Via the Freakonomics blog (yes, the same as the book, which is a really interesting read), comes this astronomy test for 7th graders (link is to a MS Word document).
Take a look. The questions are not ridiculously hard — though they aren’t trivial — but somehow the terse, harsh phrasing of them makes the test seem harder than it is. I suspect that most Americans would do abysmally on it. As usual with such tests, you need to read the instructions carefully so you know precisely what they are asking.
I had to laugh at this question though:
A display of arcs, lights, and streamers in the polar regions is called the auroras. The light is produced as charged particles come in contact with the Earth’s magnetic field. These charged particles come from
A. star particles in outer space.
B. the solar wind streaming from the sun.
C. the hot core of the sun.
D. fragments of meteoroids burning as they enter Earth’s atmosphere.
Besides the horrific grammar error in the first line, the question is technically wrong. The light is produced when the particles stream into the Earth’s atmosphere and ionize it. The particles are accelerated by the Earth’s magnetic field, so radiation is emitted, but it’s in the radio wavelengths. The visible light isn’t emitted until they slam into the air.
Tip o’ the beanie to Joshua Zucker for the link to the Freakonomics blog.
March 7th, 2007 at 10:57 pm
Aside from the question about the equatorial and polar diameters of the Earth (who remembers those things?), fairly easy.
March 8th, 2007 at 12:35 am
Randall, look at the answers again.Only one of them has a larger equatorial than polar diameter.
Question one is weird. Why is Jupiter black? What can one deduce from a wholly inaccurate picture of the solar system anyway? And Jupiter is warm due to internal heating so the whole question is based on a screwed up assumption.
The sunrise/sunset question: Really? I would have guessed Venus.
Eccentricity question: Not a good question, imo. A student who can’t distinguish between “eccentricity” and “orbital inclination” would still get the right answer.
Mars/life question: Can we be sure that no extremophiles could survive on Mars?
Approximately 8 minutes after a certain event happens, radio and television communications were disrupted in North America. What event caused this to happen?
Ans: D An intense solar wind that erupted from a solar prominence
Wrong! solar wind doesn’t travel at the speed of light.
Star-formation question: weird question, weird answer.
umbra shadow -> umbral shadow
Other than that, some reasonably sensible questions.
March 8th, 2007 at 3:08 am
There are many meteors that enter Earth’s atmosphere, but very few of them actually land on Earth.
Most of the ones that do not strike the Earth
C. as they burn up from friction move through the atmosphere.
Isn’t this incorrect? I thought it was because air on the leading edge is compressed causing it to heat up.
I’m hopeless at grammer but even I can see that the wording of this test is terrible.
March 8th, 2007 at 3:44 am
Well, since this is 7th Grade, the answers to most of these questions would have been stated explicitly in class, and that this test would really involve a minimal amount of reasoning. For example, I imagine that the eccentricities of the planets’ orbits would have needed to be discussed. The basic reasoning applied in question 1 is probably just that Jupiter is closest to the sun, therefore you would expect a higher surface temperature from this basic understanding. Aside from the intimidating phraseology, this test is really just looking at some basic concepts like the difference between rotation and revolution. That said, the real issue here is the phraseology. Everything could and should be stated much better, although that all boils down to the teacher’s own skills.
March 8th, 2007 at 3:48 am
We homeschool our 7th grader and I’m teaching him Astronomy out of my old college textbooks. I’m going to give him this test tonight only to spark further discussion.
The grammar issues seem to be lost in translation errors. Was this test originally written in another language?
March 8th, 2007 at 4:52 am
The question which gave the Freakonomics author so much embarassment hasn’t enough data included with it to arrive at the correct answer. The way it’s presented implies that the students covered the subject in class and already ought to have known the relationship between Earth on June 21st and 1/4 orbit away. That’s why the blog author had so much trouble, because for him “June 21st” was meaningless data.
March 8th, 2007 at 5:04 am
csrster said:
“The sunrise/sunset question: Really? I would have guessed Venus.”
Mercury is tidally locked with the sun. So its rotation is the same as its orbital period.
March 8th, 2007 at 5:22 am
Mercury does not have rotation period equal to orbital period.
March 8th, 2007 at 6:04 am
What grammar error? “A display … is called the auroras.”
“The display” would sound better, though.
