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Comment by cobbzilla | Hacker News Reader

I had a fun mind-play with my kids; I asked them if numbers like "one" and "two" really exist. They said yes, of course.

OK, I said, show me a plain old "one". Nope, that's one fork; nope that's one ball; nope, you get the idea.

You cannot show just "one" unattached to anything else.

The concept of "one" is an idea. It only exists as a "real" concept in your mind because it exists as the same concept in the minds of others, and it's a very useful concept in describing the world around us.

This odd fact becomes ever more apparent when you find out about cultures that have very different approaches to quantitative reasoning, like the Pirahã in Brazil [1]. They don't have number words beyond "one", words roughly meaning "some" and "many" are used for anything more than one.

[1] https://www.sciencedaily.com/releases/2008/07/080714111940.h...

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That's just "Exist as physical objects exist"

Ie., you're asking someone to find you an object with spatio-temporal properties which, as an object, does not have spatio-temporal properties.

Likewise you could ask, "find me a smile?!!" and then deny every example was a smile because "it was only a face smiling!".

"Existence" is defined relative to a context in which it can be evaluated, and it -- in general -- does not imply any particular properties.

"To Exit" in general is "to be found in some domain"

2 can be found in the domain of numbers

This reminds me of my Italian grammar teacher telling me that nouns can be broken into two categories: ‘concrete’ and ‘abstract’ (for example, ‘chair’ and ‘love’ respectively). Then came a totally mind bending digression for my eight-year-old mind when she mumbled “well actually all nouns are abstract because there’s no such thing as a chair divorced from reality, there’s nobly instantiations of these abstract concepts we consider close enough to be concrete”. That totally blew my mind. Together with reading The Computational Beauty Of Nature” when it first came out nine years ago those were the two key experiences that drove me towards choosing to get a degree in mathematics.

  > all nouns are abstract because there’s no such thing as a chair divorced from reality,
  > there’s nobly instantiations of these abstract concepts we consider close enough to be
  > concrete

Very Plato for an 8 year old.

https://en.wikipedia.org/wiki/Prat%C4%ABtyasamutp%C4%81da

Agree. Maybe it is more helpful to think of numbers as adjectives than nouns. Oneness plus twoness equals threeness. The part of speech is sort of irrelevant but it obviates a debate over whether or not instantiation of the unattached idea of a number is important, while still allowing math to occur.

Yes, I could have really tortured my kids and said, you can't even show me a "ball", because it will always be a specific ball and not the archetypal concept of "ball".

I probably should, it'd be fun and they're a bit older than when I pulled the "one" game.

Make sure you say "show me ball" instead of "a ball"...

The "technical" term amongst philosophers is "ontological category":

http://blog.rongarret.info/2015/02/31-flavors-of-ontology.ht...

I believe that in fact the numbers do exist as physical objects exist. Just in their own universe.

When we reason about numbers, we're embedding a representation of a universe of numbers into our universe.

What we call "physical existence" could is also probably just be "math all the way down". Just not in such a way that the number two per se can be an entity for us to behold.

I believe that in fact the numbers do exist as physical objects exist. Just in their own universe.

How is it any different than believing that unicorns exist as physical objects, just in their own universe?

What we call "physical existence" could...just be "math all the way down".

Or, math is also a number of simplified alternate views of reality of varying degrees of "applicability." (Where "applicability" has to do with predictive power over reality.)

> How is it any different than believing that unicorns exist as physical objects, just in their own universe?

Good question, but I think there might be a difference. Suppose, in a galaxy far, far away, there are aliens. They probably don't have the concept of unicorns. However, they probably have discovered numbers, pi, Pythagoras theorem, e^(i pi) + 1 = 0, etc.

So, does the fact that something is discovered (rather than invented), and can be discovered many times independently in identical fashion, confer it some sort of elevated ontological status?

However, they probably have discovered numbers, pi, Pythagoras theorem, e^(i pi) + 1 = 0, etc.

We can only be confident of that if they're in this universe. Also, this is only a conjecture. It's just something some of us imagine would be true. You can't elevate such an idea to the level of empirical data.

