The daily Alaskan., 1909-12-17
THE PARKWAY STARS
Their Color Serves as an Index
 to Their Age.
WHAT MAKES THEM TWINKLE?

stars twinkle, the planets giving out a steady light That is the way we tell a star from a planet with the naked eye.
 But why does the srar twinkle at all? The answer to this seems to be on ac- count of the greater distances of the stars. the nearest fixed star being sey- eral thousand times farther from us than the farthcst planet So around this as a starting point have been built two theories. One is that as the visual angle, or angle subtended by the star from the eye, is so very small that very small bodies in space com Ing between the star and the eye would give the effect of twinkling.
 Now. as regards those small bodies actually being iu space as hypothecat- ed there is no doubt, for there are mil lions of fragments of disrupted worlds flying around in orbits about our sun. The only question is whether there are enough to cause the eternal twinkling that is observed. Science cannot say that enough do not exist, for she can not perceive the existence of the small est fragments that actually could cause this effect, even with Der finest instru- ments.
 To illustrate, then, my meaning as regards this covering of the visual angle, suppose you tlke a dime be- tween your thumb anl finger and hold lt between your eye and the moon un- til it just covers the moon. It will be found to be quite close to the eye. Now take a quarter and hold 1t so that 1t just covers the moon Its distance Is at once seen to be about four times the dimes from the eye Thus it is seen that the farther outward the object is placed the larger the object necessary. This is in accord with what is known as the law of inverse squares.
 But now take a dime or even a pin head. and no matter how far you hold lt from the eye it will easily cover the largest star in the heavens This is on account of the enormous distance of the star, the liues drawn from its sides to the eye iuclosiug an angle so minute that almost anything will dll iL So thus we see that this theory is not im- possible, though perhaps somewhat im- probable.
 The other theory bases its argument on the air currents. Air currents are caused by light and heated air rising and cold and heavy air taking its place. Now, when light goes from heavy to a light gas. or vice versa, it is bent one way or the other. So this would certainly happen to the light from all the heavenly bodies. The reason it is not noticed in the case of the planets or the sun is that they send us many more rays as compared to the stars.
 Many reasons are put forward to show the truth of this theory. A star twlnEles more on the horizon than it does in the zenith. for its light has to come through a greater thickness of atmosphere; also greater twinkling is observed in winter than in summer and when rapid and brilliant twinkling is seen 1t is a very good prophecy of rain or snow, as it shows the upper re- gions of the air to be iu state of rapid motion of varying air currents, hot and cold currents meeting, com minglIng and rotating probably.
 This also accounts for the changes in the brightness of a star, for at times a part and not an of its light is bent away from the eye. 1t has been uo- ticed also that stars color has some thing to do with Its twinkling on ac- count of the different refractiyities of the different coIors. A white or blue star, such as the Dog star, wrinkles most: next comes the yellow and last the red. If one cares to look for a red star, Betelgeux is one and can be found in one corner of the cOustella- ton Orion.
 A rather interesting thing has been ascertalued in astronomy as regards the relation between tbc color of a star and its age. The white or blue stars are considered young or in the prime of life, with many more million years to their career, while a red star, as Betelgeux, is on the waue and will grad ually go out in the next few million years. See if it doesn't. The yellow stars of course come between the blue and the red in point of age It is en- couraglng to fnd that our own sun is classified as white star, -A A. l.. Hodges in Cincinnati Commercial Trib- uue