Re: The relatvisitic computer

Sorcerer wrote:
"Brian Kennelly" <bwkennelly@xxxxxxx> wrote in message news:PVLYg.5758$gM1.4157@xxxxxxxxxxxxx
Sorcerer wrote:
"The Ghost In The Machine" <ewill@xxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:d5hb04-kk.ln1@xxxxxxxxxxxxxxxxxxxxxxxxxx
| In sci.physics.relativity, Brian Kennelly
| <bwkennelly@xxxxxxx>
| wrote
| on Sun, 15 Oct 2006 20:10:51 -0700
| <%KCYg.5742$gM1.1670@fed1read12>:
| > Sorcerer wrote:
| >> "Brian Kennelly" <bwkennelly@xxxxxxx> wrote in message
| >> news:E0CYg.5734$gM1.2334@xxxxxxxxxxxxx
| >> | what I do not understand is how
| >> | that animation sheds any light on your assertion that Einstein
| >> | used a divide by zero trick.
| >>
| >> Of course you don't, logic is beyond you. The ray travels an
| >> infinitesimally small distance from A to A
| > No, it travels from A to B and back to A, a non-zero distance.
| >
| >> in time t'A- tA
| > The time for travel is also non-zero.
| >
| >> with velocties c and -c, and that is a divide-by-zero trick.
| > It travels from A to B at velocity c, time tB-tA.
| > It travels from B to A at velocity c, time tA'-tB
|
| Be EXTREMELY careful here.
|
| It travels from A to B at velocity +c, speed c.
| It travels back from B to A at velocity -c, speed c.
|
| So average velocity is 0 (and thus more or less useless),
| but average speed is c.
|
| > The total distance is AB+BA=2AB
| > The total time is tA'-tB+tB-tA=tA'-tA.
|
| This part, of course, is more or less correct (though one
| again has to be careful since AB could be a scalar, in
| which case one can interpret it as length, or a vector,
| in which case AB+BA is not 2AB, but 0 again), and the
| time is easily measured, especially if the Moon contains a
| suitable reflector. (And it does -- 4 of them. The 5th
| one is now lost although it was operable for a time.
| Most likely the rover fell into something. :-/ )
|
| >
| > No zeroes.
| >
| > If you walk 100 meters and back, your average speed is 200
| > meters divided by the total walking time. Why is that so hard
| > for you to understand?
|
| Precision is an issue here; the average speed is indeed that;
| however, the average velocity is zero and therefore not really
| worth considering.
|
| The main problem Androcles appears to have is with the term
| "Lichtgeschwindigkeit", which can be translated "light speed"
| or "light velocity", and is somewhat ambiguous. However,
| most ignore this translation anomaly and do much as you did above. :-)

I dont give a *** about the word, the equations are what do NOT matter.

| This term appears in the original German (Zur Elektrodynamik bewegter
| Körper); an English translation (On the Electrodynamics of Moving
| Bodies) is available at
| http://www.fourmilab.ch/etexts/einstein/specrel/www/
| which Androcles has read. (The German variant is available as a PDF file
| but I've lost my bookmarks so I'd have to find it.)
|
| >
| >>
| >> You didn't answer my question, fuckwit. Hint: The answer is "2"
| >> Try again: how many slopes does Einstein's c have?
| > 'c' has slope zero with respect to any coordinate. The speed of
| > light is the same everywhere and everywhen.
|
| It also turns out that, if one postulates x^2 = c^2t^2, then
| x'^2 = c^2t'^2 if (x,t) and (x',t') are related by the Lorentz.
| In other words, if a spherical shell

My laser pointer doesn't use a spherical shell.
Kennelly has just the speed of light is zero in all frames
of reference.
| Sorry, no.
Not sorry, yes. " 'c' has slope zero with respect to any coordinate."

It is elementary calculus that the slope of a constant is zero. That is not equivalent to stating that the constant is zero.

Because I have been off-line for a few days, I will give you a break and propose the question you were trying to ask when you so clumsily asked for the slope of 'c'.

What is the minimum number of slopes necessary to depict a round trip on a space time diagram?

The answer is '2'.

Now, why is this unimportant for Einstein's equation for 'c'?

Because he was discussing the speed of light over a path, and path length is always measured in a positive sense. The length of any path including two distinct points will be positive. A round trip is a special case.

The time for such a trip will also always be positive.

The average speed (path/time) will be a positive number.

In the case of light, Einstein proposed that this number is a universal constant, but no part of that definition involved a zero quantity.

.

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