Joe Tanalski, age 13, of Del Mar, Calif
Will the sun ever burn out?
Lately Andy explained some of the modern theories concerning the life story of a star. This subject is so vast, both in size and in time, that our minds find it very hard to grasp. A few facts about the scope of our own particular star, the sun, may help to make the subject more real to us. The sun, like all the starts, had a beginning and will some day come to the end of its long and brilliant career,
The earth is estimated to be about four billion years old and during all that time the sun has been pouring forth its energy with great extravagance. It is perhaps a billion years older than its children, the planets, If it were made of coal, this radiant star would have burned to ashes in a few thousand years. However, it is a nuclear furnace, ceaselessly converting matter into energy. Its fuel is hydrgen gas and every second some four billion tons of matter are converted into energy and radiated out into space.
It is estimated that, since the seething furnace began, enough matter to make several planets has been turned into energy. However, the sun can afford to squander its fuel at this rate for long ages to come. The planets, the comets, and all the sun's children contain only a fraction of one per cent of the matter in the sun. Some experts estimate that it has enough fuel to burn for 12 billion years and others say that the amount of fuel supply could last another 30 billion years. The great furnace, of course, is a ball of seething gases, Its diameter is 1 860,000. miles and its volume is about one and a third million times greater than the volume of the earth. Its surface temperature is about 6,000 degrees Centigrade and its seething interior is around 20 million degrees.
Each square centimeter radiates 1.8 horsepower day and night. About one part in two billion parts of its total energy falls upon our earth and this radiant energy supports all life on our planet.
The nuclear furnace of the sun is thought to have somewhat the same _ reaction which takes place in a hydrogen bomb. Atoms of hydrogen are built into larger atoms of helium and the energy released is waste material from this nuclear fu sion. It is believed that the process takes place in mall units involving four atoms of hydrogen. A helium atom requires most, but not all, of the particles in the four hydrogen atoms. In the seething nuclear furnace, these surplus particles are converted into radiant energy,
An earth year is the time it takes our world to orbit the sun. The sun, with its children, is traveling a vast orbit through the Galaxy at a speed of 135 miles a second. It makes one of these orbits in a cosmic year, which is equal to 200 million earth years. On this scale, the sun is now about 25. years old and well may live to a ripe old age of U0 cosmic years.