For the past two centuries, monographs and textbooks on spherical astronomy have all presented astronomical refraction in much the same way. The differential equation for the refracted ray is developed; series expansions are introduced that allow calculation of numerical values in the part of the sky where most astronomical observations are made; and the region near the horizon is usually ignored. Because these series expansions diverge before reaching the horizon, the few authors who treat refraction near the horizon have used entirely different expansions than the ones valid near the zenith, so that no unified picture emerges. In any case, the mathematical transformations used to evaluate the integrals entirely disguise the physics.
- Pub Date:
- April 2006