Neither are they computers. How interesting.
And important. Because we cannot extend the boundary of "crystalline" to include interstellar gas. It doesn't work that way. We can't reduce the boundary to exclude the salt crystal.
And a bacterium would still behave differently from a mush of random biochemicals. How interesting.
Are you aware that the realisation that the chemical processes occurring in living things are the same as those occurring in non-living was one of the great breakthroughs in science? That the removal of the barrier which allowed scientists to talk about life as something physically special was just as important as Darwinian theory in our understanding of the world?
It used to be thought that there was some special property existing in living tissue. We now realise that there isn't, and for the most part, vitalism is dead.
How interesting. This invalidates the notion of computing how, exactly?
Because you don't have a precise definition with problematic areas. You have a definition that cannot be tied down to anything in particular. We know this because we walked through a series of phenomena, each in turn being incorporated in the concept of computing, until we ended up with almost everything being a computation. And now you think you can solve this problem by setting arbitrary boundaries.
So does the definition of a crystal, you genius.
Did you miss the part of my definition where I said "effectively means according to an arbitrary threshold?"
There is no hard threshold for a crystal. Some crystals are much more ordered than others. The way we determine the threshold for a crystal is the point at which the system displays a non-linear behavior difference. It is different for every system. You don't know this?
But the criteria for setting the boundaries are objective and designed to be applicable as rules. They aren't intended to allow people to pick and choose what they do and don't call crystals.
Also, setting the definitions doesn't change the actual behaviour of the material we are considering. Saying that a piece of iron consists of an aggregation of micro-crystals doesn't mean that we are able to cleave it like a diamond.
I didn't define that threshold for computing, because I don't need to. All I have to say is that it exists -- and it does. One can put it anywhere they want. You can say a bowl of soup computes if you want to put the threshold very low. I could call liquid water crystalline if I put the threshold very low. What you cannot say is that a bowl of soup computes just as well as a computer, because my definition prevents it. Just like you cannot say that the structure of liquid water is as ordered as that of ice. And at some point, there is a non-linear behavior difference in the ability of a system to categorize input -- it begins to compute. At some point, there is a non-linear change in the order of a system -- it crystallizes.
Yes, and we are able to define precisely what we mean by crystallisation, on an atomic scale. We can do this on the basis of understanding the phenomenon. The difference between the definition of computing and the definition of crystallisation is the difference between entirely objective standards, and apparently random whim.
When you connect electronic components properly, there is a huge non-linear difference in the system behavior.
And you seem to think this is physically meaningful, without being able to explain just how. All kinds of objects react in a non-linear way to stimuli. If you balance a keyboard "properly" then you get a huge difference in the system behaviour when you give it a little push.
You keep talking about the fact that isolated components can compute -- so what? Isolated portions of droplet can crystallize. Who cares? Do you even know what a "system" is, westprog? Are you familiar with the notion of a "system?"
And quite what does a "system" mean in
physical terms? I've asked you to define precisely what comprises the system in the case of a working computer, and you've avoided the issue.
There is no objective boundary that you can set which puts computers on one side, and everything else on the other. What criteria can it have? Complexity? That's not a meaningful concept in physics, except in terms of entropy, and I'm fairly sure you don't want an entropic definition of computing. It's not a matter of energy. A working computation can use as little energy as you can get away with. Is it lots of different things affecting each other in complex ways? That's a fairly good description of... well, everything, really.
In fact, what's
useful (not a physical term) about a computer is that it's able to minimise complexity and the effects of one component on the next.
What do these "thresholds" consists of? What physical phenomena do they describe? Are they in any sense objective - in that one could give them to a grad student and say "Figure out whether this is doing computation"?
