OUR HOME IN SPACE

Taranaki Daily News, 17 September 1932, Page 13 (Supplement)

OUR HOME IN SPACE

SCALE OF. THE UNIVERSE

(By

Rev. B. Dudley, F.R.A.S.)

Our sun is only one lions of stars. To us it is a blazing orb merely because we are near. Arcturus or Canopus it would impossible to distinguish it. In truth, although the sun dominates the y tern to which we belong, compared v th hosts of other it is an msign cant object. It is 400 times less in diameter than- Antares. How much dess, therefore, in bulk! The distances that separate suns from each other are enormous, the nearest neighbour to ours 'being 26,000,000,000,WQ miles away. And no one knows how far off is the remotest sun. Ihe majesty and extent of the heavens has grown ivith our advance m knowled e of the universe. Within the last years our conception of the vastness of the cosmic order has been Profound ly modified. According to Hubble, ** he farthest nebulae are 140,000,000 lightyears away, the greatest distance yet known to astronomy;, although still re moter objects are. suspected, a suspcion that will doubtless be confirmed when the nreat-200-inch. mirror has been completed and. mounted ready, for use. . Among these mighty hosts, we live,' move, and-have .our being .on. & tiny ball occupying its own little, corner the ST an infinitesimal pinpoint m the universe. across the-enorm-ous <mlf outside the bounds of the solar system, which is itself but a minute speck in comparison, lies the Mil y 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 real ty the enfolding coils of a gigantic spiral. Beyond this system, across still S rea er gulfs of the infinite void, are to be found the extra-galactic _ nebulae that take no part in the rotating movement of the spiral in which we live. TOese also are spirals which work out their own individual careers; they constitute universes independent of ours, many of them being as vast. Two million such universes have been, discovered. Our own galactic system is so wide that Iteht. which shoots a distance of 670,000,000 miles an hour, would take hun-dreds-of thousands of 'light-years -to cross it. “Every universe outside our system,” wrote Dr. Harlow Shapley re T cently, “is to-day regarded a? 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 tele■scopes, a- region, in which—for .no other ■conclusion seems, possible—universe must , follow universe in procession up •to-infinity?’ ‘ . Jaaps, • who .is a past-master in the matter, of drawing comparisons and ■similies. '.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 biscyite and spreading ■them'-'so, as to fill a.sphere ofmile radius,, thus spacing. them at, about ■yards apart. The’sphete represents.the range, of vision of the existing 100-mch ■telescope;' each biscuit . represents a great'; nebula-: of' some 4000 Rarsecs dia- . ■meter. A few nebulae of exceptional ■«ize must be represented by- articles rather, larger . than biscuits, while our system .of stars would be represented by a flat cake 13 inches in diameter and inches' iff thickness.” On this sea'le. Jeans estimates, the earth is far .below ■the limits either of . vision or of imagination. . It isdittle more .than, an electron in one of the atoms of his model. To bring it up to size of even the smallest 3 partiedes 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 lightyear. The latter has come to be too ■small a measuring rod in modern astronomy. A. light year is the distance that light travels at the unimaginable ■velocity of 186,000 miles per second. It it equal to, about' 63,000 times the disdance 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'2oo,ooo times the distance ■from earth to.eun; .that ,is to say, 200,■OOO multiplied by 03,000,000 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 or- three and twenty-six hundredths Iteht-vears of the sun shows the immensity of the scale on which, the universe is built. . . , : Stars that are 10, 50 or even 100 lightyears from the earth are our nearest ■neighbours in space, leaving out of consideration the moon and the planets •and other bodies that belong to the .sun’s family. We live then,. in a sense, in a roomier universe than our grand-parents. (Since the telescope first.'began to explore ■the heavens min 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. Ihe sun was created to give man. light by day, ■the moon and stars to shine on 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 avernus for. the wicked.” The astronomer has combined 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 sun. nearly 1,000,000 •times bigger —a sun whiefli in turn is itself only a minute speck in the surrounding immensity. The eternal silence of the infinite spaces terrified Pascal (so he tells us), while the poet Watson, who has since fallen upon evil days, exclaims how . . . oftentimes he feels The. intolerable vastness bow him down, The awful homeless spaces scare his soul. And we have an inkling of the emotion that stirred in the breast of Carlyle when, as an astronomer friend with whom he had been gazing at the starry host informed him of some of the latest findings of science, he exclaimed, “Man, it’s just dreadful, it’s just dreadful!” It is hard for even the keenest human intelligence and imagination 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.