Physics 20073 - Study Guide #2

Updated through Thursday, July 17. Current study questions can be found here.

(40)
If the Kyoto protocol were enacted, how would that change projected atmospheric concentrations of carbon dioxide over the next 100 years?

(41)
Briefly explain why climate scientists weren't satisfied with the Kyoto treaty and also why politicians were also not satisfied (summarize one of the reasons given in each case).

(42)
What are three types of renewable power sources mentioned in the film? Briefly explain two major drawbacks that are associated with renewable energy sources.

(43)
One alternative source of power that may help account for current energy production and future growth is nuclear energy. What are two major long-term drawbacks associated with nuclear energy?

(44)
What are breeder reactors? How might breeder reactors overcome one of these drawbacks, and what is a major problem associated with breeder reactors?

(45)
What was the political fate of the Kyoto treaty in the United States?

(46)
From the reading "Philosophy and the Scientific Method," what is the primary difference between a scientific and a non-scientific belief? What is the major weakness of using irrefutable beliefs as a basis for a system of knowledge? I strongly recommend you check your answer on this one with me. (TQ)

(47)
Use the barrel of apples example from the reading to help explain why a small representative sample is better than a large unrepresentative sample. (TQ)

(48)
Two of the most easily recognizable constellations that are up in the sky at this time of year are Pegasus and Sagittarius. Find the following information about these two constellations:

This is pretty easy to find on the web. A good place to go for mythology is http://www.emufarm.org/~cmbell/myth/myth.html, but remember to keep your summary fairly short so it is easy to remember the most important parts. A good place to go for simple star charts is http://www.dibonsmith.com/constel.htm. For star names and other information, try http://www.astro.wisc.edu/~dolan/constellations/. (TQ)

(50)
Read the Wikipedia article about Geothermal energy at http://en.wikipedia.org/wiki/Geothermal_power and describe how any one of the three different types of reactors works, then briefly explain two benefits and two drawbacks of geothermal energy compared to other energy sources.

The following four questions are from the August 2007 Scientific American article, "The Physical Science behind Climate Change". Below are instructions on how to access Scientific American articles online using the TCU library's website.

(1) Go to www.lib.tcu.edu.
(2) On the drop-down menu next to the search box, change it from "Words Anywhere" to "Journal/Serial name begins with..."
(3) Type "Scientific American" into the search box, then click on the Search button.
(4) On the search results page, click on "*SCIENTIFIC AMERICAN*"
(5) On the next page, in detail record #1, click on the fourth "full text available..." link. It reads "Full text available to the TCU community from Scientific American Archive Online: 01/01/1993 to present".
(6) You may have to type in your TCU ID number at this point if you are accessing the library from off-campus.
(7) Type your subject of interest or article name in the search box. For example, "nuclear power" or "global warming" or "renewable energy". You can then view the text or download a pdf file containing the entire article with diagrams and pictures.

(51)
What is radiative forcing? What does "positive" radiative forcing and "negative" radiative forcing mean? Give an example of each in climate science. (TQ)

(52)
What are two ways in which global warming results in sea level rise? (TQ)

(53)
What evidence in our atmosphere suggests that the recent warming of the past century is not due to changes in solar activity? (TQ)

(54)
Even if we were to stop emitting Carbon altogether today, the climate would continue to warm for at least another couple of decades, if not longer. Explain why. (TQ)

(55)
Read http://www.nineplanets.org/hypo.html#nemesis to find out about the Sun's hypothetical companion star, Nemesis. Based on all-sky searches for nearby and extremely dim stars, it seems unlikely today that such a star exists. Why did some Astronomers believe that such a star exists? How would such a star affect the Earth? (TQ)

(56)
A common belief among Astronomers is that the initial collapse of our solar nebula was triggered by some event like a nearby supernova. Recent evidence from the Chandra X-Ray observatory, however, has cast doubt on that hypothesis. Read http://chandra.harvard.edu/press/01_releases/press_090601solar.html and answer the following: What evidence (having to do with isotopes) makes some Astronomers believe that a supernova was involved in the origin of our solar system? How do the Chandra observations explain the isotope evidence discussed above without resorting to a supernova? (TQ)

(57)
NASA's web pages for the Terrestrial Planet Finder contain details about various techniques for finding extrasolar planets. Visit http://planetquest.jpl.nasa.gov/science/finding_planets.cfm and briefly explain three other indirect techniques for finding extrasolar planets besides the "Doppler wobble" technique. (TQ)

(58)
From http://planetquest.jpl.nasa.gov/science/finding_life.cfm, answer the following: What is the habitable zone? Which gas, oxygen or ozone, is probably a better indicator of the existence of life on a planet and why? (TQ)

(59)
Read the press release at http://astron.berkeley.edu/~gmarcy/hd/press_release.html and answer the following: What is significant about star HD 209458? What is different about the HD 209458 system compared to other systems in which Marcy and Butler have used Doppler wobbling observations to suggest the existence of planetary companions? How does the planetary companion of HD 209458 compare to Jupiter, in size and density? (TQ)

(60)
Read the comments by Phil and Phyllis Morrison at http://astron.berkeley.edu/~gmarcy/morrisons_transit.html and answer the following: The Kepler probe has a mission that is described by the authors and a purpose to find extrasolar planets. How will the Kepler probe find (perhaps lots of) planets without using Doppler wobble measurements? (TQ)

(61)
Explain how nuclear fission generates energy in nuclear power plants.

