Haruki cemetery tidy-up

The last clean-up of the Haruki cemetery was just a day after Ohigan on 22 September when the fall 2009 ethnobotany class cleaned up the garden. With the next ethnobotany class clean-up slated for 23 March 2010, there was a need to do some grass whacking and general tidying up during this solstice season.

My son assisted in the hand-pulling.

The memorial stone for Hoshino Noritake.

I also cleaned up around the lemon grass. Soaked with sweat we called our effort "good enough" around eleven in the morning and headed off to find lunch.

Semi-grandchild and cupcakes

Shrue's sister first came to live with us in order to attend sixth grade here on Pohnpei back in the late 1990s. She would live with us for a total of seven years. I did not raise her per se, she was mature when she arrived. Still she is like a daughter. Her visit this Christmas with her baby was like the arrival of a grandchild. Or semi-pseudo-grandchild.

My youngest proudly displays her Christmas cupcakes.

Later they were frosted and coated with sprinkles.

Textbooks, content, and the journey

Text books were once written to serve dual purposes. The first and primary purpose was for use during a course by a student. The second and secondary purpose was as a reference text after the class had ended. This second purpose meant that texts often included more material than the course with the intent that the text would be comprehensive as reference material long after the course was over.


That second use of texts, however, is arguably a relic of history now. Post-course today one turns first to the Internet for further information on a topic, not one's collection of college texts. This second purpose of the texts which drove texts to be overly comprehensive with a detailed index is no longer present. 


Another reason texts tended to bloat in terms of material relative to one term was the need for one text to serve many different instructors in many different institutions. Each instructor had their own preferences on how to focus and guide the course.


Web based materials, however, turn an individual instructor into a publisher. These texts can be more tightly focused on the course material and do not need to serve a post-course subject comprehensive encyclopedic function. Even when, as I do, the text is printed out, it is a fraction of the size and heft of a typical multi-hundred page text. This is especially true in physical science where commercial texts attempt to cover every single physical science. I refer to these as "a thousand facts in 45 days."


I argue that student's come out of reading such a text with the impression that science is a collection of stated facts, memorized information, taken essentially on faith as one cannot possibly due the thousands of experiments that underlie the facts. I also do not subscribe to the idea that one can do a few experiments to show the validity of a few facts and then ask that the rest be taken on faith.


Science as a field does not take anything on faith, why should we ask that of our students? In exercise sport science we learn of muscle specific responses. Only the muscles you work out get stronger, hence weakness can develop in unused muscles even in top athletes unless they engage in cross-training and strength training. Only the facts that are shown experientially can be taken as cognitively apprehended.


Large science texts play into the science-as-faith misconception and the confusion that then results later in life.


My own texts would be seen as deficient by the old paradigm, I see them as course companions, guidebooks to a journey through the course on which I am the guide and adventure facilitator. I happen to know where the trails are, where the pits and pitfalls are along the road. And I might occasionally help a student see a new vista on the journey.


If you see a course as knowledge transfer leading to a pile of acquired knowledge at the end of the course, then you will be unhappy with my approach. I am keenly aware that students will remember little to nothing ten years after the course. How much algebra do you remember? Yet we can all remember trips we took, places we went, decades ago. I seek to tap the latter, engaging in a journey. In physical science the trip centers on specific conceptual threads - the experimental process, the mathematical models that provide predictability, and writing. 

Ethnobotany is a more physical experience with frequent hikes, walks, and field trips coupled with student presentations.


Just as a guide book is not a "coffee table picture book," so should a modern text book for a course be more of the former and less of latter. More a light weight guide that facilitates exploration rather than being such a massive text edifice that it impedes that exploration. Look at a modern science text - would you really take that with you on a vacation to the western Pacific? Build a text that small and light, that the students will actually use and carry to class daily. One that they are invited to write in while on their journey.

At the end of the term my student's text book should look like a tattered and torn guide book that has taken the student to places they have never been. Should they one day decide to revisit the countries - the fields of knowledge - to which I have taken them through during the term, there is always the Internet.

