Moon Phases

Final Thoughts of the Semester

2006-05-10T16:55:00.000-04:00

Some final thoughts from my "Physics for Teachers" students ... the question was "What is the one thing you learned this semester that you definitely want to include if you are ever teaching science to elementary grades?"

I learned that science can be fun! I never enjoyed science growing up and I believe it was because of the way I was taught. I learned that there are a variety of ways you can teach science and many activities and fun projects there are to do.

This class gave me a whole new perspective on teaching science! Hands-on and relating experiments to real life will encourage students to participate and learn a lot of new and cool stuff.

Not to be so afraid of Physics.

When we were learning about electricity I really liked the demonstration. I think that it would really allow the kids to see how electricity works, and it would also allow them to make hypotheses and discoveries on their own.

I learned that there are many ways to integrate more than one subject when you are teaching. For example, when teaching about constellations, you can also talk about how different cultures have different names for them.

I would want to teach about forces and how forces work in our life. This is because I learned so much about forces that I didn't know before, for example normal force, gravitational etc.

Students grasp the concepts better when they are actually doing science, not just reading about it and filling in a worksheet.

I enjoyed learning about the force diagrams. I think force diagrams is a brilliant way to show forces and motion. Some children learn better visually.

String Theory

2006-03-12T21:52:00.000-05:00

Last week in Physics II we were focusing on understanding "why" we are searching for a theory that encompasses all four fundamental forces, and why String Theory may or may not be the answer. We've been watching Brian Greene's The Elegant Universe during lab period and tonight I'm sitting here grading student reports on String Theory. I have to say how I love how my students get into this in the oddest ways. Take this part of a response to my question to explain String Theory, including some of the problems with it:

The String Theory would be able to solve things both great and itty bitty small within the same equation. In the heart of every bit of matter there are these things that scientists call strings, or as Dr. Seuss would say "strings and things," or at least that is the idea we are going for. A string is said to be a hundred hundred billion times smaller than atoms, they are just little buggers that potentially make up great objects. If the necessity to understand GR and QM at the same level for one object wasn't in such demand, I am sure Einstein's dream would have been left in the dust years ago now, but it wasn't. Is this theory for real? I would have to say no as would many others, but who is to say since it can't be proven wrong? The problem with the modern "Theory of Everything" is that everything can be explained about anything involving GR or QM in one equation, but nothing can really be proven beyond that equation. So if it can't be proven right or wrong experimentally speaking then is it right or is it wrong? Also, it is found that there are about five theories that supposedly define String Theory but they are far from in harmony with one another. For these very reasons some theorists call modern String Theory a hypothesis rather than a theory. Go String Theory!

Whew!

The really neat thing is that all this talk of Quantum Mechanics and String Theory has piqued "math curiousity" in a handful of my students. They want to understand the math that would let them use these theories.

*maki-girl

The History of the Universe (in 1.5 hours)

2006-03-09T11:15:00.000-05:00

Today was my second day volunteering at L. Elementary school with Mrs. B's 6th graders. Mrs. B is a wonderful, experienced 6th grade teacher who does a lot of great activities with her students to try to draw connections across different subject areas, involve different types of learners etc. She has about 15 students, including one "special needs." Last week we talked a lot about what's in the Universe (stars, galaxies etc.) and got ready to start our nightly sky observations. They have planispheres and are practicing finding certain constellations, and observing the moon etc. Their challenge (from me) for the next few nights is to observe a planet.

But anyways, today Mrs. B and I had decided to have them work on the history of the Universe. We strung up four clotheslines in the classroom and broke the students into four groups. Each group was given a set of 12 cards with different "events" on them, like "The Sun was formed." or "The Big Bang" or "Carbon and oxygen were formed." Their challenge was to put the cards in the right order AND spacing. So getting the right sequence of events and also trying to figure out when all these different things happened. So we set them to work with lots of great instructions from Mrs. B reminding them to work as a team. Mrs. B. and I did not help them at all, but just listened as they decided on the ordering of events. Then, the groups took turns explaining their ordering, including their rationale. Then the groups asked questions of the other groups. Then they did any reordering they felt they needed. Then they discussed again. (Mrs. B. called this "processing.") Then I talked with them about how astronomers are still sorting out "our clothesline" but currently, this is what we think happened and I explained the ordering. Then they rearranged their clotheslines as no one had it quite right, but some groups were close. Then we asked them to work on the spacing. And finally we talked about what we think the spacing is, but emphasizing that we are still studying this, and there is still lots of debate among astronomers about ordering and spacing, just as they were debating.

I found it really interesting to hear their thought processes and Mrs. B. was really happy with the level of thought this provoked in them, especially since they had just finished studying matter and were trying to draw on that knowledge.

