Illinois Junior Academy of Science - Yearbook (Urbana, IL)

Page 41 text:

ASTRCNOMY K G vnsnmi MOYluMlZN'l'S cl-,1,1'.s1'1,x1, , BODIES

Page 40 text:

Science and Archaeology FRANK D'ARCY Northbrook Junior High KLRLRL 'WN If U Sri' Carbon 14 is created when a nitrogen atom is struck by a cosmic ray. The result is Carbon 14. Carbon 14 is radioactive, that is, it gives off beta particles. The Carbon 14 is absorbed by all life. When an organism dies it loses Carbon 14 at a steady rate, in 5,568 years one half is left, in 11,136 years one fourth, etc. By measuring the Carbon 14 we know how old an object is. In pottery, radioactive matter such as uranium thorium and potassium give out alpha, beta and gamma rays. The rays knock stable atom's electrons out of their natural orbit. These electrons are trapped in the clay and when heated to 5000 C. they are forced back into their normal orbits. When this happens each electron emits a photon of light. This light is measured and the more light the older the object is. This is known as thermoluminescence. In clay there are particles that are magnitized. They point all ways and cancel each other out. When heated to 600 C. they tend to align themselves along with the magnetic poles of that day. Since magnetic poles shift, to find out how old an object is, all we have to do is find the way the particles in the clay point and look up the date when the poles were in that position, this is known as archaeomag- netism. In bones fluorine and uranium is absorbed when water seeps through to the bones. At the same time nitrogen is lost through protein decay. Because the amount of fluorine and uranium gained and the amount of nitrogen lost depends on the place and conditions in which the bones were found, scientists have come up with an average for normal condition - this is the fluorine process. There are two main types of aerial photographs: vertical and oblique. Vertical are the results of crop growth. Over trenches plants grow bigger and more luxurant, and so have a darker color. Over walls the plant growth is stunted and the plant color is lighter. Oblique photos are the results of shadows. Over buried walls slight hills are formed. These cast shadows. Four Cultures Ai' Yankeetown ELLEN MARTIN Carl Sandburg Junior High The theory that four consecutive cultures of four dif- ferent groups of Indians had occupied the Yankeetown area at different times could only be proved by Archaeological excavation. The idea was that the four following cultures had at one time existed here: A. Archaic culture - wandering food gathering and hunters: had primitive tools: no pottery. B. Baumer culture -- an early woodland culture who were food gatherers and storers, hunters with more refined stone tools and pottery. C. Middle Woodland -- more advanced cultivators of foods: hunters with stone toolsg some copper and food gath- erers and storers, D. Late Woodland - advanced cultivators and hunters: more refined tools 3 some metal toolsg pottery of more durable nature. Since I am a member of the Chicago Archaeological Society, I was invited, along with my family to attend Dr. Emily Blassingham's 'dig' at Yankeetown and observe the work going on to prove the above theory. The evidence uncovered pointed to the affirmation of the theory, the dig was fruitful, and there was significant evidence that there had, indeed, been four cultures at Yan- keetown. Dr. Blassingham hopes to return to the area for further study, and I hope to be able to go and participate, agam.

Page 42 text:

Determining Relative Lunar Distances ancl Appli- cations ULDIS SAULE Willowbrook High School Villa Park This project is the result of my particular interest in the lunar field of astrophysics. I have serously been engaged in the hobby of astronomy and astrophysics for the last four years. In this project I have developed an original method to determine with accuracy distances on the moon. This involved correcting the apparent distances for distortion due to spherical perspective. I have developed a method to de- termine the altitudes of features on the moon by measuring the shadows cast by them from photographs which I have taken through an eight inch reflecting telescope. Using these methods I have measured the depths and diameters of craters on the moon and from this I have derived an equation which relates crater depth to crater diameter. I have also developed an equation which enables me to determine the angle of inclination of the inner wall of a crater if the crater's depth and diameter are known. Recently I have completed a series of equations which will make it possible for me to compare the volume of the part of a lunar crater below the relative surface of the moon with the volume of the crater's wall above the relative surface of the moon. Movements of Celestial Boclies JOHN SORTINO Brother Rice High School Chicago Sponsor: Brother Kelleher Will Mil S tfiai.i:s'1'mi, . -. t mmuzs 1 l ,Mi o - zyi 73, f it 1 . 'Q fvrs , , , In summary I would like to say that my project has much to do with the laws of such great men as Einstein, Kepler, Bache, Newton, Galileo, Hubble, Hooke, and Halley. It takes in one of the greatest problem in astronomy, mo- tions in the universe. It takes in many theories such as the big-bank theory of the life of a galaxy, and Hubble's theory on galatical classification. It has to do with many proven facts such as Newton's law of gravity and law of inertia: Galileo's proof that any two objects will fall to the ground at the same rate g and Kepler's elliptical law, law of equal areas, and harmonic law, My project shows that the gravi- tational center between the earth and moon moves around the sun, and the rotation period is the same as the period of revolution for the moon. All these laws, theories, and rules prove that the universe does have set patterns, where motion is no exception. Many things in the universe are a mystery. How motions started? and What keeps the motion going ? - are mysteries which only time will solve.