500

Although our days remain nearly twelve hours long year round, the equation of time shifts sunrise and sunset during the year. Sitting at nearly seven degrees north latitude, October and November bring earlier sunsets. Here near the equator, there is no dusk, just a sudden shutting off of the light of day. While in June there is light until almost seven in the evening, by November dark falls on a rainy evening by six. The difference is just enough to impact my evening running. Due to primarily to dogs, I tend to avoid running after dark.

Thus in the northern hemisphere fall my evening running is usually negatively impacted, and this fall was no exception. My goal is to attain 200 minutes of running during any sevey day period. I track this with an OpenOffice.org Calc spreadsheet.

In August and September I was averaging 189 minutes of running over any seven day span. With the darkness effect impacting my evening running habit, October and November collapsed to 116 minutes over any seven day period, well under the CDC guideline recommendations for a minimum of 150 minutes of exercise per week.

The end of the school term and final examinations slammed early December. Working until dark shut down running many evenings and my seven day running sum crashed to 64 minutes. A few evenings of end-of-term sakau usually led to a couple lethargic days off afterward, contributing to the crash.

In running the rule is to not increase one's time or distance by more than 10% per week. Of course, that presumes one is running at all. With my pace having slid to a seven minute kilometer, one could hardly call what I am doing running. Trudging at best. Thirty-one years of slow slogging have taught me that when my running collapses, I can ramp back up fairly quickly. Maybe that is an advantage to having legs with thirty-one years of running in them.

With graduation over and winter break having begun in earnest, I put in a 77 minute effort followed the next day by a 60 minute run. On the third day I ran up around past PICS, out to Palipowe, thence to the airport, and home. 16.7 kilometers in a rather appalling 124 minutes. Over the next three days I put in 40 minute, 58 minute, and 66 minute efforts. That put me at 426 minutes in six days.

426 minutes put me within 31 minutes of my maximum seven day time, 457 minutes, set on 22 November 2008. I was also 38 minutes from having put in 200 minutes after my 124 minutes. And just over an hour from 500 minutes. The latter had the appeal of being a centade.

I ran a familiar route, GPS in hand, heading up around past PICS, out to Koahn market in Nett, and then back to Mesenieng and the Spanish Wall at Santiago de la Ascension. I was slow at a 7'18" kilometer, and clocked 84 minutes to attain 510 total minutes for the seven day period.

With no aches or pains for the effort, and another week of tropical winter break ahead, I hope to continue to put in runs with a goal of about an hour each evening. When I joggle I tend to drop back to around a 40 minute run, and I often do a last joggle/first joggle of the year around New Year.

Marbles or Hot Wheels?

One of the conceptual themes that threads through SC 130 Physical Science at the College of Micronesia-FSM is the theme of the mathematical models. Many theories in physical science are framed as mathematical models, equations that make predictions about the behavior of a system.

Many of the laboratories center on linear mathematical models. There is no mathematical pre-requisite for the course. Students in the course may be in developmental mathematics courses. At best, they are either in college algebra or have completed college algebra.

Although the students enter the course with weak mathematical backgrounds, the intent of the course for mathematically weaker students is to introduce them to mathematical models through observable systems. The hope is that the physically observable system will provide cognitive hooks for the abstract mathematical models.

Yet even while introducing linear models, the course seeks to expose the students to more complex mathematical vistas. To take the student higher on the mountain of magically mathematical entities, to let them glimpse other models.

While laboratory three includes a simple quadratic relationship in the fall time for a ball, the following week potential and kinetic energy are used to produce a square root relationship. A marble is released on a banana leaf ramp and the speed of the marble after leaving the bottom of the ramp is measured using a meter stick and a stop watch. The marble is started low on the ramp and with each increase in elevation the class is asked to predict the next velocity. The students tend to make a linear assumption about the speed. The resulting plot, however, is not linear.

