HHHH - Philosophy and Science, Feynman and Pine readings
In the reading by Pine, he gives an example of a study of teenage sex problems. One possible way to reduce such problems is sex education classes. To test the effectiveness of such classes, suppose we survey a representative sample of students who have taken such a class and we find that 20% of couples who have taken a class have problems of some kind. What is one additional thing we must do before we have any idea whether these classes work? Explain fully!
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About 10-15 years ago, scientists set out to use the latest infrared technology to search for disks of gas and dust around nearby Sun-like stars. They expected to find such disks around many such stars. Explain why they expected this, in 2-3 sentences (note that I am not asking how they did it).
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The history of Astronomy is filled with a variety of misconceptions that were later corrected by careful application of the scientific method. Two examples are the idea of the geocentric universe and the heliocentric universe.
a) (4 pts) Explain why Greek astronomers felt that the “celestial sphere” rotated about the Earth, rather than the Earth rotating beneath a motionless sky.
b) (4 pts) Although Copernicus’ heliocentric model of the solar system worked more simply than the complex geocentric model (which had the Earth at the center of the solar system and the solar system orbiting Earth), most Astronomers didn’t accept the model at the time. Explain a logical (not political or faith-based) reason for their refusal to adopt the Copernican system.
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To date, our search for extrasolar planets has yielded about a dozen candidate systems, each with planets that are at least as massive as Jupiter orbiting their parent star.
a) (4 pts) Using the assumption that the Copernican Principle is valid, we also expect to find planets in these systems with masses similar to that of Earth in these systems. Explain why.
b) (4 pts) Why haven’t we found such planets in these systems?
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One of the interesting results of the early Viking missions to Mars was the apparent discovery of biological organisms (according to the evidence of some chemical reactions in the soil during a few of the experiments). Explain how the use of control experiments tested (and ultimately falsified) these initial findings.
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The Copernican theory of the solar system states that the planets move in circular orbits around the Sun. When this idea was introduced, it conflicted with the centuries-old idea that the Earth is at the center of the solar system (with all the planets orbiting the Earth). Naturally, most people were unwilling to accept this new theory for the simple reason that it reflected a radical departure from the old view, supported by the church. Scientists have no such biases (at least, we like to tell that to ourselves, and we will assume that is the case here).
So you'd think that scientists would be quick to accept the Copernican theory, which is closer to the actual truth than the old geocentric model. In fact, most scientists did *not* accept the Copernican model. Explain two reasons why not (both reasons have to do with predictions made by the Copernican model that weren't seen to be true).
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Explain why Galileo's observations of the moons orbiting Jupiter was such an important step in overturning the old geocentric model of the solar system.
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For this particular question, we will not deal with social and religious biases (such as "the heliocentric theory wasn't accepted because it went against the views of the church"...these views aren't consistent with rational scientific thought). Even though the Copernican theory of the solar system was more accurate than the geocentric theory of the solar system, most scientists weren't willing to accept it on the grounds that it failed two crucial tests.
a) (7 pts) The Keplerian theory of the solar system (slightly different from the Copernican theory in that Kepler used ellipses for planetary orbits instead of circles) was more acceptable to most scientists. Why? What did Kepler's theory do that Copernicus' theory didn't do? Explain.
b) (7 pts) Both theories had a fundamental problem, however, because they both made the same (seemingly incorrect) prediction. Explain what this prediction was and why it appeared that the prediction was false.
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The reading "Philosophy and the Scientific Method" covers several topics that are vital to understanding scientific thinking.
a) (7 pts) The author explains that irrefutable beliefs are very compelling since they offer a secure finality to our views, helping us to face life's contingencies and uncertainties. What is the major weakness of irrefutable beliefs?
b) (7 pts) The author explains that both scientific and nonscientific ideas lead to seemingly unbelieveable conclusions, such as apocalyptic predictions, "quantum tunneling" or "black holes", but scientific ideas are more useful because of an important distinction. What is the major difference between these two kinds of ideas?
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The apparent lack of stellar parallax was a problem that greatly obstructed the acceptance of Copernicus' heliocentric model by the scientific community.
a) (7 pts) Why did the geocentric model predict there would be no parallax angles for stars?
b) (7 pts) Explain how the Copernican model could be considered consistent with reality provided stellar distances are incredibly high.
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Briefly answer the following questions about the philosophy of science:
a) (6 pts) Should the validity of an idea depend at all on whether it seems to agree with or violate common sense? Explain in 1-2 sentences why or why not.
b) (8 pts) State briefly the difference between scientific and non-scientific ideas, and use this difference to help explain why a belief system based on irrefutable ideas is not such a good idea.
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Although Copernicus' heliocentric model of the solar system was much closer to the actual description of the solar system than the old geocentric model, scientists at the time didn't really accept it. One reason was because of a lack of measured parallax angles.
a) (8 pts) Explain why a lack of observed parallax in stars led scientists to believe that the geocentric model was correct rather than the heliocentric model.
b) (6 pts) What was another problem with the heliocentric model that led scientists away from accepting it as a correct description of motions in the solar system? Briefly describe the evidence that was found to contradict Copernicus' model.
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A common misconception is that the phases of the moon are caused by the shadow of the Earth falling on the Moon.
a) (8 pts) Draw an overhead view of the Earth, Moon and Sun during first quarter phase (assume everything rotates/orbits counterclockwise), and use this to help refute this misconception.
b) (6 pts) The planet Venus also shows phases like the Moon. How did Galileo use this information to help refute the geocentric hypothesis for the solar system?
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From the reading "Cargo Cult Science", why was Mr. Young's rat-running experiment an "A-number-one" experiment compared to other rat-running experiments?
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The reading "Philosophy and the Scientific Method" covers several topics that are vital to understanding scientific thinking.
a) (3 pts) The author explains that both scientific and nonscientific ideas lead to seemingly unbelieveable conclusions, such as apocalyptic predictions, "quantum tunneling" or "black holes", but scientific ideas are more useful because of an important distinction. What is the major difference between these two kinds of ideas?
b) (5 pts) The author explains that irrefutable beliefs are very compelling since they offer a secure finality to our views, helping us to face life's contingencies and uncertainties. What is the major weakness of irrefutable beliefs as a system of knowledge? Explain.