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Showing posts from June, 2011

Index of Refraction

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Laboratory eleven was trimmed to focus only on the apparent depth of an object below the surface of the water.  Lavanaleen, Jeremy, and Lewis This modification was made in part because the morning lecture combined pinhole cameras and lenses. The focus had been on the bending of light due to refraction. Mirrors just seemed like too much of an add-on that would distract and confuse from the core concept.   Jackleen Summer is fast and furious, the course is moving at three regular term weeks per one summer week. Huge amounts of material are being explored by the students. Merseny

This summer the class is not using the A204 computer laboratory. I required students to bring a scientific calculator to class. One student has a lap top computer. Nayleen

Arthur and Raynard
Salinta, Joyleen, and Tracy
Joyleen and Tracy

The morning commute

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My morning commute is not exactly high stress rush hour driving on smog-filled, twelve lane wide slabs of concrete surrounded by dingy and decaying metropolitan infrastructure.


My morning commute is an oxygen filled rush through an insanely humid, lush, tropical landscape. Of course the infrastructure here also decays and rather suddenly. Come around a corner a tad too fast and you might not be able to stop in time to avoid the decayed infrastructure or a roll-over accident in the road. Beach hibiscus tree tends to roll with time. Like a slow motion tumbleweed. Sometimes into the road.


Twenty-four hours after the first photo taken over my hood, at that same location, a Hibiscus tiliaceus tree had rolled, or fallen - your choice - into the road. Note the Acalypha wilkesiana (copper leaf) shrub on the right in both images. As another driver coming in from Kitti remarked, "Udahn kohlo!"

Spectrum tubes and CD spectroscopes

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With no access to the computer laboratory for laboratory ten, I opted to focus on spectra. Summer 2010 I built the laboratory off of a morning lecture on colors, color vision,color blindness achromatopsiacolor constancyretinex and GIMP. This summer the delayed start put laboratory ten on the Tuesday behind midterm and after the DVD Inconvenient Truth was shown to the class on Monday. This meant that I had to cover the midterm and lab hand-back notes along with spectrum material. So I dropped the color material and focused on the electromagnetic spectrum. 
Lavanaleen and Arthur examine the spectrum of hydrogen
In the laboratory session the students worked with CD-ROM based spectroscopes. The class had six to work with. I built one in class so the students could see the construction process. 
After viewing the continuous spectra of the sun, I dug out a box of old spectrum tubes and a spectrum tube power supply also from 1970. Exposed electrodes. 5000 volts. Probably time to buy one t…

Speed of Sound

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Section 091 began with a RipStik sine wave and continued on to consider a bouncing ball and waves on a light chain. I ripped the paper oddly, wound up with three sheets. The wave was pretty horrible, I found only one usable section on a 68 cm wide portion of paper. The data can be seen below.







Inlaboratory ninethephysical scienceclass synched clapping boards to echo arrivals to generate data that leads to measuring the speed of sound. The class began with my bounding a ball off of the back wall, the ball that I had used in the lecture in the morning. I think this really helped make clear the concept of the echo flying out and back. I measured the distance to the wall and back, I also timed the ball flight time. Then I worked out the speed of the ball. I think this helps make the lab below more concrete. 


a determination of the dry bulb (32°C) and wet bulb (28°C) temperatures. Using the tables fromsection 8.1, the relative humidity was determined to be 74%.

