Reality — What is this thing?
I have written about pretty far-out stuff on this blog. Future superintelligent computers going haywire (here), possible multiverses containing our doppelgängers giving us non-local immortality (here), the hypothesis that we live in a simulation (here). You have to have a certain kind of worldview to take these speculations seriously. In this post I will try to convey what that worldview looks like. This will involve some hand-waving and elaborating on subjects I’m far from an expert in. I might misrepresent facts in any of these subjects (please let me know if I do).
It’s easy to take modern technology for granted, but if you think about it for a second you’ll realise that it’s pretty remarkable. Sometimes it can feel like magic. At the risk of rehashing a boring cliché, I will remind you of some of the miracles of modern technology. There are wagons made of metal pulled by invisible superhorses. Stiff giant birds gracefully carrying hundreds of people thousands of kilometers (or miles) in the sky. People touching a slab of lit-up glass in their hands that can send and receive messages, talk to almost anyone regardless of distance, play any music, display any image or video, buy almost anything, get directions to anywhere and distribute information invisibly through the air that is accessible to billions of people virtually without delay, each slab powered by billions of small electrical switches, switching on and off billions of times a second (1). There are robots on Mars, and we landed one on a comet. People are floating in a space station cruising around the Earth faster than the fastest bullet.
It feels like the last couple of centuries, the development of technology has really taken off. I think this is supported by the evidence. For instance, change in economic output has gone from almost horizontal to almost vertical when plotted on a graph over the last two millennia (2).
For the first time in human history, economical growth has outpaced population growth, making most people significantly richer. The global average income has increased tenfold (3) and the fraction of the world population living in extreme poverty has declined from about 90 percent to 10 percent since the 19th century (4). The effect of modern technology is not always positive, a demonstration of the unchecked and sometimes unintended power of our technology is our impact on the climate. A sign of modern technology can be seen on the carbon dioxide record, which looks normal for hundreds of thousands of years until about 1950 when it shoots straight up. With deliberate climate engineering, a large country could apparently usher in an ice age if it feels like it by spending a tiny fraction of its GDP; humanity wields terrifying power (5). It can feel as though the present is the normal state for things to be in. The AI safety pioneer Eliezer Yudkowsky jokingly points out in one of his talks that the world seems to tend towards greater and greater ”normality” over time. He brings up that women used to be unable to vote, that seems odd. Going back further, things were even stranger. However, if you could take an outside view of human life since the origin of our species, it would be in the latest few pages of this epic where things became really strange, after all, we spent about 95% of our existence on this planet so far as hunter-gatherers. I regard it as somewhat likely that this trend towards greater strangeness to continue in the upcoming chapters.
Our ability to manipulate the world at an ever greater degree is strongly linked to our increasing scientific understanding of the world. Philosopher Rebecca Goldstein says about science that it ”gets reality itself to collaborate with us”, by ”prob[ing] reality so that it will answer us back when we are getting it wrong” (6). Someone has an idea about how some facet of reality works and comes up with a test that they think will settle whether they’re wrong, then others try the experiment themselves to check if the originator of the hypothesis deluded herself, or at least when the process is healthy which admittedly is not always the case. Ideally, scientists should always be on the lookout for subtle ways in which the predictions of a theory fails. For instance, in the 19th century people were confused by Mercurys orbit, because it did not seem to follow the law of Newtonian physics. When Einstein proposed general relativity, where gravity is conceptualized as the curvature of spacetime, Mercurys orbit made sense (7). This was a big point in favour of the theory. Scientists make progress by trying to refute themselves and others and only what survives scrutiny is given credence. This simple falsification-based view of science can be amplified with the more extensive and somewhat counterintuitive Bayesian account which I won’t cover here. It specifies how your credences in any theory or hypothesis should change as new evidence becomes available.
