The Nuclear Option

For me, this will mark my final entry for the year. Many things have changed in my classes during the last few weeks. Molly had to leave for the remainder of the year due to medical issues, and a substitute teacher, Mr. Mustapha, has taken over. While I always felt that Molly and I had different ways of approaching the students, Mr. Mustapha seems to share much of my philosophy. He has been more willing to write referrals and tries to be as fair and consistent as possible. Nevertheless, the students still realize that they're basically on a boat without a captain, and Mr. Flowers has started delivering the lecture for half of each class. It is in this environment that I gave my final presentation, one that I had been thinking about for quite some time.

As the year has progressed, my presentations have become more simple with each time. Part of this may be attributed to time constraints on myself, but there's a more overriding reason for it. Previously I had tried to fit into the curriculum as best I could, making math the first priority and application secondary. While there is no reason a priori that this could not work, I found that my talks ended up becoming rather dry in spite of the best intentions. This time, I focused almost entirely on the application with few equations and only a very broad overview of how math was related. For this reason, my usual slideshow was cut down to about 7 slides that complemented the talk rather than led it. This change was also inspired by some interesting notes made by Edward Tufte on the subject of slideshows. For this reason, I will briefly outline the talk below.

Slide One: The Gadget
I began by informing the students that this would be my last day with them. I had planned on being a bit more subtle about the affair, but Molly's sudden departure proved rather disruptive. I mentioned that I would be going to Cleveland to work with NASA for about 10 weeks on my research. I brought up that I'd be shifting from a math oriented approach to one that focused on the application but assured them that math governed each aspect of the talk. Afterward, I asked the students what kind of engineer I was and reiterated common perceptions about the word "nuclear". I then drew their attention to the slide and told them that it was a recreation of the first nuclear bomb ever detonated, The Gadget. For some historical background, I mentioned the Manhattan Project, its duration and some of the people involved.

Slide Two: Ivy Mike
After mentioning that the first nuclear test occurred in July 1945, I projected a rendition of the Ivy Mike test. I used my hands to indicate the approximate scale of the picture. I mentioned the TNT-equivalent of the first nuclear test and tried to describe the sheer magnitude of the event.

Slide Three: Uranium
I told the students that we were getting a bit ahead of ourselves, and really had started at the end of a long story. After probing them for their knowledge about atoms, I also attempted to convey the size scale of an atom. I also described the basic subatomic components along with a qualitative description of radioactive decay. In particular, that uranium is always a bit unstable, but that  it can take around 100 million years on average for a single atom to decay.

Slide Four: Fission
This was an excellent segue into how adding a single neutron could disrupt the balance of the atom and cause it to split apart. Because the image of smaller nuclei being flung away from and fissile atom inherently implies kinetic energy, it was simple to describe the reaction as exothermic without resorting to the concept of mass difference. I also indicated that on average two or so additional neutrons were generated for every fission. When asking what would happen if I grouped together a large number of uranium nuclei, it became pretty clear that there would be a large growth in energy and neutrons.

Slide Five: Hiroshima
After building up to the excitement of understanding the bomb, I shifted toward its effects. I mentioned what happens immediately after a blast and the resulting effects on the people below. I tried to emphasize the human aspect of the situation and expressed my dismay that one of the greatest scientific achievements was also immediately used to kill hundreds of thousands of people. That the event also signified the beginning of my field made it especially relevant.

Slide Six: Atoms for Peace
The idea of an uncontrolled chain reaction was pretty well developed by this point, so I introduced the concept of a neutron absorber and moderator. Using a clever combination of the two, one can create a device where the number of neutrons is always constant as is the energy output. I mentioned that the energy output could be used to heat water, run a turbine and generate electricity. As a side note, I gave a brief description of Cherenkov radiation, in terms of the wake following a boat in water. Following all the advantages of nuclear fission plants, I also discussed the fact that every method of generating energy produces and undesirable byproduct, in this case nuclear waste.

Slide Seven: The Z Machine
This led to the concept of a nuclear reactor with a less objectionable byproduct. I mentioned that energy could also be produced by joining small nuclei together, and that the natural deuterium found in the water could provide the Earth with power for millions of years. The only byproduct being helium (I neglected to mention the low-level activation of reactor materials). This led to the question of why fusion isn't being used for all power, at which point I expressed how the reactions require an environment that's hotter than the sun. I briefly described several approaches; the magnetic bottle, inertial confinement fusion (both NIF and the Z Machine). I ended by describing how this was the material that had captured my imagination and got me into the discipline I chose. I thanked the students for letting me work with them throughout the year, and said goodbye.

