Honors
Seminar in Natural Sciences,
143:070
Final Examination--SAMPLE
Most answers should be a half page to a page in
length. Longer than a
page should occur only in special circumstances. We don’t want to read a
thesis. Write legibly, in complete sentences, and preferably in pen. No
whining.
Walk with Ursus!
1. In class we often used the term “bottleneck” to describe developments in the evolution of higher life. Discuss this concept and give an example.
2. Overall, did you find the biological, the geological, or the astronomical bottlenecks to be the most serious? Be decisive and pick one rather than superficially talk about all of them. Clearly describe your example and explain why you find it particularly potent.
3. In
the end, how
convinced were you by the thesis of Rare Earth? Since this is an opinion question, any answer is
acceptable; you will be graded on the
clarity of your assessment of the thesis, and which arguments pro or con you
4. Plate tectonics is an important feature of the Earth as a planet. Based on the discussion in Rare Earth, what is the most important function plate tectonics could play in keeping the Earth suitable for higher life forms?
5. If (as suggested in the book) plate tectonics was a crucial process for the development of higher life on Earth, what does this imply about the likelihood of higher life arising on a planet which forms 13 billion years from now?
6. In grade school geography you learned that 70% of the Earth’s surface is covered by water. From an exobiological perspective, why is this remarkable?
7. The book Rare Earth attributes great importance to the role played by the Earth’s magnetic field. Why do the authors believe this to be the case? Why might they have exaggerated its importance?
8. What role might the Earth’s moon have played in the series of events leading to you sitting here? Why is the Moon considered to be a contributor to the Rare Earth Hypothesis?
9. How long ago did the solar system form? We want a number here!
10. A future NASA mission will be the Terrestrial Planet Finder (TPF) whose mission will be the discovery of terrestrial planets around other stars, and the determination of whether life exists on those planets. In view of the very limited detail in the observations of those planets, how is it possible to determine the presence or absence of life?
11. In class we discussed the “Drake equation” and ground out some numbers with it. What lesson does one draw from these calculations and the attempt to estimate the number of civilizations in the galaxy? We don’t require that you write down the equation and discuss the mathematics of its origin (if you comfortable with it, feel free to do so). However, you should express in words the conclusion or conclusions one draws from an exercise with the equation.
12. Define in one or two paragraphs what is meant by the Rare Earth Hypothesis.
13. Speaking of the animal Homo Sapiens, the authors of Rare Earth write: “But we are not as ordinary as Western science has made us out to be for two millennia”. What idea are they expressing? Do you agree or disagree with the idea expressed?
14. Define the Fermi Paradox. A proper and intelligible definition should take about half a page to a page.
15. Discuss a possible resolution of the Fermi Paradox.
16. Briefly discuss the status of the search for life elsewhere in the solar system. Your discussion should include developments likely to occur within the next two decades.
17. What properties of water make it an excellent solvent for carbon based life? What is ammonia’s most significant weakness as a possible replacement for water?
18. Because life as we know it is an interlocked cycle of reactions, it seems implausible to some that such a complex system could arise spontaneously. In recent years, several discoveries have removed some of the difficulties with a theory of spontaneous origins for life. Name two of these discoveries and explain why they make spontaneous origins more plausible.