One seemingly necessary condition for successful science is mathematics. Galileo Galilei, who helped birth the scientific revolution, compared nature to a book written in the language of mathematics (8). Physicist Eugene Wigner wrote about ”The Unreasonable Effectiveness of Mathematics in the Natural Sciences”, the (perhaps surprising) fact that nature follows intelligible mathematical rules. After Maxwell discovered his equation for electromagnetism we mastered electricity, rockets use Newton’s law of gravitation to reach orbit, nuclear power, as well as weapons, were developed through discoveries in particle physics, and the computer industry depends on quantum mechanics in order to make transistors work (9). Engineering students are taught physics and math because we make technologies work by understanding the forces and laws that govern them, although maybe also because those are difficult subjects that can be used to signal a students competence. In some cases, the necessity of science for technological development might be overstated, it could be the case that some technologies that came after scientific breakthroughs could have been invented and perfected without scientific theories and could rely only on trial-and-error and heuristics, but it would likely take a lot more time and resources. I suspect that for modern technology, in general, this approach would be infeasible.
One way to benchmark the pace of technological progress is by comparing it to the first ”design process” (10) in the universe: evolution. Humans have in a few centuries developed technology with abilities that took evolution by natural selection millions of years to acquire and perfect. Flying, seeing and hearing (i.e. detecting photons and airwaves), harnessing and storing solar energy to take a few examples. Sometimes when we put serious effort into an ability, we have pushed that ability further than evolution ever has. Airplanes fly faster than any bird, boring machines can dig through harder material than any animal can. This is partly because we arguably use a more efficient ”design process” than evolution, we make use of our (imperfect) scientific understanding, reasoning and planning ability as opposed to evolution which lacks any understanding or foresight, and partly because we can choose any desired set of features to optimize, whereas evolution can be said to only optimize inclusive fitness. We can also make use of designs unavailable to evolution because the designs from evolution can only improve gradually. A classic example is the wheel: there is no use in a half-finished couple of wheels and there are no roads in nature. Nuclear power is another technology that will arguably never be available to the ”design process” of evolution because it seems to require rare, enriched non-organic materials, large facilities, and planning.
An unbreakable pattern
So far I’ve suggested that we live in a strange era in which we are rearranging matter into useful stuff much faster than evolution accomplished similar things, in large parts thanks to scientific progress. I want to say two things with this.
Firstly, it should not be too far fetched to think that we can keep this pace up and eventually outperform evolution in the design of intelligent things, perhaps not far from now, which should unlock even faster technological developments – a telescoping of the future, to use Nick Bostrom’s words – a superintelligence could possibly invent in a day what would take humans thousands of years. The upcoming chapters could be strange indeed. Intelligence is an evolved ability (governed by the laws of physics I might add) that we are making progress on understanding and reproducing artificially, and just like with many other technologies we can probably take the desired ability to further heights than can be found in nature. It has been pointed out (though I can’t remember where) that after a certain human cognitive ability has been automated, it can instantly or soon after be done faster and better artificially.
The second thing I would point out is that if you work from the assumption that the world is intelligible and constituted of physical stuff interacting according to mathematical rules, you can make remarkably precise predictions (11) and do remarkably powerful stuff. We have, to my knowledge, never found anything that contradicts this assumption. Lightning was thought to be angry God’s, disease and natural disaster were thought to be God punishing the sinners, and sacrifice was thought to control the weather. Supernatural accounts of natural phenomena have one by one been overtaken by a scientific explanation, never has the refinement of explanation gone the other way. This makes me think that the world might really be constituted entirely of physical stuff following mathematical rules. This means that there would be no purpose at the fundamental level of reality, just clockwork. Furthermore, no one makes sure that whatever goes on is fair, and there is unfortunately no fixed limit on how bad it’s allowed to get. We would have no benevolent cosmic father who looks after us and steps in if things get really out of hand (12). It’s just particles (or waves in quantum fields) mindlessly following rules without exception. As long as it’s allowed by the laws of physics, it can happen. The physicist Sean Carroll describes the world poetically as caught in the grip of an unbreakable pattern. The rough idea is that reality is a sequence of states, snapshots, following each other according to mathematical rules. Each state determines the next, like the Fibonacci sequence or the states of Conway’s game of life evolving according to a fixed set of rules.