The reactions were different in my two classes, but more students were engaged than ever before. I got a lot of strange questions ranging from superpowers, to nuclear guns, to how bombs are actually built, and more all of which were entertaining and interesting. Third hour still suffered from several students that couldn't keep from talking loudly and interrupting me (including one that was eventually sent away by referral). After being instructed to stop talking to their friends another student harassed me with the poorly veiled sarcastic remarks before asking how science had anything to do with math. If the dear reader will recall, I have gotten this question almost every time I have given a presentation and always from this student. I asked the student to stop interrupting me and that the issue had already been explained to them several times, including at the very beginning of the talk. This of course drew accusations that I was being rude and dismissive. I barely managed to eke out the end of my talk about how I had learned about communicating technical principles from them and doubt that many heard it anyway.

Fourth hour was generally more receptive and those that didn't care had the decency to just fall asleep. Several seemed genuinely interested and appeared to get a lot out of the talk. It also helped that many of the students that are usually disruptive just didn't bother showing up. I had a great time with the talk and feel like this talk was the first unequivocal success for me this year. Afterward when I thanked the students they began to clap for me, and that was about it.

In respect to the TF program, this year has been a bit of a rollercoaster. I'd feel exhausted whenever I left YHS, but always managed to rebuild my eagerness for the next week in the hope that things would progress. With the end of the school year in sight, I think it is fair to say that some students did progress, but a large number simply remained stagnant. While the behavior has greatly improved, there is still a large margin between where the students are now and what is acceptable. If the final grades are a true reflection of how much the students understand algebra, I would be surprised if more than 60% were moved on to geometry. I was in the district for a limited time, and understand it much less than those that work there day in and day out, but my impression is that instead of trying to bring the students to the expectations, the expectations are brought to the students. In addition, my discussions with students and teachers indicate that many parents' involvement in the education of their children is minimal. On top of it all, many of the students have an air of entitlement about them; that the teacher and myself were there to serve them. The combination of all these factors is a bit frightening.

While my exposure to the politics of YHS was small, the tension between the faculty of YHS and the White House was palpable. How the school is reorganized under its new principal during the summer will be indicative of how the school will evolve over the next few years. There is a lot of mistrust floating around, and while everyone agrees that something is wrong, no one can agree on what it is. Hell, no one even knows what missing the AYP requirements again would mean. At the very least Mr. Moore must prove himself a charismatic leader that is capable of convincing others in his plans. There is a still a lot of loyalty and respect for Mr. Brown, and many don't seem to understand his departure. To make a long post longer, below is a compilation of some changes that I think should be implemented.

  • Return to the old grading system: Basically, the current system assures that the student cannot receive below a 50 on assignment so that poor performance on a single assignment is not overwhelmingly discouraging and an enormous setback. While this is an admirable goal, the reality is that this policy artificially inflates grades and gives the appearance of improved performance. It has become quite difficult to fail a class (though some students still manage) and I can guarantee that many students will be moving on to sophomore level classes without adequate understanding. In addition, if a class has enough grades, then a single bad grade will not doom a student anyway. Stop lying to yourselves.
  • Intervene for recurring absences: There are some students that miss almost every day of class, a formula for failure (or moving on without understanding the material). While parents are notified of each absence, there appears to be little effort to alter the situation or any efforts are inadequate. While the Program of Study lays out an extensive policy, I cannot help but wonder at its implementation. At the very least, I notice that it promises in-school suspension for recurring cases, but there is no such thing available. I have heard of students missing over 100 classes in just this semester or around 1 out of 5 days of school. This is just plain embarassing.
  • Confiscation of electronic devices: Look, all this pussyfooting about liability is dust under the rug. If students are listening to music or text messaging the only option for teachers is to remove them from their classroom. This reduces instruction time and helps no one. That no one seems to have come up with a better solution is scary.
  • Comprehensive school-wide behavior policy: There has been some effort to produce something similar to this, but it's limited to a small set of rules posted on everyone's doors. A group of teachers, students, and parents should be assembled to develop a single document on expectations and rights of students as well as appropriate reactions if expectations are not met. Once approved by the administration, the document would be signed by all parties to signify that they understand the document and promise to abide by it. A necessary corollary is that the document is fully and consistently enforced.
  • Get parental buy-in: While Molly seems to be calling parents incessantly, I have rarely seen the phone calls result in any significant change in behavior. Parents have enormous flexibility in correcting the behavior of their children, while teachers are much more limited. It is reasonable to expect then that the parents provide the brunt of corrective action. If there is a better partnership between teachers and parents, then I believe that the school would be much more effective. Of course, this is one of the more difficult suggestions to incorporate.
I'd like to make my gratitude toward Molly public. She's been a great help in learning about how to communicate with students and the working with her has been a pleasure. I wish her and her students the best in the coming years, and hope that others will take a chance to get involved in the TF program.