March 8th, 2007 at 6:04 am
The sunrise/sunset question got me, too. Mercury was thought to be tidally locked with the sun (88 days), but now it is thought to be a 2/3 relationship, with it making a rotation every 59 days. http://www.mira.org/fts0/planets/092/text/txt001x.htm gives a mercurian day (noon to noon) as about 175 days, and a Venusian day at 117 days.
March 8th, 2007 at 6:28 am
heh, opps. My information on that is obviously a wee bit outdated:P.
March 8th, 2007 at 6:31 am
Why exactly does the solar wind not qualify as star particles in outer space?
March 8th, 2007 at 6:58 am
The Antarctic octopus gets farked…
Fark is having an octopus photoshop contest — most of the entries make me go “eh”, but there are a few nice ones. Phil Plait thinks this could be a symbol of rapprochement between the brilliant analysts of the natural……
March 8th, 2007 at 7:15 am
I like answer D for the question about what would happen if the earth moon and sun were to line up:
D. The spin of the Earth could be speeded up.
Speeded indeed.
March 8th, 2007 at 7:16 am
The trick is that Venus spins retrograde, so the movement of the sun through the sky due to revolution shortens the day, while mercury’s revolution slows down the sun (keeping it in the sky for a longer time). Thus, Mercury has the longest sidereal day (noon-to-noon, or dawn-to-dusk) despite Venus having the slowest rotation speed.
Aside from the factually incorrect questions (like the one that suggests solar wind travels at light speed rather than taking days to reach Earth), I disliked #4, which shows a chart of the planets’ distances from the sun and asks “which statement is true”. While C *IS* true, the chart in no way indicates what an “inner planet” is, nor why Jupiter should be excluded. The question depends on the reader knowing ahead of time what an inner planet is — and if the reader does know that, the chart is irrelevant to finding the right answer.
March 8th, 2007 at 7:48 am
I thought it was interesting that every question was about the Solar System. Nothing about clusters, nebulae, galaxies, or cosmology. If this test was given early in the semester that would be understandable, but if it represents the entirety of the class curriculum I’d be disappointed.
March 8th, 2007 at 7:51 am
I also thought the one about the differences between Mars and Earth, although possibly correct, is not necessarily correct. It is conceivable for life as we know to exist is some niche environments, perhaps underground, and it is certainly true that many people think it is similar enough to Earth that building a colony would be worth it (although logistic issues such as getting there may preclude it).
March 8th, 2007 at 7:51 am
A sidereal day is not noon-to-noon, but the time it takes for a planet to rotate 360 degrees. A noon-to-noon day is a solar day, which is the amount of time it takes for the sun to return to the same place in the sky. That takes into account the revolution as well as the rotation. I think Phil had a Blog entry describing the different periods a little while back.
The retrograde motion of Venus does make the sidereal day there longer than a solar day.
March 8th, 2007 at 7:53 am
Jesus, that’s meant for 7th graders? I was an astronomy buff when I was in 7th grade, but back then, I didn’t understand ‘exactlly’ how the tides worked or ‘exactlly’ when the equinox was.
March 8th, 2007 at 7:56 am
I agree with you, John, at 06:04am, but I would vary your latter suggestion to, “The display … is called an Aurora.”
I tried the test and was going well until I struck the non-existant diagrams. Yes I know they may be available in MS Word or whatever, but I don’t and won’t install it.
So I lost interest in the test, and I guess I failed. Does that mean I have to repeat Grade 7?
Ivan.
March 8th, 2007 at 7:57 am
Quick addition: I know that a solar day technically isn’t the sun returning to the same place in the sky, but since Mercury has almost zero axial tilt it would pretty much rise and set in the same place every day.
March 8th, 2007 at 8:09 am
The diagram “At which position in Earth’s orbit are daylight and nighttime equal?” is misleading. From the looks of the diagram at position 2 the south pole is pointing towards the sun, which would put one hemisphere in total light and the other in total darkness. That would obviously lead to very different days and nights. It is true that such a scenario is impossible, but a bunch of the questions deal with hypothetical scenarios.
March 8th, 2007 at 9:09 am
Re Doug’s comment about the test involving only the solar system. When I was a supervisor at Hyde Memorial Observatory I had teachers argue with me that the solar system IS the universe and it therefore contains everything. The idea comes from the way they design the program starting with the solar system. They spend 90% of the time on that then cover the rest in a day or two, if at all. Both kids and teachers get the idea that nebula and galaxies are just junk to be ignored in our solar system. I even had one teacher report me to the school system as totally ignorant of this “fact” saying that she was highly disappointed that both the “planetarium guy” and the “observatory guy” don’t begin to understand the solar system.