So, does the fact that something is discovered (rather than invented), and can be discovered many times independently in identical fashion, confer it some sort of elevated ontological status?

Unicorns. Kirin. Narwhals. Rhinos. So you have two independent origins in culture for such a creature, plus two appearances of something similar in nature. Does that confer it some sort of elevated ontological status?

> Unicorns. Kirin. Narwhals. Rhinos. So you have two independent origins in culture for such a creature, plus two appearances of something similar in nature.

It's not at all clear that the cultural constructs are independent of each other or real world creatures. Particularly in the Western case, some of the earliest Greek accounts of the unicorn as well as Marco Polo’s account confirming its existence and difference from the contemporary evolution of the image stem from the distant East (from the European perspective) and clearly are describing a rhinoceros. They are also very similar to accounts of the Kirin.

Kirin is giraffe and upset Confucius as it should not appear in his chaotic time.

Some accounts of Kirin, yes, appear quite likely to be giraffes, others are nearly identical to the Western accounts of the monoceros of distant India (one of the original of the unicorn legend) and are almost certainly accounts of rhinoceros.

I would sadly have to say no. Because in some completely different universe unlike ours, the aliens have no concept of, say, "hemoglobin" because there isn't matter like ours: no atoms, no iron, no carbon. Unlike numbers, hemoglobin and unicorns contain a kind of arbitrary complexity. Yet one is definitely real. Some real entities are far removed from elementary math (even though they may ultimately rest upon it, many levels down). The question is: are unicorns bunk, or are they like hemoglobin.

I'm not claiming that if something exists (haemoglobin), we must have a notion of it and true statements about it in every universe.

Rather: if we have a notion of something and statements about it in every universe, then it must exist. However, come to think of it, that's bonkers.

Still, it's remarkable that mathematics allows us to make reproducible true statements about fictional objects.

> They probably don't have the concept of unicorns.

What would happen to your epistemology if every alien civilization has unicorns but some lack π?

> every alien civilization has unicorns

I knew it, Unicorns are real!!11!

I am not sure I can conceive of aliens that don't have pi (how can they have cylindrical rockets?).

Anyway, maybe we should let the professionals deal with this.

https://plato.stanford.edu/entries/platonism-mathematics/

https://plato.stanford.edu/entries/intuitionism/

https://plato.stanford.edu/entries/mathphil-indis/

https://plato.stanford.edu/entries/nominalism-mathematics/

https://plato.stanford.edu/entries/philosophy-mathematics/

> How is it any different than believing that unicorns exist as physical objects, just in their own universe?

We have very well-developed representations of the number universe that we can embed into our own universe. These things are governed by precise axioms. By contrast, we don't have such well-developed "unicorn universe".

(For starters, what is the definition of "unicorn"? If it's just a horse with a horn, then such a thing is plausible with genetic engineering in our universe.) As we endow the unicorn with additional properties, then it becomes less and less clear that there exists a universe where such a thing can exists other than as an imaginary being. If the concept of a unicorn could be axiomatized, then it could constitute a universe.

> Or, math is also a number of simplified alternate views of reality.

Well, that's the math that we do; not the math that we (possibly) are.

Indeed. The current better known attempts at a "unicorn universe" have problems with power scaling and the square-cube law. https://www.reddit.com/r/mylittlepony/comments/mrs81/accordi...

Do you have a good definition of what constitutes a "well-developed" universe?

>Do you have a good definition of what constitutes a "well-developed" universe?

An easy definition would be one where everyone agrees on the exact mechanics and sequence of states. The fibonacci sequence is well-developed: it has an exact definition that every competent simulator can simulate the same way. If I say my favorite number is the 1000th item in the sequence (starting with 0, 1, 1 as items #1, #2, #3), then everyone can calculate the 1000th item the same way.

If we all try to talk about what happens in the "unicorn universe", everyone has their own different ideas about that. There's no unambiguous rules for how the unicorn universe is calculated. Everyone has a different "unicorn universe" in their heads, and each of those universes operates on our own mind's whims rather than any rules we can describe to each other.

