HOW BIG IS THE UNIVERSE?

Otago Witness, Issue 3830, 9 August 1927, Page 16

HOW BIG IS THE UNIVERSE?

THE LATEST ASTONISHING RESEARCH.

By

the Rev. B. Dudley,

F.R.A.S.

It requires a great effort of the imagination to realise the vastness of our muchtroubled. much-rejoicing world. But having made the best possible attempt to comprehend its dimensions, we must still further stretch the pinions of imagination in order to gain a viewpoint from which to take in the enormous proportions of the solar system in which the earth is but a tiny dot. That system is no than 6000 million miles across. That is to say, the orbit of Neptune, the emotest known planet in the sun’s family, is 6000 million miles in diameter. Within, its limits roll the earth’s neighbours— Mercuiy, Venus, Mars, Jupiter. Saturn, and Uranus. A noted journalist recently said that the eternal silence of these in-

finite spaces made him afraid. If, however, the earth is a tinv point in the solar system, that system is itself hut another dot in the uinverse within which it moves. On a calm, clear night we look up at a group of stars well known to us as the constellation of the Southern Cross, and then remember what we have previously learned about them —namely, that they are hundreds of millions of times larger than our earth, and we feel a thrill of wonder But marvel does not cease here. The distances that separate the solar system from some of the soI called fixed stars are so great that they cannot be measured in miles. _ Instead of this, we reckon them up .in what are called light years. In a single year ray of light travels rather more than 5.840.000,000.000 (nearlv six billion) miles.

This distance represents a light year. It is not long ago that the bounds of the universe were believed to be "only” 2000 light years away 1 But with improved instruments and better means of measuring these terrible distances, the known universe has greatly enlarged itself, so to speak. So much larger has it grown in fact, that the light vear is no longer a large enough unit of measurement. Tha word “parsec” was coined a few years ago by Professor Turner —“an inelegant but convenient portmanteau word,” someone has called it—representing about two hundred thousand times the distance from the earth to the sun (the recognised astronomical unit). The parsec is 3.26 (a little more than three and a-quarter) light years. . , , , The series of observations and calculations that resulted in the extension of our ideas as to the scale on which the universe is built began during the latter stages of the Great War, and took place at the Solar Observatory, Mount Wilson, California, and are attributable largely to the genius of George Ellery Hale, whose powerful equipment for this class of work is unequalled anywhere. Arthur R. Rinks, of London, writing in the May issue of the Nineteenth Century, says: “That observatory alone is responsible for extending the scale of the known universe by a least a hundred times in the ten years 1914 to 1924, and by another 40 times since last Christmas.” And now we have, more recently still, the astounding* results of the work of Hr Hubble, anj other first-class specialist, whose great I achievements run along the lines of penetration. into stellar-distances. His findings are of the nature of “a new surprise.” In a recent number of the Astrophysical Journal, this expert tells us that the new lOOin telescope, probing into the awful depths of space, has detected faint nebulae whose distances are in the vicinity of 43 million parsecs. Remember that a light year is the distance that light travels in a year at the rate of 186,000 miles a second : and that a single paisec is about three and a-ouarter light years, and then some faint impression begins to dawn upon the mind as to the size of the universe. Hubble finds that there are about two million nebulae at an average distance apart of 600.000 narsecs. This Requires thinking about. Thus from hundreds of thousands of light-years as representing celestial distance'in 1916 we. have leaped (there is no other word) to, not hundreds of thousands, but millions of parsecs. If these distant nebulae belong to our universe what a magnificent system it is!—a system of overwhelming grandeur and glory ! What if. as Hubble and manv other competent authorities think, thev are far beyond the bounds of our universe, and represent "island universes,” external universes of stars comparable to our own, the brightest and nearest of which onlv we see on a clear, star-lit ni"ht ’ Put the whole together in tbon <T ht. call it the Greater Universe and then cease talking. Ba still and silent, get lost in thinking, thinking. And then having thought and wondered and worshipped the eternal Power that pulsates all things, from the least I daisy that smiles among the blades of grass to the giant star Canopus get up and about the dailv round and common task as if there were nothing in all the world so interesting as one’s work. Sir Henry Holland wrote: “There is no nlace where the wild ambitions of the world. are so thoroughly rebuked and dwarfed into littleness as in the Astronomical Observatory.” - The noble science at least does this for ns: it belns us to recognise the splendour and significance of little things, for the small and the great alike belong to one vast and well-ordered scheme. As Amiel savs. “At whatever noint on the earth you stand, von are equally near to heaven and the infinite.” . We are even in the presence of an infinite and eternal energy, from which all thm<rs nroceed.