The Full Monty

Last Friday I gave a presentation that I had been rather excited about. After seeing kids shoot dice incessantly, I decided that I'd do a talk on probability. I hoped that when I had finished, everyone would understand dice and never want to play the lottery. I planned for the talk to go for about fifteen minutes, and I think that I finally had my timing down. As dictated by Moore's Law, Molly was out sick and I was suddenly faced with the class all by myself.

The beginning the class went much like most classes did when run by Molly. We covered the starter, answers, and went over the homework. However the students were terrifically more difficult to settle down. Several refused to pay attention and found that they liked wandering around the classroom better. I always had pity for substitute teachers, but I must say that this reinforced that sympathy by a few orders of magnitude. I tried reprimanding the worst students, but waiting quietly until everyone realized I had stopped talking seemed to have a more profound effect. In particular I was grateful to the several students that actually took to encouraging their classmates to pay attention. I had the pleasure of stopping a near fight, and by the time class had ended I was completely worn out.

Before beginning the talk I gave the students their homework and asked that they either follow the talk or quietly complete their homework. Another TF had tried something similar with his class and it seemed to work very well. I forgot that in his case he had physically separated the two groups of students, in my case I left them in their seats which was a bit disconcerting. Disappointingly few seemed to care about what I had to say with only about 3 in each class giving the talk much thought.

The presentation began with an explanation of probability and a simple example, then moved on to the slightly more complex case of two die (including a quick MATLAB simulation). Afterward, I explained independent probability and showed how the odds for the lottery were calculated. Then I presented an oddly morbid list of things more likely than winning the lottery, and ended with the Monty Hall problem. This presentation was deliberately shorter and less complicated than my previous ones. I had very little writing on the slides, and made an effort to reserve them for visualizing the talk. In that sense, the lecture went much more smoothly than before. The Monty Hall problem was particularly fascinating for the students, though by the time I got to it most of the students had tuned out or settled in on their homework. I probably would have been better served by starting with it instead of ending with it.

While I have tried to aid Molly in meting out reprimands, I did not have the authority or the mental preparation to go it alone. After suffering through the question dozens of times I can understand her impatience with students asking to use the bathroom (though I still believe the school policy of locking them during lunch hours is absurd). The presentation also likely suffered from not being directly related to the class material, but I had made the decision to consciously break from it. In the past having to track the curriculum with my presentations always felt rather limiting and I saw a chance to try something different. In any case, I intend on doing one more presentation on my final day at the end of this month. The subject will still be somewhat distinct from class lessons, but I hope to use some of the other lessons from Friday to better inform this one.

See below for the presentation and MATLAB code:
Dice Code


Lillian's Lines

On the suggestion of Max over at the MathForum, I recently did a Problem of the Week called Lillian's Lines (#5180). In our discussions, we found that some of the problems I had done in the past were a bit abstract for the students to really get a hold of. In contrast, this one had a very straightforward solution (provided active participation and understanding of the rules), and several more in-depth solutions.

Simply put, the problem presents a square grid that is 36 by 28 squares. One takes a ruler and starts in the upper left corner, then draws a line at 45 degrees to the outer edge. Here, the line "bounces" at 45 degrees and continues on to the next outer edge. This process is repeated until the line ends up at a corner. The question asked is how many squares did the line cross through to get to the corner. The scale of the problem is large enough to make even the simple solution require some time to get. In addition, several examples were provided that hinted at patterns in the lines that could be used to reduce the magnitude of the problem.

I began by providing each student a print out of the problem statement (minus the question), a sheet of graphing paper, and a ruler. In each class I had two students read through the problem and then conducted my simplified version of Noticing and Wondering. As previously detailed, this involved asking the students to point out what they thought was important in the problem statement, I'd then highlight the relevant passage on the overhead. Quite a few noticed the recurrence of what they called the "fish" pattern and the "upside down heart" pattern. I then presented the question to them, and asked that they try and work through the problem themselves. With about 5 minutes left in my discussion, I called the students' attention back to the front in order to discuss their solutions.

The simplified Noticing and Wondering worked about as well as I could have hoped with several students providing input. Usually singling students out to provide some kind of response is asking for the silent treatment, but in this case most were glad to respond. Even with some modest guidance and hints no one appeared to make the connection that the larger problem could be simplified. As usual, there were minor issues as I struggled to write on the board and projector simultaneously, but this will hopefully be solved with further practice on my part. While I understand the great value in group work, past experience suggested I'd have more results if I asked the students to work individually and Molly agreed in this respect. Mary Beth had come along to observe the class, but got swept up with Molly and I as we walked around and helped the students work on the problem. Surprisingly few were able to follow the rules in the problem statement, and only one or two came up with the final solution. Many had problems understanding the importance of making each line precisely 45 degrees. I made an effort to highlight this fact in the second class with an additional diagram, but I still noticed many students were being a bit impulsive in drawing their lines.