Here are some interesting thought processes we heard:
- 1 student decided to break up the clothesline into 14 chunks of 1 billion years each
- 1 group decided to watch another group and see how they were spacing their cards (just like lots of my college students don't want to or refuse to think for themselves)
- 1 group decided that hydrogen and helium had to form first, because you need something for the Big Bang to happen "to"
- Many groups reasoned that hydrogen and helium formed first, because they are gases and stars are made of gas
- Two groups thought there could be no oxygen before the Earth was formed because "there's no oxygen in space"
- 1 student suggested maybe there's a little oxygen in space, just not a lot
- 1 student suggested that maybe oxygen is like other elements and can form in space
- Many groups reasoned that the Sun has to form before the Earth forms, and the Milky Way before the Sun
- All groups had dinosaurs evolving before people
- All groups has stars forming before galaxies because "galaxies are made of stars"

No groups had the spacing even close, but that is no surprise as I am always amazed when I think about how almost everything (elements formed, stars formed, galaxies formed, the Milky Way formed etc) happened in the first billion years of the Universe. Some groups were able to reason that human evolution was at the very very end of the clothesline. I tried to give them some clues about this by earlier talking about how long ago the first animals evolved etc. and some groups remembered that.

Finally we asked them to verbalize what they were most surprised about or what they found interesting. They were all surprised by how early on a lot of the action was, and how "late" humans were. They were surprised that there was not much space between "dinosaurs" and "people." They were intrigued by me mentioning that some elements are made in stars and I think we'll talk about this further.

So, all in all, a good, fun class ... and then they were off to art class!

*maki-girl

The Test

2005-09-29T16:15:00.000-04:00

I meant to post the test as well, but our power went off. Everything seems (hopefully) back to normal after an afternoon in the dark.

Here are the six questions they had:

1. Oprah Winfrey has invited you on to her talk show to discuss your specialty: The Big Bang!
(a) Explain the Big Bang Theory in a way that the typical Oprah viewer can understand.
(b) For those skeptical Americans watching Oprah, also explain one piece of evidence that supports the Big Bang Theory.

2. (a) Explain why astronomers think that dark matter exists if we cannot see it and have no idea what it is.
(b) One possibility for dark matter is black holes. Explain how these form.
(** Note: We talked in class about many possibilities for dark matter and how the black hole idea is not very likely. Just in case you think I'm off my rocker.)
(c) What are two other possibilities for what dark matter could be?

3. Your body contains a lot of hydrogen and carbon. Describe where and how these elements were originally produced.

4. You observe a star in the Andromeda galaxy which has approximately the mass of the Sun. Its brightness suddenly increases.
(a) Describe what could have happened to that star. (There are multiple possibilities, just pick one.)
(b) Whatever happened to the star happened many years ago, but we are just observing this event now. Why?

5. Hubble thought his tuning fork might describe how galaxies evolve.
(a) Briefly describe or sketch Hubble's tuning fork.
(b) Explain why Hubble's tuning fork does not illustrate galactic evolution.
(c) Discuss one method we use to learn about galactic evolution. Mention at least one problem with this method.

6. In astronomy news we've been talking about various astronomy topics and how they may affect us on earth to highlight the importance of scientific literacy. Choose one topic we've discussed in astronomy news. Explain it and discuss its relevance to us.

Note: After further reflection a main problem seems to not necessarily be misunderstanding the content (although that is a problem, too) but not answering the question I asked. For example, telling me WHAT a black hole is and not HOW it formed. Telling me why the Hubble tuning fork isn't a great classification system, not why it doesn't say anything about evolution.

Any thoughts/comments/criticism is welcome. Thank you for comforting words!

The First Few Billion Years

2005-09-29T11:17:00.000-04:00

Well I just finished tallying up the grades on the first astronomy test. The test was on the material covered during the "first three billion years" of the course which included the Big Bang Theory, the first stars and galaxies, stellar and galactic classification and evolution. As well as dark matter and dark energy and scientific literacy/astronomy news.

The average grade was a disappointing 77% (C) with a high of 95% (A) and a low of 47% (F). I don't think I am teaching that differently from last year and I think the test was of a similar difficulty level, but this year's students are performing much worse than last year. Nevermind the fact that one of the six questions on the test was a "freebie." (They had to discuss one "astronomy news" topic we covered and why it was relevant/important.) No one ran out of time on the test.

So it makes me wonder things like:
- Are they just not studying?
- Am I not communicating well?
- Were my expectations not clear?
- How can I motivate them to do better?
- What do I do about the fact that most of them are in there because they thought astronomy would be easy?

I definitely don't think the course is too hard but it does require work. Maybe this will give them a kick start??

I know you, hoagie boy, say that when I give a test I should already know how they'll do. And I did, with the exception of one student who just totally blanked on galactic evolution. The thing is I KNEW many of them were not understanding stellar evolution for example. I covered it a few different ways to try to help them out, and we also did some lab work on it. I left lots of time for review but no one wanted to ask any questions. How do I convince them to take some responsibility for their learning?

That is not to say it's all bad. Some students did very well and most students understood the bulk of the material. They may have not been able to fully explain everything but had a general idea about things.

I am just not looking forward to giving them their tests back tomorrow.

When is a law not quite right?

