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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Nearly all navigation is an attempt to join landmarks together. Even those on boats crossing oceans are probably hoping to find a landmark they recognise as the final part of their journey.

The word, ‘landmark’, simply means something that makes a location recognisable. It is deliberately vague as it can apply to anything, a landmark may be extraordinary – the statue of Christ the Redeemer towering over Rio de Janeiro’s from Corcovado mountain. Or it may be mundane – a red postbox at the edge of a village.

The more confident you can be that you have both successfully identified a landmark and that you know exactly where that landmark is, the more confident you can be that you know where you are.

A landmark does not need to be grand, it does not even need to be recognised by others, just so long as it is recognised by you.…

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If you look closely at these two pictures you can see how the aircraft contrail cuts the lower cumulus clouds at a slightly different place in the second picture. It is not dramatic, but one clue that the upper winds at the altitude of the aircraft, probably about 35,000 ft, may be moving in a different direction to the lower winds moving the clouds. The upper wind direction is likely to be the more consistent and can be gauged by lining contrails or cirrus clouds up against fixed features like high landmarks, or even by lying under a tree.