AST 301Exam # 1 Study Guide Lectures: 1 - 4Lecture 1 (September 2)Prehistoric astronomyAstronomy is one of the oldest professions is based on what?It is based on civilizations dating significant events such as births and deaths, predicting times for harvests and planting, and navigation. Astronomy is universal to all cultures. Ancient structures were built with astronomically significant orientations because prehistoric people were more astronomically aware. Though they understood little, they observed much and observed the darker skies.What is the significance of eclipses and phases of the moon?Sun and moon were very important in the daily life of the ancients. There are solar and lunar eclipses, partial and total, penumbra, and umbra. Ancients could predict by observing cycles of repetition (saros cycle=18 yrs 11d). They were able to figure out the Earth was round because ofits spherical shadow. In a solar eclipse, the moon blocks out the sun.Lecture 2 (September 4)Historical astronomy Explain Kepler’s Three Empirical Laws and Newtons Theoretical Laws? What did it lead to?Kepler’s three empirical laws were mathematical analysis. The first law is that orbits are eclipseswith sun at one foci (nearly circular). The second law is the line between a planet and the sun sweeps out equal areas in equal times. The third law is the square of orbital period increases with cube of semi-major axis. The planets farther from the sun move faster. Newton had three theoretical laws. The first is that in the absence of force, objects move in a straight line. The second law is that force equals mass times acceleration. The third law is that action equals reaction or force=force. This led to Newton’s fourth law which states that gravity isuniversal and cannot extend undiluted forever, which is why it is an inverse square law.Lecture 3 (September 9)How can you tell if a theory is a scientific theory or not? What were Galileo’s observations?Science is the way of thinking and things, you can have a scientific theory and non-scientific theory. Unlike true science, a pseudoscience is not falsifiable—not a scientific theory because theories need to be falsifiable. Galileo observed Jupiter with a telescope to prove that some bodies don’t orbit the sun.What is an observable consequence of the Earth rotating in the opposite direction?Some consequences are that large storm systems would spin the opposite direction. The Earth’s tidal bulge would be behind the line connecting the Earth and the moon. Also, the solar day would be shorter than the sidereal day.Lecture 4 (September 11)Explain Newton’s Universal Law of Gravitation and what was flawed about it?In his Universal Law of Gravitation, Newton did explain the difference between mass and weight. However, he didn’t attempt to explain why the gravitational mass and the inertial mass are the same. To him, it was only a coincidence. While he did not explain what causes gravity, Einstein did. Einstein brought about the general theory of relativity which is the relationship between inertial mass and gravitational mass.What does our solar system consist of? Include major contents, minor contents.Our solar system is a collection of worlds. Including 8 planets, moons, asteroids, and comets (Pluto not being considered as a planet). The major contents of our solar system are terrestrial planets (inner) and giant planets (outer). The inner planets are solid and rocky such as Mercury, Venus, Earth and Mars. The outer planets are gaseous with inner rocky cores. These include Jupiter, Saturn, and Uranus. The minor contents of the solar system are asteroids and comets. Asteroids are combinations of rock and ices while comets are “dirty snowballs.” Why should we study the Earth? Explain the occurrence of earthquakes and waves?The Earth is the best studied example of a planet, primarily because we live on it and it’s the most convenient planet for humans to study. Moreover, it is the start of comparative paleontology and other planets can be compared to the Earth relative to their composition and other factors.The study of earthquakes is known as seismology. It occurs in the internal structure of the Earth from seismology. Seismic waves travel through the Earth. Primary or p-waves are longitudinal waves. These are compressional waves such as sound waves. Secondary or s waves are transverse waves such as on the ocean surface. Seismology is what revealed the inner structure of the Earth.How is the inner structure of the Earth?Revealed from seismology, the inner structure of the Earth has an atmosphere that causes earthquakes caused by the moving of tectonic plates. Earth’s core is nickel and iron; we know this because of the density of the material at the core. Earth is also hotter at the center of the surface so is heat is flowing from the center. Radioactive heating is caused by radioactive decay of bulk materials of Earth that is released as energy. The low density rock in the lithosphere slides over the
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