The world can be described at different levels, with physics being the most fundamental to the best of our knowledge. It’s not useful to talk only in terms of fundamental particles and the laws of physics when explaining why someone delivered a pizza or how plate tectonics work, even though everything that happens is determined by them. As Dan Dennett notes in a discussion about this topic, someone who knows everything about the universe at the fundamental level, but nothing else i.e. had no conception of chairs, people and pizza delivery apps (the so-called Laplace’s demon), would be surprised by the efficiency of a simple human who can predict with fairly high reliability that a pizza will be delivered to his door in 30 minutes without having the knowledge about the position and velocity of every particle in the universe, and without the computing power required to calculate their trajectories. Understanding the world at the higher level of description with emergent features like money, social trust, and language is indeed indispensable to us, even though they are not necessary for Laplace’s demon to make perfect predictions.
Do we have free will on this view, if we’re just collections of particles mindlessly following rules? I’m a compatibilist, which means that I think free will (the ability to make choices, see more in note 13) is compatible with determinism, the theory that every event is the necessary result of what happened before it. I’m not sure if the universe is deterministic, but free will better be compatible with determinism for us to have free will because introducing randomness doesn’t seem to help. I’d rather my decisions were determined by my previous experiences, intuition, and deliberation than by a roll of the dice (I think).
A concept I find useful is the distinction between the manifest and scientific image of the world, the world as it appears to our senses and the world as it is unveiled by science. The manifest image and the scientific image aren’t always easy to reconcile, as in the case of free will where the feeling that you could have done otherwise which some people see as essential for free will clashes with the scientific view of brains as collections of particles obeying physical laws. In this case, I think the feeling is mistaken and that our notion of free will should be adjusted to fit the scientific view. The manifest image and the scientific image are true in different senses, the manifest image is true in the sense that what your experience of the world is a real experience. Even if you’re a brain in a vat, you can claim things like “I experience a red car” and not be mistaken, but you can be mistaken about the causes of your experience (the car might exist only as a representation in signals fed into your visual system). The scientific image is our best account of the causes of our experiences, and we can reach beyond our raw senses with microscopes, telescopes, infrared cameras and other tools to get a richer view of reality. I think we should trust our scientific understanding over our hunches and raw perception when they disagree about the cause of our experiences since we know from experience that our senses can be simply fooled by for example conjuring tricks and visual illusions. It shouldn’t be surprising if the universe violates our common sense, we’re evolved to deal with the challenges of the African savanna – not understanding the nature of reality (I recommend this talk by Richard Dawkins on the topic).
The most important thing I can’t fit into the scientific, naturalist, view is consciousness. I don’t understand how it can exist. But it is among the last things we would deny. While apparent causes of experiences can be illusory, conscious experience itself, I submit, cannot be an illusion. It’s the very stage where illusions can appear. However, it seems to be a hard problem to explain why and how physical processes give rise to subjective experience. ”As physicists work toward completing a theory of the universe and biologists unravel the molecular complexity of life, a glaring incompleteness in this scientific vision becomes apparent. The ‘theory of everything’ that appears to be emerging includes everything but us […] We need a ‘theory of everything’ that does not leave it absurd that we exist.” says the back of Incomplete Nature by Terrance Deacon, which exposes his attempt of filling the missing piece. I’ve read two different accounts of consciousness by naturalists, Incomplete Nature and Dennett’s Consciousness explained as well as Brian Tomasik’s writings on consciousness, which echoes Dennett’s. Reading these accounts didn’t get me closer to feeling satisfied with a resolution, though I can’t claim that I fully understand them. Steven Pinker summarises (14) the believed function that consciousness plays according to some neuroscientists as a blackboard in the brain where ”a diverse set of computational modules can post their results in a common format that all the other modules can ’see’” These modules include perception, memory, language and action planning. This seems like a plausible account of the biological function of consciousness to me, but it doesn’t explain the nature of first-person experience.
