Re: Einstein's Doppler equation wrong?

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Date: Sat, 30 Oct 2004 03:19:49 GMT

"sal" <pragmatist@nospam.org> wrote in message
news:pan.2004.10.30.02.22.31.661633@nospam.org...
: Just a few odds and ends.
:
: On Thu, 28 Oct 2004 13:13:26 +0000, Androcles wrote:
:
: > "sal" <pragmatist@nospam.org> wrote in message
: > news:pan.2004.10.28.01.58.30.58603@nospam.org...
: > : On Wed, 27 Oct 2004 22:07:57 +0000, Androcles wrote:
: > :
: > : > :
: > : > : If pressure impulses in air did that, we wouldn't be able to
: > : > : understand each other when we talked!
: > : >
: > : > They do. An organ pipe resonates.
: > :
: > : That's not _quite_ the same effect, though, I think.
: >
: > I'll refer you to Christiaan Huyghens. Take ANY point ...
:
: Hmmm .... you may be right. This deserves more thought than I'm
likely to
: give it...

Well, give thought to this.
'j' is used as the sqrt(-1) to avoid confusion with 'i' which
represents current, and you've done a pretty good job at confusing it.
'j' is NEVER current.

I agree with Maxwell, and Maxwell says the current is phase shifted,
leading 90 degrees from the voltage, whatever the assistant professor,
the fumble mumbler, yourself or anyone else says.
Say "uncle":-)

:
: [ ... ]
:
: > :[SAL, on transmission line echoes:]
:
: > : Again, it's the bounce from the end that gives the echoes.
Terminate
: > : it properly, so there's no "bounce", and the signal comes out
the
: > : other end perfectly "clean".
: >
: > I disagree. I consider there to be two boundaries, one at each
end, with
: > a resonant standing wave between antenna and "resistor". In
reality we
: > do not use a resistor anyway, we use an impedance. That is known
as
: > "terminating properly". Just because the units of impedance are
the same
: > as the units of resistance does not imply a terminating resistor
is
: > employed.
:
: Ever done anything with ethernet, using the old thinnet drop cables?
If
: you unplug the computer, you _must_ plug in a terminator in its
place (or
: somebody from network operations comes and yells at you). The
terminator
: consisted of a connector with a small resistor tying the core and
shield
: of the coax together. At least in the ones I've seen, it really was
just a
: simple resistor; I think it was either 50 or 75 ohms.
:
: Without the terminator, the thinnet cable spits back echoes into the
: network, and the whole segment either goes dead or gets really slow
as a
: result of errors and "ghost" collisions. With the terminator,
packets run
: down to the end of the cable and just vanish.
:
: A dead short at the end would act just like an open, as far as
scrambling
: the network goes, except that the echoes would come back "reversed",
with
: the voltage inverted versus the outbound signal.
:
: (The vampire taps didn't have the same problem, of course -- pull
out the
: needle and you're all set, no terminator required.)
:
: Similarly, a SCSI bus needs to be terminated to avoid echoes.
Nowadays
: the termination is active and involves a hunk of circuitry. In the
"old
: days", fifteen years ago, passive terminators were typically used:
it was
: just a resistor pack, plugged onto the second SCSI connector on the
last
: device in the chain. (I don't know what the values were.)

Something needs looking into, because a 100 kW transmitter doesn't use
a resistive load, the signal still goes up a pipe to the antenna at
the top of a ruddy great tower and we are talking about the same
frequency as the receiver is tuned to. 50 ohms resistance at 100 kW is
gonna be a stinking hot coil of metal radiating 100 kW of heat, not
FM, whichever end of the pipe you place it, and your reciever had
better be close to the tower, not 100 miles away.
Where is that current going? Up one side of the pipe and down the
other.

Capacitors are added to inductive loads in industry to reduce current
in the cables and switchgear leading to the motors. Motors use minimum
resistance
or energy is wasted as heat.

: [ ... ]
:
: > Kitchen science:
: > Add a few drops of vegetable oil to a saucer of water, then add
dish
: > washing liquid and watch what happens.
:
: I think I know the answer but I may try it anyway.
:
: > Here's another. Dice a carrot and potato. Mix. Now separate the
carrot
: > from the potato. No, not by hand. Do it the easy way.
:
: Uh .... Drop them in a bowl of water, and one of them will float but
not
: the other?

Yep. Carrots float. Potatoes sink.
 Just thought you might like to amuse your youngster.
Salt and sand, of course, everyone knows that one.

:
: If that doesn't work, offer the whole mess to a rabbit. After a
while
: only the potato will be left on the plate.
:
: If it's not either of those then I really don't know.
:
:
: --
: I can be contacted through http://www.physicsinsights.org
:

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