Posted: Sep 13, 2017 1:24 pm
DavidMcC wrote:John Platko wrote:...
2) Agential states are knowledge
3) Therefore agential states must be able to survive noise, to some extent, and therefore be error correctable.
4) For 3 to be possible there must be more than one physical set of states that map to a given agential state so that if an error is introduced by noise in the set of physical states that define an agential state, the state can still be recovered. There are many ways agential states can be encoded to provide for error correction but suffice it to say that if there is only one physical state mapping to an agential state, then if that physical state mapping changes in any way, then that agential state is lost. Such an information mechanism does not meet the definition of Knowledge because it can't meet the survivability criteria.
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If I read this correcly, you are claiming that we can't forget anything that we know, otherwise we didn't know it in the first place!
I can see why you might conclude that, perhaps I led you astray by highlighting one aspect of the definition of Knowledge, maybe if I highlight a different aspect I can clear up this misunderstanding:
The most important kind of abstract constructor is knowledge. Knowledge is information which, once it is physically instantiated in a suitable environment, tends to cause itself to remain so: it survives criticism, testing, random noise, and error-correction.
This is a tendency, one that is imperfect. Deutsch handles this more technically by saying:
from
Presumably no perfect constructors can exist in nature. A factory is only an approximation to one, as are some of its constituents such as robots and conveyor belts, because of their non-zero error rates (producing something other than the specified output), and because in the absence of maintenance they gradually deteriorate. A task A is possible (which I write as A✓) if the laws of nature impose no limit, short of perfection, on how accurately A could be performed, nor on how well things that are capable of approximately performing it could retain their ability to do so. Otherwise A is impossible (which I write as A✘ ).
And in more detail
3.14 Imperfect constructors As I remarked in 1.1, no perfect constructor can exist in nature. If nothing else, thermal noise causes random transitions, so there is always a non-zero probability that the wrong transformation will happen or that the device will undergo a change large enough to destroy its functionality ...
Please see the paper in the link I provided for a full read of 3.14 as it's difficult to post all the equations here.
But, given enough time, I suspect that any knowledge that an individual has at any given time, can be forgotten, unless of course, you refer to knowledge databases (ie, electronic hardware, libraries, etc), rather than the contents of an individual's brain.
Indeed it is reasonable to suspect that. And as we've seen when we dug deeper into the definition of knowledge, perfection is not required, just certain tendencies, one of them being the ability to error correct. And as I pointed out, for that to be possible, an agential state must be physical state Multiple Realizable. In theory, this can achieve any level of robustness desired short of perfection, in practice we find what the limits are in each case.
Excellent question! Good thinking!
