How can you really say you you've learnt the alphabet if you haven't read the document in which the first use of the letter Y appeared?

Because you can successfully use it to communicate with other people. That's the grounding truth. If you'd only ever read about it and never actually employed it then yes, you would not be able to make that claim.

That's exactly what OP was doing, or does teaching kids not qualify somehow?

It's not the same thing. A language is a closed system, it just requires that the participants agree on the rules in order to be successful. Biology is not a language, it's a field of study of phenomena that exist independently of minds. If you read a biology textbook (or an LLM's output about biology) and then relate to someone else what you've read, you and the other person can discuss the topic, and be no closer to ascertain whether what you two understand has any basis in reality.

> Biology is not a language, it's a field of study of phenomena that exist independently of minds.

Your personal assertion is quite wrong at a fundamental level. Biology refers to the field or study, not individual specimens. The field is comprised of the understanding that people over time compiled on nature, along with arbitrary frameworks that help people organize and reason about the topic.

Take the concept of species, and species classification. A specimens exists regardless of being classified or not. However, the same specimen can be classified differently depending on the state of the body of knowledge at the time. In some cases you had species being reclassified due to new findings, such as genetic tests.

Once you understand this, you learn that you can't claim that a field of study is anything other than abstractions and partial and incomplete observations compiled form people throughout time.

Biology is in some sense a language, how do we even agree on what the boundaries of biology vs other domains of science are without participants agreeing on the rules?

In any case I think you have an overly narrow definition of learning that we're unlikely to come to terms over.

He's talking about learning that makes you operational. If you can speak with someone, then you've learned language. If you can get a computer to do something, then you've learned some programming.

The equivalent for biology would be to grow a plant or a few plants and animals successfully. That's operational at a certain level, you could also be operational at a lower or higher level.

No, it doesn't necessarily need to be applicable, it just needs to be testable. The size of the Earth for example may not affect you directly in any way, but it's something you can verify to some degree of precision. But if you just read about it, can you really say that you know it? What if all you believe about the size and shape of the Earth is from what you've asked an LLM? Do you still know it?

EDIT: Perhaps not the best example, because the size and shape of the Earth are data that are repeated often enough that an LLM would be unlikely to quote it grossly incorrectly, but I think my point still comes across.

I’ve been burned by this enough that I no longer say that I’ve learned something if my only interaction with it is explanation from books. You can get snippets of knowledge and a framework of understanding, but true learning only comes with deep interaction of the concepts (practice, simulation, experiments, observations) and not merely reading.

>how do we even agree on what the boundaries of biology vs other domains of science are without participants agreeing on the rules?

Those boundaries are completely imaginary and don't exist in reality. In reality there's no biology, there's only elementary particles interacting physically. Whether you agree with someone else to classify a phenomenon as biological or chemical, you're not refining your knowledge of the real world, you're just performing an organizational task.

But, say, how many times the tympanic ear evolved independently is a real phenomenon that can be investigated, and it's something that you're either correct, incorrect, or ignorant about. If I tell you it evolved five times, what more can either of us gleam about the real facts by just discussing this factoid back and forth, if neither of us has access to any additional knowledge or way to put this datum to the test?

Same question applies if you only check it against your children's biology books

For majority of people, especially children, book is an authoritative source. Virtually no one outside of research fields and very excited enthusiasts will check sources in depth to see whether what is shown in the book is true or not.

So, I think the point OP is making is that most people don't really check sources while learning things 'the conventional way'.

We have to distinguish learning from, let's call it, recreational education. If you're learning a topic, you're not going to be using a single book. Not even schoolchildren do that. Regardless of whether you consider a book an authoritative source, if you read multiple books those books will have to agree with each other, and where they don't you'll experience some confusion until you can resolve the contradiction.

If you're only ingesting information from a single source, be that a book, a teacher, or an LLM, then you haven't really learned, because your knowledge base is unmoored. You can't learn history by studying Tolkien's mythos.

