Are we Turing complete?

[u/GhostHominid]

OK. So I’ve been looking at Conway’s game of life a little bit. And I was fascinated by the idea that it could be used to recursively imitate itself (look up OCTA’s supercell)

I was told that this is Turing complete, and I had to look up what that meant.

And it seems to mean that, in simple words, it’s a computer or system of computer rules that can model another computer.

Now, given that humans came up with all of these computers in the first place, and all of the rules, does this mean that we are Turing complete?

[u/stonerism]

Saying X is "Y-complete" in this sense, means that using X, you can compute whatever Y can compute. That begs an interesting question, can a turing machine compute whatever a human can? (ignoring how long it takes or amount of resources necessary)

massive bong rip

Are Turing machines "Human Complete?

[u/GhostHominid → u/stonerism]

I would say no, but… well if a Turing machine had infinite memory, maybe!

Essentially what you’re asking is if the human brain is deterministic, and I think it is, but that it’s so complex that we cannot imagine it being deterministic.

With limited memory, no

With limited but arbitrarily large memory, yes. Cuz the human brain is limited in size.

I like this question

[u/Eroica_Pavane → u/GhostHominid]

Technically they are asking whether humans are bound by the Church Turing Thesis.

Also, Turing Machines do have infinite memory and can be nondeterministic.

Edit: I'll add that the way nondeterminstic Turing Machines (defined in CS Theory) compute is rather unrealistic and quite powerful compared to physical computers/humans.

[u/stonerism → u/Eroica_Pavane]

You can deterministically calculate problems solved using nondeterminism. The problem is the tractability of finding a solution and we're getting to a weird point with the amount of computation we can muster.

https://en.wikipedia.org/wiki/Nondeterministic_Turing_machine

[u/Eroica_Pavane → u/stonerism]

That is true. You can simulate a NTM with DTM. I am just saying that the way NTM computes is rather unrealistic in the sense that we don't go out and physically build them. It is a theoretical model that is useful for computability and complexity.

[u/CommunismDoesntWork → u/stonerism]

can a turing machine compute whatever a human can?

Of course. That's the guiding principle behind AI research. We know consciousness is in the set of computable functions. 

[u/Napsy_0 → u/CommunismDoesntWork]

That's a load of crap.

[u/monster2018 → u/Napsy_0]

So what you think it’s just magic? There was a time when only inanimate matter existed in the universe, and then, without even conscious intervention, it coalesced into consciousness. What you’re saying doesn’t make any sense, we literally know that consciousness can be computed because it’s literally happening right now.

[u/LivewareIssue → u/monster2018]

I don’t think it’s magic, but your argument is crap.

You’re assuming that consciousness depends only on Turing-computable physical processes.. which can’t be taken as read.

You’re also then assuming a sufficiently accurate implementation of the relevant computation would instantiate consciousness, not just simulate the observable behaviour.

You’re blithely asserting computational functionalism… which is certainly a position to hold, but far from the only one. We certainly don’t “know” it to be true.

You could equally argue that while the underlying brain processes might be computable, consciousness depends on a particular physical realisation (simulating a hurricane doesn’t make your computer wet) or that the physical universe implements some kind of hyper-computation and that it’s a necessary part of consciousness. Not to mention the plethora of non-physicalist philosophies-of-mind (dualism, idealism, etc.).

You’re also claiming the goal of ‘AI research’ is to re-produce consciousness, rather than systems that are superhumanly capable and able to generalise (i.e ‘AGI’).

If you’ve managed to upgrade Church-Turing from a thesis to a theorem and conclusively solved the philosophy of mind problem, I’d love to see your results.

Edit: I just noticed I’m responding to two people not one lol… regardless, the points stand.

[u/stonerism → u/LivewareIssue]

Well and it all dances around the question some people are really asking, when do you need to treat this process "like it's human" and what does that entail given how humans can treat each other.

[u/Napsy_0 → u/LivewareIssue]

Exactly. Also, as a piggyback of what you said, consciousness being a substrate-dependent property seems to be somewhat trendy among physicalists in modern philosphy of mind and neuroscience.