How far the sky goes ?
When we speak of the sky, we usually mean the vault of the heavens, or the great arch which seems to lie like an inverted bowl over the earth. We say that the sky is blue, that there are thunder clouds in the sky or that the sky looks stormy or clear. In this sense we mean the nearer sky, the atmosphere, in which our weather and all our sun set and sunrise colors occur. This is not all of the sky, however even though it is now believed that the atmosphere stretches up to a height of probably 600 miles above the earth.
Beyond the part of the sky that takes on color and that we see changing from moment to moment, lays the great universe of space. We look out through the atmosphere to that greater sky beyond, where the planets, the stars and galaxies move majestically upon their paths. This sky universe is so vast that no one knows where it begins or ends. We don’t even know whether it has a beginning or an end.
Astronomers using their great telescopes have not yet found any end to the multitudes of stars out there. With each new and larger telescope they have been able to see farther out into the universe. The distances are so great that they do not measure them in terms of miles, any more then we measure the distance around the world in inches. Astronomers use the light-year, the distance light travels in one year, as their yardstick. This great measuring, rod is a long one, 6,000,000,000,000 miles long.
With the 100 inch telescope at Mount Wilson, California, astronomers have photographed objects are 240,000,000 times 6,000,000,000,000 miles. We know then, that the sky extends at least that far in all directions from the earth. With the new giant telescope on Palomar Mountain we shall perhaps be able to explore the sky as far as 6,000,000,000,000,000,000,000 miles on all sides of the earth. Whether we shall find that the stars grow fewer in number when we get so far away or perhaps that there are no more stars out there, only time can tell.
By Rehana khan(111/10)
