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Re: Television Broadcast Weirdness
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Quote Hugh:
No. It's quite possible to perform quite involved maths functions with analogue electronics. I suggest you google-search for the standard PPM circuits to see how involved it is.
Let me clarify what I was on about... Mathematics is a human construct that involves numbers, and because of that, there is never any maths done outside of humans unless numbers are explicitly represented -- never any maths done by analogue electronics, and in general, never any maths done outside of humans if humans have not developed numerical algorithms and implemented them in machines, where inside those machines, there are explicit representations of numbers.
This might seem merely philosophical and not terribly practical, but it is what distinguishes analogue from digital electronics: in the latter, there are explicit representations of numbers in the hardware, where as in the former, there is an analogue of the physical process being analyzed.
So, for example, we can determine the frequency at which a circuit oscillates by using a digital computer to solve numerically the differential equation that describes that circuit; or, we can use an analogue computer instead, switching in the various circuit elements to create physically the circuit in question, then apply a voltage to its input, then observe at which frequency it oscillates. Since we know which differential equation corresponds to that circuit, the frequency that we observe is the same as the frequency sought in solving the equation using mathematics, even though no mathematics is performed by the analogue circuit.
As an even simpler example, imagine that you want to determine the speed reached by a ball after it has fallen from rest in a vacuum for a certain amount of time. You could simply multiply g and t, where g is the acceleration due to gravity and t is the elapsed time; or, you could actually drop a ball in a vacuum, let it fall for a certain amount of time, then measure its speed. Now, clearly, in using the latter method, neither the ball nor you have multiplied g and t, or have done any maths whatsoever. You, your watch, the ball, etc. constitute the analogue computer; your brain, engaged to multiply g and t, constitutes the digital computer.
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Robert Eidschun
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