At this point I introduce the theory that will lead to the model that I will propose for the velocity. I believe that sometimes one should see things that they do not understand, that are just beyond one's comprehension. This particular system trades potential energy for kinetic energy. The complication with using a marble, however, is that potential energy goes into both linear kinetic energy and rotational kinetic energy. Conservation of energy - the underlying concept - asserts:

potential energy = kinetic energy

potential energy = linear kinetic energy + rotational kinetic energy

mgh = ½mv² + ½Iω²

In cgs units the result is velocity = 37.42√height

The details including the rotation inertia I for a sphere are worked out in detail in section 041 of the course companion.

The rotational energy of the marble does not change the model, but the additional energy term introduces another layer of complexity. The upside is that the system can be reproduced almost anywhere in the Federated States of Micronesia. That is another intent of the course. Many students go on to be elementary school teachers for the nation. Science equipment budgets for the rural elementary schools is frequently zero. Demonstrating physical science concepts with expensive, high precision equipment would make science appear to be out of the reach of an elementary school teacher. In addition, the technology could get in the way of understanding the universality of the underlying concepts. The students could come to believe that physical laws only apply to exotic systems measured with mysterious black boxes.

This past fall the division acquired a Hot Wheels® set that included track and a car. During the winter break I explored the height versus velocity relationshp for the car on the track.

The cars have very small, light wheels that permit neglecting the rotational component of the kinetic energy. This also means a slightly different constant in the mathematical model. The car is predicted to have a velocity:

velocity = 44.27√height

A comparison of the marble velocity , the marble theoretic velocity, the Hot Wheels® velocity, and the Hot Wheels® theoretic velocity is depicted in the following chart.

Note that the marble theoretic velocity (green line), is a better match to the observed marble velocity (blue line) than the theoretic velocity without taking into consideration the rotational kinetic energy (orange line). The adjustment for the rotational kinetic energy provides a better match to the observed data for the marble.

An initial test of the Hot Wheels® system (red line) suggests that the system does not fit as well as the model. The exponent is larger, closer to one, the system appears to be more linear than the marble on the banana leaf ramp.The system is still a non-linear system, but less obviously non-linear than the marble data.

A difference noted during the actual measurements was that the Hot Wheels® car tended to slow down more quickly than the marble. Although the cars are well designed to roll with minimal friction on their bright orange tracks, there is still a frictional component between the wheels, axles, and axle mounts. The marbles, being axle-free, roll will almost no significant frictional component.

Given the above, I am likely to go ahead and demonstrate both systems in class, but plot only the marble data.

Christmas presents

After marching earlier today in the church, a return home meant a chance to open presents from grandma.

Took me a while to explain that the concept was a plane-a-day for a year, not 365 planes in one day. Now the calendar graces the living room shelf - it is our only 2010 calendar in the house.

The girls look over a cook book. The youngest was excited when she learned that a cake with sprinkles and pink decorating gel accompanied the cook book.

That is an expression of genuine joy. I hadn't a clue as to what would have made her happy this Christmas, but grandma pegged it. 

When I was a lad, my middle sister and I would often abandon our own gifts and wind up playing with the Fisher Price my youngest sister had received. This was that toy this year, by the end of the evening all three were engaged in firing off Hot Wheels cars. The rig was eventually populated with toy soldiers who would go flying off when a car shot past.

Christmas marching

Christmas marching at the Kosrae Congregational Church in Kolonia. This year there were two stars from the family in the etawi srisrik marching. Stars are female unit leads in the Kosraean church marching. 

Marchers move in units. In Kosrae a typical unit might be four marchers. The strength of this arrangement is that only the lead marcher needs to know the complex marching formation. The others in the unit can simply follow along. This allows those who missed practices due to work or other obligations to join in the marching and singing - no one need feel left out.

All of the women's dresses are of the same fabric, but the styles vary. Look closely at the top image and the image above - the pleated dark green band is in a different location. Each dress is hand sewn from new material each year. And each dress looks similar and yet is unique. Individuality within group coherence. 

The men are wearing shirts that match, but a different material than that of the women. The intent is of overall color coordination between the genders. The star the men carry is called a tefuroh. The tefuroh contains a star, but is not referred to as a star.


Although not obvious in a still image, the marchers are singing songs composed new each Christmas. The songs are religious, celebrating Christmas, and are marching hymns. There are some parallels to the concepts of the bands and costumes of Mardis Gras in the Caribbean, but there are more differences than similarities.

