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Is life a form of computation?

thereader.mitpress.mit.edu

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Re: Is life a form of computation?

#71

Post by mannykannot »

jes5199 wrote: post #40
AIPedant wrote: post #29

Articles like this indicate we should lock down the definition of "computation" that meaningfully distinguishes computing machines from other physical phenomena - a computation is a process that maps symbols (or strings of symbols) to other symbols, obeying certain simple rules[1]. A computer is a machine that does computations. In that sense life is obviously not a computation: it makes some sense to view DNA as sym…

our relationship to computation got weird when we moved to digital computers. Like, I don’t think anyone was saying “life is like millions of slide-rules solving logarithms in parallel”. but now that computers are de-materialized, they can be a metaphor for pretty much anything

Good point - maybe the analogy to computation arises simply because digital computation and the synthesis of DNA, RNA and proteins are all performed by discrete-state machines?

Re: Is life a form of computation?

#74

Post by zabzonk »

AIPedant wrote: post #69
ants_everywhere wrote: post #62

Earlier quoted context omitted.

analog computers don't generally compute by operating on symbols. For example see the classic video on fire control computers https://youtu.be/s1i-dnAH9Y4?t=496 OP's specific phrasing is that they "map symbols to symbols". Analog computers don't do that. Some can, but that's not their definition. Turing machines et al. are a model of computation in mathematics. Humans do math by operating on symbols, so that's why th…

No, analog computers truly are symbolic. The simplest analog computer - the abacus - is obviously symbolic, and thus is also true for WW2 gun fire control computers, ball-and-shaft integrators, etc. They do not use inscriptions which is maybe where you're getting confused. But the turning of a differential gear to perform an addition is a symbolic operation: we are no more interested in the mechanics of the gear than…

Surely an abacus is a simple form of digital computer? The position/state of the beads is not continuous, ignoring the necessary changes of position/state.

Re: Is life a form of computation?

#75

Post by jes5199 »

mannykannot wrote: post #71
jes5199 wrote: post #40

Earlier quoted context omitted.

our relationship to computation got weird when we moved to digital computers. Like, I don’t think anyone was saying “life is like millions of slide-rules solving logarithms in parallel”. but now that computers are de-materialized, they can be a metaphor for pretty much anything

Good point - maybe the analogy to computation arises simply because digital computation and the synthesis of DNA, RNA and proteins are all performed by discrete-state machines?

does DNA/RNA keep state other than the position of the read head?

Re: Is life a form of computation?

#76

Post by dvsfish »

nathan_douglas wrote: post #33

Classic John Von Neumann, inventing both the Von Neumann architecture and non-Von Neumann architectures.

What a brilliant irony. Excellent comment.

I suppose "non-Von Neumann architectures" would just instead have someone else's name associated with it had it been invented by someone else.

Re: Is life a form of computation?

#77

Post by ants_everywhere »

AIPedant wrote: post #69
ants_everywhere wrote: post #62

Earlier quoted context omitted.

analog computers don't generally compute by operating on symbols. For example see the classic video on fire control computers https://youtu.be/s1i-dnAH9Y4?t=496 OP's specific phrasing is that they "map symbols to symbols". Analog computers don't do that. Some can, but that's not their definition. Turing machines et al. are a model of computation in mathematics. Humans do math by operating on symbols, so that's why th…

No, analog computers truly are symbolic. The simplest analog computer - the abacus - is obviously symbolic, and thus is also true for WW2 gun fire control computers, ball-and-shaft integrators, etc. They do not use inscriptions which is maybe where you're getting confused. But the turning of a differential gear to perform an addition is a symbolic operation: we are no more interested in the mechanics of the gear than…

I'm not confused, and an abacus is a digital computer.

You keep referring to what we are interested in, but that's not a relevant quantity here.

A symbol is a discrete sign that has some sort of symbol table (explicit or not) describing the mapping of the sign to the intended interpretation. An analog computer often directly solves the physical problem (e.g. an ODE) by building a device whose behavior is governed by that ODE. That is, it solves the ODE by just applying the laws of physics directly to the world.

If your claim is that analog computers are symbolic but the same physical process is not merely because we are "interested in" the result then I don't agree. And you'd also be committed to saying proteins are symbolic if we build an analog computer that runs on DNA and proteins. In which case it seems like they become always symbolic if we're always interested in life as computation.

Re: Is life a form of computation?

#78

Post by nomel »

heavyset_go wrote: post #35
karmakurtisaani wrote: post #9

I don't see the point of asking this question. Like, sure, all physical systems follow certain rules, so any such process will develop in a way that it look like a computation of an algorithm. Also, evolution itself is constantly optimizing organisms to best adapt to their environment, just like a computation. So asking if life is a computation seems mostly like a semantic musing. Define "life" and define "computatio…

> Also, evolution itself is constantly optimizing organisms to best adapt to their environment, just like a computation. There is no optimization, if organisms can reproduce, they'll continue to exist. That does not mean they are the "best adapted" or on a trajectory toward better adaptation. It's entirely possible for a germ line to become less fit over time, even to the point of extinction, and that's still evoluti…

> Time has shown that is the case for most germ lines.

This is true, but that sure seems unfair. ;) You have multiple competing systems, in the case of a germ. The system that human related germs are competing with is around 30 trillion times the size, with the advantage of some fairly incredible emergent properties that come from that. The germ is evolving, but in a system that completely overwhelms it, with evolved tricks to specifically force the germ along the "unhappy path" of evolution.

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