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What is it about a physical process that means it is performing computation? It transforms input to output -- some computation systems are just less powerful t

by kd0amg 15y ago

What is it about a physical process that means it is performing computation? It transforms input to output -- some computation systems are just less powerful than others :-P People often think that Information Theory provides an answer, but it doesn't really enlighten us about what information is and what its nature is. Can you point to any particular problems with the notion of information as that which reduces entropy (which is itself a quantification of what is unknown about some system)?

jamesrcole 15y ago
Information Theory provides a measure of a quantity, not an account of what that "stuff" is. I do not think that 'that which reduces entropy' is an account of information. How is a system informed by an input that 'carries information'? What details is the system able to 'learn about' from that input/information? What's happening there is just a physical interaction of the 'inputs' interacting with the system. How is that information related to the meaning of the information - how does that work? If the brain is just computation, how does the "semantic information" in the brain work?
- kd0amg 15y ago
  How is a system informed by an input that 'carries information'? It processes the input to determine what actions to take next. What details is the system able to 'learn about' from that input/information? Some facility for conditional execution (not just something like an "if...then...else" control structure -- the ability to compute non-constant functions). What's happening there is just a physical interaction of the 'inputs' interacting with the system. So? How is that information related to the meaning of the information - how does that work? If the brain is just computation, how does the "semantic information" in the brain work? What is "meaning of the information"? What is "semantic information"?
  - jamesrcole 15y ago
    How is a system informed by an input that 'carries information'? -> It processes the input to determine what actions to take next. So what qualifies as an input? What qualifies as an action? How do you tell if some physical system, e.g. some biological system, contains 'inputs' and 'actions'? What's happening there is just a physical interaction of the 'inputs' interacting with the system. So? See my last point. How is that information related to the meaning of the information - how does that work? If the brain is just computation, how does the "semantic information" in the brain work? -> What is "meaning of the information"? What is "semantic information"? Information informs about certain details, a system can take the information and understand its meaning. 'semantic information' - sometimes people use this notion to distinguish between 'data' and 'information' that is more meaningful, like the sort of information that humans can process.
    - kd0amg 15y ago
      So what qualifies as an input? That which affects the system What qualifies as an action? Changes in the system's internal state or output How do you tell if some physical system, e.g. some biological system, contains 'inputs' and 'actions'? You can test whether its state changes in response to external stimuli (n.b. this is no way to test this perfectly). See my last point. Looking back, it seems like you think I've made some claim about the system having "learned" something. Information informs about certain details, a system can take the information and understand its meaning. I agree that a system which computes can take the information and act in a way that depends on it, but what do you mean by "understand"? sometimes people use this notion to distinguish between 'data' and 'information' that is more meaningful, like the sort of information that humans can process. This is not a definition of either term I asked about.
      - jamesrcole 15y ago
        So what qualifies as an input? -> That which affects the system That applies to any causal interaction with the system. What do you mean by 'system'? How do you objectively determine whether some physical details are a 'system'? What qualifies as an action? -> Changes in the system's internal state or output Same kinds of issues. What is the objective criteria for 'system', 'internal state', 'output'? What are the relevant sorts of 'changes' - there's all sorts of physical changes that are not relevant. How do you tell if some physical system, e.g. some biological system, contains 'inputs' and 'actions'? -> You can test whether its state changes in response to external stimuli (n.b. this is no way to test this perfectly). but you need some objective criteria for what changes count as stimuli and what are just "meaningless" interactions with the system. Information informs about certain details, a system can take the information and understand its meaning. -> I agree that a system which computes can take the information and act in a way that depends on it, but what do you mean by "understand"? Act in a way that is appropriate to what the information is about. and btw this is an imprecise and vague description of 'understand'. a proper theoretical account would be a lot more precise. sometimes people use this notion to distinguish between 'data' and 'information' that is more meaningful, like the sort of information that humans can process. -> This is not a definition of either term I asked about. these aren't my terms/notions. if you really want to know what people mean by them there's stuff online.

by kd0amg 15y ago

jamesrcole 15y ago

Information Theory provides a measure of a quantity, not an account of what that "stuff" is. I do not think that 'that which reduces entropy' is an account of information. How is a system informed by an input that 'carries information'? What details is the system able to 'learn about' from that input/information? What's happening there is just a physical interaction of the 'inputs' interacting with the system. How is that information related to the meaning of the information - how does that work? If the brain is just computation, how does the "semantic information" in the brain work?

kd0amg 15y ago
How is a system informed by an input that 'carries information'? It processes the input to determine what actions to take next. What details is the system able to 'learn about' from that input/information? Some facility for conditional execution (not just something like an "if...then...else" control structure -- the ability to compute non-constant functions). What's happening there is just a physical interaction of the 'inputs' interacting with the system. So? How is that information related to the meaning of the information - how does that work? If the brain is just computation, how does the "semantic information" in the brain work? What is "meaning of the information"? What is "semantic information"?
- jamesrcole 15y ago
  How is a system informed by an input that 'carries information'? -> It processes the input to determine what actions to take next. So what qualifies as an input? What qualifies as an action? How do you tell if some physical system, e.g. some biological system, contains 'inputs' and 'actions'? What's happening there is just a physical interaction of the 'inputs' interacting with the system. So? See my last point. How is that information related to the meaning of the information - how does that work? If the brain is just computation, how does the "semantic information" in the brain work? -> What is "meaning of the information"? What is "semantic information"? Information informs about certain details, a system can take the information and understand its meaning. 'semantic information' - sometimes people use this notion to distinguish between 'data' and 'information' that is more meaningful, like the sort of information that humans can process.
  - kd0amg 15y ago
    So what qualifies as an input? That which affects the system What qualifies as an action? Changes in the system's internal state or output How do you tell if some physical system, e.g. some biological system, contains 'inputs' and 'actions'? You can test whether its state changes in response to external stimuli (n.b. this is no way to test this perfectly). See my last point. Looking back, it seems like you think I've made some claim about the system having "learned" something. Information informs about certain details, a system can take the information and understand its meaning. I agree that a system which computes can take the information and act in a way that depends on it, but what do you mean by "understand"? sometimes people use this notion to distinguish between 'data' and 'information' that is more meaningful, like the sort of information that humans can process. This is not a definition of either term I asked about.
    - jamesrcole 15y ago
      So what qualifies as an input? -> That which affects the system That applies to any causal interaction with the system. What do you mean by 'system'? How do you objectively determine whether some physical details are a 'system'? What qualifies as an action? -> Changes in the system's internal state or output Same kinds of issues. What is the objective criteria for 'system', 'internal state', 'output'? What are the relevant sorts of 'changes' - there's all sorts of physical changes that are not relevant. How do you tell if some physical system, e.g. some biological system, contains 'inputs' and 'actions'? -> You can test whether its state changes in response to external stimuli (n.b. this is no way to test this perfectly). but you need some objective criteria for what changes count as stimuli and what are just "meaningless" interactions with the system. Information informs about certain details, a system can take the information and understand its meaning. -> I agree that a system which computes can take the information and act in a way that depends on it, but what do you mean by "understand"? Act in a way that is appropriate to what the information is about. and btw this is an imprecise and vague description of 'understand'. a proper theoretical account would be a lot more precise. sometimes people use this notion to distinguish between 'data' and 'information' that is more meaningful, like the sort of information that humans can process. -> This is not a definition of either term I asked about. these aren't my terms/notions. if you really want to know what people mean by them there's stuff online.