If we all try to talk about what happens in the "unicorn universe", everyone has their own different ideas about that.

Homo sapiens has this issue with this universe. Even if you subset that group to just scientists, there are still differences of opinion.

Reality itself is well-defined in that it acts consistently with itself. We as humans don't have a well-defined embedding of this universe into itself. We would need to know the complete underlying rules of physics for that.

That other "universe" is just patterns embedded in our brains. That's all you need.

You could likewise argue that sounds exist in a different universe, but are only "embedded" into the air using pressure waves, but why would you ever think you needed a different universe of sounds when you've already got pressure waves in air? I mean... what's "not enough" about that for you?

>What we call "physical existence" could is also probably just be "math all the way down".

This is a needless diversion. Mathematics is the study of structure. Physical reality has structure, and very well could "be structure" in some equivalent sense, but to say it is math is just abject poetic nonsense. This change of language would literally make no significant difference to anybody about anything. You may as well be declaring the world to be flat and asking everybody else to go and change all our language to make it true.

> abject poetic nonsense.

No it isn't! Either it is math all the way down, or else it isn't.

If it isn't, then what is at the bottom?

So this is actually an existential question.

Suppose we reach a final description of reality that is entirely accurate (no longer an approximation that fails to account for some structures and processes).

Won't that description consist of nothing but math?

Then, if it is complete, how does that description account for the fact that reality isn't math? If there is a difference between reality and math, can't that be described with math, so then it goes away?

If you want math to just be a description of a structure that itself isn't math, then the structure has to have attributes that are not covered by the math. The math is then using a substitute structure with fewer properties as a proxy for that structure. Once all the attributes are rolled into the math, there ceases to be a difference between that target structure and the math; it is that mathematical object. To prove otherwise requires one to name the difference. If two entities are completely described and found to be the same, they are just one entity.

> You may as well be declaring the world to be flat.

It is testable that the world isn't flat.

My guess is that eventually, if we manage to ever reach that point of total knowledge, there are certain properties of the universe that exist for no reason; they just are. Whether that's at the level of today's fundamental particles/qft or much deeper is anyone's guess.

Example: space-time exists in n(>=4) dimensions, there are several quantum fields that exist in that space-time and evolve/interact according to the equations of qft, gravity has some mathematical description (better than the ones we have now). And that's it, there's nothing else for us to know. Of course, we can never know for certain whether we've bottomed-out our description of reality, so physicists will always have some hope.

Now, if the universe is described entirely by mathematics, bootstrapped by a few base cases (the existence of fields/particles/space-time/strings/etc), I'd be comfortable with that. I'm not sure what a truly satisfying understanding of reality would look like beyond that.

> there are certain properties of the universe that exist for no reason; they just are.

But we have that in math and logic: axioms!

> Of course, we can never know for certain whether we've bottomed-out our description of reality

That we do not know is a fact; but is it a fact that we can never know?

What if one fine day we do know?

> But we have that in math and logic: axioms!

Yes and no. Axioms are chosen such that the math that is based on them makes sense to us (because the math reflects what we'd expect in the real world) and isn't self-contradictory.

So they do exist for a reason.

> That we do not know is a fact; but is it a fact that we can never know?

What if our universe actually has randomness that appears to come from "outside the system", i.e. there is really no way to predict the outcome of certain things from inside the system.

Picture you're sitting in a box trying to play Mikado. In theory you should be able to perfectly predict the outcome of every move you make - except there's a stranger shaking the box you're sitting in at truly random intervals.

For our reality this would mean that there's no way for us to develop an understanding of certain things and predict their behavior.

So essentially the end of the line for all sciences except theology and philosophy.

This possibility makes me somewhat uncomfortable.

On the other hand maybe everything is perfectly deterministic within our universe.

>Suppose we reach a final description of reality that is entirely accurate (no longer an approximation that fails to account for some structures and processes).

> Won't that description consist of nothing but math?