Maimai times ten seconds while R…

Anti-Fog Laboratory Eight

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Mostly inspired by my own vehicle, but also in part inspired by MythBusters, I decided to test anti-fog options for cars without air conditioning in the marine rainy tropics. I opened the laboratory by coating both sides of one piece of glass louver with Rain-x Interior Glass Anti-Fog. I intentionally kept the bottle obscured behind items on my desk and I did not draw attention to what I was doing. I put the Rain-X coated glass and an uncoated louver into a stand-up freezer for thirty seconds. When I took out the louver pieces, one fogged up and the other did not.
Tracy applies ammonia to both sides of a piece of glass
The class, which had not been paying any attention, was now puzzled by this occurrence. A quick poll found that roughly half the class was acquainted with local cars in which the air conditioning did not work - the primary if not only choice for clearing a foggy windshield in the tropics. Heat will also work, but at 28° C (82° F) few people want to run the heat.
Nayleen p…

Before Blogtime: Center

06 February 1993
Every evening the center of the world is Queen's Park, Port of Spain, Trinidad. Queen's Park was originally the British royal grazing lands outside of Port of Spain, until Port of Spain grew up and around the vast grazing lands. Now Queen's Park is perhaps the largest in-city park in the world, containing dozens of cricket and soccer fields along with a complete horse racing track and stables.
Every evening over a thousand Trinidadians come to the park to play, to lime, and to exercise. Around the edge of the park runs a wide sidewalk, carrying walkers, joggers, and runners in both directions around the park. Along the sidewalk vendors sell food from every corner of the world, Caribbean, African, East Indian, American, Filipino, and French foods are all available along the way.
Walking and jogging on the sidewalk are people from every continent on the earth, with the possible exception of Antarctica. As the sun sets warmly on this multicultural parade ar…

Introducing Sine Waves in Trigonometry with a RipStik

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In order to introduce the graph of a sine wave in MS 101 Algebra and Trigonometry, chapter 6.4 of Larson's text of the same name. This was done out on the porch.
 Starting my run towards a sheet of paper on the porch.
 The towel is wet and dyed with blue food color. Only after I did these runs did I discover that the cement was rough enough to effectively emboss the sine wave into the paper without the need for the wet towel. I would later successfully perform a "dry imprint" using the RipStik in my physical science class two days later.

 The RipStik produced a wavelength of 32 centimeters at a period of 0.4 seconds with an amplitude of 4 centimeters. WolframAlpha was used to then generate a graph of the function. My inability to determine how to control the aspect ratio results in an exaggerated vertical axis for the graph.

Larson does not introduce wavelength, focusing instead on period. Larson also leaves the calculation of the frequency for a homework problem involving…

My Micronesian Household

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My household is at present provably un-American. Less than a thousand families in the United States have a family composition identical to mine.
The New York Times applet helpfully suggests that I remove household members, possibly to become more American. If I remove my sibling-in-law I actually crack the surface and emerge as a one in 1608 households in the United States.
The numbers climb even higher if I toss the child and keep the mother-of-the-child, joining the ranks of 88,891 households in the United States.
Of course, returning to a nuclear married family puts the numbers up by a factor of 91 times higher - a huge gain. As married-wth-two-children my family joins over eight million other families. We would become downright common. The applet notes that the greatest number of households with the above composition make between $75,000 and $150,000 a year. 

If I were to add back in the one currently abroad, however, the numbers slide back down again.

I like that my family is uni…

Finding Binky amid latitudes and longitudes

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With the lecture section beginning at 9:30, immediately on the heels of MS 101 Algebra & Trigonometry, hidingwas problematic. The solution was Binky. I hid Binky early in the morning and then was, for the first time, able to accompany the class on the hunt for Binky. "Binky! Binky! Where are you Binky‽"

While introducing the GPS receivers I also demonstrated to the class the GPS capabilities of a FujiFilm FinePix XP30 GPS digital camera. For the image of Nayleen and Sucyang the camera reported a position of N 6° 54' 32", E 158° 09' 40" (N 6° 54.534', E 158° 09.666').
Five teams set off on the hunt for Binky. Merseny watches the changing latitude and longitude.

The class would enjoy cloudy but rain-free skies throughout the day.
At the main road Merseny confers with Sucyang. The paper contains the latitude and longitude at which Binky is hidden, N 6° 54.656', E 158° 09.439'. Nayleen follows along.
Arthur heads off-road into the wet reh padi…