2005-09-06T09:37:00.000-04:00

I just graded my first set of physics homeworks, based on the introductions to Chapters 1 and 2 in "Six Easy Pieces" where Feynman discusses "approximate" versus "true" laws, and how physics is "done" using a chess game analogy. (If you don't have a copy of the book, the introduction to Chapter 1 is available on amazon.com using this link.)

Here are some interesting answers to the question "What does it mean for a law to be "approximate"?" (Some interesting in how "wrong" they are, and some in how "right" they are.)

* "A law is said to be approximate when it is correct and applies to everyday life. The term approximate law is also used by physicists who know that we do not know all the laws thus far. A law is "slightly" wrong if it is in a trivial way, or if the law is inaccurate after experimenting and checking results back and forth."

* "To say that a law is approximate means that we as scientists first find the wrong answer and then find the right one. To be considered slightly wrong an experiment is believed to be inaccurate."

* "The law has an asterisk, an exception where it is actually wrong."

* "A law that is "approximate" means that the law has not been fully known and tested with experiments to get out all the "wrong" truths. Approximate involves assumptions. Thus, this law is slightly wrong because it is only a part of the "whole truth."

* "For a law to be "approximate", it means that it is a small portion of the whole nature of the law."

* "An approximate law is when the law is mostly correct, or maybe it's only right in certain conditions."

* "A law is approximate if it is known to be wrong under certain conditions. Therefore "law" is probabely not the best word. "Guideline" is a better word."

* "An approximate law is one that only partically explains the relationship of the variables involved."

* "For a law to be approximate, it is correct for all general purposes."

* "A law is "approximate" when it is considered to be the truth given the evidence at that period of time."

* "A law is slightly wrong if we invented it in the past, but through experimentation laws can be learned, unlearned, changed, and sometimes corrected. It's all just part of the process of science where we discover amazing aspects of our world."

And when they pondered Feynman's analogy about physics being like a chess game:

"We can keep observing the big game of chess but we may never find out how the pieces got there in the first place."

"I find this to be interesting because he involves both kinds of physicists, the spectator being the theorists, and the chess game as the researchers."

"I have always thought that science was too difficult for me to understand, but the way that Feynman described it made perfect sense. Reading that gave me a better outlook on the field and my future in this course."

"I have never thought of science as an attempt to learn the rules of a game before, and the analogy is useful and soothing."

"I know the basic rules of chess but yet I don't fully understand the game and then looking at the topic of physics, I know and have heard of many of the topics, but still don't know much about them and still leaving me intrigued about both. [...] This idea helps make the thought of studying physics easier and more interesting."

"I never thought about us being a bunch of observers of a game really, and discovering new rules."

And we're off!

2005-09-01T08:52:00.000-04:00

And we're off! Another semester has begun here, and I am teaching the same load as last Fall (Physics I and Astronomy) except I've added two lab sections to Astronomy. As I mentioned, I ditched the standard physics textbook and am using Feynman's Six Easy Pieces as the only required reference. So far, so good. We have spent the first two classes talking about what physics is, why bother studying it, and also talking about the "old" and "new" physics. The "new" physics seems "old" to the students--they were surprised to hear that relativity and all that is a 20th century thing. They seemed excited/enthusiastic/interested when I described my expectations for them in the class. I emphasized that we will focus both on understanding the concepts and then dealing with them mathematically, and I also discussed how the labs are not following "cookbooks" but exploring what we've been talking about in class.

In fact, a student just called me to talk about class yesterday because he had to miss it for a business meeting. (He's a non-trad.) He said, "Brace yourself--I opened up this Feynman book and I actually found in interesting!" Cool. You could be pessimistic and say he's only sucking up, but I will believe his sincerity for now.

The students in astronomy seem much less enthusiastic. I don't know if it's because many of them are MDS majors (multi-disciplinary studies ... mostly pre-service teachers) and they all know each other and are all really young and want to be "cool" or if they are not into astronomy or if I am not getting them into it. The few guys I have in the class seem MUCH more interested. But that class has been going well, too. The first five minutes is always "astronomy news of the day" and I've been doing it so far, but next week they'll start taking turns doing it. This means they actually have to go to the library and find some sort of astronomy article and read it and then tell us about it. It's part of my literacy mission. Remember this summer when the 10th planet thing was pretty big news? A lot of my friends/family had heard about it etc. TWO people in my class (out of 24) admitted to hearing about it, and 0 had heard about Deep Impact.

If I was all grumpy and old and jaded and selfish I might be tempted to say I only want to teach science majors.

But thankfully I'm not like that yet.

Back for More

2005-06-14T21:45:00.000-04:00

I took a break for a semester (from blogging about teaching, not from teaching) but now I'm thinking ahead to next semester. I have the same course load again--Physics I and Intro Astronomy--except now astronomy has a lab, too.

My experiment this semester is going to be teaching physics without assigning a textbook. Instead we're going to use Feynman's Six Easy Pieces.

That's enough to think about for now.

