September Equinox 2015

Unfortunately the teaching community still hasn't come around to explaining the seasons properly by splitting the cause into two separate daylight/darkness cycles and their respective rotations to the central Sun.

As the Earth move through space and around the Sun, it turns unevenly so that presently the North and South polar latitudes now are positioned close to the circle of illumination creating the respective orbital dawn in the Southern hemisphere and approaching orbital twilight at the North pole. These latitudes exist roughly 23 1/2 degrees above the fully illuminated face as determined by the Earth's orbital plane.

So we have the normal daily daylight/darkness cycle due to diurnal rotation and at habitable latitudes closer to the Equator and temperatures respond to the appearance and disappearance of the Sun and solar radiation each 24 hours and then there is the long term temperature fluctuations owing to the orbital surface rotation and experienced as the seasons split between hemispheres.

The days of trying to explain the Earth tilting towards and away from the Sun causing summer and winter should be over as common sense prevails and 21st century people consider the seasons from the perspective of the two known daylight/darkness cycles and their underlying cause. There is also the variations in the natural noon cycles to consider owing to the same dynamical causes.

It is also a lot of fun with the new approach and kids will love it.