Some tests I’ve seen and books by school systems are very bad saying that solar prominences are the “flames that give us our heat and light”, “astronaughts” (sic) are weightless because they are beyond the reach of gravity and so many more. We even had the local school system buy EVERY school a basic bare bones 6″ Dobsonian scope and tell us to educate the teachers on how to find planets, stars, galaxies nebula and other faint fuzzies in the DAYTIME skies. The teachers couldn’t be expected to work at night so had to do this in the day. Oh yes, every time she referred to the Dobs the head of science for the school system called them microscopes! And we were incompetent because we couldn’t show the teachers how to find M42 at 4 in the afternoon in the spring. She’d checked a planetarium program and knew it was up. Oh yes, never point a “microscope” at the sun was the mantra so therefore daytime solar viewing was not allowed. It would have been easy to fit the scopes with permanent solar filters so they could at least be used but that was too dangerous. For several years now, they’ve sat unused because they can’t be used without a teacher present and the teacher can’t work at night. When the bosses are this dumb its a wonder the kids learn anything.
Yes there are excellent astronomy teachers out there, unfortunately not enough of them.
March 8th, 2007 at 9:13 am
Phil, what grammar error do you mean? I suppose one could argue there is a case issue - “A display… is called the auroras.”
Many of the questions do not require actual astronomy knowledge or recall of the details from class, but merely good test taking deduction skills. A person could easily get a B on the test just by applying some sorting. For instance:
The question about relative distance from the Sun.
Okay, I didn’t paste the diagram. Still, A) is obviously incorrect. From the diagram, B) is obviously incorrect. C) lists Mars as an outer planet - no way. That leaves D) as the only answer. So it does not matter if there’s no reason why Jupiter is not considered an inner planet, there’s only one possible correct answer.
Others only need a general recall of the topic, not exact knowledge.
For example, the question on page 6 about the layers of the Sun.
Now I don’t recall studying this and don’t know offhand the correct answer, but I know the core is innermost and corona is outermost. There’s only one answer with those two criteria met - D). So I don’t need to know anything about the radiative and convective zones or the photosphere and chromosphere.
Similarly, if I know that the root “photo” applies to light, then that is all I need to answer
I deduce that the visible layer is the layer that has the Latin word for light in it. Now if they had listed the chromosphere, I might have had a harder time, since chromo means color.
crster, for question 1, I also wondered why Jupiter was solid black. I also wonder why they used real planet names in the wrong order rather than using fictional planet names - Marduk, Vulcan, Diskworld, Planet X. That would eliminate confusion. But the question does explicitly state to use the diagram given, so if limiting to the information in the diagram, the actual planet order is irrelevant, and any knowledge of Jupiter’s interior processes is irrelevant.
You are correct about the “eccentricity” question. It appears they are using “eccentricity” to refer to the inclination rather than the ellipticality.
The Sun formation question was really weird. That one does not make much sense. There’s no connection between the answer and the question.
Michael H, the term “friction” is used in the broad sense. Compressive heating due to velocity melts the leading edge, which is removed through drag to pull the liquid off, exposing more object to the compressive heating. It’s friction dragging the layers off to keep it eroding away.
The question that the Freakonomics guy had trouble with also bothered me. The Earth doesn’t have any axial tilt in the diagram, which is why June 21st has to be specified. I’m sitting here trying to figure out why the south pole goes over the Sun, before I finally work out what they mean. Stupid 2-D representations!
Eric Said:
> Why exactly does the solar wind not qualify as star particles in outer space?
The question you refer to is the aurora question? Star particles is being differentiated from Sun particles. Yes, we know the Sun is a star, but it has a special privilege with respect to the Solar System and is thus distinct for the purposes of this test.
Here’s one that really bugged me:
While technically true, it is misleading. Tides are not directly caused by gravity the same way gravity pulls us to the surface. Rather, tides are caused by the differential pulling of gravity - pulling one part more than another part. So how is this shown in the questions about tides?
There are three essentially the same figures of a triangular arrangement of the Sun, Earth, and Moon, and there is one that has them in a line. Ergo the correct answer is that one. But the question still presents the misleading implication that the tides are caused by direct pulling, not differential pulling.
Then there’s this one:
The diagram has the Moon 90deg out from the Sun. Okay, define “normal”.
Then there’s this:
If the Sun were not present, the planets would not have formed in the first place, so none of the above.