It was interesting to note here that the two classes acted very differently when set off on their own. The first class worked quietly for a few minutes before devolving into commotion and tangential discussion. A few continued their work in spite of the disturbance, but at this point the class appears irretrievable. The second class worked for almost the entire allotted time, and those that didn't work quietly minded their own business. In both cases it took a while to get the students started, but the fact that the problem could readily be solved with some effort definitely appeared to have some appeal.

I wanted to allow the students long enough to reach the solution, but unfortunately my time was limited to 20-25 minutes in both classes. There were no moans of inadequate time when I called the attention back to the front, but I do think that they might've felt cheated. I walked each class through the solution by reducing the problem slowly, and at each step asked the students careful questions so they could lead the way forward. I never did make it to some of the other more interesting solutions, but I felt like those that listened at least had a good starting point.

Ultimately, the problem was a mixed success much like each one before. It is apparent that the patience and work ethic of the students has improved by leaps and bounds over the beginning of the year. At the same time I feel like they do not have a lot of the intuition necessary to solve even the simple problems. In my preparation for the lecture, I hadn't even considered that they would have such trouble drawing 45 degree lines. Mary Beth noted that there didn't seem to be enough time to work the problem out properly. I don't necessarily agree with that characterization. The time was limited for the second class because the majority were actually engaged in solving the problem, but the time allotted was far too long for the first class that lacked the discipline to put more than a passing moment's effort into the work. I had hoped that scheduling my days for Thursday and Friday would help to alleviate the problem of cramming an entire complex problem into twenty minutes, but the scheduling issues have proved to be greater than anticipated. I'm more convinced that the original vision of doing the problems on a day to day basis is the right approach, despite the interruption in continuity but in my position I'm simply not around to make this happen.

This very well may be the last Math Forum problem I do this year so I'd like to make a few notes on the overall experience. The library of problems is immensely useful and well-organized though some have more support materials than others. While most are rooted in real-life applications of math, they still seem a bit off the mark for the students. That is, the students may like football, but that doesn't mean they'll necessarily enjoy a math problem about football. At this point, I think that outright trickery and deception is required to teach mathematics. The problem solving process that went along with the Math Forum problems is very logically set out, but seems better suited to classes with superior behavioral characteristics than mine. Only a small subset of students would engage in Noticing and Wondering, and many times the students seemed to be unclear about the point of the whole exercise. I admit that some of the issues lie with the instructor rather than the students. I could have been more clear in my explanations and instructions to the students. Of particular note, my time management could be greatly improved. While I think there is potential for the program, it really should be implemented on a daily basis and ergo by the primary teacher.



As mentioned in the prior post, some of the students' behavior is disrespectful, absurd, destructive and a whole list of other things I'd rather not say. To provide some examples;
  • Tardiness -Today less than half of the class returned from lunch on time. The usual problem was compounded by the lack of bells (the MME is still going on), but even on a regular day up to 1/3 of the class can be late. Even worse, they're late not because they couldn't get to class on time but because they loiter just outside the door and refuse to come to class when told to do so.
  • Texting -It happens all the time. For some it seems like an outlet when they find the material too difficult or confusing, others just a way to pass time. In either case, most will respond when told to put away their phones and then wait several minutes to remove them again. I've had several tell me to wait until they finish their text, and others that will start texting after asking me to explain a problem. On a brief side note; why students play back music on their phones as they walk around is entirely beyond me.
  • Insubordination - The other day a student was given a ruler to use for graphing on a quiz. Throughout the quiz he talked continuously despite being told not to, and furthermore decided that insulting other students and making a wide array of noises was a great idea. After the quiz he took to spinning around his ruler and throwing it at which point Molly asked that I take it away. I told him to hand me the ruler and he started to play the game where he pulled it away at the last instant. In the background the teacher is trying to continue instruction while scolding him, and I'm getting awfully close to telling him how I really felt about his antics. I think Molly has given up on sending students out in all but the worse cases as she had removed the student several times during the week to no effect. It's awful to feel completely impotent as an instructor.
In each case, the consequences are either mild or inconsistent which (I think) give the students the impression that the teachers have no authority. My understanding is that our class is not an exception in this respect either. I rarely had kind words for my teachers in high school, but I was damn sure never to say them in any situation where the teacher in question could hear me. At YHS it's not uncommon to hear a few students each day muttering obscenities at me behind my back. My father would say that I have a bleeding heart for the number of times I've tried to help students that just immediately prior insulted me, I'm all for second chances. However, at this point I've begun to wonder if there's some sense in KIPP's military-style discipline. Even if the school adopted stringent and uniform policies that were enforced equally by each teacher, the necessary momentum to change the attitude of high schoolers has got to be enormous.

