BETWEEN THE STARS

Taranaki Daily News, 27 May 1933, Page 1 (Supplement)

BETWEEN THE STARS

OUR ROOMIER UNIVERSE

(By

Rev. B. Dudley,

F.R.A.S.)

A lecture by Sir James Jeans was recently outlined in the cables. It was designed to convey to his hearers some impression of the majesty of the heavens, a conception of the enormous distances which separate star from star and system from system. A few particulars in amplification of the theme with which the lecture dwelt may be found acceptable to readers who would become acquainted with the revelations of science to the modem astronomer. Our sun, it has been discovered, is only one of many millions of stars. To us it is a blazing orb merely because we are near. From Arcturus or Canopus it would be quite impossible to distinguish it. In truth, although the sun dominates the system to which we belong, compared with other stars it is an insignificant object. It is 400 times less in diameter than Antares. How much therefore in bulk I 1 The distances that separate suns from each other are enormous, the nearest neighbour to us being 26,000,000,000,000 miles away. And no one knows how far off is the remotest.. The majesty and extent of the heavens has grown with our knowledge of the universe. Within the last few years c. conception of the vastness of the cosmic order has been profoundly modified. According to Hubble the farthest nebulae are 140,000,000 light years away, the greatest distance yet known to astronomy; although still remoter objects are suspected, a suspicion which will doubtless be confirmed when the great 200 in. mirror has been completed. •? Among these mighty hosts we live and move and have our being on a tiny ball occupying its own little corner of the sky—an infinitesimal pinpoint in the universe. Away across the enormous gulf outside the bounds of the solar system, which is itself but a minute speck in comparison, lies the Milky Way, a complete ring of stars, forming the limits of the great scheme known.as the galactic system—the outer walls as it were of our domain; but in reality the enfolding coils, of a gigantic spiral. Beyond this system, across still greater, gulfs of the. infinite void, are to be found the extragalactic nebulae that take no part in the rotating movement of the spiral in which we live.

These also are spirals which work out their own individual careers. They constitute uni verses independent of ours, many of them being as vast. Two million such universes have been discovered. Our. own-galactic system is so . wide that' light, which shoots a distance of 670,000,000 . miles an hour, would take hundreds of thousands of light-years to cross it. “Every- universe outside our system,” wrote Dr. Harlow: Shapley, “is to-day regarded as a galactic system, with a diameter probably exceeding 300,000 light years.” Still farther away in immensity, above or below us, according to the point we occupy on this little world of ours, lies the realm of the unexplored, the realm beyond the reach of our mightiest telescopes, a region in! which—for no other conclusion seems possible—“universe must follow universe in procession up to.infinity ” Jeans, , who is x a past-master in the matter of drawing comparisons and similies that assist the imagination, puts' the case for us in. this way: “We can construct an imaginary model of'the system of the great nebulae by taking about 50 -tons of biscuits and spreading them so as to fill a sphere having a mile radius, thus spacing them at about 25 yds. apart. The sphere represents. the range of vision of the existing 100-inch telescope; • each biscuit represents a great nebula of some 4000 parsecs diameter. A few' 'nebulae of exceptional size must be represented by articles rather larger than biscuits, while our system of stars would be -represented by a flat cake. 13ins. s in diameter and- 2|ins. in thickness. “On this scale, Jeans estimates, the, earth is far below the limits either of vision or of imagination. It is . little more than an electron in one of the atoms of his model. . To bring it up to the size of even the smallest particles which are visible in the most powerful microscopes we should have to multiply its dimensions many millions of times. A parsec is a distance very .much greater than the light-year. The latter lias come to be too small a measuring rod in modern astronomy. A light-year is the distance light travels at the unimaginable velocity of 186,000 miles a second. It is equal to about 63,000 times the distance of the earth from the sun, or approximately 6,000,000,000,000,000 miles. The parsec is equal to 3.26 light-years, and is about 200,000 times the distance of the earth from the sun; that is to say 200,000 multiplied by 93,000,000. It is the distance of a star with the “parallax of a second,” a fact which its name, parsec, conveys to us. The fact that there is no known star Within one parsec of the sun shows the immensity of the scale on which the universe is built.

We . live, then, in a sense, in a roomier universe than our grand-parents. Since the telescope first began to explore the heavens man has been compelled to domesticate himself in a new cosmos. Creation was once, as a noted theologian writes “a comparatively smug affair; the earth was its centre and man its raison d’etre.” Our planet was thought of as the fixed point round which everything revolved. The sun was created to give light to man day by day, the moon and stars to shine upon him by night. “At a handy distance above him,” continues the same writer, “was a paradise for the good, and beneath, within easy distance, an avemus for the wicked.” z The astronomer has combmed with all truth-loving theologians in overturning this conception. The scene they now contemplate is one in which our earth is found to be the insignificant satellite of a star nearly a million times bigger—a sun-which in turn is itself only a minute speck' in the surrounding immensity. In view of the findings of recent science we gain some inkling of the emotion which stirred in the breast of Thomas Carlyle when, while an astronomer friend with whom he had been gazing at the starry host informed him of some of the latest discoveries, he exclaimed,. “Man, it’s just dreadful!” It is hard for even the keenest human intelligence to grow fully acclimatised to the immensity. We are only beginning to feel our .way about in the larger habitation wherein we find ourselves, and to get something like a true conception of our home in space. If the stars are lamps, then they, light an endless pathway. As said Sir Edwin Arnold once: “Veil after veil, will lift—but there must be veil after veil behind.” There is no place , where the wild ambitions of the world- are so thoroughly rebuked and dwarfed into littleness as in the' astronomical observatory.