At around this time of the year, ‘cool’ vicars like to say to kids – “Hey guys don’t forget that chocolate isn’t the real reason for the season” before blathering on about a revolutionary figure from two thousand years ago who fought to overturn the hypocrisy of organised religion – entirely missing the irony.
But of course both the kids and the cool vicar are wrong, far from being chocolate or Jesus, the real reason for the season is axial tilt, also known as obliquity.
The 23.43679 degree tilt of the Earth’s axis (oscillating between 22.1 and 24.5 degrees on a 41,000 year cycle) means that the northern and southern hemispheres of the Earth alternately tip towards and away from the sun during its orbit of the sun.
The upshot of all this is that the sun’s rays are more concentrated during the summer and strike the Earth’s surface at more of a glancing angle in the winter – not to be confused with being closer to the sun during the summer months, which it isn’t…
On March 20 at 9.58pm we celebrated (or just calmly noticed it in our desk diary and nodded appreciatively) the Vernal Equinox – this is the date when the sun is exactly above the equator and length of the day and night are equal.
This marks the astrological start of Spring – not to be confused with the meteorological start of Spring, which is based on the annual temperature cycle. There is also an Autumn equinox at the end of September.
The Spring Equinox is a huge deal for those living in the North Pole as it is the first time the sun peers above the horizon, having taken a six month holiday around the other side of the globe and marks the start of a six month period of uninterrupted sunlight.
While that might be welcomed by polar bears, it’s bad news for penguins – living as they do in the southern polar regions.
All they have to look forward to is six months of unremitting darkness, biting cold and the constant smell of fish. A bit like Margate in the off-season.