A quick change from the green of etawi srisrik to the blue of group one blue team and this marcher is ready for another session of marching and singing.

The costume change, so to speak, had to occur in a tight five minutes between etawi srisrik and group one. 

Star responsibilities in two choirs meant practice two to three evenings a week during December, shifting to every evening this past week. Women carry the stars on poles, typically young women in their teens or twenties.

During the marching the adult women throw candy and small toys to the audience. Thus the bright glow is partly from the warmth of the air in the church, partly from sugar.

Shrue follows Bobo. The adult men and women do not usually carry stars. They are usually the vocal strength of the choir. 


At times the marchers will form shapes - letters or stars. If a letter is formed, the choir will call out a word beginning with that letter related to Christmas. These shapes cannot always be clearly discerned from the pews.

The adult women also pack arsenals of candy. This is often thrown into the air. Hard candy brings a new meaning to hard when one is hit in the head by candy rain.


After the marching is over, food is served and everyone enjoys Christmas dinner on the front porch of the church. 

SVG animation II: Motion graphs

I wanted to have a rolling ball move along a surface while a time versus distance graph plotted the time and position of the animated rolling ball. After looking over Animating Your SVG by Charles McCathienvile at Dev.Opera I felt that animating attributeName="d" in the path element would produce the desired effect. The ball, meanwhile, would be animated using animateMotion and an mpath child element. 


The resulting SVG animation failed to run in Google Chrome 4.0.249.43 but worked very nicely in Opera 10.10. This was a puzzle, and disappointing. My target is Ubuntu 9.10 computers running FireFox 3.5. Unfortunately not even Gecko 1.9.3/FireFox 3.7 will support animateMotion. Google Chrome, however, will run on Ubuntu 9.10, and is in place on some of the machines already. So a Chrome friendly solution, which might also run in FireFox 3.7, was desired. 

The animation works as I expected in Opera, but failed in Chrome. The "d" path line appears instantaneously and then disappears in Chrome. Since Opera shows a smooth animation with the correct fill="freeze" at the end, I have to think the problem is in Chrome and not my code.

I found that by animating the "cx" and "cy" attributes on a circle element I could achieve an equally useful effect to illustrate linear and accelerated motion. There are still some oddities. The linear animation works better in Chrome. In Opera the coordinate circle disappears in the "last decade" and remains invisible unless a screen repaint is forced. In Chrome, the linear animation keeps its radial gradient fill, but the accelerated motion animation loses its radial gradient fill. As the underlying animation techniques are the same, this is a puzzle.


I would not have made any progress on these physical science animations without the Opera article noted above and the wonderful series of SVG animation tests by Dr. Olaf Hoffmann.



Ultimately I will probably have to install Opera in the Ubuntu laboratory as Chrome does not support MathMl, another important technology on a physical science page. Still, that will not resolve everything as Opera did not render an embedded XHTML table in an SVG which in turn was embedded in an XHTML5 file. Maybe I cannot have SVG animation animateMotion, animate attributeName="d", MathMl, and foreignObject all in one file and render it. Every browser will object to one or another of the items in that list. 

SVG animation

An article on the CSS animation reminded me that the last time I tried SVG animation browsers could not yet render the animation. Realizing the standard dated back to 2003, Knowing that the CSS animation effort involved concepts and even commands that paralleled SVG animation - both having roots in SMIL animation, I realized that SVG animation might have landed in the wild. 


A quick look see found that while FireFox 3.5 could not render a simple animation I had thrown together,  Google Chrome could. This reinforced my sense that Mozilla has moved forward more slowly on the SVG front since FireFox 1.5, pushing ahead instead on CSS3, Canvas, and technologies such as TraceMonkey. With Chrome not yet rendering MathMl, SVG animation in Chrome is deficient for physical science diagrams. 


Gecko 1.9.3 will include some animation capabilities which may land in FireFox 1.7, but the critical animateMotion that I used in my simple colliding marbles diagram is not implemented in 1.9.3. At present my prime use of SVG is for static diagrams, the web pages are sections in a physical science course materials support text. Animations cannot print out, hence they are most likely to be used as supplemental material accessed by links from the on line version of the text.