Math is just words. Any description of anything can be reduced to math if you assume the proper math will be developed to describe it. But the same could be said of any subject. You could say the universe is Mandarin Chinese if you find a perfect description in that language. You could say the universe is binary code if you found a perfect description of it in binary. You could say the universe is tree bark if you found a perfect description of it in tree bark.

You're saying nothing useful. You're just confusing the map for the territory. (And arguably, you will never find a complete description of the entire universe that fits in a network of human brains, so the universe can't be math for that reason alone.)

> You're just confusing the map for the territory.

I am not at all! We do math with symbols and diagrams, but those symbols and diagrams are about something: they are maps, and there is a territory that they are about. When I say "math", I include the concepts, not just the symbolic, graphical and other representations.

So what I'm saying is that if/when mathematics provides a complete map to that territory which is "the world", that territory must then be made of exactly the same stuff as other described-by-math territory-entities like "ellipse", "pi", "finite field", "Hilbert space", ... the map of mathematics doesn't describe any other kind of territory.

I'm not saying that the symbols and pictures used to carry out math (the "maps") are the world.

> you will never find a complete description of the entire universe that fits in a network of human brains

The description of the state of it as it is before us is monstrously large, but the initial conditions and rules might not be. E.g. the Mandelbrot set is just iterating on z^2 + c for various c. To describe isn't necessarily to evaluate.

The concepts are also just symbols, just in different media. They are also a map.

>if/when mathematics provides a complete map to that territory which is "the world",

Then it will encode all the information that exists in the universe. Which will not fit in your head, and thus will not be mathematics. Just because a territory is trivially a map of itself doesn't mean it is useful to call it a map.

>The description of the state of it as it is before us is monstrously large, but the initial conditions and rules might not be.

Reality isn't just the initial rules. It has state. That state must be described for you to have a complete description of reality. Yes, we could mathematically describe the complete laws of nature. But reality is necessarily more than just that, because the state is really damn relevant. You can't just ignore it because it doesn't fit your argument.

>Reality isn't just the initial rules. It has state. That state must be described for you to have a complete description of reality.

If reality is deterministic, then all the state is derivable from the rules and the initial state, and it's possible we could figure out the rules and initial state and become relatively sure of them. (We probably wouldn't be able to calculate the future, since evaluating the rules within reality probably necessarily takes more steps than reality takes during that time. But we might be able to calculate enough to see that it matches up with what we think the early universe must have looked like. We might notice that even the smallest of tweaks to the rules or initial state creates an avalanche of changes that doesn't line up with what we believe the early universe looked like, so we can be sure there are no free parameters.) It's fully possible that the rules and initial state could fit in someone's head. They might be ridiculously simple, like Conway's game of life in a few more dimensions.

(If you think "reality can't be deterministic because true randomness or quantum events exist", well you can fit true randomness into a deterministic theory by having the world branch of every random event outcome. The Many-Worlds Interpretation could be viewed as doing something like this for quantum events; it's a deterministic theory.)

Even if reality is deterministic, you still have to know which state to derive. And that process will have to account for all of the same information.

The strange thing about mathematics, as opposed to other noncorporeal ideas, is that it is nearly uniquely suited to being transmitted between brains. My idea of the number "three" and your idea the number "three" are probably very similar. This sort sensation that they have an independent existence leads people to the Platonic notion of a mathematical "realm" or "universe".

(personally I think mathematics exists in our brains, but also and crucially in the interactions between our brains, since a proof is never accepted until it is reviewed and so on. A proof that's just in my brain is no proof at all, even if it happens to be correct)

You could say that about most language we use: it's meant for transmitting thoughts between human brains. Why would it be bad at it?

Besides, there are plenty of mathematical concepts which are hard to understand. I don't see any uniqueness to math here.

Yeah, mathematical objects like numbers are concepts in our brains, or imaginary objects. Numbers in particular are imaginary objects used for counting. You can set up an isomorphism between these numbers and real-world objects, e.g., to count them.

