SOURCES OF THE WORLD’S STORMS

Hokitika Guardian, 20 June 1931, Page 3

SOURCES OF THE WORLD’S STORMS

AID FOR AIR PILOTS IN PtRIIL? HOW RADIO RULES THE WAVES. (From a Special Correspondent.) LONDON, May 14. Radio may soon be used to trace the source of every thunderstorm in ' progress within two or three thousand miles of the observer. If this hope Is realised, aeroplane pilots will be able to steer their course to avoid one of their worst perils. Scientists at the Radio Research Station at Slough, (about. 20 miles from London) under the British Government Department of Scientific andi Industrial Research, are now engaged on elaborate experiments to establish beyond doubt the reliability of their methods. They have invented one of the most sensitive and remarkable pieces of apparatus that the wonders of wireless have yet produced. It is called a “cathode ray direction-finder” and it records, by the flickering, pf a little point of light, every ■important electrical disturbance that'goes on in pan of the earth’s atmosphere for thousands of miles around.

This Slough station is the only place in the world where the instruments are made. They were invented by the Superintendent, Mr Watson Watt. Two of them have, just been supplied to the Australian Radio Board, where they are to be used for a new Australian storm tracking research scheme. Others are under construction for Canada and .wo have been supplied, by special request, to the Uunited States Navy. A DETECTIVE FOR LIGHTNING. The apparatus lives in a little wooden hut which looks more like a chickenhouse than a’Laboratory. Here hypersensitive apparatus reacts every time there is a Hash of lightning on a distant continbnt.

The laboratory, a mass of wires and knobs, is plunged into darkness. Scientists bend over a little point of fight, which is jumping about like a thing possessed. “That looks like South Germany,” says the chief storm-tracker, “Nothing very much. . .' . ah! that’s an Atlantic disturbance, I should say, moving it. There’s something going on down Morocco way.” A cinema, which records every movement of the light, clicks away, making a,permanent record of far distant storms and depressions.

Each atmospheric lasts oniy about a five-lmndredotli of a second and is: recorded absolutely instantaneously. As many as 3,000 signals a second may be received. HELP FOR THE AIR MAIL. But. this only shows the direction of l,he. ; stjeum... Scientists mvattt "to ; find (its precise location oh the map. So they have set up another exactly similar direction-finder in Scotland, about 403 miles away, with a land line connect-ing-'the' stations. The signals are Sent 'between the laboratories to synchronise the films exactly. One firm is posted down from Scotland and the two are projected simultaneously on to a map >f the world. Where two flashes cross is where that atmospheric originated.

The scientists can now trace the .ource of a storm within two hours, while by earlier methods it took four days. , This time could be reduced to a few minutes if the Scottish instrument were arranged to transit its indicaions over the land by a simple method, already worked out, which is aF lied to picture transmission. <This might make all the difference to aircraft, which depend on such observations to keep out of disturbed areas, and should also he of great value In forecasts for ships, farmers, and holiday-makers.

These, of course, are practical applications of the new method of direction finding. Still more important, experts believe, is the theoretical question of “What, why, and how is an atmospheric?” They have discovered that all atmospherics are clue to electrical discharges or lightning. The Slough station’s object is to study the pure phvsics and higher mathematics of radio so as to provide a background of knowledge on which the radio engineer, can base his improvements.

WHY WAVES GO WRONG

“The practical side of wireless,” I was told, “has outstripped the theoretical. Wireless waves do certain things, but often radio engineers don’t know why. This may lead to unforseen trouble, and the big advances of the future are likely to come only after more is known about the fundamental behaviour of waves.” These scientists can sort out the millions of waves which crowd the ether, travelling at 18(1,000 miles per second, as easily as we can distinguish differ'mt t’ pes of car in a stream of traffic. Hne fascinating field of study is called “way.e propagation”, which . means (lip adventures which befall a wave as it travels. When a signal is sent off. scientists explained, the impulse travels by different rentes, One set of waves pops alone the ground, and this is picked up liv broadcast receiving sets over short distances, and by shins. The other, however ,goes upward and i.s reflected down again from the upper atmosnhore, somewhat as light is reflected from a "’irrow. “MOFT FRTOR” AT ’PFA. I Afanv radio troubles are caused hv I rl-poo two waves not jo : nir>g on nnr?<>. I evaetlv in step. When (he peak ef one wave coincides with the trough of an-

other, you get what scientists call a “fringe”; and “fadings” familiar t listeners, results. These fringes h v ..euuaiiy imeii photographed and t>u. distinct wines can he seen into/..i.i) t ,. .ng. "Night error” in direction-finding at sea is cuua~d b\ tn so uo\. m i.mn.g AilVoS. it 13 L.ILH 10..Me, until 1 . Ivliq, vViAffess bearings, that direcuon-hnd-ers are 3U or 40, or even,. more, degrees out at night. m.-ia.i srie.,li. J Ls ua ; e perfected’ a new type of directionunder which does not pick up the parts of the wave causing these troubles and which thus el luinattS the error.

For lonjz r Ui.si.iuu:.! signals, .men as those boiivceii jtiupne station.:., the “dowiicnming ' v.a.c is me important 0110. . Scit mists are studying lunv it. is refleetid Irom the upper atmosphere called the “ucaviside” layer alter a mail of that name who first suggested that such a conducting layer was mailed to e\plain the success of radii communication. For years this remained a hyp thesis, . and it is only within the last ten years that definite proof of the existence oi the layer was obtained by scim lists working for .lie British Radio Research Foard. Heaviside, then an old n an, was'often' 1 a medal for his original work, but r ."used it 1) cause by that time he was more interested in roses than in radio. MESSAGES TO MARS? These layers (.for the' same workers have shown that there are at least two of them, at about GO and 120 miles above the earth’s surface) consists of electrons. Short-waves travel further through them before getting reflected back than do long-waves. There come a point, scientists believe, when very short waves go right through the layer and on into space. “If there were any radio communications with Mars” a scientist said to me, “that is how it would be done.” At Slough they are trying to find out—not with this object—the shortest wave which can be sent*without getting lost. They believe it may lie somewhere between the ranges of 5 and lU' metres. Wireless “echoes” are another problem. An echo is caused by the wave going right round the world and being picked up on the second lap. cornin': from behind. Apparatus has been designed that will not pick up these backdoor waves.

SPLIT SECONDS,

The almost incredible accuracy needed for work on this “wave propagation” is such that scientists can measure an effect produced by a time difference of a tew millionths of a second. They study the angle at whiph an invisible wave iiits an inaccessible layer made up of theoretical particles, us happily as if they were working out a new stroke in squash-racquets. The man in charge of this work is Professor 15. V. Appleton of King’s College, London. He has an international reputation and the work under his direction at Slough is acknowledged to be the finest of its kind in the world.

The last Imperial Conference stressed the fact that the Empire’s progress depends .largely on the efficiency of imperial communications. Wireless has become one of the most vital of these. The Empire must be linked in the oth"r was as well as bv sea and air, That is why the British Government is supporting a research.centre where it is encouraging the British genius for invention to extract the fundamental ‘•ecret's of radio out of the immense mysteries of space, so that the knowledge gained can be applied to the ’"■actical problems of a work-a-day Empire.