Monday Morning

2004-12-06T11:16:00.000-05:00

We are chugging along and have almost reached the end of the semester! We have covered all the planned material in astronomy and I have left it open to cover whatever the students would like for the rest of the time (about 4 more classes). I solicited suggestions and got the following:

- latest news in astronomy
- interesting facts that people don't know ("I want to be able to go to my friends and tell them things that wow them.")
- asteroids and asteroid belt
- sun spots and solar flares
- groups of stars (history; do they change? how?)
- how close are we to discovering a new form of space travel?
- contellations for different seasons
- other solar systems ("Is ours a standard model? Are there other solar systems that have two or more suns?")
- worm holes and parallel universes

In physics we finished heat flow and are now ready to move into heat engines and refrigerators. I think their brains are feeling really full! I know mine is!

Newspapers & Distribution Functions

2004-12-02T09:36:00.000-05:00

We devoted all of astronomy class on Wednesday to getting the newspaper organized. I was pleasantly surprised by people's enthusiasm and participation. I hardly had to nudge them at all. They came up with great ideas and set their own deadlines etc. One student even volunteered to do the whole layout on the computer -- this saves me some work :) I am really excited to see how this turns out!

We spent physics class on heat capacity ... not exciting and a lot of people have had chemistry already so it was pretty boring for them I think. I am wondering if I should drop thermal physics from Physics I since almost everyone who may need this content takes chemistry anyways. Then we could spend time on modern physics or something they won't get any other place. Lab went so-so yesterday. I encountered one very angry student who said she could not see the point of the questions I was asking. I am not sure why she was so angry (although I overheard her telling a friend that her long-term boyfriend just broke up with her ...) so I am hoping it was not really about the lab. No one else complained so I don't know? We had a few very tall people in Wednesday lab which gave a bigger difference between the average and rms quantities. I think I'll do a histogram of the heights from each lab section and compare the values and discuss them in class on Friday so everyone is on track and getting the point.

A Sleepy Monday

2004-11-29T11:24:00.000-05:00

I think no one (including me!) was ready to be back in class this morning! But we perservered. I handed out the last astronomy observing assignment (Saturn, Gemini, Orion) and also the newspaper assignment. We're going to spend Wednesday in class brainstorming and organizing the newspaper. We also talked about meteors, comets, and asteroids and of course I had to show all the pictures of people and cars and things that have been hit by space junk.

In physics we finished up molecular motion with mean free path and diffusion and started on the idea of heat. The rms thing is still driving them nuts but I hope that lab this week will help that. They'll figure out for everyone in the class, the average height and rms height etc. Let's hope we don't have a normal distribution :)

Only three weeks left! I can't believe it!!

Space Travel and the Ideal Gas

2004-11-23T10:00:00.000-05:00

Monday in astronomy we talked about space travel, including the shuttle of course but other sorts of possibilities (speculative). There was a lot of student interest and I think we should spend more time on this next year -- maybe have them speculate on how we could travel faster/cheaper etc. I also have to remember they are so young (!) that the shuttle and all are kind of routine to them.

In physics we continued on with the ideal gas, talking about how the kinetic energy is 3/2 kT and the Maxwell-Boltzmann distribution for V(rms). These ideas were difficult for them -- why is V(rms) =/ V(bar) =/ V(most probable) and how do I read these curves anyways? So we will spend more time on this, perhaps in lab next week.

I got my feedback from the Dean today about her observation of my teaching. She said that overall it was good and I was very clear, the students were following very well, and were comfortable enough with me and understanding the material enough that they could ask questions. She said it was great to see me comfortable enough to say "I don't know, but I'll find out." to some of the questions. Her suggestions were to get out from behind the lab bench more (! I know! You told me the same and I will work on this :) and once I have the physics down, to add a little bit of historical knowledge. For example, the students were very curious about who was this "Mr. Fahrenheit" and why did he have a different idea from "Mr. Celsius"? So I think that was all positive. We went over also my "service" and "scholarly work" areas of performance review and she was pleased with those as well. So, all in all, a good meeting. I also was very good and managed not to be too defensive :)

Friday: Misconceptions

2004-11-20T19:57:00.000-05:00

We spent Friday in Physics class answering some questions students had during the week and addressing some misconceptions that popped up during lab. One question was, as you heat a ring of metal or a tin can, why doesn't it expand IN? I.e. Why doesn't the hole get smaller instead of bigger? Another was, how does a change in elevation affect the ice point of water? (We had discussed how it affects the steam point.) And another question was, if you warm up gas and it takes up more volume then do you have MORE gas? Does it make sense to fill up your car when it's cold out so you get "more" gas in your tank? And we discussed why water expands when it gets colder. And finally we cleared up the misconception that in a bulb thermometer, the only thing that expands is the alcohol or mercury. This put us a little behind in what we should have covered by now, but I think it was time well spent. The students whose questions I addressed actually thanked me after class and said a lot of professors just never answer questions! (Yikes!) They had been questions that during the week I had not been able to adequately answer so I did a little research and talked to the chemistry professors before class on Friday. So I was very happy with that class actually.

My Astronomy students had their test on Friday. I think it was "harder" than the first one, but every student had a chance to finish this time, so that was good. They are so funny -- they say "thank you" when they turn their tests in!