March 8th, 2007 at 9:19 am
John and Icesmith (maybe others) are correct - there is no grammer error inthe first sentence.
March 8th, 2007 at 9:53 am
actually, there is a grammatical mistake in the first sentence. Allow me to clarify:
“A display [prepositional phrase removed] is called the auroras.”
There is no singular noun in the predicate, which does not agree with the singular noun in the subject. Also, “A display” should have the same article as “aurora”.
Thus, the grammatically correct sentence would read:
“A display of arcs, lights, and streamers in the polar regions is called an aurora.”
And before anyone asks, no I wasn’t an English major in college- just a person who had a lot of English (Americanized, of course) grammar pounded into him in high school.
March 8th, 2007 at 11:07 am
Chris
Ok - I buy that - I had actually misread “auroras” as “aurora” anyway. I agree your construct is best. Since BA didn’t specify which specific “horrific grammer error”, he is now free to choose the one you point out
Personally, I also disagree with the comma-and, but that is a foible and a quibble.
Jack
March 8th, 2007 at 2:36 pm
Grammar aside, what is the equation for calculating tidal force? Is this it? DF = Dr(2GmM/r^3) where the D stands for delta?
March 8th, 2007 at 2:47 pm
All the diagrams are completely horrible!! It’s an entire test of “what not to use to teach your kids astronomy”!! Ahhh!!!
*sigh* Sadly, most tests in all subjects are worded poorly and full of horrendous diagrams and easy to figure out patterns. Generally, if it’s any kind of standardized, there’s a way to crack it without actually knowing the material.
March 8th, 2007 at 2:58 pm
In fact, the solar day question can be much more complicated because of the high eccentricity of Mercury’s orbit. I believe it was Steve Soter and Carl Sagan who first pointed out that near perhelion the sun will actually be seen to do a retrograde loop, slowing, reversing, slowing, and proceeding again. An observer for whom the sun is rising near perhelion could see the Sun rise, then set, and rise again over a period of just a few days.
Many of these questions appear to me to require memorization of facts, sometimes obscure facts. I doubt that many college astronomy majors could take their knowledge of the periods of rotaion and orbital motion of the planets to correctly come up with the solar day values as required by this question.
March 8th, 2007 at 3:30 pm
Hah. Well that’s cool John Oliver. I hadn’t read about that before:).
*Awards John Oliver a gold star*
March 8th, 2007 at 4:18 pm
Oops, just read that the equation I quoted above is the difference in the tidal forces on Earth due to the Sun and Moon. I’ve got the correct equation for just two bodies, but the site doesn’t list what all the variables mean. Anyone help? http://filer.case.edu/sjr16/advanced/earth_moon.html
It’s the first equation in the Tides section. Thanks!
March 9th, 2007 at 12:12 am
As a general point, I did wonder why so many of the diagrams were apparently drawn by a pre-schooler. I’m only suprised the Sun in the first question doesn’t have a smiley face like the ones my daughter draws.
March 9th, 2007 at 12:17 am
Icemith. If you are using Windows you don’t need Word as Wordpad will open it complete with diagrams. Usually found under Start\All Programs\Accessories if you haven’t used it before.
March 9th, 2007 at 9:44 am
Crux, I’ll try.
FT with the arrow over it = the vector Force of the Tides
G = Gravitational constant
MMoon = mass of Moon
Rhat = the vector distance between the Moon cg and the location on Earth being considered
Dhat = the vector closest distance between the Earth and Moon
R = magnitute of Rhat
D = magnitude of Dhat
yhat appears to equal the vector offset for the location being measured from the line between the centers of mass of the Earth and Moon.
Amanda said:
> Generally, if it’s any kind of standardized, there’s a way to crack it without actually knowing the material.
I had a college geography class that was very difficult to “crack”. The teacher killed a couple of the standard elimination techniques students use on multiple choice questions by including about 8 or 10 options for every question. Not only A, B, C, or D, but also options for A and B, A and C, B and C, B and D, and A, B, and D - for every question. You couldn’t just assume that because it included multiple options it must be one of the multiple options. You couldn’t very well use partial knowledge to eliminate from one or two multiple options. Her fill in the blank section had an options list with more options than questions to answer. So even if you eliminated all the ones you knew, you still had several answers to pick from on the ones you had to guess.
March 9th, 2007 at 10:31 am
“auroras” should be aurorae.
I don’t know what the test is supposed actually to test, besides some rigid, rote learning program. Also, a few of the questions are quite badly phrased.
