On Fri, 26 Jun 2009 21:56:10 +0100, "Androcles"
[snip] You need to rethink your basics see below.
There is no change at the source itself .. nothing happens to it. As
already pointed out. Similar to when you move away from a sound
source,
the longer wavelength of that wave (in your frame of reference)
No No No. If you move away from a sound source the wavelength
does NOT change.
Yes it does. This gif animation proves it.
http://www.androcles01.pwp.blueyonder.co.uk/Wave/Relative.gif
Note that the frequency doesn't change.
I recently said, "Androcles might be raving mad but he is usually
correct".
I wish to retract that statement and replace it with "Androcles IS
certainly
raving mad and is rarely correct".
You silly animation shows two sound sources of the same frequency emitting
sound into media, in which the speed of sound is different.
Nope. Only one sound source at the top, an observer that moves with the
wave and one cycle of what he perceives at the bottom.
The observer marks out on the ground the amplitude of the wave as he sees
it.
The 'ground' isn't in his FoR. Put him in an open ended box (to imply
his FoR) and have him/the box moving w.r.t the source. If he draws the
amplitude on the bottom of the box all he will draw is a side to side
line once per cycle. You cannot measure the wavelength in your FoR with
a single probe.
Suppose a tapered plank of wood passed through his box (FoR) and he
measured the changing width (amplitude) passing a point in his FoR. It
tells him nothing about the length of the plank only about the time it
takes the plank to pass through and its maximum and minimum width. To
measure the length of the plank you need two measuring points and if you
conclude that the apparent length of the plank changes with first order
velocity you have made a major discovery which will revolutionise
physics.
If you have two beams of light that the plank breaks you can repeat the
experiment adjusting their position until it breaks one just as it
clears the other. They are then a plank length apart. You can change
your speed relative to the plank and its length won't change.
Besides, diffraction gratings show a wavelength shift, not a frequency
shift.
Don't pommie engineers learn any physics?
Don't aussie sheep know how to model their ridiculous claims?
The wavelength stays the same but your speed relative to the wave
changes.
That is my point. You may know the formula but you clearly are unable
to
visualise what is happening.
In the frame of the moving pointer the wavelength has clearly changed.
No.
Oh, ok, so you are blind. Sorry to have troubled you. Please show your
white
cane when writing, I was under the false impression you understood what
"clearly" means when I displayed a changed wavelength seen by a moving
pointer in a gif.
John is perfectly correct. ...and you ARE clinically insane.
You'll deny optical data from stars next.
--
John Kennaugh