(62)
What prevents most countries from having nuclear reactors or weapons? What is "enriched" Uranium? What is "depleted" Uranium, and what is one of its main uses?

(63)
Explain why nuclear fusion reactions require extremely high temperatures.

(64)
Where does the energy come from in fusion reactions? What are Deuterium and Tritium? Explain how nuclear fusion (D-T fusion) generates dangerous waste products.

(65)
Why is it difficult to contain fusion reactions? Explain inertial and magnetic confinement.

(66)
What is a Q-value, and how does it relate to the viability of nuclear fusion as an energy source?

(67)
Why is the sky blue during the daytime? Why does the sun appear red at sunset? Why does the moon appear red during total lunar eclipses?

(68)
Photos from the surface of the Moon (you can find several in your book) demonstrate that even during the daytime, when the Sun is shining on the surface of the Moon, the sky is pitch black. Explain why.

(69)
Explain how spectral absorption and emission lines are created. Given a simple energy level diagram for an atom, be able to state what energies of light can be emitted or absorbed (without taking into account the electron possibly leaving the atom altogether or coming in from the outside).

(70)
Explain why each different element has its own unique spectral fingerprint (what is a spectral fingerprint and how is it created?). How do we use this knowledge to determine the composition of other planetary atmospheres?

(71)
State the two rules associated with Doppler shifting.

(72)
Explain the difference between radial and transverse velocity, with the help of a simple diagram.

(73)
Explain how we use the Doppler shift to determine the rotation speed of planets. How and why does the rotation speed of a planet affect the spectral lines coming from that planet?

(74)
Briefly explain the catastrophe hypothesis for the origin of the solar system. Name and briefly explain an argument that tends to contradict this hypothesis.

(75)
Briefly explain the capture hypothesis for the origin of the solar system. Name and explain two arguments (different from the argument in question 74) that tend to contradict this hypothesis.

(76)
Explain why the solar nebula collapsed into a disk shape as a result of its rotation.

(77)
Given the condensation temperatures for the four main components of planets (metal, rock, ice and gas) and an indication of the temperature in various parts of the solar nebula disk, be able to identify and explain which components you would expect to condense into solid form at various locations in the solar system.

(78)
Explain how evidence found in meteorites tends to confirm our ideas about the accumulation phase of the origin of the solar system.

(79)
Name and briefly explain three reasons why Jupiter is so much larger than the Earth.

(80)
Know and explain the relationship between the mass of a typical gas particle and the velocity of a typical gas particle.

(81)
Given the equation for escape velocity, be sure you understand how escape velocity depends on the mass and size of a planet. For example, if planet A and planet B have the same mass but planet B has a larger size, which planet has a lower escape velocity and why? Which planet is easier to escape and why?

(82)
Name and explain two reasons why the Earth cannot accumulate Hydrogen gas while Jupiter can.

(83)
Why does the Earth have a hard time capturing Hydrogen while easily maintaining an abundance of gases like Carbon Dioxide?

(84)
Explain why we believe Uranus and Neptune are so much less massive than Jupiter and Saturn, despite the fact that the two outermost planets presumably formed under conditions (colder temperatures, larger feeding zones) that were even more favorable to larger masses.

(85)
Use a graph of continuous radiation for the Sun and a planet like Jupiter to help explain why direct imaging of other planetary systems in visible light is probably hopeless and why there is some hope in the idea of infrared imaging (if the resolution problem can be overcome).

(86)
Explain how we use Doppler shifting evidence to deduce the existence of planets around other stars. How do we estimate the mass of the companion? How do we estimate the distance from the companion planet to its parent star?

(87)
Explain why searches for other planetary systems so far have been biased in favor of discovering high mass planetary companions as well as planetary companions that are very close to their parent stars.

(88)
Explain why we cannot necessarily believe that indirect observations of planetary companions via Doppler wobbling are truly planetary companions. Are our assumed companion planet masses higher or lower than true planet masses in tilted systems? Explain.

(89)
Explain the details and significance of the discovery of an eclipsing (or transiting) extrasolar planetary system. Why was this discovery important for extrasolar planet hunters?