STARLIGHT

Press, Volume LXXII, Issue 21759, 16 April 1936, Page 6 (Supplement)

STARLIGHT

KB MOVEMENTS OF THE EARTH

has looked at the sftilly on two nights a week llj&tt, or even on the same fcjtwro different times vith jtars between will have nom: the stars change their Bg&he sky. rlt is remarkPfSthis simple fact is not Even Charles, f&iadejhe mistake of thinkPltHey stars remained in the

Ktions all the time. He story about an invalid who

■e-same star shining torch tower, in the ill -night, and night f Of course you all '■■ impossible. stars move? Do they BMirt-A-'-- or do tne y onl y ap_ SKSWto do so? When you are S|?«jMn a train and looking gS» : 'She window you see the 2ffilisP uw ! n S past—telegraph Hgl*»ges;-'. fields, houses, and ""SjSU rush across the windows.

the scenery that train. Is it the 4SBJi£s an7 Yes . the stars a|l^fe : S' Very near 'y still as ■ , §jeiiffNKL' concer ned) and it is moves. S? over quickly the WS£&£&P* earth so that we »«!* understand better tPwrattr* a PPear to move. !Ba8&^ eaith is a spinning movJn S ball as i round * ne su n veT «i"ira^g I srA an<i at tne same /31naB&£uaelf as it goes. The fMMPjctJJed the revolu-

(By B. W. Collins)

tion of the earth in its orbit round the sun. The second is its rotation on its axis. The axis is the imaginary line through the centre of the earth round which it rotates. The ends of this axis on the surface of the earth are the North and South Poles. The spots in the sky to which this axis points are known as the North and South Poles of the heavens (or the celestial poles, in contrast to the terrestrial or poles of the earth poles). The plane

in which the earth's orbit lies (an imaginary flat sheet), or the plane of the orbit as it is called, is known as the ecliptic. When produced (extended outwards in all directions) it cuts the sky in a great circle, which is also called tne ecliptic. It has been given this name because all the eclipses of the sun and moon occur on ttns circle. The earth's axis always points in the same direction among the stars, and the plane of the or-

bit always remains the same. The axis is inclined to the plane of the orbit at an angle of 66* Therefore the plane through the earth's equator is inclined to the ecliptic at 23* degrees. The rotation of the earth causes day ana nieht Its revolution round tne sun is the cause of the The apparent movements ot tne stars are due to both these motions Study the diagrams carefully if you want to understand properly the next article, which will deal witn the movements of the stars.