering proposals to see if they'll work before deploying them for real.
Their project is described in a study published in the journal Nature Climate Change.
Who are the planet-builders?
Credit: Henry & Co./Unsplash/leberus/Adobe Stock/Big Think
Destination Earth is the brainchild of the European Centre for Medium-Range Weather Forecasts (ECMWF), the European Space Agency (ESA), and the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT).
The project manager and lead author of the study is Peter Bauer of the ECMWF. His contribution to the project has to do with the climate science aspects of Earth's virtual twin. The computer side of things will be the domain of Torsten Hoefler of ETH Zurich and Thomas Schulthess of the Swiss National Supercomputing Centre (CSCS).
Watching time go by on the digital Earth
Credit: Logan Armstrong/Unsplash
The basic idea of the digital twin is that it will allow scientists to observe climate change in motion as it progresses. "If you are planning a two-meter high dike in The Netherlands, for example," says Bauer in an ETH press release, "I can run through the data in my digital twin and check whether the dike will in all likelihood still protect against expected extreme events in 2050."
Most important will be trying out geo-engineering ideas and seeing how they track over time. The press release specifically notes the value the twin will bring to "strategic planning of fresh water and food supplies or wind farms and solar plants."
Aging models and AI
Credit: ECMWF
Capturing the subtleties and intricacies of our planet faithfully in order to model plausible outcomes is going to require an equally complex computer model. Construction of the digital Earth begins with the refinement of current weather models, with a goal of eventually being able to simulate conditions in as small an area as a kilometer. Current models are not nearly as fine-grained, a shortcoming that hampers their ability to make accurate predictions given that the large weather systems are really aggregates of many smaller meteorological systems influencing each other.
The authors of the paper assert that today's meteorological models fall far short of what's possible, their development having basically become stuck in place about a decade ago. They say that current models take advantage of only about 5 percent of today's available processing power. The solution is the tight collaboration between Earth scientists and computer scientists at the heart of Destination Earth to develop cutting-edge models.
The twin will also be able to take advantage of rapidly advancing developments in artificial intelligence. Obviously, AI is very good at detecting patterns in large amounts of data. The study anticipates multiple roles for AI here, including the promotion of operational efficiency with new ways of accurately representing physical processes, as well as the development of novel data-compression strategies.
A massive endeavor
The team will feed the twin massive amounts of weather data—as well as data regarding human activity—to get the digital planet going and then continually as new data emerge, making the model more and more complex and more and more accurate.
At full scale, a digital twin of an entire planet would require a suitably massive amount of horsepower. The authors of the study propose a system with 20,000 GPUs that will require 20 megawatts to run. And since the ultimate goal is to help the Earth and not make things worse, they say they'd like to site its digital twin in an area power from a CO2-netural electrical source.
