The natural Navigation: The Right Course, Naturally

Happy Winter Solstice One and All!

Here’s an interesting solstice fact for you: the Earth is actually receiving more solar radiation at this time of year than at any other time. This is because the Earth does not orbit the sun in a circle, but in an ellipse. In the northern hemisphere winter the Earth is at its closest to the sun, a point called ‘perihelion’, but in summer it is at its furthest point, or ‘aphelion’.

The Guardian have published a little article on the timing of the winter solstice.

However, my favourite solstice image is on a different page. The same technique used in the photo on that page, from the same position, but on the summer solstice would probably not catch the sun at all, or perhaps just a glimpse of it in the top corners.

At this time of year the sun is always…

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I have just been watching a beautiful full moon rising above the trees in the east. It was shrouded in layers of cirrostratus for a few minutes, but then rose above them.

In winter full moons rise north of east, in summer they rise south of east. They rise further from east the nearer we get to the solstices. The full moon always behaves in the opposite way to the sun, in time and direction, as it is opposite the sun in its cycle.

Happy Spring Equinox!

My plans this morning, as announced in the Telegraph, were to head to the top of a hill and catch the sun rising due east. Sadly, the air is cooler than its dewpoint… the humidity is greater than 100%… there is a low level of nimbostratus… however you want to put it: the weather is not very good and the visibility is terrible.

Had I been able to see the sun it would have risen due east. The vernal and autumnal equinoxes being the only two days of the year when the sun rises due east.

Something that you cannot notice on any individual day, but only by studying the sun’s rising position over the course of a year from the same location, is that its rising and setting positions are changing by more at this time of year than at any other time. Near the…

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An engaging group for the Beginner’s Guide to Natural Navigation course at the Royal Geographical Society yesterday. Diverse in age and interests as always. When we were discussing the difference in the sun’s behaviour between the solstices and equinox it felt more poignant that we are so close to the autumnal equinox itself. We looked at a model of the Earth orbiting the sun, then shifted our attention to shadows. A couple of days ago I took advantage of the sunshine to practice what I preach.

This chalk line in this picture shows the shadow tips joined over a period of a few hours on the morning of the 21st September. The line comes very close to a straight line, but even on the equinox it is never a perfectly straight line – unless you happen to be standing on the equator when the sun would rise due east, pass…

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The Gooley family spent Sunday afternoon mucking about at Stonehenge and then heating baked beans and pasta on the VW campervan stove. A modern, but not very, ceremony that paid homage to some ancient rituals.

I was perhaps the only tourist walking around the perimeter who was taking note of the varying moss and lichen growth as I worked my way round the stones from the north side through west, south, east and back. It wasn’t the subtle shifts in colour that held my thoughts though.

There is surprisingly little that is properly understood about Stonehenge, but some solid deductions are possible. The alignment of the stones confirms a true understanding of solstices by its architects. It is tempting to think that solstices were a widely understood phenomenon even in ancient times and not give this aspect much more thought, but that would be to do a disservice to…

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