I agree about your metal example, but it differs significantly from my discussion of the list-output program for the non-trivial reason I gave: specifically, the output is defined by its impact on people’s cognitive structure.
Look at it this way: Tim_Tyler claims that I know everything there is to know about the output of a program that spits out the integers from 1 to 100. But, when I get the output, what makes me agree that I am in fact looking at those integers? Let’s say that when printing it out (my argument can be converted to one about monitor output), I see blank pages. Well, then I know something messed up: the printer ran out of ink, was disabled, etc.
Now, here’s where it gets tricky: what if instead it only sorta messes up: the ink is low and so it’s applied unevenly so that only parts of the numbers are missing? Well, depending on how badly it messes up, I may or may not still recognize the numbers as being the integers 1-100. It depends on whether it retains enough of the critical characteristics of those numbers for me to so recognize them.
To tie it back to my original point, what this all means is that the output is only defined with respect to a certain cognitive system: that determines whether the numbers are in fact recognizable as 9′s, etc. If it’s not yet clear what the difference is between this and metal’s melting point, keep in mind that we can write a program to find a metal’s melting point, but we can’t write a program that will look at a printout and know if it retains enough of its form that a human recognizes it as any specific letter—not yet, anyway.
Okay, fair challenge.
I agree about your metal example, but it differs significantly from my discussion of the list-output program for the non-trivial reason I gave: specifically, the output is defined by its impact on people’s cognitive structure.
Look at it this way: Tim_Tyler claims that I know everything there is to know about the output of a program that spits out the integers from 1 to 100. But, when I get the output, what makes me agree that I am in fact looking at those integers? Let’s say that when printing it out (my argument can be converted to one about monitor output), I see blank pages. Well, then I know something messed up: the printer ran out of ink, was disabled, etc.
Now, here’s where it gets tricky: what if instead it only sorta messes up: the ink is low and so it’s applied unevenly so that only parts of the numbers are missing? Well, depending on how badly it messes up, I may or may not still recognize the numbers as being the integers 1-100. It depends on whether it retains enough of the critical characteristics of those numbers for me to so recognize them.
To tie it back to my original point, what this all means is that the output is only defined with respect to a certain cognitive system: that determines whether the numbers are in fact recognizable as 9′s, etc. If it’s not yet clear what the difference is between this and metal’s melting point, keep in mind that we can write a program to find a metal’s melting point, but we can’t write a program that will look at a printout and know if it retains enough of its form that a human recognizes it as any specific letter—not yet, anyway.