PHY 102 1nd Edition Lecture 3 Outline of Last Lecture I. Eudoxos (continued)II. Angle of Measurementa. Definitioni. Two names associated with the measurementsii. How big is the moon?iii. How far is the moon?iv. How far is the sun?v. How big is the sun?vi. How big is Earth?Outline of Current Lecture I. Blue Book 1.1 #2, 4II. The Age of Measurement (continued)III. MallardIV. Blue Book 1.2 #2, 4Current LectureI. Blue Book 1.1 #2, 4II. The Age of Measurement (continued)a. One of the most significant chapters in Greek scienceThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.b. It coincided with the work of Archimedes, one of the (if not the) greatest mathematical physicists of all time, who made significant measurements on fluidsc. Alas, Greek science ended with the rise of the Roman civilization, which was dominated by pragmatism of politics, law and militaryi. You never hear Roman physicist or mathematiciand. The only other development in astronomy was the solution of the problem of thechange in brightness of planets in their retrogressione. Apolloniousi. A contributor to this solution was Apollonious who used epicycles to explain both the retrograde motion as well as change in brightness1. Instead of concentric spheres (as in homocentric model of Eudoxus), put the planet on a circle (called the epicycle) and let the circle move on a bigger circle (called deferent)2. Planets move uniformly on epicycle and epicycle moves uniformly (with a different speed) on deferent3. The combination of the two uniform motions gives both retrogression and change in brightnessf. Ptolemyi. The introduction of epicycles was the last major step in building a theory that explained the observed motions of the planets1. Of course, minor steps were needed to “fine-tune” the theory in the face of more precise observationsa. For example, all planets needed more than one epicycle to account for their motionb. Epicycle after epicycle = geocentricii. Wrote the definitive book Almajest on astronomy1. Over eighty epicycles2. An earth that was no longer at the center3. Planets no longer moved uniformlyiii. Theory lasted for 1400 yearsIII. Practice Mallard quizzes as many times as you wishIV. Blue Book 1.2 #2,
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