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Updated through Monday, September 14.

(1)

From the reading "Cargo Cult Science", explain "why the planes don't land" to a typical islander who might ask, in a few sentences. (TQ)

(2)

From the reading "Cargo Cult Science", briefly summarize the story of Mr. Young's experiment and why those who ignore his work cannot really trust their conclusions. (TQ)

(3)

From the reading "Cargo Cult Science", briefly explain the story of the Millikan oil drop experiment and the subsequent history. Explain why this was such an embarrassing episode for scientists. (TQ)

(4)

What are sundogs? What causes them? You can find out some information about them at http://antwrp.gsfc.nasa.gov/apod/ap990823.html, an archive of the excellent "Astronomy Picture of the Day" website (a great bookmark to check daily). Try looking for one someday near sunset when there are lots of high, thin icy cirrus clouds near the western horizon. You can often see them as little multi-colored "cloudbows". (TQ)

(5)

Two of the most easily recognizable constellations that are up in the sky at this time of year are Cygnus and Ursa Major. Find the following information about these two constellations:

• Approximate location in the sky at 10pm tonight (rough altitude and azimuth) according to the sky chart on A-33 of your text (the sky chart for July, August and September),
• star chart (sketch of the pattern of the 6-8 brightest stars that make up the constellation),
• name of the two stars designated alpha and beta (not necessarily the two brightest stars),
• 2-3 sentence summary of the mythology behind the constellation.

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.astro.wisc.edu/~dolan/constellations/. When you are done, go out at night and find the constellation and explain what you know to a friend or classmate. It's fun to do and easier to remember that way. (TQ)

(6)

Explain the daily motion of stars and be able to draw this on a celestial sphere diagram.

(7)

Explain why some stars are circumpolar. Use a celestial sphere diagram to help explain why stars at higher declinations are more likely to be circumpolar stars.

(8)

Does everyone in the northern hemisphere at a given latitude see the same constellations during the night on a given date? Explain.

(9)

Explain why we see different constellations overhead at the same time of night on different days of the year. Again, a simple diagram may help.

(10)

A common misconception is that the seasons are caused by the Earth being closer to or further away from the Sun. Name and explain three different lines of evidence that contradict this idea.

(11)

Although the northern hemisphere of the Earth is slightly closer to the Sun than the southern hemisphere (during the northern hemisphere's summer), this shouldn't result in a significant difference in temperature between the two hemispheres. Explain why.

(12)

What is the ecliptic? What is the difference between the Sun's daily path and its annual path? Be able to draw this difference on a simple celestial sphere diagram.

(13)

Be able to draw a simple horizon diagram (horizon plus hemispherical sky) from Fort Worth's latitude, showing the altitude above the horizon of the NCP, Celestial Equator and June/December paths of the Sun. Be able to use this diagram to explain two reasons why summer months (June) are warmer in Fort Worth compared to winter months (December).

(14)

If the Earth's axis were not tilted (thus, it would make an angle of 90 degrees with respect to the plane of the Ecliptic), would we have seasons in Fort Worth? What would the ecliptic look like on a celestial sphere? What would the paths of the Sun look like at different times of the year from Fort Worth? Explain. (TQ)

(15)

Be able to draw a simple horizon diagram (horizon plus hemispherical sky) from any latitude on Earth showing the altitude above the horizon of the NCP, Celestial Equator and SCP (if applicable). Also be able to draw the June, Mar/Sep and December paths of the Sun at these various latitudes.

(16)

Using a diagram like figure 2.15 in your book (showing the Earth as viewed from one side during Northern or Southern summer), be able to show that the day length is longer and sunlight is more direct in the summer.

(17)

Name and explain two arguments that refute the misconception that the phases of the Moon are caused by the shadow of the Earth. Diagrams would certainly help here.

(18)

Why are planets spherical? One way to approach this question is to think of it this way: Why aren't planets shaped like giant cubes? Or footballs? (TQ)

(19)

Given a diagram of the Sun and Earth as seen from above. Be able to draw in the proper location of the Moon on the diagram for each of the eight major phases we discussed in class.

(20)

Use a side view of the Moon's orbit and the Ecliptic plane to help explain why the Moon doesn't undergo a lunar or solar eclipse every month.

(21)

Describe the difference between a solar eclipse and a lunar eclipse. Why are solar eclipses less common than lunar eclipses? Your book can help with the last part.

(22)

Explain the difference between an annular and a total solar eclipse. Why are solar eclipses sometimes annular and sometimes total? Use the equation of angular size to help answer this one.

(23)

A common misconception (caused by a psychological effect) is that the Moon has a much larger angular size when it is close to the horizon and a much smaller angular size when it is high up in the sky. Describe a simple experiment you could perform to physically disprove this notion.

(24)

Using the equation of angular size and a diagram of the Earth and Moon (during full moon, for example), provide a mathematical argument to refute the notion that the angular size of the Moon is greater when it is on the horizon.

(25)

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)

(26)

In the reading, Pine says that in order to distinguish correlation from causation, we have to isolate variables to see if one effect really causes another or if perhaps the cause is some other unknown, unanticipated thing. In the context of the sex education study, describe the error made by the angry letter-writer. Give four examples of variables that must be controlled in order to prove or disprove the letter-writers hypothesis. (TQ)

(27)

Using the smoking example from the reading, help explain the difference between reasonably true and conceivably true. (TQ)

(28)

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)

(29)

Another term for the kind of light (electromagnetic radiation) emitted by the sun and most other objects in nature, regardless of their temperature or composition, is "blackbody radiation". Why is it called "blackbody radiation"? (TQ)

(30)

Be sure you understand what a spectrum is. What two things happen to the spectrum of an object as it is heated (be able to sketch this)? Given two spectra, be able to identify which has a higher or lower temperature.

(31)

A greenhouse gas is defined as a gas that blocks infrared radiation. Use the laws of continuous radiation to explain why greenhouse gases result in a net warming of the Earth. As part of your answer, address the following point: Greenhouse gases block both incoming and outgoing radiation. Why don't these effects simply cancel each other out, leading to no net change in temperature?

(32)

Explain how we know (by observing the Moon) that the Earth's average temperature is warmed by about 60 degrees Fahrenheit thanks to the greenhouse effect.

(33)

Some "global warming skeptics" have argued that the levels of Carbon Dioxide in our atmosphere vary naturally throughout history, so how do we know that recent increases are caused by fossil fuel burning rather than by natural sources of carbon (I'm asking about evidence related to Carbon isotopes here)?

(34)

One potential consequence of global warming will be a relatively fast rise in sea levels as a result of melting ice (mainly in West Antarctica, since it is currently on land) and one other mechanism, described in the first few paragraphs of the following scientific discussion summary:http://www.faqs.org/faqs/sea-level-faq/. Read these paragraphs and summarize in a sentence or two another mechanism besides melting ice that may cause sea levels to rise as the Earth warms up. (TQ)

In preparation for our discussion of climate change, I invite you to read a background article from a recent "Scientific American" magazine that goes into much greater depth than your book. To find articles online from magazines in the TCU library, you can follow these instructions (you will need this later when I assign articles).

(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 the title of the article or your subject of interest in the search box. For example, "nuclear power" or "global warming" or "solar grand plan". You can then view the text or download a pdf file containing the entire article with diagrams and pictures.

The article I would like you to look for is entitled "The Physical Science Behind Climate Change". Again, this is not required reading, just recommended if this is an issue that really interests you and you want to come to class during the next couple of weeks well-prepared and informed. There are many more articles on the topic, too, if you care to search for topics like "climate change" or "global warming".