I don't want to be so glum though. There are a number of students that are respectful, but they can be hard to notice with everything else going on and they're certainly not the majority. I was hesitant to bring up the subject because I harbored some belief that an instructor could be so compelling that they shouldn't have to resort to anything so crude as punishment. As the behavioral issues have continued through about 7 months of classes, it is apparent that something fundamental should change. The trouble is in determining what that is.

    Passer Rating

    Yesterday I finished grading the worksheets I had handed out to accompany my talk. Even being very generous with the points, I believe the average was somewhere around 70%. I have come to expect such averages on exams in classes on complex topics, but not in a situation where the students are almost handed the answers. In fact, I am not convinced that I could have made it easier. One question required that they answer with "zero"; maybe they took me too literally when I said that the answer was "zero". For all the trouble I had in the first class, they actually had better grades on the worksheet, but not by much. As before, the situation just makes me question whether my instruction is that bad or if the students just don't see or don't care about an opportunity for an easy grade. Maybe it was so easy that it was demeaning.


    Stemming the Tide

    While not entirely relevant to high school learning, there was recently a House panel on STEM education at the college level. The participants were informative and offered suggestions on improving the declining fields.

    Fixing US STEM education is possible, but will take money

    In particular, I was pleased that there someone else noticed the lack of teaching preparation for graduate students. It always boggled my mind that there are stringent requirements for teacher specific education when it comes to primary and secondary schooling, but none at the collegiate level. Part of the reason I decided to participate in the TF outreach program was to become a better instructor and communicator, but I could have just as easily completed my degree with no experience in teaching whatsoever.

    While it was not the focus of the panel, it is unfortunate that the article didn't place a little more emphasis on improving STEM outreach in K-12. I agree that there is a great import to retaining students at higher levels, but the Boeing representative is correct in singling out the perception of engineers by youth. I do not believe that the instruction quality in college could change appreciably in the last 40 years and yet the number of STEM degrees relative to total degrees has been falling. Something to think about.



    As a much delayed followup to my presentation on sound, today I gave a presentation on how math fits in to football. I worked on the presentation quite a bit which included several videos, an accompanying worksheet, and two live demonstrations. Molly and I discussed having the presentation run for the entire class which is the reason for the ambitious composition. I practiced the talk with some less physics-inclined friends and went to class feeling like there was some chance the subject would go over better than previous ones. Of course, everyone knows what's said about the best laid plans...

     If you'd like to see the presentation and worksheet, they're available at the following two links:

    Football Presentation
    Football Worksheet

    Let's start our playback of today's presentation by stating that I probably bit off more than I could chew. I knew there would be problems getting students to concentrate on a single subject for more than 20 minutes (see previous talks and the field trip tours), but thought that the variety in the presentation would be enough to keep them under my thumb. Turns out that I was wrong about that. I did not get through the talk with the first class, and after some last minute changes, only eked through the second. Part of the reason for this was the prevalence of troublesome students another is that there was too much material. I got so worried about having enough material to cover the lecture that the opposite happened.

    The Presentation
    Whenever discussing physics or other science subjects I always hear the question, "but what does this have to do with math?" Well, usually it's not a question and is worded a bit more aggressively, but you get the point. I tried to short-circuit this sentiment by explaining that physics was simply how we use math to model the world around us. A bit general, but at least some of the students nodded their heads. To drive the point home, I described a couple of famous equations that described physical phenomena. From here I transitioned to some of the important kinematic equations that physics students first learn. I defined what each term meant and provided a written description on the back of their worksheets. We went over examples of potential and kinetic energy. Finally, I asked them to write examples of how kinematics could be related to football and then presented four examples of my own that would be the body of my talk.

    The first question (one football player tackling another) was a chance to explain the conservation of moment. I began by showing them a head-on collision of two steam engines. Like all of the later video clips, it was one of the more popular parts of the talk. I made an analogy between the trains and two colliding football players, but indicated that the mass and velocities of the players would not necessarily be the same. In the first class, I attempted to lead them through the process of solving how fast one player must be going to stop another (in one dimension). In the second class, I skipped this section in an effort to save time and address the more important points of the talk. After the situation was presented, I showed them a clip of two such players colliding and asked them to make connections between the math and reality.

    We next talked about conservation of energy, in the form of a car colliding with a concrete wall. I pointed out that the car had energy before the collision and asked the students to discuss and describe where that energy went afterward. At this point I ran out of time with the first class. In the second class, I continued on to described how the kinetic energy of two colliding football players could cause one to clip into the air. I had planned on calculating a specific height however, as before, the numerical part was skipped for time and clarity. Again, I included a video of a real football player getting flipped into the air.

