The natural Navigation: The Right Course, Naturally

Tristan


I managed to rope in a friend at the end of an evening’s BBQ and together we plumb-bobbed Polaris, set out two posts and then strung a string between them. We checked with a compass and, despite the evening’s beers, we were actually almost spot on!

The next day we checked the shadow at 1.00 (12 noon GMT) and found this lined up on our string. Impressed or what!

Richard

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Hi Richard,

I can see I’m going to need to come up with some sort of merit/badge/star system just to complete the back to school experience!

A link that I will have mentioned on the day is here:

http://aa.usno.navy.mil/data/docs/AltAz.php

If you plug in your latitude and longitude, it will give you the altitude and azimuth of the sun (or moon) for a whole day by GMT. Due south is often very close to clock midday, but it can wander off it depending on your longitude and because of something called…

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As we approach the summer solstice the sun has so much north in it that no side of buildings, trees or other exposed areas will stay in the shade all day.

This is a northern roof getting a good late afternoon roasting. The moss, which in mid-winter is a plump dark green is in full retreat at this time of year. It is well-established and will survive until the sun starts moving south again in three weeks.

A walk along the edge of Nutbourne marshes on the weekend was an early taste of real summer. A sunny May day often feels hotter than a midsummer one to me, perhaps because I have not yet acclimatised. There were thousands of midges and flies, swirling up from the drying seaweed to complete the sensation.

These two pictures show the same field and only two minutes of walking passed between each shot. It is late afternoon and one of these is taken looking north, the shadows falling to the east and right of each furrow ridge.

When taking this picture of the moon last night the shutter speed was much slower than I had planned. The resulting photograph struck me as a reminder that it is the sun’s light that we see when looking at the moon.

I try not to let politics enter my mind too much when out walking, but sometimes it helps to be aware of some of the tinkering that the political animals are up to. In the interests of the environment farmers are discouraged from working the land right up to the edge of woodland. They can set some of this land aside, typically a strip up to 8m, and be compensated for it through the government’s Entry Level Stewardship scheme.

The farmers are finely tuned into what is and is not productive land, they know from experience the parts of their fields that are not high-yielding. This will very often coincide with the areas that the sun does not reach fully, the shadows on the north side of tall trees for example. There is a bias towards finding these ‘buffer strips’ on the northern side of woodland, at the southern edge…

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The rape flowers are coming into bloom over the South Downs, but they don’t all bloom at the same time.

The crop tends to be on a field that will get a good amount of sunlight anyway, often south-facing, but even within the fields there are subtle shade differences. The flowers tend to appear first in the south-facing dips in the land. This is probably because they are getting plenty of sun, but being sheltered from the cooling winds. As a general rule, nature moves faster the warmer things are.

This morning’s sun was a strong enough clue, but if we wanted to know which way was southeast then these aircraft contrails are pointing the way to the continent.

It looks like a particularly busy morning for aircraft, but this is just a reflection of atmospheric conditions. The hydrogen-rich jet fuel has mixed with oxygen, reacted in the engines and formed, among lots of other lovely and not so lovely things, water. In certain temperatures and humidity levels this water freezes into ice crystals. The high cirrus clouds that we normally see are also composed entirely of ice.

The length of time that a contrail survives depends on the humidity, if the air is dry it will sublimate away, but if saturated they will last as long as other cirrus clouds.

I can remember sitting at a restaurant in the small and perfectly formed fishing village of Trehiguier in southern Brittany last July. I had my back to the sun, which was setting behind the row of houses behind me. I watched the crisp edge of a chimney corner move upwards and to the right as the sun slipped down and to the left behind me. My poor wife had to watch me gauging the sun with a fist and then outstretched fingers and then listen to me predict when the chimney shadow would reach our table.

Last night my wife was spared such ordeals as I was working outside, in a small patch of woodland. I watched the sun’s light moving up the trees in front of me. Unlike the crisp edges of the chimney shadow, the edges were blended. The shadows were moving upwards but not following discrete lines. The…

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This isn’t about the Force, although I did read recently that a lot of Scottish policemen have put ‘Jedi’ down as their religion on their work forms.

More days than not I spot an example of the sun influencing nature in a way that is new to me in some way. In general terms it is fairly old news that a place that receives no direct sunlight will appear different in some way. It is in the detail that the novelty is to be found. The more obvious signs might be that it has different plants growing and an abundance of mosses and lichens.

The more fascinating signs are subtler, created by factors that are minute but combine to create an effect. The first picture shows how broadbrush nature can be. Despite looking in one direction towards a single hillside, as many as six different bands of colour are visible.

The second picture…

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Possibly the worst blog post title that I have yet come up with, and there have been a few…

Our cat, Murphy, can be seen reflecting the direction of the last of the suns rays here.

The tree shadows in the distance have broken free from the woodland in the background too for the first time this year at sunset.

In the spirit of randomness to which this posting has succumbed I thought you might like this puzzle, set by a friend and former NN alumni.

Do not be alarmed if my postings continue to be sporadic, poorly constructed, lacking in theme, good titles, concise argument or beautiful short sentences. Most of that energy is being directed into the book at the moment.