A Physics student got accepted into the Clarkson Engineering program -- that's the school we are paired with in the 3+2 engineering program. (Well, we were -- we have now ended the program except for the students in the pipeline.) Many of his classes transfer so he can indeed finish up his second degree in an extra two years. I hope that he is prepared well enough. I agreed with his math advisor that he take some extra math next semester to brush up on calculus and differential equations. I am not worried about him not knowing enough content (he has to take classes like fluid dynamics, statics, thermodynamics) but I am worried that his math is pretty rusty since his upper level science courses have been in biology.

History of the Universe

2004-11-18T21:39:00.000-05:00

I haven't had a chance to look all through it yet, but this looks like an interesting website similar to what I'm trying to do with my astronomy class:

History of the Universe

Some Perspective

2004-11-18T09:23:00.000-05:00

I showed this famous "pale blue dot" image of our Earth taken by Voyager at the edge of our Solar system to my astronomy students this week. Would people stop fighting and hurting each other if they took a moment to think of our place in the Universe?

The End is Near

2004-11-18T09:14:00.000-05:00

There are only a few weeks of classes left in the semester -- I can hardly believe it! My physics students took their second test last Friday and everyone did quite well. The lowest test grade was a C. They seemed to understand this material much better than the first chunk of mechanics, plus I shortened the test a little bit to give everyone a chance to finish. Now we've started on Thermal Physics and so far have talked about temperature, how to measure temperature, and how different materials respond to a change in temperature. We talked about how you have to take thermal expansion into account when laying railway tracks, building bridges, roads etc. and they had quite a few questions about that, so they seemed pretty interested. They were also very interested in the fact that the steam and ice point of water change depending where you are on the Earth. They are also all quite perplexed by why water acts so 'weird' -- it expands when it gets colder. So we are going to spend 5 or so minutes on that tomorrow. It's really chemistry stuff, but I guess it's all the same really. In lab this week they had to figure out how a bulb thermometer, bimetallic strip thermometer, Galileo thermometer and turkey pop-up timer work. They also had to predict and then measure cooling curves for various situations. One student brought in a 9 year old neighbour who she helps to home school. He understood probably 75% of the lab and was actually HELPING his lab group. Which goes to show (I think) how much MORE we could be doing in elementary and middle school. And high school for that matter.

My astronomy students have their second test tomorrow. We have covered a lot since the last test -- the nature of space-time, the universe from our perspective, telescopes, the solar system, extra-solar planets and extraterrestrial life. They are also working on revising their 2nd astronomy articles. Most students wrote very good articles on lots of different topics -- how the moon affects us on Earth, how animals and plants react to a solar eclipse, the nature of light, the expansion of space-time, is Pluto a planet or not ... so it was good reading and I think they are ready to publish their newspaper!

Life on Other Worlds/The End of Mechanics

2004-11-10T13:38:00.000-05:00

We have moved beyond our solar system in astronomy and began talking about extra-solar planets today. Friday we'll get into the possibility of life on other planets. Maybe I'll even pop in the Drake equation. Their first equation. Yikes! I think they can handle it and I think it's pretty interesting. They're all into this other lifeforms stuff, and wanting to know what other planets are like, what's out there ... I'm glad to see they are still curious after 11 weeks of me!

In physics today we finished up Mechanics with a review for the test on Friday. The student who's failing slept through the review :( He is just digging a bigger hole for himself. One student missed class and left a message for me explaining that he had to take his girlfriend to the hospital because of a "contraceptive emergency." Yikes! Way, way, way too much information!!! Anyways, I think the students are ready for this test, and I think they are going to do well. I am more confident than I was for the first test. Also, I am much better at writing equations on the board (and not mixing up all my subscripts) now that I am making myself sleep more. So that's positive.

Yesterday I had a physics student inform me that someone "just like me" was on MTV's Made the other day. Apparently, a "science girl" was getting made over into a hip hop dancer. He said that she looked just like me, and was all serious and sciency just like me. He said he informed his roommates that his physics professor was on TV. Eek!!!!!

At least life is not boring!

A Hailstorm of Diamonds

2004-11-08T11:28:00.000-05:00

We finished up the gas giants today in astronomy class. They all decided they want to move to Uranus and harvest all those diamonds that are raining down on the planet :) We talked about the shepherd satellites and the rings and all on all the gas giants which is the only thing I really thought was cool in Stan's class and they seemed to think that was pretty interesting. I saw Venus and Jupiter this morning and encouraged them to observe them tomorrow morning (they have an extra credit observing assignment they can do) and one student told me she saw the Northern Lights last night! Darn, I missed them -- I was being lazy and sleeping (it WAS 2:30 a.m.!)

We spent today in physics going over some misconceptions and also talking about studying strategies for the test. I hope it helped ... we will find out!