Post-script: After puzzling over the language in the standard without enlightenment, I found that Dr. Hoffman had already put together a test suite that includes the samples of code that I needed in order to understand how to actually write useful, timing dependent animations. His subsection on animation is by far the best tutorial I have seen. Kalahngan o danke!

Mean run time post-sakau II

An earlier anecdotal study looked post-sakau (Piper methysticum, Pacific island kava) exercise recovery. At that time the data set encompassed 217 days. With a larger set of 466 days of data, the seven day recovery time to run duration returning to near the long term average still appears to be essentially the case. There remains, however, some indication that my mean run duration does bounce back by the fourth day, as I had previously believed. The cumulative average, however, does not show a full recovery to the longer term mean for 14 days. There is a drop in the mean run times on the tenth and eleventh days. The underlying sample size is 19 instances of ten days post-sakau and 19 instances of being eleven days post-sakau.

That sample size suggests the drop in the average is real and not a statistical fluke. By the 24th day, however, the underlying sample size is five instances of being 25 days post-sakau. The difficulty with attaining data out in this tail is that I have to forgo sakau for long stretches. That I have done so five times is in itself worthy of note.

Based on my own self-perception, I usually avoid sakau in the seven days prior to a five kilometer run and fourteen days prior to a ten kilometer run.

Funeral for Benson Moses

Colleague and friend Benson Moses passed away on the 19th of December. Friends, colleagues, and traditional leaders gathered the next day in Mand to join the family in mourning their loss.

Spensin, Paul, and Bruce lead services in his home. At this point the home was filled with family and college colleagues.

After services in the home, the casket was carried over to the Mand Congregational Church for mass.

Just after this image was taken, the church filled to standing room only, with an overflow crowd on the lawns outside. One observer noted that the funeral was the largest he had seen in Mand.

Isipao Madolehnihmw led the traditional leadership's participation in the funeral.

Traditional tributes included sakau, yams, pigs, and giant swamp taro.

As the sun set in the west, the time had come for his final rest. At any age there is sorrow in the loss of a loved one. If one passes away at 115 years old, there is a sense that one has lived as full a life as possible. When someone young leaves us, when there is young wife and children grieving, there is a physically painful sense of grief and loss.

The drive home provided a chance to be lost in thought and sadness, the rivers overflowing with two days of rainfall, as if the sky had joined in mourning the loss.

Graduation fall 2009

The College of Micronesia-FSM celebrated its 50th commencement exercises, themed "Facing the new horizon with determination."

LaToya and Lynn celebrate with Valedictorian LaShauna after the ceremony.

Cousins Chersea and Breechlyn.

Graduate and member of staff Amerihter was one of three members of the maintenance division to graduate today. With her is Vinnesalyn.

Norma and Ivyrose - graduations are family affairs for the college, we all can celebrate together the success of our students and our children.

First mission accomplished, on to the next challenge. Kimberly enjoying the moment. There are more images from the graduation. For those on the college intranet there is a set of the images on a web page the college web server. For those located outside of Pohnpei, a Picasa web album is available, linked below.

COM-FSM fall 2009 graduation

Christmas Concert

'Tis the season of parental photo scrums around choirs of little angels. A coveted role in a skit can get a child extra time on stage.

He and the young woman with him had the role of running across the stage proclaiming that the Messiah is coming. Running and shouting - already type cast.

Above, the two are ready to run.

Meanwhile a choir of angels sang, including my youngest.

Singing Joy to the World at the close of the show.

Second Life: A Kuhnian paradigm shift in higher education?

I picked up mention of myself in a keynote by Scott Diener at the Ascilite conference, 6th December 2009, in Auckland. Scott is the Associate Director, IT Services (Academic Support) at The University of Auckland. He too is interested in the cybercloud as a learning space. In a seminar last August, Scott proposed "learning in the clouds." His vision, however, is not that of eLuminate, BlackBoard, SmartBoards, nor mash-ups of Google docs, blogs, and social media. "Scott Diener has created a simulated hospital emergency room where small teams of medical and nursing students can learn to diagnose and treat patients requiring emergency treatment"¹ - in Second Life.

