Science Siftings

New Zealand Tablet, 25 January 1917, Page 47

Science Siftings

By ‘Volt.’

,_ . ' ■. - . Why the Stars Twinkle. , Although the twinkling of the stars is commonly referred to, they do not twinkle at all. The stars are really suns that throw out light, just as our sun lights the earth. When the rays of light from the stars strike the air which surrounds the earth they have to pierce many little particles which are always "floating about in the atmosphere. It is this interference between us and the source of light which gives the appearance of twinkling. On certain nights the light of the stars will appear so bright and clear as to attract particular attention. This is because the air is so clear there is less interference than usual with the rays of light in reaching the earth. Trades of Little Animals. Bees are geometricians. The cells are constructed so that with the least quantity of material they have the largest spaces and least possible loss of interstice. The mole is a meterologist. Eels are electricians. The nautilus is a navigator : ho raises and lowers his sails—casts and weighs anchor, and performs other nautical acts. Whole tribes of birds are musicians. The beaver is an architect, builder, and wood-cutter ; he cuts down trees and erects houses and dams. The marmot is a civil engineer ; he not only builds houses, but constructs aqueducts and drains to keep them dry. Ihe white ants maintain a regular army of soldiers. Wasps are paper manufacturers. Caterpillars are silk spinners. The squirrel is a ferryman; with a chip or a piece of bark lor a _boa( and his tail for a sail he crosses the stream. Dogs, wolves, jackals, and many otheis ate hunters. Ihe monkey is a rope dancer, The black bear and the heron are fishermen, and the busy ants are regular day laborers. Signs of Rain. One of the most trusted weather maxims is ‘ the weather must change with the change of the moon.’ This, however, was tested .five thousand times in succession by a Government Weather Bureau, but while the weather changed eighteen hundred times there were thirty-two hundred times when it did not. But there are plenty of soundly scientific weather signs. For instance, the ‘ ring around the moon,’ which is produced by a thin, filmy cloud made up of minute particles of me, generally means it will pour ‘ cats and dogs ’ within three days at most. in eighty-six cases out of a hundred the rule holds good. A still better sign is the riiio- around the sun.’ This is science pure and simple, and so is the old maxim; The farther the sight, the nearer the rain.’ It is not pessimism that makes people along the coast predict a downpour when they can pick out the separate houses on a far-away island, or people in mountainous regions call it ‘ too good to last when a distant peak, generally invisible, comes into view. They are shrewd meterologists in making these predictions, and also in declaring that sounds carry better when a rainstorm is brewing. Of all nice convincing weather signs, however, a ‘ sickening skv ’ is pretty nearly the most reliable. When the deep warm blue grows paler, and then whitish, and your spirits drop, and shadows fray at the edges and disappear, then you have a sickening sky. Rain is not being brought up ready-made from afar, it is being manufactured directly overhead. The color of the sky, then, is a fairly trustworthy sign in and of itself, and so is the color of the clouds. Intensely white clouds against an intensely blue sky means bright weather ahead. Greyish clouds on a lightish blue foretell rain. -