You may be interested in: https://en.wikipedia.org/wiki/Mathematical_universe_hypothes...

> You cannot show just "one" unattached to anything else.

Also interesting to try to show "zero" of something. Zero is fun because it took longer to exist as a number than one & two, and there was some debate over whether it should be a number. "How can nothing be something?"

Historically true, but glad it's there so ℤ is a group. The way to think about 0 for a child is what you add to anything so it stays the same, ie nothing.

Hate to be pedantic, but ℤ︎ is a set (not a group) and even with 0 adjoined it only forms a group under the operators of addition, subtraction, and multiplication.. If you want a set that also forms a group under division you need to ‘upgrade’ to the set ℚ︎.

ℤ︎ (…, -2, -1, 0, 1, 2, …) and + forms a group. It is also a ring with * and +. ℚ︎ with * and + forms a field.

Yes, that's what qubex said, in correcting the error in your previous comment.

ℤ︎ with * is not a group, there is no inverse for 0. When being pedantic it's good to be correct.

You are perfectly correct, I was wrong. Upon closer reflection it appears impossible to have a nontrivial set (meaning other than {0}) that forms a group both under addition and under multiplication because the identity element of the former does not have an inverse in the latter. However, take this with a grain of salt, because I haven't had time to prove this to my own satisfaction yet (and I am loathe to go googling for answers in my own field of expertise).

My abstract algebra professor would be horrified by my misstatement, and I shall go to bring flowers as a sign of atonement and rememberance to his grave at the earliest available opportunity.

Ah! I wrote the below before seeing your comment:

Numbers don't exist. Take the number two. You can have two apples but that's not the number two. You can write the numeral "2", but that's not the number two. It's one line. The word "two" has three letters, it's obviously not the number two. In fact, the number two doesn't exist (or it's existence is not contingent on an arrangement of matter/energy. No pattern of matter/energy/space/time is actually THE number two.)

To me, it's wonderful to reflect on the epistemological status of numbers. They don't seem to exist, but we talk about them as if they do. Certainly they are useful. But they don't exist any more than, say, Sherlock Holmes does.

It's also much fun to reflect that, whatever the epistemological status of number, that status is shared by computer languages and algorithms and much else. E.g. the C language doesn't exist. The C standard(s) exist, many C compilers exist, lots and lots of C code exist, etc., but the language itself doesn't exist anywhere, any more than does the number two.

Numbers don't exist - unless you're a Platonist.

The experience of numbers certainly exists. The reason you recognise one-ness and two-ness in objects is because your brain experiences a difference between one-object and a-pair-of-those-objects.

The experience is subjective. If you have two objects that are identical except for the fact that one is red and the other is blue, you can parse them as one-each-of-red-and-blue or as two-identical-things. Both interpretations are logically consistent, but the most useful interpretation depends on the context, and your specific needs as defined by the context.

It's easy to underestimate how subjective math is.

I've long suspected that this is why math eventually dissolves into incompleteness theorems. You can't prove a subjective experience, and eventually all mathematical reasoning reduces to subjectivity - even something basic like true/false, which is essentially just an interpretation of experience. (And can be very unreliable.)

Math is really an introspective map of experiences and processes that we find collectively consistent. We like to tell ourselves it's external and objective. But how can we tell the difference between true objectivity and subjective consistency when we only have shared human subjectivity to use as a reference?

Proof that at least one number exists: Take for our logic first order logic with equality[1]. Take for our definition of the word "number" the Peano axioms[2]. The first Peano axiom is "0 is a natural number." Define "N" to be the unary relation "is a natural number." In our formal language, we write the first Peano axiom as "N0". By the principle of existential generalization[3], we have "∃x Nx", which we read as "there exists x such that x is a natural number." Q.E.D.

I assume you find the above deeply unsatisfying. Most people do. Yet I find it clarifies the matter entirely! If a person's conception of "number" is consistent with the Peano axioms, and if that person's use of the word "exists" includes the existential logical quantifier, then for that person "numbers exist" is a theorem. If a person uses other definitions, the matter may be otherwise.

