Pentcho Valev wrote:
Albert Einstein, "Relativity", Chapter 7: "There is hardly a simpler
law in physics than that according to which light is propagated in
empty space. Every child at school knows, or believes he knows, that
this propagation takes place in straight lines with a velocity c=300000
km/s."

Chapter 22: "...the law of the constancy of the velocity of light in
vacuo, which constitutes one of the two fundamental assumptions in the
special theory of relativity and to which we have already frequently
referred, cannot claim any unlimited validity. A curvature of rays of
light can only take place when the velocity of propagation of light
VARIES WITH POSITION."

The rational world would ask: How does the velocity of propagation of
light VARY WITH POSITION? Increases and becomes greater than c=300000
km/s? Decreases? Increase and decrease depend on what?

The zombie world asks nothing. It learns by rote, celebrates, worships,
sings dithyrambs, eats and teaches how to learn by rote, celebrate,
worship, sing dithyrambs and eat.

Pentcho Valev

The velocity of light in GR is a function of position because spacetime
is not flat because of the existence of gravitating objects which curve
spacetime (again, according to the way GR theorizes about spacetime).
It was for this reason that Einstein predicted that a light beam
passing the sun would be deflected from its straight path.