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STUDY GUIDE FOR EXAM 1
1. YOU MUST NOT USE YOUR LAPTOP OR YOUR CELLPHONE
2.HINTS ON TAKING "OPEN BOOK AND NOTES" TESTS:
a. Study as if it were a closed book test. You do not have time to look up each answer.
b. Carefully read the Chapter Summary, learn the “New Terms”, try to do the Review Questions, and the Discussion Questions. Work as many Problems as you can. Feel free to ask me if you are having problems doing them.
c. Don't forget the index or the glossary.
d. Read the test questions carefully!
e. Go through the test once and answer all the questions that you can. Then go back and do the other questions.
f. Mark on the test booklet: cross off obviously wrong answers, work the problems, and show your work. Circle the answer on the test booklet - this is the last resort if you have made a mistake on the answer sheet.
g. Carefully darken in the answer on the answer sheet, do not rip, mutilate, fold, or spindle it.
g. Check your answer sheet. Make sure you have answered all 50 questions.
h. MAKE SURE THAT YOUR NAME IS ON THE ANSWER SHEET AND YOU HAVE PUT IN YOUR FULL UNIVERSITY ID NUMBER-LEFT JUSTIFIED. I will subtract points if this is not done.
I. BRING A PICTURE ID. I WILL ASK YOU TO PLACE IT ON THE TABLE IN FRONT OF YOU AND I WILL GO AROUND THE CLASS DURING THE EXAM CHECKING EACH ID.
Chapter 4: Origins of Modern Astronomy
a. Where is Stonehenge? What was it used for? Where are some other Astronomical Alignments located? What is archeo-astronomy? What does it tell us about primitive people?
b. Look at the contributions of the Greeks. What was their world picture? What did Aristarchus do? What did he believe about the Earth?
c. What is Parallax? Why did the fact that stars did not show any Parallax motion convince the Greeks that the Earth was not moving? Why were they wrong?
d. What did Eratosthenes measure? How did he do it?
e. What is retrograde motion? What did Ptolemy invent to explain retrograde motion (incorrectly, of course)? How accurate were his predictions? The name of the Acircles upon circles@ model is the epicycle model. The circles are epicycles and they revolve around the earth on deferents. (Pages 58-59)
f. Who were Copernicus, Tycho, Kepler, and Galileo and what were their contributions to studies of the motions of the earth and planets? How did Copernicus change the solar system in his attempt to understand retrograde motion? What did Tycho do? Where did he do it? Note that the name of his observatory was Uraniborg.
g. What did Kepler do? Where did he obtain the observations that he analyzed?
h. What did Galileo do? Where did he live? What evidence convinced him that Copernicus and Kepler were right? What did he see through his telescope? What did he invent?
I. Who discovered the Galilean moons and how? Know that Venus goes through phases just like the Moon. What does this tell us -and Galileo - about the structure of the solar system?
j. Know Kepler=s 3 Laws of planetary motion. What is an ellipse? The Focus of the Ellipse, The semi-major axis of the ellipse. How do we calculate the semi-major axis? (Table 4-1)
k. Look at Figure 4-22. Try to understand where, in time, the various astronomers contributed to the development of astronomy.
Chapter 5. Newton, Galileo, and Gravity (Skip Einstein)
a. When was Newton born?
b. Know about Galileo and the experiments that he performed. He learned that falling bodies are accelerated, that the amount of acceleration did not depend on the mass of the object, and that motion was as natural as standing still.
c. Know Newton=s 3 laws of motion. What is momentum? Why is velocity not the same thing as speed? What is acceleration? What does F=ma mean? What happens if we apply the same amount of force to objects with different masses? (Table 5-1)
d. Know the Law of Gravity. What is an inverse square law? How is the recoil of a rifle explained by Newton=s third law? What about a rocket launch?
e. What is the center of mass of two bodies revolving around each other? Why do we talk about an orbiting space craft as being in AFree Fall@?
f. What is the circular velocity of an object in orbit? Remember that Ar@ is the distance from the center of the earth, sun, etc to the satellite. What is the distance from the center of the Earth to an object in Geosynchronous orbit? Why do we care about Geosynchronous orbits? (Pages 84-85)
g. The different kinds of orbits in an inverse-square-law force are ellipse, circle, parabola, hyperbola, straight line. Some are closed and some are open. The escape speed is that speed that allows a space craft to escape from a planet. That does not mean that it has escaped from the gravity of the planet. Just that it will never fall back to the planet.
h. Read how Newton re-discussed Kepler=s laws and >explained=them. What does Kepler=s Third law look like after Newton worked on it. How can we use it to determine the mass of the Sun, of Jupiter, the Earth, binary stars, ... (discussed in class)?
i. SKIP 5-3
Chapter 6: Light and Telescopes
a. What is meant by electromagnetic radiation? What are some of the properties of light?
b. What is meant by the wavelength and frequency of light?
c. What is an Angstrom? I use Angstroms in class not nanometers. What is the velocity of light?
d. What is a photon? What is meant by the wave-particle duality of light?
e. What is the relationship between wavelength, frequency, and energy of light? How does the energy of a photon of light depend on its wavelength? What kind of light is most energetic, least energetic?
f. What are the various parts of the spectrum? Note the definitions of infra-red, ultraviolet, X-ray, Gamma-ray, ..Know the different kinds of light (page 100 Figure 6.).
g. What is meant by atmospheric windows? Where in the spectrum is the atmosphere transparent, opaque?
h. What are refracting telescopes? Reflection telescopes? How do they differ?
i. What is the objective? Eyepiece?
j. What is the fundamental difficulty with refracting telescopes? (Chromatic Aberration)
k. How does a telescope form an image? Note that the image is upside down. How is the Eye like a telescope? What is the focus of a lens or mirror? What is the focal length of a lens or mirror?
