Fig 1The seasonsDrag the year · ← → one monthJun 21 · noon sun 68.4° · day 15.4 h
Earth: the lit half is where the Sun shines; the axis never changes directionMonth ring: one turn of the arm is one yearGauge and scale: noon Sun height and daylight hours at 45°NThe axis stays fixed at 23.4° while the Earth goes round, so the North Pole leans away from the Sun in December and toward it in June. At 45°N that swings the noon Sun from 21.6° to 68.4° and the day from 8.6 to 15.4 hours: a high Sun packs the same rays onto less ground and long days pile on heat — summer. A low Sun spreads its heat thin over short days — winter. Distance barely matters; perihelion falls in January.