How to tell the time using the sun and other natural signs

 Peter Wohlleben invites us to take a closer look and interpret the signs that nature conveys in his book The Weather Detective.


What does your watch have to do with nature? Well, nothing actually, and that’s exactly why we should talk about it.

A clock is supposed to represent the position of the Sun. This is also the reason why the hour hand moves around the clock face from left to right, like the trajectory of the Sun from the east (when looking south at the Sun, the east is to the left) over to the west (on the right). This is purely an optical illusion, of course; in reality it is our planet that is rotating.

Since you carry a handy astronomical instrument around with you on your wrist, you may as well put your watch to use for other purposes. It can be used as a compass if you’re disoriented: if you point the hour hand towards the Sun, then south is always between the hour hand and 12 o’clock. 

(During the summer time, when our clocks shift forwards an hour, 12 noon should be replaced by 1 p.m.)

At 12 noon, the Sun should be exactly in the sound and thus be at its highest position in the sky. Should. But remember that clock time is a compromise and compromises are always flawed. The Earth is a sphere, and when the Sun is exactly at its zenith in Berlin, for example, it takes another 26 minutes for the Sun to reach its highest point at Cologne, around 360 miles west.

But if you would rather use a different instrument to tell the time you can turn towards the birds or the flowers for example. Carl Linnaeus, a Swedish natural scientist of the 18th century, made an exciting discovery during his nature walks. He realised that the flowers of different species of plants opened their flowers at different times of the day, with impressive reliability. They were so reliable, in fact, that they could rival the accuracy of the church clocks at the time. 

Pumpkin and courgettes kick things off first by opening their flowers at 5 o’clock in the morning. From 8a.m., the marigolds spread out their petals, and the daisies follow at 9. When the Sun is at its zenith in the south, midday flowers (Mesembryanthemum, also known as ice plants) open their blossoms. Between 2 p.m. and 3 p.m., dandelions start to close up, and by 3 p.m. the gourds have finished for the day. At around 6 p.m., poppies also shut up shop.

But why do plants go to the trouble of opening their flowers at different times? The reason for this is to attract pollinating insects, which risk being overwhelmed by choice. At the rush hour, when many flowers are open for business, the bees can’t possibly visit all of the plants on offer, so some flowers would have to go without a visit. It gives you a competitive edge if you tout your nectar and pollen later in the day, when your rivals are asleep. So it’s a way of improving the chances of pollination. It also helps the bees to take advantage of the available stocks of nectar, to bring as much as they can back to the hive for the winter. The more nectar supplies they bring back, the more bees survive of the next generation, which in turn ensures better pollination chances next year.

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