STAR SCIENCE

Taranaki Daily News, 27 January 1934, Page 13 (Supplement)

STAR SCIENCE

RANDOM SELECTIONS

(By

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

The facts, findings and inferences of modem astronomy read like a fairy tale, and prove the old saying that truth is stranger than fiction. Without going into processes and methods, one may discover much to wonder at in some of the following statements made at random, beginning anywhere and finishing at the same place. ' # * The great Mount Wilson telescope, if such a test were possible, could detect the light of a candle at 5000 miles, or that of an arc-light at the distance of the moon (240,000 miles). The bolometer measures a temperature so low as the 10-millionth of a degree. # # * * But little more than a decade ago an estimate of the number of stars m our own galaxy gave the host as 1,500,000,000. Now we are compelled to report the number to be nearer 40,000,000,000,000. This estimate is reliable, being based upon counts of the stars on a photographic chart of the entire heavens. And our galaxy—the Milky Way system —is only one of many millions of similar schemes. # # # * Sir James Jeans, speaking on the possibility of intelligence in other worlds, states that he finds it difficult to imagine life of any high order except on planets warmed by the sun, and that he is o the opinion that even after a. star has lived its life of millions of millions of years, the chance, so far as we can calculate it, is still about 100,000 to one against its being a sun surrounded by planets. “In every respect,” he holds, “—space, time, physical conditions—life is limited ' to an almost inconceivably small comer of the universe.” Another great astronomer suggests that among such swarms of suns as occupy space, a 100,000 to one chance would provide innumerable centres of life and growth. As a noted scientific lecturer and writer has recently stated, “Somehow it seems as though the universe would be out of. tune if ours were the only planet in time and space where life has appeared. As naturally as harvest-time brings the ripened grain, many a sun at the appropriate season must become the centre of manifold populations; though we can only conjecture. « * * • The beams of light which are caught by our telescopes to-night as they pour in upon us from the far-off nebulae left their sources when our little earth was in the full enjoyment of its youth ana vigour countless ages before man appeared upon its surface. By the time some of the remote parts of the universe are sending their light waves into the regions we now occupy the human race will long since have ceased to be. The earth and its thrilling history will have become, as a transient episode in the evolution of stars and atoms. #-■ # * Our galactic system is a disc-shaped, or watch-like, system, bounded by the Milky Way. It contains at least 334 clusters of suns and thousands of millions' of individual, double and multiple stars, interspersed with vast luminous and dark nebulae. Its thickness is about 3300 light-years, while its equatorial diameter is about 33,000 light tears.,. Our sun is at the present time 1150 lightyears from the centre of the mighty scheme and 30 light-years north of its central plane. •* # •

It has long been known that the star Sirius, the brightest in the entire heavens, has a faint companion. Sirius is itself more than 2500 times as bright as this attendant, but its mass is only 2J times as great, a fact that is determined from the motions of the two stars as they revolve about each other. The companion must be only about twice the size of the earth and yet about 4000 times as dense. Calculation shows it to be' 60,000 times as dense as water—just about a ton to the cubic inch.

The great nebulae in space have been compared to star-cities, London being taken to represent our own city of stars. Each of the two nearest star-cities is on this scale compared to Cambridge and Oxford. Each inch in London or Cambridge or Oxford represents about one and a-half million million miles in the corresponding star-cities, the distance, that is, which light travels in three months. Each inch in the open country between London and Cambridge or Oxford represents the same distance in astronomical space. A model on these dimensions is/ of course, exceedingly small, reducing the annual path of the earth round the sun to a speck the eight-thousandth of an inch in diameter; while the entire solar system, including the outermost planet, Pluto, becomes the size of a grain of sand. All the stars visible to the unassisted sight lie within a few feet. To flash a signal from one star-city to the next and get back an answer requires 60,000 tunes the span of a man’s life. Keeping still to this scale, with our own star-city as London and our nearest neighbour as Cambridge, the remotest nebulae must be placed 8500 miles from London 1

It is known that radiation .has weight and that therefore a stream of weight is forever pouring out from every part of a star’s surface. The total radiation streaming out from the sun has a weight of 4,000,000 tons a second, 'which is, writes Jeans, about 10,000 times the rate at which water flows under Westminster Bridge. “Its weight,” he states, “is diminishing as surely as if there were 10,000 gashes in its surface, with a whole River Thames pouring out of each. At this moment it weighs many millions of tons less than when you began reading this chapter; by this time to-morrow it will weigh 350,000,000,000 tons less than now.” Well might he ask in bewilderment where all this weight comes from.

As the sun is constantly losing weight its gravitational grip on the planets is growing feebler and feebler; so that all the planets, including the earth, are forever moving farther apart, retreating constantly from the sun out into the cold depths of space. All the stars of the Galactic System are likewise increasing their distances apart; the system is expanding. In looking at the heavens above us we are beholding but the present stage of a dissolving view. The universe is both a mist and a mystery.