Planets & Rolling, rolling, rolling

2004-11-05T13:40:00.000-05:00

We continued on this week in astronomy about the planets. On Wednesday we discussed the Earth-like planets. The students seemed to enjoy all the really nice images we have of the planets and talking about what life would be like on each one, and the possibility of life evolving on different planets. The students are also coming up with topics this week for their next astronomy article. I left it wide open and have gotten a variety of ideas such as "Solar Flares," "Saturn's Rings," "The Evolution of the Sun," and "Pluto -- is it a Planet?" One biology student just came in and wants to write about Venus' atmosphere and thermophiles -- apparently these are organisms that can survive extreme heat. He wonders if maybe they could survive on Venus.

I did have a student complain to me about her grade on her last paper. I didn't grade it really high because she didn't make very many revisions. However, she complained that the feedback she got wasn't very useful for revising. I think next time I will have them attach a paragraph to their revised papers explaining what revisions they made, if the comments were helpful or not etc. She seemed very upset but calmed down after I talk with her about it. Tragedy averted!

In physics this week we finishing up rotational motion, culminating today with angular momentum. I think the students are feeling lost in equations and I don't blame them. When we start up with thermodynamics I am contemplating having them keep and updating an equation sheet as we go or something like that. We'll see. Anyways, they seem pretty good with torque, but weaker with the concept of rotational inertia, although I think the lab activities helped. They enjoyed sitting in their twirly chairs and using the bicycle wheel to spin around. They also were very interested in neutron stars and how they spin really fast because of their collapse.

Another week over with! Next week I have to hand out evaluations. I won't get to read them until after I turn in final grades. I wonder what students are going to say?

Third Rock from the Sun

2004-11-01T13:17:00.000-05:00

We have been focusing for the past two classes in astronomy on understanding why the sky looks like it does. Many of my students observed the lunar eclipse on Wednesday, and I have now given them a new assignment -- to observe Jupiter and Venus. They are really obvious in the pre-dawn sky right now, so those students who get up early will be able to see them. Don't worry, it's an optional assignment because I know that's WAY too early for many students! We also talked about how the motions of the stars and moon were used to keep time for many cultures. We talked about the Hawaiian moon calendar (they have a name for every single day of the lunar cycle, and things you are supposed to do for each day), Stonehenge, Newgrange etc. And then we moved into learning about our solar system and just started today with an inventory of its contents. (Yes, someone did ask about Pluto ... is it a planet or not!)

We are launching into our last part of mechanics in physics class and this requires quite a bit of synthesis of earlier material which elicited some groans from the students. Today we talked about rotational inertia and how to calculate the rotational kinetic energy of an object. In lab today they'll play around with center of mass and rotation with questions like, why doesn't the Leaning Tower of Pisa fall over? Why do you sometimes choke up on a bat? Etc.

I had an interesting discussion with the high school physics teacher who was visiting last week. My focus has been to emphasize to the students that physics is not a big mystery, that they already have some intuition and knowledge for how the world works, and it makes sense. Hers is to emphasize how we have so many misconceptions about physics, and she starts each class with a misconception. I don't like to start things that way, because what if that's not even a misconception among many students? Now you've introduced an alternative explanation that they have to remember is incorrect! And I think it makes the topic more approachable/palatable if they start to learn "Hey, I already know some of this stuff!" Like they know Newton's First Law if they think about a passenger in a car that stops suddenly. They don't know the WHY yet, but they know what happens. Different strokes.

Over-and-out for today.

The Lunar Eclipse & a Winchester Rifle

2004-10-28T10:28:00.000-04:00

We spent yesterday in astronomy discussing the phases of the moon, eclipses and tides. I had the students come up with an explanation for the phases, which in the end they were able to do with little prodding. They came up with some incorrect ideas first (the shadow of the Earth, clouds) but in the end with the help of my antique model of the solar system they came up with what's really going on. I got a great question from a student who doesn't usually say much. He asked, "But then wouldn't the new moon come up at sunrise?" Why yes it does! So that was great. I gave them a short observing assignment for the eclipse last night so hopefully some of them did it.

Yesterday in physics we focused on conserving momentum using an example of a rifle. This would have worked great except it turns out many of them don't know a rifle kicks back when you fire it. So a different example would be better next time! We found that a Winchester .308 kicks back at 5 mph which is kind of cool to figure out (even they seemed to think that was kind of cool!) We also did some work on center of mass. I should have demos or something next time, but ran out of time this time. In the calculus section we talked about how to find the work if your force is varying (integrate) and also about the equivalence of energy and mass and how much it would cost to 'buy' the mass-energy of a penny (about a million dollars!)

I had a visitor for the first two classes yesterday (astronomy and regular physics) who was a high school physics teacher for 35 years. It was great to have her input, but sometimes a little frustrating because she has her very set way of doing things. When I discuss the idea of work with my students I always talk about what's doing the work (what is exerting the force). Like I'll say, "Laura lifts up the barbell with a force of 50 N through a displacement of 1 m. The work done is 50 N.m" or something like that. She says you should just talk about, "The work done on the barbell is 50 N.m and leave out where the force comes from so the students don't get confused." I think it's CONFUSING not to know why work is done -- there must be some force, so where does it come from? Well, maybe I am just stubborn! :)

How to make your car safer (oh yeah, and the moon)

2004-10-25T20:17:00.000-04:00

Thanks hoagieboy for fixing my name. I felt like I was some new-age moon priestess before. Another fun day was had by all (some?) in astronomy and physics today, but before I write about today I forgot to regale you with tales of Friday.

