JUMPING STARS.

Otautau Standard and Wallace County Chronicle, Volume XXVIII, Issue 1396, 25 October 1932, Page 1

JUMPING STARS.

One of .the most interesting, thingsappearing m the ' telescope' when that' instrument ip> pointing-' heavenward, is the appearance of jumping stars. 0^ course, we can see stars twinkle without^ telescope; bu£ with a telescope they imay be seen to jump and actually tot dance.. The cause, is the same — mixing,' currents of light and heavy air { causing refraction or bending;/of 4 the rays of light- coming from the star, We can se^ the same phenomenon by .looking at a small object over a • hot y radiator. The object sterns to»*jump 'and dance as if playing >hide - and. seek with dtself . ' ■ This jumping m the telescope or twinkling to the naked eye has also, been explained by what is called interference. If two sources of light are placed close /to each other, then on. a screen placed properly we can catch, an alternative band of white and dark lines. Of course if the eye be' placed at .a dark line, it can see neither source of light. The production of these dark lines is . accome-

plished by different lights waves reaching the- screen m opposite phases so as to blot out or cancel the effect due to each. In like manner it can . be shown that if the star has polychromatic (many coloured) light, it can, and has actually been observed to, change colour from this effect alone.. . . '■ ..." The best time to observe this effect of star dancing is on a cold crisp night; The telescope should be pointed to a twinkling star as near the horizon as can be found, as to see a star on the horizon we have to ldok-tl^fo\jgh «i«ch more aiinosiihere than- to see one m; the zenith.