MARVELS OF THE UNIVERSE

Nelson Evening Mail, Volume LXIV, 10 January 1931, Page 3

MARVELS OF THE UNIVERSE

TONNAGE OF LARGEST STARS LONDON. 27th November. • .. In a broadcast talk this week Sit; James Jeans (the eminent mathe-, matician and astronomer, and secretary', of the Royal Society) told the people of Great Britain some startling facts about; distances and weights of neighbouring stars. The gravitational puff of the earth, he said, whether on a ton weight or a flying cricket ball or on the moon, showed that it had the colossal weight of 60,000,000,000,000,000,000,000 tons: “In the same way we can calculate the sun’s weight from its pull on the earth, and we find that it has oq2,UUU times the weight of the - earth—for every ounce of the earth s substance the sun has very .nearly a ton.” he {said. “The sun’s gravitational puff keeps the earth from wandering off into space. If it were, not for this pull the earths speed of about 19 miles a second, would soon carry it far away from the sun into the cold depths of space, _ and we should meet an icy death within a few weeks. Just because the sun has this huge weight its gravitational puli is tremendous. A strong man who Uved on the sun would only be able to throw a cricket ball for two or three yards, and would hardly be able to lift.a 71b weight. And to perform either-of these feats he would have to be made of steel; a man of ordinary flesh and blood would be crushed flat under his own weight." SUN’S CANDLE POWER Sir James mentioned that there is a colony of four stars believed to have -a. total weight equal to nearly a thousand suns, and he said the sun gi Vo a md a light equal to that of 3,000,000,000,000,000,000,000,000,000 candles! Light traveiled at 186,000 miles a second* nnd took eight years to reach us from Sirius, which had about twenty-six times the candle-power of the sun. If Sirius replaced the sun rivers and oceans and ice continents round the poles would rapidly boil away, and life would be banished. The most unwelcome star, as far as this earth is conpcerned, would be S Doradus, which has over 300,000 times the candle-power of our sun. “If our sun suddenly became as energetic as this star its extreme heat would rapidly turn the whole earth and all objects on it, including ourselves, into vapour.” The temperature of the stars was calculated by their varying colours, which ranged from a dull red heat . through yellow and white heat 3 to vivid blue and violet. The hottest »t.ars had a temperature of perhaps 70,000 degrees Fahrenheit. From a star’s temperature we can calculate its candle-power per square inch, and if we know its total candle-power a simple division gives us the total number of square inches to its surface. This is how we calculate'the sizes of the stars.” The smallest star IS hardly greater than our earth, and . a million such stars could be packed • inside the sun. Yet other stars are so enormous that many millions of suns could be packed inside them,, and if one of them were put in the uosition of our sun we should find ourselves inside it, the radius of the star being greater than that of the earth’s orbit.-'-“Press” correspondent.