In astronomy on Friday we talked all about telescopes, why we build big ones on mountains, why we use mirrors, all different types of telescopes (radio, gamma-ray etc.), and even adaptive optics. However, we did not learn "resolving power," "Cassegrain," or "chromatic aberration." Shhhh. Don't tell any real astronomers.

In physics we learned about power and compared our body's power output at rest to a 100 W light bulb (less) and then talked about our power output when we're exercising, and all about energy being conserved (sun to plants to animals to food to us to our muscles to heat etc.) It seemed to connect really well with the students because they have all (mostly) heard about their "metabolic rate" or the hp of cars etc.

So, today in physics we learned about momentum and impulse and spent quite a while talking about how if we spread an interaction over a longer period of time, the force decreases (for the same change in momentum) -- and specifically talked about car safety, with airbags, crumple zones etc. I had the students work a problem with a car hitting a tree and finding the force on my body exerted by a) the windshield b) the seat belt and c) the airbag. They seemed pretty into it actually (!)

In physics lab today I had them work on three different concepts. The first was conservation of energy. They had to figure out the maximum kinetic energy of a big pendulum I found in the lab storeroom without being able to measure the velocity of the pendulum. (So they figured out the maximum potential energy ...) And they also had to discuss if energy is conserved why does the pendulum slow down etc. Sounds pretty simple, but I wanted to make sure they "got it." Next they worked on calculating work and power and thinking about what they really mean (in physics terms.) They calculated work and power for a few cases: walking up the stairs, jogging up the stairs, lifting a weight with only their forearm, and lifting a weight with their whole arm. They had to figure out the force needed, and had stopwatches to time how long it took to do these things. I wanted them to practice thinking about work and power, calculating them and also thinking about does a larger force mean more power etc. ? They actually really got into this part and were relating it to working out, or for the athletic trainers and the personal trainer in the class to what they do with their patients/clients. I heard lots of good comments about how running is so much more tiring because your power is 5 times greater and boy so you'd better take in a lot more food etc. It was nice to hear various connections being made and they of course liked the active part of the lab. It also helped reinforce that in physics language, the work doesn't mean "how hard something is." Like it takes the same amount of work to walk and run up the stairs. The third part they did was to try to reinforce something we worked on a few weeks ago with circular motion. They seemed pretty good with a lot of the circular motion ideas, but were having trouble grasping how the linear speed changes with your distance from the center. I kind of ran out of time getting this part ready :( But I had them calculate the angular speed of the Earth, and then look at a diagram of the solar system and figure out at what point in its orbit the earth is moving fastest and slowest (linear speed). Not the best/most exciting, but I can improve this part next time if I decide to keep this topic.

Phew! So that was physics today. I also spent A LOT (probably 3 hours total) helping students with the homework that is due on Wednesday. They are really struggling with a problem with a satellite, and trying to figure out its height above the Earth given its angular speed. (You have to figure out the net force = gravitation force = m * a and plug in for a from angular speed.) It is a lot of steps (when I watch them try to work it out!) and they seem to get lost in there. Well, some. For others it seems really straightforward.

In astronomy today we finished up telescopes by talking about how you record your data (very briefly) and then started on our new topic which is "The Universe from our Perspective." First we talked qualitatively about the sky motions they notice (stars change with the seasons, stars rise and set, moon phases, moon rises and sets, sun rises and sets, and they also added comets and shooting stars to the "motions" we see.) We talked about how we are on the Earth which is rotating and revolving around the Sun and the moon goes around the Earth etc. but did not get into the nitty gritty of how that produces all these sky motions. We then focused on the moon to get ready for the eclipse on Wednesday. We talked about how big it is, how far away it is, how it was formed, why some areas look light and dark, and why we always see the same side of the moon. I skipped one very important thing! Thank goodness a student ask what makes the moon shine! So we talked about that :) I showed some very good photographs of the moon and next class we'll talk about phases and eclipses (and tides if we have time).

All in all I think a pretty good day, although not as "active" as I would have liked. Except for the lab -- there were lots of good conversations happening and people figuring things out (and arguing about things!) I assigned them to lab groups this time to try to mesh personalities a bit better.

Ok, over and out!

Your name should work now

2004-10-24T23:52:00.000-04:00

No longer are you a crazy, hippie-inspired girl with a name like "moon phases" anymore. Maki-girl can make her presence felt on her own blog.

-hoagieboy

Peer Editing & Energy

2004-10-20T13:29:00.000-04:00

Today's topic in physics was energy, and unfortunately I have no energy today. I know the students can tell especially when I start mixing up what day of the week it is :( I am trying really hard to get all my work done before 9:30 p.m. but it is hard! So I am generally not happy with how classes went today, although it was not a complete disaster.

