Introduction Syllabus ASTR 113 Lecture 1 with Professor Dr Harold Geller Online printed copy available the first lecture only in class Grading Summarizing see webpage 33 3 each in class exam and final final is comprehensive ALL Exams calculators pencils scantron bring your own and ID only follow posted rules or F NO MAKE UP EXAMINATIONS I repeat NO MAKE UP EXAMINATIONS Extra credit using iClickers NO SUBSTITUTIONS Repeat ONLY extra credit is via the iClickers useage Introduction Textbook Universe 7th edition by Freedman and Kaufmann Optional Auxiliary Materials Personal Response System Introduction continued Web notes Will be updated routinely check back often Observing Sessions at Rooftop Observatory Offered on campus for your learning experience and enjoyment F K Chapters 4 5 Review Basic ideas reviewed in this lecture Read textbook and think about what is being said iClicker Kepler s Laws of Planetary Motion Kepler s First Law of Planetary Motion planets orbit sun in an ellipse with sun at one foci Kepler s Second Law of Planetary Motion planets sweep out equal areas in equal times travel faster when closer slower when farther Kepler s Third Law of Planetary Motion orbital period squared is proportional to semimajor axis cubed P2 a3 Newton s Laws of Motion and Gravity Newton s First Law of Motion body at rest tends to stay at rest and body in uniform motion will stay in straight line uniform motion unless acted upon by an outside force Newton s Second Law of Motion the acceleration of a body is proportional to the force being applied F m a 1 Newton s Laws of Motion and Gravity Wien s Law Newton s Third Law of Motion Peak wavelength is inversely proportional to the temperature of the blackbody for every force there is an equal and opposite force action and reaction Cooler Body Newton s Law of Gravitational Attraction force is proportional to masses and inversely proportional to the distance squared Peak Wavelength Hotter Body F G m M r2 Intensity Frequency Stefan Boltzmann Law Energy radiated by blackbody is proportional to the temperature to the 4th power Kirchoff s Spectral Laws Kirchoff s Spectral Laws empirical Continuous Spectrum what produces them Energyvs Temperature 60000 Emission Spectrum 50000 what produces them E T4 Energy 40000 30000 Absorption Spectrum 20000 what produces them 10000 0 0 2 4 6 8 10 12 14 16 Temperature Kirchoff s First Spectral Law Any hot body produces a continuous spectrum if it s hot enough it looks something like this digitally like this Intensity Kirchoff s Second Spectral Law Any gas to which energy is applied either as heat or a high voltage will produce an emission line spectrum like this or digitally like this Intensity Wavelength Wavelength 2 Kirchoff s Third Spectral Law The Photoelectric Effect Any gas placed between a continuous spectrum source and the observer will produce a absorption line spectrum like this A prelude to the Bohr atom experiment explained by Einstein but performed by others what caused this strange result or digitally like this Intensity Wavelength Prelude to Bohr Bohr s Atom Einstein used Planck s quantized particles Best described the workings of the Hydrogen atom energy of photon is related to frequency of light not intensity need high enough frequency to get electrons released from metallic surface one proton and one electron around the proton moving in orbits that are discretized quantized so that no intermediate orbits are allowed Absorption Emission E h f Maxwell s Electromagnetism Electricity according to Gauss relates electricity to electric charge Faraday s Law relates electric fields to magnetic fields Doppler Effect Don t worry about notation here A change in measured frequency caused by the motion of the observer or the source classical example of pitch of train coming towards you and moving away Magnetism according to Gauss relates magnetism to electricity Ampere Maxwell Law relates magnetic field to electricity 3 Conclusion To understand the stars and our Sun is a star galaxies and the universe at large cosmology you need to understand Physics Forces gravity electromagnetic strong weak Matter protons electrons quarks bosons etc Theories Laws and Effects Newton s Kepler s Kirchoff s Stefan Boltzmann Doppler Photoelectric Relativity etc Chemistry Atoms elements molecules and their models e g Bohr And for Chapter 30 even a little biology 4
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