The University of Michigan-Dearborn is leading an effort in Second Life to help students to see the point of the knowledge they are acquiring-the real-world impact that their knowledge can achieve. Hong Kong Polytechnic University holds sixteen student orientation workshops in Second Life for their 400 new freshmen who join the hotel and tourism department. Meanwhile at the University of Arizona the Timeline of Earth project is a product of 2 semesters of a non-major astronomy class at the University of Arizona. Students in the class create, research, build, and script exhibits for ’spotlight times’ during the Earth’s 4.6 billion year history all within Second Life.

What is Second Life? Think the movie "Matrix" and you will be half way home. In his blog, Scott speaks of concepts such as "free range education," while in the keynote he asked, "What happens to universities if the library no longer the protected space?"

Second Life presents a potentially Kuhnian paradigm shift in education. A vision of the professor as one who professes to have knowledge about how to find the scrolls in the new library at Alexandria - the Internet. A wise and insightful person in the agora who could help you solve a problem for a few drachma, or these days a few euros. 400 millions dollars changed hand in Second Life last year according to Scott.

What if the real future of distance education is not the model based on works for "us" as an institution - a teacher centered model - but a free range model of independent instructors in Second Life, with "graduation" being replaced by competency examinations (think Cisco Networks certification or teacher testing). Educause recently published "The Tower and The Cloud" focused on the role of higher education in an age of cloud computing. What happens to our institutions?

Ultimately Scott's argument is a numbers argument. The college admits 400 students to associate degree programs for each fall term. US President Obama has set a goal for all Americans to have at least two years of post-secondary education. That sounds about right as a goal for education on planet earth in 2009. But there are something on the order of 4100 high school seniors to be served here in the FSM. The college is able to serve little better than 10% of the students. Scott makes the same argument on a planetary scale,  "World population 1950-2050 [will see growth from a] world population [of] seven billion [in 2010] to nine billion by 2050 (US census Bureau) - how do we educate this phenomenal number of people? Traditional models are just not going to scale - we would need to build 25000 university of Aucklands (40,000 students) EVERY year - this is unsustainable."

Only the Internet scales that rapidly. In a year FaceBook went from 100 million users to 350 million users and discussion of supporting a billion users has already been floated. Second Life has had scaling issues, but these are easier to solve than building 25,000 colleges per year.

For a couple images from the University of Auckland in Second Life, see Scott's blog.

Office clean-up day

Time to clean off the top of my desk and the various shelves in my office. The general rule is that any paper I have not touched in a year can be tossed. Any pile of paper that has been untouched for five years does not have to be sorted through.

Movies have professors in offices lined with book shelves. I have three shelves in a single case, each shelf is three and half feet long. So I have to prune my text collection to that with which I cannot part.

Next up - the filing cabinet. Maybe tomorrow. I allow myself only five linear feet of files. Of course, I have the advantage that the bulk of my own work is stored in the nooks and crannies of cyberspace.

Blast from the past: 1967

End of term cleaning up of my desk yielded this 1967 drawing from behind an old early 21st century iMac.

Not sure what cemetery that would have been back in '67.

End of term assessment reports

My end of term course level assessment reports are posted on the college web site. Some of the thinking underneath the structure of my current assessment efforts are laid out in a presentation I gave in 2006. This term I looked at attendance across multiple terms, and the fall 2009 term end reports on student learning in statistics and physical science.

New subsections in the physical science report include a look at whether writing improved across the term and the results of a survey of what was the student's favorite and least favorite laboratory.

I also updated the ethnobotany course assessment portal. The portal is designed to be used as an interactive exploration of work done by the class this term with references to past experiences in [square brackets]. While this is not a direct measurement of student learning, I have argued that this provides a course level portfolio assessment. Although indirect, the outcome, "Students will be able to communicate and describe the healing uses of local plants and the cultural contexts in which that healing occurs," is arguably well evidenced by online evidence. The web page provides photographic evidence of a student accomplishing that particular outcome.

