The days are getting longer and in Australia, the switch to daylight saving time is almost upon us (for about 70% of the population, anyway). But why do we have longer days in summer and shorter days in winter? It’s all about the tilt Earth goes around the Sun in an almost circular orbit. But not everything is lined up perfectly. Earth’s axis is tilted by 23.44 degrees relative to its orbit around the Sun. Imagine Earth’s orbit as a flat frisbee with the Sun in the middle and Earth as a ball on a stick going around the edge.…