Re: Wa tis "imaginary signal" in "physical reality" context was [Re: Conversion of data to complex numbers??]

Fred Marshall wrote: 
Jerry,

I've been lurking and not giving you any support I'm afraid. I'm also afraid that engaging in this thread is to go slumming intellectually. What a lot of crap is being thrown about!

I think the idea of an instantaneous measurement (or one of any practical short length) isn't really to the point here. Otherwise I agree with you on much of what you've said / responded with. Anyway, a very long history of the "voltage on the wire (pair)" has the same characteristics.

One can presumably measure a signal as a function of time - and care not from whence it originates. If it's a sinusoid then it will have amplitude and frequency characteristics. it will be real (i.e. physical) in every sense.

One cannot define "phase" in such a condition because there is no defined time reference. By that, I don't mean there isn't a time scale or time base but, rather, there is no point in time that is identified as a *reference* point in time. Without that reference, there can be no phase measurement or delay measurement.

Well, I suppose that one could provide a time base as a dimension reference and say that frequency is a dimension - we just don't usually talk in those terms.

In normal treatments, once a time reference is established then there are two dimensions in the context of sinusoids at frequency w: amplitude and phase or delay. Once the amplitude AND phase can be stated then there are two dimensions..... that's it, very simple.

I don't think there's anything more to be said about it.

Well, Fred, neither do I, but thanks for saying it anyway. As to instantaneous measurements, I backed into it as a way to isolate the measurement and so render it in starker contrast. I created a diversion; sorry!

Jerry
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