Take the thermal noise generated in part of the circuit. By setting a threshold we can interpret it as a sequence 110101011 etc. Now if this list sequence was enormous we would eventually have a pixel by pixel description of any picture, letter by letter description of every book, state after state description of the tape on any Turing machine etc (basically a Library of Babel situation). Now of course we would need a crazy long sequence for this, but there is similar noise associated with the motion of every atom in the circuit, likewise the noise is far more complex if we don’t truncate it to 0′s and 1′s, and finally there are many many many encodings of our resulting strings (does 110 represent the letter A, 0101 a blue pixel and so on).
If I chose ahead of time the procedure of how the thermal noise fluctuates and I seed in two instances of noise I think of as representing 2 and 3, and after a while it outputs a thermal noise I think of as 5 then I am ok calling that a computation. But why should my naming of the noise and dictating how the system develops be required for computation to occur?
Random sequences aren’t really interesting. Even the digits of pi are believed to contain every possible sequence of integers. The hard part is finding where each sequence is located. The index is likely to be longer than the sequence itself!
And a sequence of digits isn’t computation. A recording of your neural activity isn’t conscious. It’s just a static object.
If I chose ahead of time the procedure of how the thermal noise fluctuates and I seed in two instances of noise I think of as representing 2 and 3, and after a while it outputs a thermal noise I think of as 5 then I am ok calling that a computation.
But there is no computation happening there. It’s just random noise. It’s just as likely to output 5 as 6 or 3. There is no causal link between you inputting “2+3” and the output.
I agree with your sentiment. I am hoping though that one can define formally what a computation is given a physical system. Perhaps you are on to something with the causal requirement, but I think this is hard to pin down precisely. The noise is still being caused by the previous state of the system, so how can we sensibly talk about cause in a physical system. It seems like we would be more interested in ‘causes’ associated to more agent-like objects like an engine than formless things like the previous state of a cloud of gas. Actually I think Caspar’s article was trying to formalize something like this but I don’t understand it that well: http://lesswrong.com/r/discussion/lw/msg/publication_on_formalizing_preference/
I think causality is the only requirement for “computation”. Step A causes step B. A computation has happened. If A and B are independent, then there is no computation happening..
Take the thermal noise generated in part of the circuit. By setting a threshold we can interpret it as a sequence 110101011 etc. Now if this list sequence was enormous we would eventually have a pixel by pixel description of any picture, letter by letter description of every book, state after state description of the tape on any Turing machine etc (basically a Library of Babel situation). Now of course we would need a crazy long sequence for this, but there is similar noise associated with the motion of every atom in the circuit, likewise the noise is far more complex if we don’t truncate it to 0′s and 1′s, and finally there are many many many encodings of our resulting strings (does 110 represent the letter A, 0101 a blue pixel and so on).
If I chose ahead of time the procedure of how the thermal noise fluctuates and I seed in two instances of noise I think of as representing 2 and 3, and after a while it outputs a thermal noise I think of as 5 then I am ok calling that a computation. But why should my naming of the noise and dictating how the system develops be required for computation to occur?
Random sequences aren’t really interesting. Even the digits of pi are believed to contain every possible sequence of integers. The hard part is finding where each sequence is located. The index is likely to be longer than the sequence itself!
And a sequence of digits isn’t computation. A recording of your neural activity isn’t conscious. It’s just a static object.
But there is no computation happening there. It’s just random noise. It’s just as likely to output 5 as 6 or 3. There is no causal link between you inputting “2+3” and the output.
I agree with your sentiment. I am hoping though that one can define formally what a computation is given a physical system. Perhaps you are on to something with the causal requirement, but I think this is hard to pin down precisely. The noise is still being caused by the previous state of the system, so how can we sensibly talk about cause in a physical system. It seems like we would be more interested in ‘causes’ associated to more agent-like objects like an engine than formless things like the previous state of a cloud of gas. Actually I think Caspar’s article was trying to formalize something like this but I don’t understand it that well: http://lesswrong.com/r/discussion/lw/msg/publication_on_formalizing_preference/
Read Causal Universes first if you haven’t.
I think causality is the only requirement for “computation”. Step A causes step B. A computation has happened. If A and B are independent, then there is no computation happening..