Concrete high-profile example: in "Surely You're Joking, Mr. Feynman!", Feynman told of a ball which, in a Brazilian college-level physics book, was described as having a 40% higher acceleration that it would actually have in practice.

Turns out that the author had done a thought experiment but neglected to factor in the rotational inertia.

Self-consistency and consistency with your lived experience are good heuristics. Reality is self-consistent, so anything that doesn't add up indicated an error in the source or your understanding of it (or both).

EDIT:

I think it's a kind thing you need to tune yourself into. OTOH, I've observed many (most?) people seemingly being completely oblivious to self-consistency issues of their beliefs and mental models, or even texts they're reading or instructions they're following, and yet... somehow they're generally more successful at life because of it ¯\_(ツ)_/¯.

> I've observed many (most?) people seemingly being completely oblivious to self-consistency issues of their beliefs and mental models, or even texts they're reading or instructions they're following, and yet... somehow they're generally more successful at life because of it

What do you mean by "successful at life" here? Genuine happiness, fulfillment in life? Or in the sense of doing well by what society holds as it's current interpretion of what one should strive for, and otherwise just kinda drifting through life?

Because if it's the latter, I'd say that is to be expected. It's much simpler to put your energy into fulfilling the expectations of whoever is your superior in your current group, mostly get the expected reward, and then just coast. Reflection and experimentation, which is required to get to self-consistent views, takes effort and and the willingness to question existing beliefs, which will also be uncomfortable times.

How do you do that with topics not directly experimenceable, like quantum mechanics or, as in this case, silicon manufacture?

The very first thing I mention: self-consistency. It's the only thing you have if you don't have any empirical data. It's the only thing anyone has, really. QM scientists reading QM papers and experiment reports of other people, and talking with each other, are still relying on self-consistency to sniff their own (or other people's) mistakes.

>The very first thing I mention: self-consistency.

So if I consistently tell you that that lithium atoms are heavier than carbon atoms, that would make it more likely to be true?

>QM scientists reading QM papers and experiment reports of other people, and talking with each other, are still relying on self-consistency to sniff their own (or other people's) mistakes.

Physicists don't need self-consistency. They can test consistency against reality itself. That's not self-consistency, that's just plain old empiricism.

> So if I consistently tell you that that lithium atoms are heavier than carbon atoms, that would make it more likely to be true?

Nope. But if you said that, and used it as part of an explanation of some process, and every step logically checked out, and the outcome checked out too, and agreed with other things you said, and other things others said, then yes, I'd be likely to believe you.

Alas, a quick look at the periodic table raises a red flag - your explanation is inconsistent with the periodic table and what I know about its structure.

That doesn't necessarily say you are wrong - could be me. But judging by the tone of your comment vs. heaps of other things I know that are consistent with my understanding of chemistry and inconsistent with your statement...

> Physicists don't need self-consistency. They can test consistency against reality itself. That's not self-consistency, that's just plain old empiricism.

No they can't. No one has that much time or money. Physicists aren't routinely replicating every core result empirically for themselves. They rely on the descriptions of experiments and data that they read, and the self-consistency and extreme interconnectedness of reality, which means that wrong information will not add up with someone's experiment, expectations, or lived experience somewhere, and will be quickly flagged as wrong.

Empiricism is only useful because reality is self-consistent. If it weren't, you couldn't really infer anything from empirical evidence because things would just be whatever they wanted to be.

(Or more precisely: we can't prove reality is self-consistent, but if it isn't, nothing can ever make any sense, and we may just as well pack up our technological civilization and go back to the caves we crawled out of. Fortunately, empirical evidence supports the notion of reality being self-consistent to the extent we can observe it :).)

>But if you said that, and [...] I'd be likely to believe you.

That wasn't what I asked. I was very deliberate, I asked if it would be more likely to be true. What's under discussion is not your standard of evidence, but whether non-contradiction by itself is sufficient to conclude that a claim is true.

