The relativity of c and local measurement

If gravity is a refractive gradient, RSI concludes that the absolute speed of light (c) varies. A light wave moves more slowly through the slackened medium of a planetary gravity well than through the full-tension medium of deep space.

Experiments, however, always measure the same value of c. RSI holds that this does not contradict the variable speed but explains it. Measuring a speed requires a clock and a ruler, and every clock and ruler is built of knots in the same medium.

Near the Earth, light is slower than in deep space by the fraction 2GM/rc². Two things change in an observer's instruments at once. Their clocks tick more slowly, by GM/rc², because the knots' internal rhythm, the 137-Escapement, slows in the slackened medium. Their rulers shrink by the same GM/rc². Together the slower clock and the shorter ruler absorb the full slowing of light, so any local measurement yields the standard constant. Deriving this even split from the medium is an open goal.