Uncle Ben
2009-06-10 17:23:54 UTC
...
wave,
wiggles the electrons. The electrons, being accelerated, radiate the
light, but with a phase lag. The incident light and the re-radiated
light interfere to produced a delayed composite light wave.
The slowing of the resulting light, relative to the incident light,
is
responsible for the index of refraction.
When the medium is moving, the phase of the re-radiated light is
affected. The easiest way to account for the magnitude of the effect
is to do it in a frame of reference in which the medium is at rest.
This light is moving slower than c, and when referred back to the
laboratory frame has the result predicted.
Uncle Ben
This re-radiation theory is going to complicate SRT no end. Maybe itThe movement of a medium cannot affect the speed of light unless
there
is some sort of interaction between the atomic structure of moving
water and light that is different
to the interaction with still water. Maybe the light impacts more
water molecules per second in that case. This has nothing to do
with
relativity, it seem more like a ballistic effect.- Hide quoted
text -
- Show quoted text -
It is an electrical effect. The light, being an electromagneticthere
is some sort of interaction between the atomic structure of moving
water and light that is different
to the interaction with still water. Maybe the light impacts more
water molecules per second in that case. This has nothing to do
with
relativity, it seem more like a ballistic effect.- Hide quoted
text -
- Show quoted text -
wave,
wiggles the electrons. The electrons, being accelerated, radiate the
light, but with a phase lag. The incident light and the re-radiated
light interfere to produced a delayed composite light wave.
The slowing of the resulting light, relative to the incident light,
is
responsible for the index of refraction.
When the medium is moving, the phase of the re-radiated light is
affected. The easiest way to account for the magnitude of the effect
is to do it in a frame of reference in which the medium is at rest.
This light is moving slower than c, and when referred back to the
laboratory frame has the result predicted.
Uncle Ben
has.
Re-radiation means that a secondary source for the light emission
exists within the medium.
The fact the the water is moving with respect to the original source
means that movement of the source has an effect on the speed of
light contrary to popular belief. What if the source was moving at
the same velocity as the column of water? What then?
I guess the phase lag explains everything- Hide quoted text -
- Show quoted text -
1. The index of refraction
2. The effect of a moving medium
1a. Every electrical eng9ineer knows that alternating current in a
wire makes the wire radiate electromagnetic energy. That is how radio
works. Light going through glass makes the electrons in the glass
jiggle like AC, and that makes them radiate like an antenna
1b. When light goes through glass the superposition of the incident
light and the delayed re-radiated light produces an electromagnetic
wave that moves slower than light in a vacuum.
This explains the index of refraction.
2. (This is where Androcles gets confused.) Given a slower-than-c
light wave in a medium at rest, find its speed with respect to a
laboratory speeding backward at low speed. This is where the
composition of velocites comes in.
This explains the Fizeau effect.
Now where is the difficulty you are having? (Androcles and Sue are
hoeless, but the jury is still out on you, Gehan.)
Uncle Ben
laboratory speeding backward at low speed
You just lost me completely there.. A light wave moves slower in a
medium
OK. If the medium moves with respect to the light wave how can it be
proof
of relativistic effects?- Hide quoted text -
- Show quoted text -
The Fizeau effect is the effect a moving medium has on the speed of
light w.r.t. the laboratory frame in which it is moving.
The effect of a non-vacuum medium is to slow the light down. Light
travels in water (n=4/3) only 3/4 as fast as it does in a vaccum: v1
= c/n. Now that we know this, the problem is, what happens to the
speed of light when the water is moving at some speed v2 that depends
on your water pressure but certainly is not relativistic.
Our friend Androcles, stuck firmly in the Eighteenth Century, would
say that the speed of light in the moving water is v1 + v2, because he
thinks that relative speeds just add together.
But in the Twenty-first Century, we know that the answer is (v1+v2)/
(1+ v1*v2/c^2), where v1 = c/n and v2 = speed of water. Work this out
and you get the right answer, according to actual measurements.
=============================================
Our redneck Bonehead, stuck firmly in the Nineteenth Century,
is waving his hands and offering no evidence or mathematical
derivation for his idiotic claim.
In the Twenty-first Century, we know that the answer is v1+ v2 as it
always was and in agreement with the PoR.- Hide quoted text -
- Show quoted text -
close reading of Einstein's 1905 paper, it seems to have flown right
out of your head.
See Section 5, second equation. If you can't handle the notation,
consult any modern treatment of the composition of velocities.
If you've lost the reference, try
http://www.fourmilab.ch/etexts/einstein/specrel/specrel.pdf
Uncle Ben