Before the Beginning ???

Painius wrote:

"Double-A" wrote in message...


ps.com...

Painius wrote:
"Double-A" wrote in message
oups.com...
Hi Paine,
When we measure the speed of light in our own local reference frame,
it
is c. But when we observe it in another reference frame, such as
close
to the Sun, it does not measure out to be travelling at c.
You appear to be talking about the eclipse experiment
that was the first evidence for the validity of relativity
theory, Double A. If i recall correctly, c was considered
a "scalar" quantity that did not change. The acceleration
which was noted was the effect of the curved path taken
by the light from the star which was near the edge of the
Sun. So it was the change in *vectorial* direction of the
light, but not actually a change in the value of c, the
*scalar* speed of light, which accounted for the noted
acceleration.
I was thinking of the Shapiro Effect.
http://www.geocities.com/newastronomy/animate.htm
Of course this is an abservation made about radio waves, but radio
waves are photons too and are in fact a low frequency form of light.
There is nothing about it that contradicts relativity, in fact Einstein
predicted it. But what I am talking about is purely a matter of
perspective.
If you looked at this from a Newtonian mindset, you would definately
say, "Aha! Light travels slower near the Sun." It is only when you
put on the Einsteinian colored glasses that you say, "Oh, the speed of
light could not have changed. That's fundamental! So, there must be
something wrong with our clock! Our clock's speed must change
depending on where it is."
The point is that if your number one article of faith is that the speed
of light never changes, then you'll mentally move heaven and Earth
before admitting that it does.
Double-A
Okay, i'm with you now. I must be seeing the Shapiro
effect wrongly. I assumed that the increased time it took
for the RF waves to travel was due to the increased
DISTANCE caused by the path curvature due to the
Sun's gravity field. If the Sun wasn't there to make these
paths curve, then the RF waves would travel in a straight
line, and therefore they would travel a shorter distance,
isn't this correct?
So why would the scalar speed of the RF wave have to
decrease?
happy days and...
starry starry nights!
--
Selene in crescent wane,
She rises in her palace,
Her smile brings to mind
The Cheshire cat in "Alice"!
Indelibly yours,
Paine http://www.savethechildren.org/
http://www.painellsworth.net


Double-A writes:

Hi Paine,

Sorry but I didn't have an answer for you back when you posted this a
couple months ago, but I have now come across some new information.

The question was whether the delay in photons passing close to the Sun
was sufficiently explained by the increased distance resulting from the
bending of their path due to the Sun's gravity field.

The following is from a paper by Dr. Paul Marmot of the University of
Ottawa. I know he has some unusal views, but I believe his
calculations here are in standard form.


Dr. Paul Marmot:

"Delay Due to the Geometrical Bending of Light.
We have seen above that general relativity predicts that light
passing near the solar limb is deflected by an angle of 1.75". The same
theory predicts that due to the same gravitational potential, the
radiation takes a longer time to travel the distance between the Earth
and Mars. Figure 1 illustrates how light is deflected when grazing the
Sun.


Geometrical Time Delay
Figure 1

One can see on figure 1 that if the trajectory of light is not
a straight line (dotted line), it takes a longer time to travel between
Mars and the Earth. The increase of time Dtb due only to the
geometrical bending of light by d = 1.75" is given by the relationship:


(You can visit the site to see the actual equations)

We find that Dtb = 0.010 ms or 3.2 meters. The increase of time
D tb (with respect to a straight line) taken by light to travel from
the Earth to Mars due to the geometrical bending of light is extremely
small and negligible with respect to the delay (125 ms or 36 km)
predicted by relativity as given in equation 5. Consequently, the angle
made by light grazing the Sun is totally insufficient to explain the
increase of distance (or delay) compatible with the prediction of
general relativity as given in equations 3 and 5. This geometrical
delay caused by the bending is not the main cause of the delay
predicted by general relativity. It is several thousand times too
small."

http://www.newtonphysics.on.ca/ECLIPSE/Eclipse.html


Double-A:

So it is not the increased length of the path due to bending that is
responsible for the significant part of the time delay.

My point is that from our perpective light is travelling slower when it
passes near the Sun. This also suggests that light travelling through
space outside the graviy well of the Sun must be travelling faster than
c as measured on Earth.

Some constant!

Double-A