Re: The Shapiro delay is bull***

On Mar 31, 1:23 am, Albertito <albertito1...@xxxxxxxxx> wrote:
We consider the case where a ray of light is deflected
by a gravitational field, yielding a hyperbolic path.

God, can't you make it a sentence without saying something stupid? The
form of the path can't be decided beforehand.

For
a Shapiro delay, it suffices to consider a photon travelling
at speed c along that hyperbolic path.

Wrong. The prescription is to evaluate the time it takes to traverse a
null path and compare wrt the flat background path. Which you do not
do, or even consider.

Take two points
of that path, one point A is where the observer is located
and the other B where the target is. We assume that
hyperbolic path is fixed, and a  photon will travel a round-
trip at speed c along it, from A to B and from B to A. If
L is the length of that hyperbolic arc, then we have two
times. T_AB is the time the photon will take to travel from
A to B, and T_BA is the time it will take from B to A. If the
path were a straight line, then the round-trip time would
reduce to T_0 = 2R/c, where R is the distance between A
and B. Since a hyperbolic path, L, is longer than the straight
path R, we expect a signal delay as

                 dT = 2L/c - 2R/c
                 dT = (2/c) (L  - R)

This is not Shapiro delay. This is some random crap you picked out of
your nose.


But, we all know the length L of a hyperbolic arc has no
analytic solution.

Totally wrong.

Then, why is a Shapiro delay expressed
by an equation  as

             dT = - (2GM/c^3) ln( 1 - a.b)
             where a.b is the dot product between
             a (unit vector pointing from the observer to the target)
             and
             b (unit vector pointing from the observer to M) ?

Open a textbook and look at the derivation and you'll understand why,
idiot.


If that equation were correct, then we would get an analytical
solution for L, as

             (2/c) (L  -  R) = - (2GM/c^3) ln( 1 - a.b)
             L  -  R = - (GM/c^2) ln( 1 - a.b)
             L  = R  - (GM/c^2) ln( 1 - a.b).

The length L of a hyperbolic arc can be expressed by
an elliptic integral of second kind, but I can't see that elliptic
integral in the above equation. Mathematically,  Shapiro delay
equation is bull***. If that equation can predict the observed
phenomenon, it just can in an approximated manner.

First off, the entire argument is fucking stupid since not once did
you refer to GR in your "derivation". Second, OF COURSE IT IS
APPROXIMATED! Things like lensing and Shapiro delay were discovered by
analyzing the weak field limit of GR.
.