If this is a test that is really given to year 7 kids somewhere, and it can properly grade the students (i.e. it’s at the right level so 99% of students don’t bomb, or 99% don’t blitz it, but there’s a good range of results), then I’m impressed. It’s not an easy test.
March 9th, 2007 at 10:40 am
Also, yeah, two mistakes (at least) in the test. One was about whether Mercury or Venus has the longest “day” (time for the Sun to cross from horizon to horizon). I would have picked Venus, not Mercury. Surely that’s right? The other was about solar flares causing radio disruption on Earth (or “North America” as the US-centric testers phrase it) eight minutes after occurring. Let’s ignore Einsteinian relativistic notions of simultaneity … solar flares’ effects on radio and satellite transmissions aren’t electromagnetic, they don’t occur eight minutes after they “occur” on the sun.
March 11th, 2007 at 8:09 am
WAIT! THIS ISN’T WHAT IT’S BEING PORTRAYED TO BE!
Let’s apply some skeptical sleuthing to this document before we get too engaged in the feeding frenzy of content criticism. Don’t be Dan Rather-credulous!
The Illinois State Board of Education has published its released test questions on its website. These are not those questions.
The document whose items are being criticised here appears to be a practice test cobbled together at an Illinois school district (Oconee County). The sources are kindly listed (New York’s Regents Exam, Scott-Foresman Publishing, etc.). My guess is that this document was prepared for internal use only. You can’t get at it from the front end.
So dig in a criticize the items; it’s good fun (and some of them are real dogs). But don’t blame the great state of Illinois for using them to abuse its 7th-graders.
March 11th, 2007 at 2:12 pm
Yikes! Here’s one from the official Illinois science test (ISAT) found here
http://www.isbe.state.il.us/assessment/pdfs/2007_ISAT_Sample_Book_Gr_7_s.pdf
In Illinois, the constellation Orion can be seen in the night sky in winter. Why can this constellation not be seen in the summer?
A Earth is tilted away from the constellation.
B Earth orbits to the other side of the sun.
C Brighter constellations block Orion from view in the Northern Hemisphere.
D The orbit of the moon blocks Orion from view in the Northern Hemisphere.
If you answered A, take a giant step backwards because you got it wrong!
March 11th, 2007 at 7:46 pm
Dean, the correct answer is B. That would be true if the Earth were tilted or not.
March 12th, 2007 at 1:22 am
Indeed; Orion drifts to the daytime side of the sky, yes? I didn’t have the correct visual-spatial diagram in my noggin. So much for my seventh-grade astro-knowledge.
Anyway, that Mercury/Venus one is still a kicker. Luckily it was not on the actual ISAT. Nor was that lightspeed solar wind blooper. Nor the aurora booboo you cited in the original post, or the Black Jupiter question.
It did, however, include a dubious physics item that had two correct answers. The item asked what could be observed when light passes from one medium to another. Refraction is the best answer, but reflection can also be observed in such a case (that’s why you can see yourself in a window). The question would have been better if reflection had not been an option.
Writing really good multiple choice items is a non-trivial task.
March 12th, 2007 at 12:44 pm
Dean Baird, while it is correct that both refraction and reflection occur at the transition, the question was a little more specific.
The additional remark “and change speed” is significant, and indicates the correct answer is “refraction”.
I note they still include the odd question and figure about when the Earth has equal day and night, with the same figure. Overall, there’s better writing, but I did note:
The wording is unclear. The “Earth’s gravitational pull” typically means the acceleration field, i.e. the g. But that is incorrect for this question. The intent they seem to have for the phrase is that the object is pulled harder - but that’s just another way to say the red ball is heavier, i.e. weighs more. That just restates the question. The answer they were looking for is something about the relative masses of the two balls, vs. the sizes of the balls.
What about the Jet Stream? Aren’t major wind patterns caused by Earth’s rotation?
Dean, it also wasn’t readily apparent to me why B was correct for the Orion question, but with a little thought after the fact it makes sense.
Magnum, regarding the rotation rates of Mercury and Venus, the difference is the difference between rotation to starfield and Sun-respective rotation. The starfield rotations of Mercury and Venus are ~58.6 days and ~-243 days. The Sun respective rotations (i.e. noon to noon) are ~176 vs ~117 days. The difference is the motion around the Sun itself, changing the orientation of noon to the starfield. See http://www.mira.org/fts0/planets/092/text/txt001x.htm .