    Next up was a question on how one could throw a football as far as possible for a given amount of effort. Here, I wanted to show that while the math could be very difficult, we could use a simple experiment to approximate the result. To begin, I showed them the result of the actual derivation for range as a function of angle. This was followed by a discussion on how to model how a football player throws a ball. Eventually, with the help of several students I used a ball launcher to create a plot of range versus angle. I then showed them a plot of the functional relation derived earlier so that they could see the differences and similarities between the experiment and model.

    As the talk progressed, I allowed the material to become progressively qualitative so that more advanced concepts could be addressed. I ended by trying to explain to them why spin on a football is important. Several of the students knew that a football would wobble or tumble if thrown without spin, but didn't know why it occurred. I gave a phenomenological explanation of angular momentum and some common examples. I had several students help me conduct the common demonstration of this by using a spinning bicycle wheel.

    I ended by emphasizing some of the points that I thought were the most important and intentionally focused more on the basic concepts than the specific use of math or algebra.

    Talking, texting, dice throwing, and other thrown objects were a handful of all the distractions that ran throughout the talk. One student even thought it was appropriate to say "this is boring," on the start of every single slide. Molly and I did our best to contain these problems, but I tried to push on with the talk in order to cover each individual topic. On one hand, having to stop the presentation every three minutes to reprimand a student is not useful at all, but on the other if they're permitted to continue talking or doing whatever else it interrupts everyone anyway. I have some other thoughts about this issue that I'll put in a separate post, but it was a significant problem.

    While I thought that the slide on the relation between physics and math would be useful, several students obviously did not pay attention or did not pay attention. I was asked about how any of the presentation was related to math on several later occasions, which was quite disappointing to hear. I tried to reiterate my initial point and while the students cared enough to comment on it, they did not care enough to hear my response.

    The part addressing kinetic and potential energy went much better than I had hoped and most of the students participated readily. There was some confusion between the two, but in this case the students were mostly self-correcting. Momentum was a little less successful and I spent less time than I should have giving them a physical explanation of it. On the worksheet, I gave an example of 1 newton second being about as much "power" in a tennis ball traveling 40 miles per hour, but no one bothered to read it. I also cheated a bit by not explaining the difference between speed and velocity which I thought might have confused the issue more than it was already. The kinematic equations were accepted and the students did recognize the standard rate equation.

    Most of the examples of kinematics in football were ones that the students recognized on their own. At this point, everyone was still on the same page and things were moving relatively smoothly. Conserving momentum was a little bit more difficult to get across, again because I do not think many of the students had a feel for what it is. The example dragged along painfully in the first class, especially the part about using algebra to calculate the required speed of one football player to stop another. As is good practice, I carried my variables through to the end of the calculation, but the students found it prohibitively hard to follow them. Among other problems, the students began to argue some of my points from experience. I did not have enough time to convince them that when they "dig in" they are describing a situation that's different from the model. I did try to explain that physicists use models of the world that aren't always accurate in every way so that they can first understand the principles of the system.

    Conservation of energy went a little bit better, but I was still recovering from the bad experience with the momentum slides. I was relatively brief, and the topic wasn't as interesting without calculating how high a player would flip. For those looking at the slides, I included a fudge factor of 1/5 in the calculations on the slide. This is to account for other energy losses and the fact that I didn't run through an actual conservation of momentum, otherwise the returner would be flipped 20-some feet into the air.

    The prelude to the best throwing angle went alright. Although, I was a bit annoyed when one student loudly accused me of showboating by displaying the derivation. The experiment was one of the highlights of the morning as several students were able to participate and almost every student was paying attention. Not only that, but the data matched my predictions quite well which provided me the opportunity to discuss modeling. The spin slides went fine and response to the demo was lukewarm. Everyone appeared to be tired by this point and I admit I was ready to be done as well.

    I prepared too much material and glossed over some finer points in kinematics that should have been explained with more depth. I'm not sure if it is the way I present the material or if certain students lack the ability to be respectful and pay attention, but the number and magnitude of interruptions clearly aggravated confusion may have made much of what I said worthless. The students were extremely receptive to the live demonstration, but shut down soon afterward. Even now I'm frustrated with the challenge of teaching some of the students, but there were still bright spots and students that conducted themselves well.


    Physical Links

    I'm finishing up my presentation on physics in football and have come across a few interesting links that I thought might be nice to share.

    The Naked Scientists - A large collection of podcasts, videos, and kitchen experiments that demonstrate many different scientific principles. They're put together by "media-savvy" scientists and researchers from Cambridge University. Personally, I got a kick out of the "Science Experiments from the Sporran" series, but the innuendo would be best left to more mature audiences. One experiment I quite liked was how to use buttered bread and a microwave to measure the speed of light. Overall, the site is quite well-produced and has (generally) safe and accessible experiments.