[1]: https://plato.stanford.edu/entries/logic-classical/ [2]: https://en.wikipedia.org/wiki/Peano_axioms [3]: https://en.wikipedia.org/wiki/Existential_generalization

Does an apple exist? You can show me an apple, but I would wag my finger in exactly the same way you are to people trying to show you “one”. The apple you’re showing me is not the same thing as the word “apple” which is an abstract category that encompasses all types of apples - honeycrisp, Granny Smith, etc. You could say a honeycrisp is like an instance of apple which is a base class, so then it is indeed an apple. But then youd have to say an apple is also a “fruit” and also a “food” even though those words also encompass broad categories of things.

If you buy the above, you’d have to say that a single apple is also “one”. After all, it’s just another broad category that a single apple fits in to. If not, I think you’d have to reject the fact that a honeycrisp is an apple, which seems untenable.

Reflecting on this stuff is my golf...

Even if I agree that THE number "one" is "just another broad category that a single apple fits in to", I think the epistemological status of the Broad Category is then itself just as problematical, existence-wise, as the original concept of "number", eh? We can at least display a pair of apples and "count" to "two" with them, etc. What hope do we have of enumerating (no pun intended) the Broad Category of "one"? And what do we gain from introducing it?

Numbers do not have a physical existence, but we can talk about them because in some capacity they absolutely do exist: conceptually.

There is the Tao and then there are the 10,000 things.

Numbers exist in a different way to Sherlock Holmes who of course exists as a fictional character. One of the things people look for when searching radio signals for alien life is prime numbers as intelligent species would discover those but they are not produced by mechanical processes like quasars. How could we and they discover them if they don't exist at least in some form?

Numbers don't exist.

Only for the sense of "exist" which is roughly equivalent to "can poke a hypothetical indestructible stick at it, given enough energy."

the C language doesn't exist. The C standard(s) exist, many C compilers exist, lots and lots of C code exist, etc., but the language itself doesn't exist anywhere, any more than does the number two.

For the purpose of tax law, software is defined as a "tangible good." However, in other areas of the law, it's considered intangible.

You should keep in mind that being unable to show or find an example doesn't disprove the category. You'll never show me a fork yesterday, but that doesn't mean there were no forks yesterday.

I’m a mathematician and you seem a bit confused. Natural numbers ({1, 2, 3, ... }) are for counting. Giving a bunch of objects as being prime examples of that which can be counted with natural numbers is as close as one can get (short of just scribbling down the numerals and kind-of circumventing the point). Other classes of numbers (particularly the Reals) are for measuring. Again, short of writing down examples of decimal expansions, a child could point to a (non-integer) mark on a measuring tape.

I get the feeling you’re not quite so well versed on this stuff as you think you are. Want a true example of ‘one’: the number of solutions to the intersection of two linear equations that are not parallel. Want an example of ‘two’: the number of solutions between a quadratic equation and a linear equation (given that certain existence criteria are met).

I think you need to revise your measure theory.

I think they're just trying to say "1" is not a tangible object in the physical universe, not that it does not exist as a concept. The natural numbers are just data, information, they don't exist beyond the first dimension except as descriptors to things in further dimensions, just like lines can be built up into higher dimensions but cannot be physically created for us to observe.

Maybe you're reading too much into this.

How is two straight lines crossing in one and only one place not an example of a single occurrence without reference to real world objects (which the OP dismissed as “not really being a number”).

As for reading “too much into this”, as Instated: Irma a mathematician, of course I’m going to take this seriously and make an effort to disprove naive misconceptions.

"Reification" is the term to search for if you wish to delve into the extensive Philosophical bibliography on this topic that's accumulated over the last few centuries. Within mathematics "Intuitionist Mathematics" is the rubric for the anti-reification view. This relies on computability as a substitute for "existence." The Intuitionist view has pretty much triumphed.

I’m all for reification. It’s not even limited to mathematics: ‘democracy’ is just another example of a reification from another realm of human endeavor: it gets implemented in different countries with slightly different axioms and varying degrees of success but in aggregate those nations that abide by some form of it are accepted as functional equals by other whom have likewise implemented their own instantiation of the overarching ideal.

