TO LAND a robot airborne device on an uneven surface presents a hugely difficult mathematical problem.
It’s all about vectors — those tricky combinations of speed, angle and range that haunt all snooker players. When it comes to handling a drone or trying to soft-land a probe on Mars it is, as one expert states, ‘computationally demanding’. But bees solved the maths millions of years ago, despite having extremely small brains. Your average bee flies at about 30km an hour and then lands on a flower petal which may be horizontal, vertical or at any oblique angle in between, and which may also be moving in the breeze.
Engineers are reluctant to admit that they have been outsmarted by an insect, but this fact has eventually dawned on researchers, in Sweden and Australia, and they’ve started to try and work out how bees do it. The result is startlingly simple.
The bees don’t bother with all those complicated vectors. They simply capture an image of the surface they want to land on and then measure the speed at which that image expands so they can reduce their flight speed to make a perfect landing.
This extremely obvious solution is now beginning to revolutionise the programming of drones. The principle the research is based on has several names, but probably the best one is biomimetics. It means engineering that mimics biological examples.
Bees do something else that’s rather clever. They alter the aerodynamics of their bodies to suit the speed at which they’re flying and the strength of the wind. They do it to save fuel. Bees use two sense organs to do this. They measure their speed with their eyes, gauging the speed at which their surroundings are whipping past them. But their eyes can’t measure the wind. For this they use sensory organs in their antennae. They combine both sets of data and raise or lower their abdomens in relation to their wings to give them the optimum profile for efficient flight. If only Michael O’Leary could buy aircraft as clever as a bee, he could gain a real edge.
Most of these experiments have been carried out on bees, mainly because they’re readily available. There are other flying insects that perform even more remarkable feats. Hoverflies can not only hover, some of them can fly backwards. Some bats can do this trick as well. Goats can out-perform all-terrain vehicles and moles are better at tunnelling than humans. Sperm whales can hold their breath for over an hour and dive to depths of over 2,000m where the pressure is unimaginable. Biomimetics could be a science with a future.
Pine cones are popular for floral decorations, particularly Christmas wreaths.
So popular that you can spend a lot of money buying them on the internet.
It’s more satisfying to collect your own, and even more satisfying if you know which species of conifer they come from.
The classic cone comes from the Scot’s pine (Pinus sylvestris, above) the only true conifer with a claim to Irish native status, though it may have become extinct and been re-introduced. Norway spruce, quite common in older forestry plantations, also produces a spectacular cone, a long cylinder looking like a fat Cuban cigar. The cones of Sitka spruce, the commonest tree in Ireland today, are also cylindrical, though considerably smaller. Larch produces pretty cones, though they are not much bigger than a thumbnail. Lodgepole pine is quite common in older plantations on cutaway bog and has naturalised in some places. It produces cones like a smaller version of Scot’s pine.
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