THE EARTH THE CENTRE

Shannon News, 19 February 1926, Page 4

THE EARTH THE CENTRE

OUR FISJTE UNIVERSE. *r IS IT RUNNING DOWN? LiONDON, Dec. 11. The student of pure mathematics is first confronted with the conception of inflnite when he is asked to accept the statement that the ends of a straight line meet at infinity. How square this (with the idea which Dr. Jeans, secretary of the Royal Society, has propounded this week, which seems to point to the physical universe being finite —a conclusion which Einstein, too, arrived at? Dr. Jeans suggested tentatively that the fate that Professor Millikan had been unable td'detect any variation in the amount of radiation as th e earth rotated on its' axis, was an indication that we on -:arth were situated not far from the centre of the universe. He then went on to indicate, in equally tentative manner, how the observations of Professor Millikan might make it possible for us to determine the total weight of-, matter in the universe and also the distance to which the universe extended. He thought it might even now be possible by that means definitely to exclude the contingency that the material universe was infinite in extent. It may b fc recalled in this connection that recent reliable estimates giv e the distance of the Andromeda nebula and other spiral nebulae) as being so great that a ray of light travelling 180,000 miles per second would take a millions years to reach us from itfl The density of the gases in these nebulae, Di\ Jeans pointed out, is far less than that of the air in a single electric light bulb if diffused throughout the entire volume of the Albert' Hall. Thees bodies are situated probably far outside our stellar system, and are comparable in size to our entire system.

This ia an age "which has found a new toy in wireless, and is not affrighted, by the terminology of wavelengths. Most of us can make some attempt at understanding the size approximately of the universe —according to Dr. Jeans something like a million light-years. For thos 6 who are hot on close terms with astronomical calculations, it may be explained what this term, light-years, is. A million give the universe a diameter of 5,865,696,000,000,000,000 miles. To giv e an idea of the relative size of our share in the scheme of things a further calculation may be added. If a man walked four miles an'hour without stopping day or night, he would walk round the world in 37 weeks. At a similar pace he would walk round th e universe in 256,114,200,000,000 years. Dr. Jeans becomes alarming when h e tells «.i3 that "the universe is running down like a clock which no one winds up." It is true that it seems to be running down, but the fact that it has not yet run down, and the stars are born as well as die, reassures, so that w e need not fear that the end is in the near future.