    Phun and Algodoo - Both are 2D physics simulators for computers developed as side projects by a student of Umea University. The first is the more simple of the two and focuses on mechanics while the second includes more functions for fluids and the addition of light/lenses. Algodoo is also oriented toward teaching physics to students and has been optimized for Intel's classmate PC and supposedly works well with the SMART board that is in each YHS classroom. I haven't tried Algodoo yet, but Phun was extremely addictive even if the interface wasn't as intuitive as one could have hoped. It may work well as a computer lab for physics students, though I imagine one would have to assume that the students would play around with it quite a bit.


    The Longest Journey

    Sorry for the lack of updates in recent weeks. Thursdays and Fridays have been very popular for teacher development days, wisdom teeth extraction, and (upcoming) Winter Break. On the bright side, this gave me a chance to work with Mike on putting together a field trip for our students. Coming in to this month we already had some ideas for where to go, but there was a lot of effort put into hashing out the details. This is something of a post-mortem on the trip, including some lessons learned.

    The students arrived at the North Campus of the University of Michigan around 9:30am. There were about 24 students who were chaperoned by Carol, Mary Beth, Mike and myself. Everyone was a bit groggy in the morning, but we all had directions and maps of where we were going which made it much easier. The students were split into four groups: two for algebra students and two for calculus students. We then started on the labs...

    Engineering Research Center for Reconfigurable Manufacturing Systems (ERC/RMS)
    The RMS is an NSF funded research center that focuses on anticipating future manufacturing techniques. Before even hitting the floor, our guide took us to the conference room to discuss what he'd be showing us. He wrote Newton's second law on the board and tried to explain it to the students. I'm not sure they really got what he was trying to explain, but they definitely remembered the equation as several wrote it on their surveys after the trip. At the very least, the students were able to see that there were equations underlying the demonstration. After the short lecture, we were taken to the water jet cutter, a system that uses a high velocity water stream combined with some sand to cut through almost anything. The tech had set the sytem up to cut out a small, and rather detailed, 'M'. Though there wasn't a lot to see during the cutting, I think many of the students were mesmerized by watching the computer controlled machine produce a perfect replica of the image on the screen.

    Structural Engineering Laboratory
    Next up, Matt led us through the Civil Engineering department's largest lab. Holding up small samples of concrete, he explained how adding tiny wires could significantly strengthen the largest of structures. The point sort of hit home when he pointed to the shattered concrete pillar behind him that was nearly 15 feet tall and at least a foot thick. He explained how the large hydraulic arms could slowly stress any attached sample, or how others could put up to 100 klbs of force on a small block. He also showed the results of his personal research; a hollow rectangular beam with 1" thick walls that had buckled and broken. Several students asked to see a test in action, however Matt pointed out that many of the tests could take hours to complete and the failure modes were rarely as explosive as the students hoped. Other subjects such as foundation stability, and how bridges affect the flow of water were also brought up.

    Wilson Student Center
    We then headed over to the College of Engineering's building for student projects. The building houses everything from solar car, to baja racing, human-powered submarine, concrete canoe, steel bridge, etc. Our guide, Michael, took some time to explain the origins of the project center and to emphasize that almost every single thing in the building was run by students. We later walked back to the cages to see some examples of the projects. Michael discussed how each team had a certain set of goals they were required to meet and again mentioned that everything from calculations, design, and manufacturing was student-run. The trial runs for the Formula One team, how to build a cargo-carrying glider, the dangers of being in a human-powered submarine and catastrophic bridge failure were all mentioned.

    Subsonic Wind Tunnel
    Chris took us on our final tour, this time of the subsonic wind tunnel. He explained some of the operating principles to the students, though the mention of Bernoulli's principle and settling chambers was probably a little much. More exciting, he put a model of a truck into the tunnel and showed the formation of streamlines. He then explained how the air collapse behind moving objects causes drag and some of the ways aerospace engineers try to minimize the effect. One thing that he got to mention was how valuable research experience is in finding a job, and while the students may not understand the magnitude of this right now, I think it was a great thing to mention. He also showed off a device that looked like a shuttlecock (surprisingly, no giggles) that was actually the receiver for a mid-air refueling tanker. Also unlike the other tours, he actually mentioned the amount of money such research can generate.