>Alas, a quick look at the periodic table raises a red flag

That's not self-consistency anymore, that's cross-corroboration. Which, yeah, good on you if you do that, but it's not the process being proposed either by the OP or by fy20.

>Physicists aren't routinely replicating every core result empirically for themselves.

OK, but that wasn't what I said. A physicist can't test every result, sure, but he can test those that are most relevant to his work. I'm not going to get into the philosophy of empiricism because it's not relevant here. My point was that an expert reading a peer's paper is not the least bit comparable to a layman reading an LLM's summary of a field of study. They're just not similar situations. One has the context and the capability to detect bullshit, while the other does not.

Not the OP, but I don't think you can. The understanding someone manufacturing silicon has will be not be attainable by reading about it etc. Similar for QM, no replacement for doing (some of) the math yourself, be involved in experiments etc.

> consistency with your lived experience

Aka confirmation bias.

We like explanations that fit what we expect, even if they're completely wrong.

I said consistent with your experience, not with your expectations. Lived experience is empirical data.

That would be the case if our memory wouldn't be completely fluid and built on subjective perceptions. The two sort of merge together over time, you come to see what you expect. It's only when something really out there breaches the belief model when that actually happens.

Reality is most likely self-consistent, but as we can only experience a tiny part of it it‘s impossible to tell. Also, parts of reality may appear to be contradictory with each other when some pieces are not known.

> Also, parts of reality may appear to be contradictory with each other when some pieces are not known.

Exactly. This tells you where something is off. The problem may be your lack of understanding or wrong understanding, or it may be with the source, or the framing, or you may have hit a genuine lack of data - still, the puzzles don't fit in some area.

And yes, not all self-consistent understanding is correct. But all inconsistent understanding is incorrect. And the more knowledge you gain, the less likely it is that it'll all connect self-consistently, but still be very wrong.

> But all inconsistent understanding is incorrect.

Why do you believe that?

Even if we assume that reality itself is self-consistent (what does that even mean?), why would that imply that we humans are able to find a self-consistent representation of it? Maybe reality is self-consistent in some sense but cannot even be represented by the tools we use for theory building.

My point being, the ultimate target of our understanding may be self-consistent, but the way we _necessarily_ have to reduce it to lossy theories means that we can only ever approach it with a non-zero error. And a theory focusing on one aspect, minimizing representational error from one direction of approaching it, necessarily has to make assumptions that will contradict those made by another theory trying to minimize representational error coming from another direction / domain.

> but the way we _necessarily_ have to reduce it to lossy theories means that we can only ever approach it with a non-zero error.

Yes. Fortunately, we also usually don't need the error to be zero. In practice, we usually have narrow scope at any given time, and can get away with a lot of error.

E.g. people in the past found alternatives to modern germ theory, involving evil spirits and other such shenanigans, but to the extend they covered the high-level mechanisms (curse transfers through contact, hygiene and boiling water removes the harmful effects, etc.), it doesn't really matter the theories were wrong. The beliefs were consistent with each other and empirical evidence to some degree, and to that degree were useful.

> And a theory focusing on one aspect, minimizing representational error from one direction of approaching it, necessarily has to make assumptions that will contradict those made by another theory trying to minimize representational error coming from another direction / domain.

That's fair. Our brains and attentions are finite, you always have to limit the scope. If you imagine you'd have practically forever, you could sort it out and make it all consistent to arbitrary degree (subject to fundamental computational limits, which are physical limits). In practice, the heuristic of consistency works like this:

- For things within your domain of interest, inconsistent information flags an error.

- For things at the interface between your domain of interest and another domain(s), inconsistent information flags an abstraction boundary. It's where you can observe simplifications both domains make because they don't add up (and if you adjust them to make them mutually consistent, you just allowed two domains to work together).

You don't seem to be disagreeing with GP, you're just saying that correctness may be practically impossible.