Astronomy: I had them do peer editing on each other's cosmology articles (anonymously). The good part was that I heard lots of good conversations with comments like, "I really like this analogy" or "Here's where I got confused" or "I did not know that before." I gave them a list of questions to answer after reading other students' articles and they seemed to do quite well. The bad part was that not everyone showed up (four students were missing today for some reason, which is unusual) so not everyone's article got peer edited. I can do the leftover articles myself so it's ok but I should have built some redundancy into the system. The other bad part is that I feel strange "observing" them do group work. I don't want to interfere or inhibit them, but I feel funny just kindof hanging around. Hmmmmm. I also gave them back their first tests today and most of the students did quite well. 11 A's, 5 B's, 2 C's and 1 D. Interestingly, the D was not from a student who complained that she ran out of time.

Physics: I taught the regular class today and the "calculus" tutorial. We started on energy and work today and I have to admit these are sort of hard concepts for me (work is the change in kinetic energy but only for a point particle .... ?) but I think I presented them so-so. I emphasized the difference between 'work' in our everyday lives and the 'physics' definition of work and they seemed pretty good with that. We tried some work problems, too. Then I started on kinetic energy and deriving that from work and I find it hard to do derivations because it doesn't seem like there's a point (just pushing letters and symbols around) until you get to the end. But on the other hand I don't want them to think these equations just pop out of nowhere. I'll have to work on this. So the class went so-so. Good news is we are not behind anymore because I ditched angular acceleration and non-uniform circular motion and decided to deal with work in just one dimension. It would take a lot more time to deal with work problems with vectors and two-dimensions and I figure they get the IDEA from doing it in 1 dimension without getting all hung up on the math. I am going to have to rethink what I teach next time or repace the course, but I think this is an OK compromise for now. The recitation went better than the class. We worked some 'interesting' (I think/hope) examples about why you bank the curve on a road and putting a satellite into circular orbit. I was trying to show them that all this circular motion stuff does have something to do with our lives! I am already wondering what the heck I'm going to do in lab next week. The topics are either circular motion or work/energy/power or momentum.

I think I am feeling a little (ha ha!) overwhelmed but part of it is that I want to do everything WONDERFULLY and not just adequately. And that's very hard your first time! But I would rather feel this way than be content with being adequate. So I perservere on :)

If anyone would like to suggest a discovery lab for next week I'm all ears :)

- maki girl

Space-Time and Going in Circles

2004-10-18T13:45:00.000-04:00

We did a Gedanken experiement in astronomy class this morning, to talk about why something that's simultaenous for me may not be simulatenous for you. They seemed to get it and think it was interesting. We went on to talk about space-time and the "shape" of the Universe. This part was hard as we can't picture things in that many dimensions. Next time I teach this I want to do more with this ... I think some of them don't really have an understanding of what a "dimension" is. But, as usual, I ran out of time. That is my biggest frustration with teaching. I feel I just don't have the time to make it as good as I would like. But anyways ...

We continued with uniform circular motion in physics today. I tried to, multiple times, make the connection between linear and angular quantities (displacement, speed, acceleration) as I remember when I learned all this stuff (or tried to, in college) I had no idea what angular speed was. I just knew the formula and did not connect what it really meant. I don't know how much of it they got this time around, but we're taking a second look on Wednesday with lots of examples/problems. Perhaps some lab-type stuff if I (of course) have time!

A Separate Space

2004-10-09T21:58:00.000-04:00

Here's a separate space to discuss thoughts, problems, trials, tribulations etc. associated with teaching introductory astronomy and physics classes at the college level. Things like the importance of teaching the phases of the moon and the ecliptic (notice the sarcasm). Yes, because it's all about me I am unable to share blog space with other topics.

Thoughts as my students took their first tests:

1. I was not effective. Some still cannot differentiate between mass and weight or velocity and acceleration. They still do not understand that even if I throw a ball up, or a person jumps up, the force of gravity causes them to accelerate downwards. They still do not understand how or why we break a force up into its components. I knew I did not succeed in teaching this one that well, but I thought the others went very well.

2. I did reach some students! Some who were "weaker" coming into the class performed very well on this test.

3. I need to do a better job assigning the homework for my students. The labs are good at emphasing and exploring important concepts. I need to make the homework more pertinent and meaningful.

4. I think the astronomy students are doing ok (but I haven't had a chance to read over the whole test yet for everyone).

Misconceptions I need to work on:

1. Mass and weight

2. Velocity and acceleration

3. Force of gravity/acceleration due to gravity

4. Theories and what they mean -- what does it mean that the Big Bang is a theory? How is that different than a hypothesis? How is it different (if?) from "the truth" ?

Despite being somewhat disappointed by some students on the physics test, all in all I think that all of us (my students and myself) gave it our best and we all learned something. The student who failed the physics test and was obviously upset with himself and thinks he is "too stupid" to learn physics will need a little more work. I think we should work together once a week. I think he can recover.

I know I shouldn't be too hard on myself and I am doing the best that I can. But I still wish I had done "better." Well, don't we all?