VARIABLE SPEED OF LIGHT IN A GRAVITATIONAL FIELD

Matthew Johnson wrote:
In article , Spaceman
says...

Matthew Johnson wrote:
In article , Dr. Henri

[snip]

"Not currently known"? Maybe not by you. But those of us who
actually passed upper-division E&M know the answer: in vacuum,
light always propagates with the same speed in any interial
reference frame: that speed is c.

Matthew,
Two objects (A and B) are following each other and moving at
0.5c in direction N, the object in the back (B) is following object
A from 1 light second behind it, and the relative speed between the
two is 0.
Object A turns on a lightsource.
Do you truly think it will take 1 wholesecond for object B to see
the light from A even though B is traveling at 0.5c towards the
first emission point of light?
Or would you say it takes only 1/2 second?

Obviously, the answer depends on which reference frame you measure th
time in. If you measure in the reference frame of objects A and B,
then it takes 1 second.

B says you are wrong.
These are inertial and no time dilation is occuring.
B comes up with 1/2 second timed.
If it did not, it was not moving at 0.5c to begin with.
It's basic math Matthew.
Why don't you understand basic math anymore?


But if you measure in the unnamed reference frame you alluded to when
you said "movint at speed 0.5c", then the answer is different. I'm
sure you can compute sqrt(1-(0.5)^2) as well as I can,

1/2 second is wrong in both reference frames.

Nope.
I knew you would not understand there is no "time dilation"
in the above and any transform will give the wrong time
and of course you will ignore the closing speed of object B
to the lightwave front at the 1.5c occuring.
Figures.