    Student Panel
    I'll admit, I was more focused on my lunch and finally getting a break during this section. We had four YHS alum come in to discuss how they got in to college and what the transition was like. Most of the questions were written out by the students beforehand which made it easy to answer in quick succession, but I think that it also removed any kind of interactive elements from the talk. Nevertheless, several of the questions and responses were very insightful. In particular, some of the comments about study habits were very well-thought out and hopefully made some impression on the students. I don't know if it was more encouraging or discouraging when the panelists listed their GPAs and each was > 3.9 (hell, I wasn't even close to that). Out of the whole process, I am just glad that it may have gotten some of my algebra students to start thinking about what it takes to get in to college.

    Plasmadynamics & Electric Propulsion Laboratory
    The final tour was given by my cohort, Mike. The tour circled around a 6m x 9m vacuum chamber which is used to simulate conditions in outer space. Mike and some of his labmates went over the principles of propulsion, what plasmas are, the costs involved in a research lab, free-fall, and other sci-fi-esque subjects. The students even got to see a rather unique thruster currently in testing; a first for myself as well and I even work in the field. I was surprised out how outgoing and positive the response was, even if the students were beginning to show signs of weariness. The tour ended with a bit of extra time so I had a chance to talk to some of the students one-on-one and also answer some of their additional questions about propulsion. And tell one to stop hitting the Pyrex window on the vacuum chamber.

    Overall, the students behaved themselves very well. One problem was the nagging complaints about not enough time spent sitting which I didn't consider when planning. As the tour drew on, more and more students felt compelled to hold personal discussions and ignore whoever else was talking, but this was still a very small number. One of my biggest disappointments occurred when one of the more advanced students in my class was outright derogatory about the whole experience and refused to believe that math played any part in engineering. This was countered by some unexpected compliments about the trip from the students and their surprising amount of concentration. Carol sent the results of a survey she conducted afterward and almost every comment was positive about the trip.

    Lessons Learned
    • 20 minutes is a good length for a tour, but 15 minutes might be better. Most of our tours started losing steam around the last couple minutes.
    • Walk your route beforehand, and walk like a high schooler (slower than molasses). This will help with timing the trip. Aside from a few hiccups, we did not run in to any time constraints.
    • Make the trip take less than 4 hours; we took as much time as was available to us, but it might have been too much. While the schedule worked perfectly, most of the algebra students were beginning to lose it by the end.
    • High schoolers really like Jimmy John's
    • High schoolers also really like explosions or at least hearing about them.
    • The trip may have been better with some more hands-on activities. While the students got to handle several samples from some of the labs, I think they'd really get enjoy building stuff. And souvenirs, give them souvenirs.
    • Hammer the date and time of the trip into the minds of the attendees, tattoo it on their foreheads if necessary.
    • Try to avoid bringing students that are just trying to cut class, they really take away from the rest of the trip and make it miserable for everyone around them.
    • Bring a camera so you can remember what happened.
    • Triple check the date with Mary Beth.
    • Contact any labs that you'd like to tour with at least a week in advance, if not two.
    • You can try talking while walking, but it didn't work very well for me.
    • According to Molly, many of the students (and herself) didn't realize how physical engineering is; this would be a good thing to emphasize.

    These are the people that made the trip possible. While my blog may not have the same prestige as a plaque, I think it's important to note that there were a lot of people who worked with Mike and I to put this on.
    • Mary Beth, Carol and her husband for chaperoning students to labs that they themselves had never seen before.
    • Tonya (and all the RMS students), Michael, Chris, and Matt for the wonderful tours and taking my constant harassment.
    • Mike for putting together half of this field trip.
    • The Outreach office for covering the costs of the trip, food, and other important financial concerns.


    When in the course of human events...

    it becomes necessary to tell a student "Alex!* Get your hands out of your pants," you begin to wonder if self-discipline is something of a problem. Don't worry, the situation wasn't quite as lewd as the wording would suggest (he had gym shorts on underneath and was trying to hide his phone while texting), but the phrase caused a ruckus nonetheless.

    In other news, Bonnie* was being disruptive during a class today and got moved to the back of the room (isolated from other students). The student then accused the teacher of reviving the practice of making African Americans sit in the back of buses back in the 60s, asked if the teacher was racist, and just generally made the event into a drawn out scene. Ironically, the same student frequently disparages the Chinese and asks me questions like "do you know martial arts," "do you eat Chinese food every day," etc. While my responses generally range from sarcastic to very direct, I don't think the student knows why the questions bother me. I feel like this is going to require a personal discussion at some point, a discussion that I do not look forward to having.

    Race is a recurring conversation topic and appears in all different contexts. In another instance today, two students today were making comparisons between being told not to talk during a test and being slaves. Very early in the year, I was accused of being racist for forgetting a student's name. I do not want to avoid the subject, but I have admittedly not mentioned it before, despite its prevalence. At some point in the future, I will write a more fully developed post on the matter, but for now I thought it important to at least acknowledge.

    * Names changed to protect the guilty, taken from the list of hurricane names for 2010.