This is an extract from the OPIP book. Previously, (B)obby argued to (A)lice that we need to question our existing knowledge fundamentally to make progress. Note: This post has the “Speculative Theories”-tag to indicate that what is being said should be taken with a grain of salt.
B: The basic human model of the world is this: There is certain “stuff” (objects) that moves through space as time elapses. That’s the model we’re born with. Humans find it very difficult to mentally break away from that model, as it’s so deeply ingrained into us and we rely on visualizing things to understand them.
A: How exactly?
B: For example, when we were kids, and moved a ball through the air, we perceived the air to be nothing (or emptiness). Later we learn that air isn’t nothing, but consists of a huge number of atoms. However, the basic paradigm of “something moving through nothing” hasn’t changed. We just pushed the “nothingness” deeper down (it’s now between atoms[1]). We don’t question this concept fundamentally, even though it has been disproven in the everyday world we live in.
A: We also rely on this model when trying to explain phenomena that are new to us?
B: Yes. Here’s a typical way of reasoning:
Physicist 1: “Atoms. How does that work?”
Physicist 2: “No idea.”
Physicist 1: “Okay, we need something here…”
Physicist 2: “What about imagining it like something we know. Feels familiar. Feels good.”
Physicist 1: “Alright, what exactly?”
Physicist 2: “Hm. Atoms are something small. Maybe let’s imagine them like something big. Solar system.”
Physicist 1: “Fine with me, let’s take that.”
A: Could it be that you’re slightly oversimplifying how Bohr’s model of the atom was derived?
B: I might be exaggerating a little to get my point across, which is that we constantly tend to fall back on the models we know. It’s understandable that if all you have is a hammer, every problem looks like a nail. But it may lead you astray.
A: Okay, so you’re suggesting to question everything. But how could this work? How could we make any statement at all? As soon as we open our mouths and try to explain something, we fall back to our inherited model of the world, as that’s the mindset we’re trapped in. All the terms and expressions we use are based on the old model too, right?
B: Surprisingly, there is a path to progress. The key lies in the insight that while everything we think we know is wrong, some concepts are less wrong than others.
A: Please explain.
B: Let’s take Newton’s unification of gravity as an example. He realized that the force that keeps the planets in orbit is the same as the one pulling the apple to the ground. Before Newton’s discovery, those two phenomena were regarded as entirely separate. While this new, unified theory is also wrong—remember, everything is wrong—it’s less wrong as there is now only one wrong theory instead of two wrong theories. Making something up isn’t good, but at least it’s better than making two things up. Hence, it can be considered a little closer to the truth.
A: So less is more.
B: Right. This also explains why there is a good reason to look for unification and simplification in physics (or “beauty,” but only in this strict sense of unification). Before the “less wrong” thought, there wasn’t a clear reason why this approach should be valid. Progress in physics was often accompanied by unification and simplification, leading many physicists to intuitively assume that this trend will continue. But who says that nature has to be that way? Well, now there is a theoretical justification. It’s a bit subtle, but important.
A: Alright.
B: With all due respect, I’m not sure if your “Alright” response fully appreciates what I said. I’ve just given a logical explanation for why there is unification in physics, which has been the main driver of progress over the past centuries. I’m happy with any reaction; it certainly doesn’t have to be “Oh, wow,” it can also be “I don’t think so,” “That’s total nonsense,” or, “You’re nuts.” Those are all perfectly fine responses, but it can’t just be a “Yes sure, let’s continue the chat.”
A: I just need some time to digest it.
B: Okay, that’s fine of course.
A: Does progress in physics always lead to simplification? When Einstein introduced time as an additional, fourth dimension, wasn’t that an increase in complexity?
B: It would have been if time had been a completely new concept. However, when Einstein proposed it, other physicists didn’t respond with “Time? What’s that? How do you spell it?” Einstein took two previously separate concepts and unified them into spacetime. Therefore, that too was a case of simplification and unification.
A: But there are examples where progress was made despite an outcome that can be considered complex. For example, the Standard Model of particle physics contains a plethora of particles—colloquially called a “particle zoo”—and it’s highly successful.
B: That’s true, but before that, it was even more chaotic. There were many more bizarre and seemingly unrelated particles, with new ones popping up frequently out of the blue. With the Standard Model, we now have a unifying framework with only a handful of particles. You may still call it a zoo, but like in a real zoo, the animals are known and organized into different exhibits. While it still contains some diversity, a particle zoo is an advancement to the particle circus we had before with its unexpected acts and surprises.
A: Okay, so you’re saying that it was also a massive simplification.
B: Right. As for the remaining complexity, the question is whether this is the final decision on the topic, or just temporary until a better theory is found. I’m betting on the latter.
A: How come?
B: Progress in physics has been one big history of simplification and unification. This ranges from straightforward realizations, such as heat being nothing more than uncoordinated movements of particles, to more complex ideas such as the merging of electricity and magnetism into electromagnetism, as proposed by Maxwell.
A: Is this principle of unification limited to the field of physics?
B: It also applies to other areas of science. Mendeleev’s periodic table of elements instilled order and unity into the previously chaotic field of chemistry. In biology, the discovery of DNA revealed that all life forms share a common mechanism for transmitting genetic information.
A: But the principle only applies to the hard sciences, right?
B: You can also find similar patterns in soft sciences such as psychology. Freud’s psychoanalysis aimed to unify diverse mental phenomena, such as dreams, slips of the tongue, and symptoms of mental illness, under a single theoretical framework. Likewise, Maslow’s model suggests that all human behavior can be understood in terms of a hierarchy of needs. Comparable trends can even be observed in non-scientific fields such as religion. Historically, there has been a trend from polytheism (belief in many gods) to monotheism (belief in one god), getting closer and closer to the right number.
A: Okay, so how can we reach further unifications in physics?
B: Following the “less wrong” thought, the key would be to detect flaws in human thinking. That’s the main, and maybe only, driver for progress.
A: What’s an example of such a flaw?
B: We’ve already discussed one: humans tend to visualize reality, which can cause us to cling to an outdated model that contains the same old thinking mistakes. It’s valid to use visuals to convey new perspectives, but if you assign those visuals a truth in themselves, then you’re almost certainly on the wrong track.
The book continues by elaborating on other potential thinking mistakes, and what conclusions can be drawn from them. In a later section of the book, simplification, unification, and beauty are discussed in more depth. Get it here.
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[1] It may be more accurate to say “particles” because atoms are also considered to be mostly empty (they consist of particles like protons, neutrons, and electrons). The concept of empty space also gets tricky when it comes to quantum mechanics, as will be elaborated later.
