"Astronomy" says light slows down......... Does the response to a question about gravitational lensing on page 72 of the March issue of "Astronomy" agree with other statements on this forum about the absolute nature of light speed? The question asked by "Astronomy" reader Tom Schmidt: "I noticed the photo of Einstein's Cross on page 47 in the November 2003 issue shows four images. Why aren't there many more, even a circle of images because the light from the source would be going in all directions?" Paul Schechter of the Massachusetts Institute of Technology replied (edited to present only the relevant passage): "........... In the gravitational case, the gravity of the lensing galaxy acts like the index of refraction of air. It slows down the light as it travels past the galaxy. If the quasar (which we take to be pointlike) aligns sufficiently closely with the galaxy, a second image appears. If the quasar aligns very closely, we get four images........"