The problem I have with CA being proposed as a model of a reality is that the arrow of time in CA seems to be backwards. In our reality, we know the past, but the future is uncertain. In cellular automata, the future can be predicted perfectly, but the states which were used to get to the current state are ambiguous. Large grids of such give the illusion of life (such as behaviour of predator/prey) but only a macroscopic scale even though time goes backward. But the arrow of time becomes very visible when the cells are focussed in on. If you decide to look at it in reverse time to satisfy the microscopic view, you don't get that feeling of life at the macroscopic scale.
The problem with cold showers is that cold water closes your pores and makes them harder to clean. Hot water opens them up so that the soap can get in. I have been told that it is advisable to take cold showers when travelling so that closed pores do not let bacteria in as easily.
A company I once worked for moved to a new building where a wall had been erected between where the sensors were, and where my office was. As I worked the second shift, the side of the room where I was had the ceiling lights (and A/C) turn off 10 minutes after it sensed no motion outside (sometime around 7 pm). Many of the people in that side of the office area had to rely on just the desk lamps after hours.
This situation was complained about but nothing done for about a year or so at which point I left. The problems with such systems are that when they fault just to the point of being annoying, companies do not bother to fix them. They have to affect the bottom line for there to be a change one way or the other. People's safety will become a non-issue unless fire codes or other regulations come into play.
The basic idea is as the following, and I am of course not posting it here completely. You should read the book before accepting or refuting this.
We have the set of all possible computations that can exist C0, C1, C2, C3,... (Cq where q is 0, 1, 2, 3,...) and the data they act upon is enumerated as n. So we have computations C0(n), C1(n), C2(n),... (I like to think that any data that can be listed as 0s and 1s can be thought of as a huge sinble number written in binary.)
We then have the function A which acts on the set of computations Cq and their data n. A's job is to determine if C(q, n) will continue indefinately or if it will halt. A need not ever halt, in which case we don't know if C will or not if it acts on data n. But if A(q, n) does halt, then we know that Cq(n) or C(q, n) does not ever halt.
(H) IF A(q, n) stops, then Cq(N) does not stop.
Then take the cases in which q = n (I) If A(n, n) stops, then Cn(n) does not stop.
Since A is now depending on only one number, n, it must be one of the computations in C which is the set of all computations and would include A. Let us suppose this is Ck so... (J) A(n, n) = Ck(n)
Now we take the case when n = k and we get from (J) (K) A(k, k) = Ck(k)
and from (I), with n = k
(L) A(k, k) stops, then Ck(k) does not stop.
Subtituting K in L we get:
(M) If Ck(k) stops, then Ck(k) does not stop.
From this we can see that Ck(k) will not stop because if it did then it could not (paradox). But A(k, k) cannot stop either since it is the same as Ck(k). Thus A is not able to determine if Ck(k) doesn't stop even though the human mind can see that it will not stop.
Second life allows users to create virtual objects which can be sold (or transfered) to others. These are much like physical objects in the game world, like body parts (to change the way you look) and can be sold from ingame vending machines or whatever. Most, if not all, have scripts associated with them to direct their behaviour and how they interact with other objects or users. I don't know if this is compiled to bytecode or what. Something like this probably resulted from a duplicate_when_touched() or something similar that worked around the grey goo protection.
Slashdot Mirror
The problem I have with CA being proposed as a model of a reality is that the arrow of time in CA seems to be backwards. In our reality, we know the past, but the future is uncertain. In cellular automata, the future can be predicted perfectly, but the states which were used to get to the current state are ambiguous. Large grids of such give the illusion of life (such as behaviour of predator/prey) but only a macroscopic scale even though time goes backward. But the arrow of time becomes very visible when the cells are focussed in on. If you decide to look at it in reverse time to satisfy the microscopic view, you don't get that feeling of life at the macroscopic scale.
The problem with cold showers is that cold water closes your pores and makes them harder to clean. Hot water opens them up so that the soap can get in. I have been told that it is advisable to take cold showers when travelling so that closed pores do not let bacteria in as easily.
A company I once worked for moved to a new building where a wall had been erected between where the sensors were, and where my office was. As I worked the second shift, the side of the room where I was had the ceiling lights (and A/C) turn off 10 minutes after it sensed no motion outside (sometime around 7 pm). Many of the people in that side of the office area had to rely on just the desk lamps after hours.
This situation was complained about but nothing done for about a year or so at which point I left. The problems with such systems are that when they fault just to the point of being annoying, companies do not bother to fix them. They have to affect the bottom line for there to be a change one way or the other. People's safety will become a non-issue unless fire codes or other regulations come into play.
The basic idea is as the following, and I am of course not posting it here completely. You should read the book before accepting or refuting this.
... (Cq where q is 0, 1, 2, 3, ...) and the data they act upon is enumerated as n. So we have computations C0(n), C1(n), C2(n), ... (I like to think that any data that can be listed as 0s and 1s can be thought of as a huge sinble number written in binary.)
We have the set of all possible computations that can exist C0, C1, C2, C3,
We then have the function A which acts on the set of computations Cq and their data n. A's job is to determine if C(q, n) will continue indefinately or if it will halt. A need not ever halt, in which case we don't know if C will or not if it acts on data n. But if A(q, n) does halt, then we know that Cq(n) or C(q, n) does not ever halt.
(H) IF A(q, n) stops, then Cq(N) does not stop.
Then take the cases in which q = n
(I) If A(n, n) stops, then Cn(n) does not stop.
Since A is now depending on only one number, n, it must be one of the computations in C which is the set of all computations and would include A. Let us suppose this is Ck so...
(J) A(n, n) = Ck(n)
Now we take the case when n = k and we get from (J)
(K) A(k, k) = Ck(k)
and from (I), with n = k
(L) A(k, k) stops, then Ck(k) does not stop.
Subtituting K in L we get:
(M) If Ck(k) stops, then Ck(k) does not stop.
From this we can see that Ck(k) will not stop because if it did then it could not (paradox). But A(k, k) cannot stop either since it is the same as Ck(k). Thus A is not able to determine if Ck(k) doesn't stop even though the human mind can see that it will not stop.
Second life allows users to create virtual objects which can be sold (or transfered) to others. These are much like physical objects in the game world, like body parts (to change the way you look) and can be sold from ingame vending machines or whatever. Most, if not all, have scripts associated with them to direct their behaviour and how they interact with other objects or users. I don't know if this is compiled to bytecode or what. Something like this probably resulted from a duplicate_when_touched() or something similar that worked around the grey goo protection.
Yet, Einstein was dead wrong when it came to god playing dice :)