How come some physical processes are accompanied by consciousness? This question seems kind of hopelessly difficult (15). Would any answer feel satisfactory? To any answer of the type “because of this particular process”, you could reply: why isn’t that process going on “in the dark” like any other process allegedly is? It is tempting to believe that consciousness is coming from somewhere else and that the physical process is merely summoning the consciousness, which exists outside the physical world. But how could a physical system know and report that it is conscious unless consciousness is interacting with that physical system? The non-physical would have to interact with the physical but this would seem to make the non-physical just an extension of the physical and the problem remains. The problem of consciousness is discussed lucidly in this episode of the Making Sense podcast.
To sum up, we live in highly unusual times from a zoomed-out historical perspective and we should regard it as plausible that things get increasingly strange. Science and technological development are incredibly powerful processes according to my world view. They progress much faster and produces more powerful designs than the first ”design process”, i.e. evolution does for many of the features we care about. I anticipate that these faster processes will eventually outcompete evolution in the design of intelligent systems, and this could have huge consequences. The world runs like Conway’s game of life, a mathematical pattern with simple beginnings that grew in complexity over time. It operates mindlessly without purpose and there is no guardian who limits the depth of the abysses in the landscape we traverse. On the plus side, nobody restricts the heights either (this is not to say that the depths or heights are necessarily infinite). The unbreakable mathematical pattern underlies and determines everything, including the human mind. The human mind is the first and only known entity in the universe that has learned about the unbreakable pattern and has come to know the rules the pattern follows in everyday life, i.e. the rules that govern us and our local surroundings. I give credence to the scientific worldview because of its predictive power and the technological progress it has made possible. The big question mark for me is consciousness. How can first-person experiences emerge from a mathematical pattern?
(1) I like this poetic description of computer chips by a programmer on Reddit:
”We draw magic runes on sand with light then capture lighting in it and make it dream. As coders we whisper arcane spells to the dreaming stones.”
(2) https://ourworldindata.org/economic-growth As I’m required to mention by the CC-license: graph colors are edited.
(3) Page 426 of ”An Introduction to Global Health” by Michael Seear, Obidimma Ezezika
(5) David Keith: A surprising idea for ”solving” climate change https://www.youtube.com/watch?v=XkEys3PeseA
(6) Waking Up with Sam Harris #120 – What Is and What Matters (with Rebecca Goldstein and Max Tegmark) https://youtu.be/cypm7hkJ2lQ?t=6m22s
(7) Tests of general relativity – Wikipedia
(8) Quote by Galileo: “Philosophy [nature] is written in that great bo…”
Cool fact: GPS satellites compensates for Einstein’s theory of relativity to transmit the right time. I think this is a surprising application of relativity, although it might not have been needed for GPS to work, arguably we would have figured it out with a space-clock experiment if nobody had yet figured out the theory of relativity, see https://en.wikipedia.org/wiki/Global_Positioning_System#Satellite_frequencies
(10) There is disagreement among naturalists about whether evolution should be called a ”design process” or not, so I use the term in scare quotes.
(11) In Quantum electrodynamics, one of the most accurate theories in physics, agreements between predictions of the theory and observations is within 10 parts in a billion for a certain test. https://en.m.wikipedia.org/wiki/Precision_tests_of_QED
(12) Unless we are simulated and the supervisor(s) of the simulation are benevolent
(13) There are different definitions of ”free will”, the one I’m using is from Wikipedia: ”Free will is the ability to choose between different possible courses of action unimpeded.” and more specifically I think of free will ”as a psychological capacity, such as to direct one’s behavior in a way responsive to reason”, this is the definition used by determinists, if you think the notion of ”could have done otherwise even if the conditions before the decision were exactly the same” is important in the definition of free will, then you would not be a compatibilist. I like this post by Sean Carroll on determinism and free will.
(14) Page 426, Enlightenment Now.
(15) Maybe that’s why it’s called the hard problem.