l. What is an achromatic lens? Does it really fix chromatic aberration?
m. What is the objective mirror? What is a newtonian telescope? Cassegrain telescope? Prime Focus? (Look at Pages 108-109)
n. Skip mountings.
o. Where are the Keck telescopes located? Why on a mountain top?
p. What is the light-gathering power of a telescope? On what does it depend?
q. What is the resolving power of a telescope? On what does it depend? Why is it relatively unimportant for ground based telescopes? What atmospheric effect reduces the resolving power of a telescope? What are some of the advantages of a reflector over a refractor for large astronomical telescopes.
s. Active optics means that the shape of the mirror can be changed (slightly) over a few minutes to correct for the atmosphere.
t. What are some of the new large telescopes called? LBT, VLT, ... I showed pictures and discussed them in class.
u. Why are radio telescopes so big? A radio interferometer makes a lot of separate radio antennas act as a single antenna improving the resolution. One such observatory is the VLA. Where is it located? Did you see it in the movie “Contact”? We do not listen to the signal from a radio telescope.
v. Where is the Arecibo radio telescope located?
w. We launch satellite observatories to observe in wavelengths blocked by the atmosphere or to observe without worrying about the effects of “seeing.”
x. Some of the infra-red satellites were ISO, IRAS, and Spitzer. In the UV we had IUE, EUVE, and HST. In the X-ray we have CHANDRA and XMM.
Chapter 7. Starlight and Atoms.
a. The key concept about thermal emitters (I did not call them black-bodies in class) is that they emit radiation in a pattern that depends only on their temperature not their surfaces. So we ignore reflected light.
b. Peak wavelength, which I use in class, is the same as wavelength of maximum emission.
c. Look at Figure 7-2 in order to understand the three laws of thermal emission. Know the three rules as given in class. He leaves out the first one: That a hotter thermal emitter emits more energy at every wavelength than a cooler thermal emitter.
d. What is the Stefan-Boltzmann Law? Wien’s Law? How can we use Wien’s Law to determine at what wavelength a thermal emitter radiates most strongly.? The value of the constant given in class is 5000 * 6000 because I use Angstroms not nanometers.
e. Remember the structure of an atom (nucleus with protons and neutrons plus electron cloud orbiting the nucleus)
f. What is meant by neutral, ionized, electron shells. Remember that all normal matter consists of atoms. Each atom consists of a nucleus with electron(s) in orbit around the nucleus. The nucleus consists of proton(s) and neutron(s). Know what is meant by atomic number and atomic weight. What is an isotope? How are the chemical elements labeled?
g. The Coulomb force binds the electrons to the nucleus.
h. The various orbits around the nucleus are called energy levels because it takes energy to move away from the nucleus or the atom must give up energy for the electron to jump back toward the nucleus. Remember that only certain energies (distances from the nucleus) are permitted. (Stairway analogy)
i. What is an excited atom? Ground state?
j. Know Kirchhof’s Laws as given on page 132-133: (1) A hot solid or dense gas produces a continuous spectrum. (2) A low density excited or hot gas produces a bright, emission line spectrum. (3) Put a low density gas in front of a continuous spectrum and you get a continuous spectrum with dark, absorption lines superimposed.
k. Know emission and absorption lines and where and how they are formed.
l. Skip the Balmer Thermometer
m Skip 7-4.
n. What is the most abundant element in stars? Where are most of the chemical elements produced? (Table 7-2)
o. What is the Doppler Effect or Doppler Shift. How can we use it to tell whether an object is moving toward or away from us? What is meant by a blue shift? A red shift?
p. Review the use of the Doppler effect as I discussed in class.
q. Skip Shapes of Spectral Lines
Chapter 8. The Sun
Know the data on Page 146
1. What are the photosphere, chromosphere, corona?
2. What is granulation? What is it telling us about heat flow from the interior? How long does a granule last?
3. What is convection? Conduction? Radiation?
4. What is supergranulation? Spicules are found at the edges of supergranules.
5. What do we learn from Limb Darkening?
6. How far does the Corona extend into space? How hot is the corona? What is the solar wind? What is the speed of the solar wind at the Earth’s distance from the Sun?
7. Helioseismology is the study of the interior of the Sun using the Sun’s oscillations in radius. We can study the interior of the sun just as ringing a bell tells us how the bell is made.
8. What are sunspots? Why do they appear dark? Which part is the Umbra? The Penumbra? Note that they are located in Active Regions.
9. How long is the solar sunspot cycle?
10. Skip “The Sun’s Magnetic Cycle” (approximately pages 156-160)
12. When was the Maunder minimum?
13. Skip the Butterfly diagram (part of Figure 8-13)?
14. What is a Prominence, what is a Flare? Look at the pictures on page 162-163. Note the strength of the shock-wave.
15. What is ejected from Coronal Holes?
16. Where does the energy from the sun come from? Why do we know that it must be nuclear energy?
19. Binding energy is the energy that keeps the protons and neutrons in the nucleus from flying apart.
20. Nuclear Fusion requires high temperatures and high densities to overcome the Coulomb barrier. (Like charges repel)
21.What is the proton-proton chain? Who first proposed it in 1938 (and died on March 6, 2005- mentioned in class).
22. What is a neutrino? How is energy released in the proton-proton chain? Deuterium is an isotope of hydrogen.
23. How does the energy flow from the center to the surface? What are convection, conduction, radiation?
24. What is the difference between nuclear fusion and nuclear fission. Which is most important in current nuclear power plants?
25. What does the solar neutrino experiment tell us? What are the most recent results: Discussed in class.
26. Who is the astronomer who built the Homestake Mine experiment and was awarded the Nobel Prize?