That's not what reification means, it's more a form of Platonism (Idealism), plus. See The Meno and it's discussion of the forms (say, the "form" of a spoon.) Plato would reify democracy (although he hated it) but most of us certainly do not. A nominalist (even a Berkeley follower) could discuss democracy perfectly well.

I'm pretty well versed in what reification means. Fundamentally it entails taking a theoretical concept and treating it as if it were a tangible, almost embodied, thing.

Maybe my example wasn't the best but this “democracy thing” gets discussed as if it has material properties: that it can expand, that it can be transported from one place to another, that it can be expelled from a locale, and so forth. Those are pretty material attributes to assign to something that is actually notional.

Now if you look up tangible...

I think you're caviling, at this point.

“Tangible” means touchable and has a Latin root; “tangere” still means “to touch” (though somewhat archaic) in my native Italian. That same Latin root is why we call linear equations that share the gradient of a given curve evaluated at the point where they cross to be “tangential”.

Look, we could go on with this all day. What’s your point? To show your terminology and grasp of topics is greater than mine? Is this some kind of passing match? Because I’m really not interested in these schoolyard antics.

So, how do you pinch a democracy, physically? By avoiding answering my point in my last message, you're still caviling. One progresses to the end of a conversation by honestly answering the points made, and you aren't interested in doing that.

This is why Aristotle said that the intellect cannot be material. The human intellect is able to receive and understand abstractions. However, whenever you try to represent an abstraction as a physical object or in a physical medium, it is no longer abstract. It is true that you can write about abstractions using physical ink on physical paper, but those are just symbols; they are not the abstraction. It is only when a person reads the symbols, understands them, and forms the abstraction in his mind that the abstraction comes into existence.

So, we can create programs that appear to do intelligent things, but it is the human observer that brings meaning to what the program is doing. The program might output the letters "dog" when a dog pass in front of its camera, but its the human that sees the "dog" that knows what a dog actually is.

That sounds like the illusion of consciousness. Neural networks show that you don't need "dog" in order to do whatever you need to with the idea of a dog.

You might even say the unattached "one" is more real than the fork. At the end of the universe, that fork is long gone, but "one" is still there.

But if there is no one around to appreciate or think of "one", does it still exist?

Where is "one" then, if it's still "there"? :P

A coiuple of my favourites:

- Child is put into perfectly sealed cube. They have a torch, which provides light. Since the light cannot escape the cube, what happens when they turn the torch off? Where does it go?

- If you put a brain in a jar and wired up electrodes which pulsed up every nerve ending etc to simulate reality - would the brain know it was in a jar? How? (The matrix being the modern representation)

In the case of the cube the internal temperature would rise slightly. Th kid is also emitting some heat too so that would also contribute to the rising temperature. Eventually the kid would die from lack of oxygen. If you provide oxygen to the child and remove carbon dioxide the system would no longer be sealed: adiabatic expansion of added oxygen would lower the temperature and removal of carbon dioxide would extract some heat from the cube.

Observed externally the mass of the cube (assuming you didn’t provide a life-support system as I suggested) would remain unchanged because all mass energy is still within the cube. It has simply rearranged itself in a manner unobservable to an external observer.

When they turn the light off you have a black body cavity with an intruder. Ultimately all the light would get reflected back and forth until it fell on various parts of his body whose colour allows them to absorb the incident light waves. The child would get slightly, probably imperceptibly warmer. His surface molecules would move faster and thus he’d have more heat energy.

By extension, does God exist? I don't know the answer but he seems to be very useful (at least to some members of the society!)

Sure (s)he does - inside all of us. This works for both spiritual as well as a human nature points of view.

https://books.google.com/books?id=1s5EAAAAIAAJ&pg=PA9&ci=137...

So by your definition, one is an adjective, so asking them for a noun that represents the adjective "one" violates the definition. It's sort of a trivially false disingenuous question.

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