EINSTEIN'S THEORY

Evening Post, Volume CV, Issue 81, 5 April 1923, Page 2

EINSTEIN'S THEORY

ITS VALIDITY QUESTIONED IS SPACE FINITE? A cable message may be received at any time giving the results and - conclusions following the examination of the photographs taken iv Australia of the recent eclipse of the sun, Bays the Melbourne. "Argus." Chief interest in these, perhaps, centres about their agreement, or their disagreement, with Professor Albert Einstein's theory of relativity. This theory is concerned, among .other things, with fhe degree that beams of light projected from stars across tho eclipsed sun would .bo bent as they passed through the gravitational field of the sun. Acording to the Newtonian theory the bending should be so much; according to the Einstein theory the bending should be greater. Einstein made his predictions before the eclipse of 1919,, and when the negatives were examined it waß found that if Einstein was not precisely correct in his calculations, yet' he was more nearly correct than would Newtowu have been. In two instances Einstein came within 3 per cent, of the actual observed deflection. When this was announced it created a profound sensation in the scientific world, because Newtown was supposed to have Built his theory of gravity on an absolutely indestructible foundation. But if the Einstein theory was justified in two instances it was gravely in error in regard to five—for the deflection of the beams' from seven stars was examined. In the five instances referred to the Einstein' calculations gave erroneous results, the errors varying from 11 per cent, to 60 per cent. In fairness to Einstein, however, it should be said that errors might very well have crept into the "corrections" made by the astronomers, for it is admitted that to; make corrections which would be even approximately correct is a matter of great difficulty. v Einstein's relativity theory ; though it has been accepted by many distinguished scientists, has been rejected by more; and, so far as. can be judged, the evidence against it is accumulating faster than new evidence is being marshalled in its support. It was Professor Michelson's famous experiment in 1887, when he attempted to record the drift of the ether relative to the orbital movement of the earth round the sun, that inspired Einstein to formulate his theory. Miehelson tried to measure 'the drift by means of light rays The velocity of these rays would presumably be reduced if they were projected against the drift, jus as the speed of a raotor-boat relative to a fixed point on the banks of a river would be reduced if it were driven against the current of the river. But Miehelson got purely negative results. No matter whether the rays were projected against the drift, with the drift, or across the drift, he found that the speed of light was 186,000 miles "a second. From that, result Einstein postulated that the velocity of light was independent of the. velocity of its source. That is one of the corner-stones of his revolutionary theory. It contains a, startling paradox. But the general public, strangely interested, but not always understanding just what the postulate meant, respectfully said. Why not? It was not so with the scientists; some accepted it, others rejected it absolutely ""Professor,.Miller is one .."of..the best equipped of the opponents of this subversive theory. If Michelson's experiment failed to show any ether, drift, ' that was, according to .Professor Miller, because a layer. of . etcher was dragged round by' the rough surfaces of the earth. (It should be noted that this, / too, is revolutionary, because the ether had been assumed to be of such tenuity that it could not cause friction—that is, that it 1 could not offer any resistance to "matter," and, therefore, could not b« "dragged round" by the rough surface of the earth.) If we assume, however, that a body: of ether could be "dragged round"—or, say, "dragged along" with the earth, then Miehelson was projecting his,rays across what was really a still pool of ether; and, of course, it did not matter in which direction they were projected across this pool'so far as the velocity of the light was concerned.. This was what Professor Miller assumed, and, working along these lines, he repeated Michelson's famous experiment on a much larger scale and at a much higher altitude.. At 6000 feet above sea level he claims to. have discovered a perceptible drift in the ether, a drift -which does affect the velocity of light between two given points on the earth. If this can Be proved, Einstein's whole theory may go by the board, for one of its basic postulates is that light in all cricumstances travels.at a constant velocity "irrespective of the velocity of its source.' 1 Professor Miller's experiment seems to show that the velocity of light through ether is not invariable, and that its variability depends on the drift of the ether. . ■'■■■'":.- -' If Einstein's theory of relativity is correct it disposes of that troublesome idea of infinity which none of us can grasp. For instance., in regard to velocity, he -, - says there is no such thing as infinite velocity. Nothing can travel ■'faster than light. That is the ultimate possible velocity. A projectile, according to Einstein, decreases in size continually as its velocity increases. Directly it passed (if that were conceivable) the-186.000 miles maximum it would become infinitely small —which is another way of saying that it;would cease to exist. Nor,.in regard to infinity, is even space infinite./ "Space is finite, but unbounded." - ThisT is explained by saying that* as ws can travel for ever over a sphere, of definite size without coming to an end so we can travel for ever over space which also is . spherical without ever coming to an end. What the dimensions of space are Einstein has not yet ascertained, but he assumes that it has definite dimensions. Beyong space there is "nothing" ; so if you ask what would happen if you could project'yourself out of this hypothetical spherical space he would reply, that you could not do so, for it would require you to project yourself into nothingness —into that which does not exist. Nor does the theory permit straight lines, ,as we understand them. Euclid says that parallel straight lines if extended infinitely will never meet! Einstein says that they will, just as they would meet if you extend them to sufficient length on the surface of a, globe. We always think of bodies. as having three dimensions.] Einstein says, no; they have length, breadth, depth, and also time.. Thisidea of time as a fourth dimension is whimsically considered by Wells in his "Tims machine." One of his characters mamtains that time must be a. dimension just as truly as length, breadth, and, depth are dimensions, seeing that unless a body existed for a definite time it could not exist at'all. The "imagination boggles at' this unthinkable theory, and not only the ordinary man, but thousands of trained.scientists,'..will feel relieved, if it is over thrown.