Video would provide a more direct form of evidence in ethnobotany, but videos that spanned all activities over the whole term could not be stored on servers nor transmitted over our limited bandwidth networks. The videos would be DVDs sitting in MITC essentially unused and available only to those who can physically access MITC. Photographic web pages are compact, can be stored, and can be transmitted over our networks. These pages are available both to future sections of the course, students on other campuses, even globally.This term all photographic documentation for both ethnobotany and physical science was moved to a Blogger blog.

COM-FSM Christmas party

The college of Micronesia-FSM held their annual faculty/staff Christmas party. I arrived a tad late, and only grabbed a couple of quick images before heading back home.

The business office offers up a Christmas song.

Division of Natural Sciences and Mathematics chair and a colleague enjoy the floor show.

Director of Information Technologies along with a human resources administrator.

Ripstik redux: teaching an old dog a new trick

With the intent of using the RipStik® as the centerpiece to a discussion of kinetic and potential energy in physical science next term, employing it's unique ability to climb an shallow incline, I have hired an professor of RipStikology to teach me the Zen of castor board riding. His over six months of RipStiking place him among the senior tenured faculty of castor boarding on this island. His skills have grown greatly since last August when he gained his own board.

Note on the right above the perfect placement of my professor's center of gravity over his wheels, his poise, his bent legs in an optimal position to control the board. Note the student on the left, clearly off-balance and completely clueless, about to do a face-plant into the concrete.

The student, just before he went backwards onto his derriere off the RipStik. The learning experience was interesting. My teacher kept noting the wrong placement of my feet, sounding just like I do when I explain to students that the placement of the term is incorrect in an equation. A real role reversal in the household.

I am not alone in my thoughts of using the RipStik in a science class. A young man in Mexico wrote to ask, "I'm an student from Mexico and I have to do a proyect about the Ripstik Caster Board, I read what you wrote about the Ripstik and the convervation of momentum? Would you have more information I can use for my proyect?"

Exactly how a lateral kinetic energy is converted to forward kinetic energy appears to be subtle. The force transfer mechanism appears to be similar to the basic beginner's ice skating maneuver called "swizzling" or "swizzles".

A Wikipedia article on caster boards, that is in need of some citations, argues that potential energy is being traded for forward kinetic energy. Whatever is actually occurring, the physics is fascinating. A skateboard-like device that can climb a slope, that can gain potential energy, and is not relegated solely to be purely gravity driven.

Conservation of momentum is involved, but only in that once the board is moving forward, the board tends to remain in forward motion.

There is plenty of room for speculation, a chance for young minds to roam, as in one explanation that angular momentum is involved.

Of course, to use the board in class, this old dog has to learn to ride. If nothing else, falling here is seen as greatly embarrassing, a cause for much amusement and laughter, all to my benefit in connecting with the students.

All of my children are talented. Some just have more unusual talents, such as facial alterations with rubber bands.

Green Steps 5k and essays

The Green Steps 5k run/trash-a-thon walk/tree planting triple header was held under clear skies with a bright morning sun - unusual conditions for Pohnpei.

With each run he keeps pace with me ever farther into the route. This morning the run began at Pohnpei Islands Central high school track and field, heading down main street to the Spanish wall from the days of Santiago de la Ascension. The turn-around was at the wall, and he kept apace of me all the way into Spanish wall.

As most participants walk and pick up trash along the route, he came in fourth overall behind Norris, myself, and a cousin of a neighbor.

Not far behind was my eldest. The youngest had overnighted at the home of a friend and did not make it out for the event. After the run I had to dash home, shower, and then head up to the college to spend the rest of the day marking college entrance test essays along with a team of nine other graders.

The essay marking exercise is always informative, albeit a seven hour long haul through a blur of papers. My ethnobotany essay marking rubric is an outgrowth of the entrance test essay rubric. I added spelling, doubled content value, and the section on penmanship and format. I would later adapt the ethnobotany rubric as a part of the rubric for marking laboratories in my writing intensive physical science course.