Re: Calculatating RC parallel and series impedance networks.

Just a couple of clarifications - please note the interpolations
below:

On May 27, 10:23 am, Patrick Turner <i...@xxxxxxxxxxxxxxxxxx> wrote:

And that is a perfectly lucid explanation of the "j" factor! See what
happens to you if you sniff the flowers too long on the Place de
Laplace -- you start believing in imaginary numbers! And then you
descend into the pipes (polite version) of inverse Laplace functions
below the square...

So, you go down to the pit, and meet Mr ***.....



Now, while I admire Iain's reckless bravado in attempting fully to
explain these matters to the unphysicked, I'm far too scarred in the
ways of neddy explanations ever to attempt a full frontal assault on
something as conceptually elusive as an *imaginary* number.

But you can have very useful "imaginary models" for any tube,
ie, a voltage gene to represent µ x Vg, coupled to an imaginary
resistance in series to the load resistance. The imaginary resistance is
Ra,
the "generator resistance" of the tube.

Most ppl don't understand this.

Imaginary numbers? I ain't got their yet.

Things would have to be spelled out far slower and simpler for me to get
there.

Imaginary stuff is useful. Imagine if we couldn't imagine anything.

 (There are

quite a few good reasons why pure mathematicians are more likely by
far than the general population to commit suicide.

And more likely to play fairly good chess, but hate losing.
( They worked out how to win, so how come they lost? )


The weirdness of
imaginary numbers, once you go beyond the mere mechanics which are all
that our anonymous correspondent above can see, is one such good
reason for mathematicians to hurl themselves into the infinite.) See
athttp://members.lycos.co.uk/fiultra/KISS%20141%20by%20Andre%20Jute.htm
how I got around the problem of phasors without once explicitly
mention "j" notation, phasors, vectors and other physics confusing to
the uninitiated; it's the bit on the angled bracket. My view, as a
longtime creator of palatable explanations of quite abstruse matters
for everyman (see my books athttp://members.lycos.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html
), is that he just wants to be shown the simplest form of the formula
and told which outcomes are desirable and why; he really doesn't want
to be confused with the math. For him I developed "engineering by
analogy" in which, for instance, he never has to crack Timoshenko (or
even to have heard of him) but can still design load-bearing metal
structures.

There's a simple test for the DIYer: when the explanation starts
consuming the practical result (as, most entertainingly, it has done
in this thread), the ooh-ah bird already has its head up its arse and
wants to go into reverse right smartly.

Actually, the OohAh bird is a one-pound bird that lays a two-pound
egg. Each time it does it goes - Ooh, Ah! Andre is, as is typical of
his habits, mixing his metaphors once again. He is referring to the
Vanishing Bird - a bird that flies in ever-decreasing circles until it
disappears up its own fundament, also typical of Andre on many
occasions. Circular reasoning with ever-decreasing content.

So pulling one's head out of one's arse is more difficult than sticking
it in?

Of course, one might argue on
the contrary, considering the level of expertise of the actual
contributors on RAT (that is, excluding the scum who are here only to
conduct flame wars or sell rubbish), that the level at which Iain
pitches his "simple" explanation is irrelevant because any serious
contribution is merely an excuse for a pretty abstruse round of angel-
counting by a bunch of experts. (This wasn't always true of RAT --
once it was a true school for newbies, though that never excluded very
high-level discussion among experts running side by side with neddy
instruction.)

The land of experts is riddled with wars of words.

The more lofty the argument, the more heat in the flames.

More is at stake.

Actually - Academic arguments are so vicious because the stakes are so
small. Scientific arguments tend to have solutions - sometimes very
large ones such as the recently completed soon-to-start Hadron
Collider - looking for the Higgs Boson, something discussed in
academia for now over 40 years, unproven. Some billions are at stake
in proving its existence. As with most things, the contrary argument -
proving it does not exist - is impossible.

Let this be a lesson. Proving the negative is a futile activity easily
voided by a single, solitary contrary example. So, focus on proving
postive things. Those positive things may take billions, years and
considerable frustration to prove, but the side-effect knowledge will
be immense. After all, the first cyclotron was not much larger than
it's creators hand.

http://www.symmetrymagazine.org/images/200708/cover.jpg

Any box manufacturer would have used i (sq.rt. -1) in calculating how
many boxes can be made from so much cardboard with so much waste. It
"drops in" and then "drops out" of the calculations with nary a trail
or conflict - it is merely a convenient place-holder to make the
calculations work. Today, computers do all that. But it had something
to do with calculating the diagonals in "negative" space, i became a
convenient way to make all those numbers positive - so whether the
flap folded up (positive) or down (negative) in the final box shape,
it still took an area of stock to create the flap. However, the
individual making the calculations could care less about all that as
long as there was enough stock to make the necessary finished
product.

Much of the theoretical basis for the math expressed in this thread is
of the same nature. It needs to be utilized correctly, if not
necessarily understood root-and-branch. For which Iain and all
POSITIVE contributors are to be thanked. I have stayed out of it to-
date as I had nothing much to contribute (only much to learn) other
than this bit of vague humor along a line that threatens to become
pretentious and precious, so needing deflation.

Peter Wieck
Melrose Park, PA
.