AI. 



\RCH, 



1929 



E \' O L U T I O N 



Page Eleven 



The Amateur Scientist 



A Monthly Feature conducted by Allan Strong Broms 

 The Constellation Orion 



TO the south and right on the celes- 

 tial equator you can easily identify 

 th€ magnificent constellation Orion 

 on these clear winter nights. It con- 

 sists of an irregular quadrangle of four 

 bright stars, marking the imaginary 

 shoulders and legs of the mighty 

 hunter of the Greek myths. From his 

 belt (three stars in a row) hangs a 

 glimmering sword of lesser stars. For 

 his head there is a small triangle called 

 Al Hakah, "the white spot," by the 

 Arabs. In his right hand he wields an 

 uplifted club and over his left arm 

 carries a lion's hide for shield, both 

 marked by groups of small stars. 



At opposite corners of the great 

 quadrangle are two stars of the first 

 magnitude, at the northeast, red Betel- 

 geuse, "the armpit of the central one" 

 in the Arabic, and at the southwest, 

 diamond-blue Rigel. At the northwest 

 corner is yellow Bellatrix. the Amazon 

 star, of second magnitude, and at the 

 southeast a third magnitude star, Saiph. 

 The stars of the Belt (from north to 

 south) are Mintaka, Alniham and Al- 

 nita, the first two white, the third yel- 

 lowish. 



Rigel, Mintaka and the brightest star 

 of the head triangle appear double in 

 the telescope, while Alnita is triple and 

 the central star of the Sword qua- 

 druple. Even to the naked eye, this 

 sword star has a strange shimmer. 

 Viewed through an opera glass or 

 small telescope, it is found to be sur- 

 rounded by a faint nebula, the Greek 

 name for cloud. Photographed with a 

 large telescope and many hours expos- 

 ure, this turns out to be one of the 

 most beautiful objects in the heavens. 



Mintaka and Betelgeuse are variable 

 in their brightness. The latter is some- 

 times as bright as Rigel, at other times 

 much inferior. Its variations are un- 

 predictable, being quite irregular. Re- 

 cent measurements at Mount Wilson 

 Observatory with the great 100-inch 

 telescope and by Michelson's new in- 

 terferometer method indicate that Be- 

 telgeuse is nearly 250,000,000 miles in 

 diameter or fifty million times the vol- 

 ume of our Sun. Its mass (weight). 

 however, is only thirty-five times that 

 of the Sun, for its density is very low, 

 not much more than one-thousandth 

 that of air. We would almost call that 

 a vacuum. Its surface temperature 

 turns out to be less than 3,000 degrees 

 Centigrade, while that of the Sun is 

 6,000 degrees. While the Sun is white 

 hot, Betelgeuse is merely red hot. 

 Deep inside, however, the temperature 

 undoubtedly rises to millions of de- 

 grees. It is probably a young sun just 

 condensing from a nebula. As it grows 

 older, its surface will turn white hot, 

 its heat and even its substance will 

 waste away and then, after billions of 



The Constellation Orion 



years, it will cool into a yellow star, 

 then again red, and finally a dark star. 

 Rigel, with a diameter of 18,000,000 

 miles, over twenty times that of our 

 Sun, and a surface temperature of 16,- 

 000 degrees, is at its evolutionary best. 

 It would be about fifteen times as 

 bright as Betelgeuse were it not three 

 times as far away. The effect of dis- 

 tance on brightness is also well illus- 

 trated by a star to the southwest of 

 Orion, the white Dog - Star Sirius, 

 brightest of them all, as we see them. 

 .\ctually, it is much inferior to Rigel 

 and Betelgeuse in size and real bright- 

 ness, but it quite outclasses them to us, 

 because it is so very near, a mere 

 matter of 50 million million miles. 



YOUR BLIND SPOT 



Try this experiment on yourself to 

 find the Ijlind spot in your eye. Close 

 your right eye and read slowly with 

 your left, being careful not to let 

 it waver. 



* — Watch the star disappear. If it 

 does not, hold the page closer to your 

 eye. 



In the human eye the optic nerve 

 enters the back of the eyeball, not in 

 the center, but nearer the nose, so that 

 in turning the left eye to the right at 

 the proper angle, the image of the star 

 falls on the spot where the optic nerve 

 enters. As this spot is not sensitive to 

 light, the star disappears. 



The optic nerve, while capable of 

 carrying nerve impulses that cause the 

 sensation nf light, is not itself sensitive 

 to light. If it is injured, you do not 

 feel pain, but get the sensation of 

 flashes of light. If you feel pain at the 



same time, that is because another 

 nerve carries other impulses to a pain- 

 sensing center in the brain. 



The optic nerve ends within the eye 

 as a spread-out layer, called the retina. 

 This retina covers nearly the whole 

 rear of the eyeball and is sensitive to 

 liglit. But like all the rest of us, it gets 

 tired and dull from overwork. As we 

 use its center most, we can sometimes 

 see better by using a fresher portion. 

 For instance, if you want a glimpse of 

 the Orion Nebula described in the 

 neighboring article, just look a bit 

 askance (away from the nose) with 

 either eye. If the night is clear and 

 moonless, and your eyes are good, you 

 may be rewarded with a faint, brief 

 view. In this way you reverse the blind 

 spot experiment. 



BROMS TO LECTURE 

 Allan Strong Broms, our Science 

 Editor, will deliver a course of five 

 lectures on "EVOLUTION: From Star- 

 Dust to Brain-Stuff" on consecutive 

 Friday evenings, beginning March 8th 

 at Union Auditorium, 229 West 48th 

 Street, New York. 



While these five lectures are intended 

 primarily to, interest the novice and en- 

 lighten the student, they will also be 

 worthy of the science specialist because 

 of the new material that will be pre- 

 sented. Readers need not hesitate to 

 bring their most critical friends. The 

 entire proceeds will be used for the 

 promotion of EVOLUTION. 



The subjects are announced on another 

 page. Organizations in nearby cities that 

 would like to arrange for this course of 

 lectures should write for further de- 

 tails. 



THE PROOFS OF EVOLUTIOtV 



The response to the question in our 

 last issue 'Shall we publish 'The Proofs 

 of Evolution' by Henshaw Ward as a 

 Pamphlet" was so encouraging that we 

 printed it immediately and are ready now 

 to fill orders. The quantity price is fif- 

 teen copies for a dollar, five dollars per 

 hundred. One of our readers has al- 

 ready taken five hundred, and several 

 have ordered a hundred each. This little 

 gem by Henshaw Ward promises to he- 

 come a "best seller." 



From Our Readers 



"The value of all things, EVEN OUR 

 OWN LIFE AND TIME, depends on 

 the use we make of it." — A. Nicleii. 



"I am called a modernist, but if there 

 is anything that makes me inclined to 

 become a fundamentalist it is your 

 "EVOLUTION" Magazine. What 

 corner of intelligence do you imagine 

 you are cultivating? The cover of the 

 January issue is typical of your mind. 

 If you were really "scientific" you 

 would not be crack-pated. Talk about 

 "bigotry" of Arkansas. It is liberality 

 de luxe compared with your narrow- 

 ness." Elmer Wills Serl, Minister, The 

 Church of Wide Fellowship, Southern 

 Pines, N. C. 



