The coordinate grid was laid against the sky to fix the stars and for centuries it seemed to work as planned.
Recently, slowly, almost asymptotically, the grid begins to move with respect to itself — abrading, degrading — and therefore deteriorates.
In fact, Declination -14 now sags along its whole length so that Declination +14 is taut and hums like a violin string in a high wind. Right Ascension 23 has rusted through and swings from its jointure, knocking the vernal equinox out of line.
This year spring came not late exactly, but more toward the center. Continue reading