WIRELESS WONDERS

Dominion, Volume 12, Issue 255, 23 July 1919, Page 7

WIRELESS WONDERS

SHALL WE TALK TO OTHER PLANETS?

SIR OLIVER LODGE DISCUSSES THE POSSIBILITIES The wonders of wireless telegraphy and telephony are the outcome'of researches in pure' science which were originally initiated and pursued with no thought of practical application. By combining all that was known about oscillating electric circuits and about the emission of electric waves in accordance with Maxwell's theory, the problem of tuned or selective wireless telegraphy was solved, let us 6ay, in 1897. Recently other researches, initiated by Crookes, and others, and developed by Sir J. J. Thomson, havo been pressed into tho service; and. first by Professor Fleming and then by others, have greatly improved the receiving capacity of wireless stations, so that it is possible in America, with quite -a small receiving area f to hear the great power stations in Europe. And recondite mathematical investigations have proved that hearing at the Antipodes is far from theoretically impossible

Telephony, however, goes a step beyond all this, and is really far more remarkable. That human speech can bo translated into the fluctuations of an electric current so as to.be transmissible by a wire was essentially marvellous, though it is a marvel to which by everyday use we have grown thoroughly accustomed. But that human speech, can be transmuted from sound waves into ether waves, which are capable of travelling enormous distances, and can then be retranslated into sound waves, with all their distinguishing features accurately preserved and reproduced, is still more marvellous.

Speech cannot be transmitted _ through a submarine cable; the fine crispations and significant peculiarities get smoothed or wiped out, so that the result of transmission over anything much more than fiftv miles becomes a mere unintelligible hum.

But in free space there are. no such disabilities as are met with in the cramped .space of a submerged , cable, and speech, said to be of remarkable distinctiveness, can be rcobtained from electric oscillations which have encountered nothing more perturbing than the air. Air does not help—so far as it acts it hinders; vacuum would tie better, but the ether is sufficiently forcible to overpower minor obstructions, and it is found capable of transmitting securely.and squarelv- whatever is ingeniously given to it. and still more ingeniously received..

What the Electrons Do. The main instrument made use of for this purposo is the vacuum relay; and the essential power which has been harnessed, both for sending and for receiving, is tho extraordinary mobility and tractability of the little electric units or eloctrons which are given off by matter under certain conditions in great numbers, which fly with incredible speed approaching' the speed of light, and which in a sufficiently high vacuum are beautifully amenable to control. Electrons* in motion constitute a current, and a stream of them can be deflected wither by a magnet or by an electric charge brought near them. Suppose, then, tliat an oscillating electric charge, oscillating in correspondence with tile vibrations of the human voice, is brought into the neighbourhood of a stream of electrons, this stream can bo made to vibrato in unison. It can be laterally deflected or waved to and fro if that is what is wanted; or it can bs alternately encouraged or retarded if that- is preferable. It responds to every impose, and it responds instantaneously. Ordinarily mechanical relays, though quick in the ordinary sense of quickness, bto not instantaneous. They necessarily possess inertia, and so to some extent they lag. But tho lag of a Btream of electrons, if anything at a3l, is a matter of millionths or billionths of a second. They act instantaneously. Hence the responso is perfect and follows the minutest detail.

To get such a stream of ' electrons, mimy ways might bo employed. Ultra l violet light falling on a metal is one method. X-rays is another. But the simplest plan is to employ a liot wire. A suitablo wire can be kept hot by an electric 'current, and it can bo made one of the poles of a battery so that a stream of electrons constantly emerges from it. This stream can then be controlled, as has already been vaguely indicated, by a multitude of devices, somo of which have been already described and used—used very effectively—but nono of which is as yet likely to have reached perfection. That is tho principle. The rest Is' detail. Fine and ingenious detail, but detail which can take many forms;. ana those forms are more suitable for description in the technical Press. Suffice it to say that such a device, if talked to, can supply a current varying with all tho tones of the voice; and'this varying current can be used to transmit electric waves 'after the usual methods adopted in wireless telegraphy, which has been brought to such practical success by Mr. Marconi.

Then at tho other end an ordinary wirelqss collector can receive them, can reproduce fcobly tho varying electric currents which originated them, and can then hand them over to a vacuum relay supplied with local energy, whero they will modify an electron-stream in the way above indicated. The feeblo receiveu current can, in fact, so control the stronger electric current which the relay is emitting from a local baUery that overy fluctuation can 1)5 imparted to that stronger current. This electron-derived current, relayed again if desired, can then bo applied so as to be heard in an ordinary telephone—the marvellously sini. pie familiar instrument which translates varying electric currents into articulate sound and applies it to tho human ear.

Talking to Other Planets. What the ultimate outcome of this power of long-distance telephony may be I will not attempt to prophesy. The ether waves, once meliorated, arc quite independent of matter. Mutter is (ynployod at the sending and (it the receiving end, but in nil the space between the efficient and necessary transmitting medium is vacuum, etlior, the space between tho worlds.

I do not wonder that Mr. Marconi, in his enthusiasm at tho power of speechtransmission which is thus coming into being, speaks of possible communication with other planets. Everyone, including himself, must foresee immense difficulties about that—and for myself, I venture to anticipate that science will recojnise a simpler and more direct mode 01 interchange of thoughts and ideas, though perhaps not witli dwellers, if there_ be auy, in other planets—before a physical process of transmission from world to world, in tho complicated code called language, is feasible.

However, there may be room for both methods, and posterity will know more than we do. Let us leavo it at that *nr the present.-r-"Daily Mail."