Jasper County Democrat, Volume 17, Number 93, Rensselaer, Jasper County, 27 February 1915 — why the stars twinkle. [ARTICLE]

why the stars twinkle.

The Light of the Heavenly Bodies Is Bent in Its Passage Through t,he Atmosphere. The question of childhood: “What makes the stars twinkle?” was answered probably by a bit of verse- or poetic fancy. But men asking the same question sought a scientific explanation and found it. Although we live upon its surface, we are not outside of the earth, but at the bottom of a sea of air which forms the earth’s outermost layer and extends above our heads to a height of many miles. We cannot see the stars save as we look through this atmosphere, and the light which comes through it is bent and oftentimes distorted so as to present serious obstacles to any- accurate telescopic study of the heavenly bodies. Frequently this disturbance is visible to the naked eye, and the stars are said to twinkle, i. e., to quiver and change color many times a second, solely in consequence of a disturbed condition of the air and not from anything which goes on in the star.

This effect is more marked low down in the sky than near the zenith. It is worth nothing that the planets show very little of it because the light they send to earth comes from a disk of sensible area, while a star, being much smaller and farther from the earth, has its disk reduced practically to a mere point whose light is more easily affected by local disturbances in the atmosphere than is the broader beam which comes from the planet’s disk. At all times, whether the stars twinkle or not, their light is bent in its passage through the atmosphere so that the stars hppear to stand higher up in the sky than their true positions. To the atmosphere with its suspended dust and vapor is due, also, that lengthening of day that we call twilight. Have you ever seen the twilight arch rise up in the eastern sky. just after sunset? Look for it from a hilltop or some other place with an open view to the east. —Wisconsin Bulletin.