Kevin Aylward wrote:

In summary, there are differing concepts of what linearity is being
understood to mean in the real world.


No again. Those who are confused about it, and can't admit they are
simply wrong about what amounts to a widely accepted definitional
matter
[snip]
You nor anyone else need take my word for it: it is in *all* the
Signals, Systems, and Communications texts I've ever opened up -- they
are wholly consistant with each other; check for yourself. Your
"definition" is not in any of them (af(t) = f(at)???). So I feel
justified in simply saying you are flatly wrong. If you could at least
post a citation from a text that has your definition and a worked
mathematical problem/solution (no "Circuits" junk), then at least we
could say it was all a grand misunderstanding.

herewith a self-confessed doesnt-know-it-all's analysis:
IF
y(x) = mx+c (even KA cant argue with the linearity (and time-invariance) of
this....LOL)
THEN
y(ax) = max+c
AND
ay(x) = max+ac
Elementary Sesame-Street Theory (one of these things is not like the other)
clearly shows this "definition" of linearity to be rubbish.

gwhite most certainly has it correct. KA does not.

as a slight aside, I have read H&H about 8 times, and will continue to do
so - it is one of the more useful books on electronics I have ever bought
(and I have about 600 of them). If you do not have that book - GO AND BUY
IT!! I even met WINFIELD Hill at an MIT junkfest once a few years ago, and
had an interesting discussion with him about my work on high-speed PMSM
energy storage flywheels and giant SMPS. That guy is really smart - I
suggest anyone reading this forum should pay close attention to win's
postings (i sure do). As far as being an "academic" - well, go read H&H -
its beauty lies in its practicality, unlike most texts. Just because someone
works in academia, doesnt mean they are useless (although to be fair, its
usually not a bad first guess). Likewise I have met plenty of blithering
idiots out doing "real" engineering (its a good thing - competent people end
up being well paid to fix their screw-ups). The worst ones tend to work in
sales (I presume its because they cant get real jobs)

Really this entire thread has done little more than allow Kevin Aylward to
appear like a pompous idiot, with a somewhat limited understanding. A BSc
and half-a-dozen MSc courses (one A - wow. I remember those - they are what
you get if you dont do well enough for an A+) simply makes for a failed MSc.
Of all the pomposities, I just loved this one:

In all honesty, there is not much I don't know about general analogue
design, although, obviously, I don't claim to know it all.

It kind of makes one wonder just how KA knows there isnt much he doesnt
know.

why do I post on these newsboards? am I being selfish? I dont think so. I
have had questions answered for me, so it is only fair that I answer those
that i can (quid pro quo). I also get a bit of a buzz when i can "show off".
And reading posts from others can be very informative. Some stuff is
downright hilarious (thanx KA). I could "listen" to Jim Thompson & Win
reminisce for hours - riveting stuff.