High School Mathematics-Physics SMILE Meeting
06 November 2001
Notes Prepared by Porter Johnson

Gerard Voland (Dean, Undergraduate College, IIT) and with two IIT Undergraduates;
Mike Janowiak (International Engineering Consortium)

Interprofessional Project (IPRO) on Engineering and Science Careers

They spoke to us about a website under development to promote careers in science and engineering, aimed at high school teachers and their students.  Mike represents the corporate sponsor of that project, which will operate for several semesters at IIT.  The objective of the website is to have interesting and accurate information on career options, as well as a broad spectrum of "fun projects in technology".

In the IPRO program, which has been operating at IIT for over 5 years,  all IIT undergraduates are required to complete two interprofessional projects in order to graduate. There have been about 500 IPRO projects at IIT during this period, with around 90 faculty members serving as project directors.  They passed out a survey for high school students and one for  high school teachers and guidance counselors, which we could freely share with colleagues.  The IPRO  Program maintains a website at http://ipro.iit.edu/.  One of the teachers mentioned an interdisciplinary program at South Suburban College in building and then flying an airplane.

Gerard  is seeking affiliations with regional high schools for this program to promote careers in engineering and science, and has already made arrangements with the Orland Park secondary school system.  If you would like more information, you may contact him [Tel: (312) 567-3036; Email: mailto:voland@iit.edu]

Gerard described the impetus for the IPRO project as being similar to the growth of the Moso [Chinese Bamboo] Plant:  [http://www.tytyga.com/product/Moso+Bamboo+Plants].

The moso is a bamboo plant that grows in China and other regions of the Far East. After the moso is planted, no visible growth occurs for up to five years--even under ideal conditions! Then, as if by magic, it suddenly begins growing at the rate of nearly two-and-one-half feet per day, reaching a full height of 90 feet within six weeks!

But it's not magic. The moso's rapid growth is due to the miles of [unseen] roots it develops during those first five years, five years of getting ready.


Fred Schaal (Lane Tech HS, Mathematics)  Congruences of Plane Figures
passed out a statement of the following principles on Euclidean Isometries:

  1. A composition of reflections in two parallel lines is a translation.
  2. A composition of reflections in two intersecting lines is a rotation.
  3. In a plane, two congruent figures can be mapped onto one another by a composition of at most three reflections.
  4. There are only four isometries.  They are the following:
    reflection ... translation ... rotation ... glide reflection

Fred sketched figures on the board, which provoked much discussion as to how to establish the third result.  Porter Johnson suggested reflecting first about the perpendicular bisector to two identical vertices of congruence, so that the "old figure" and "new figure" will have that vertex (X=X') in common. Then, reflect about the the bisector to the angle YXY', where vertices Y and Y' are identical. The result will either be a congruence if the figures were not initially space-reflected, or else can easily be brought into congruence if the figures were initially space reflected.

We had the feeling that there may be many inequivalent reflections to bring about this congruence.

Relevant References:

Fred also called our attention to the fact that the planets Mercury and Venus are visible in the sky just before dawn.

Ann Brandon (Joliet West HS, Physics) Newton's Third Law

Ann  brought in a pair heavy duty spring scales [up to 30 pounds], and hooked them together.  One victim/volunteer was told to pull one scale with a force of 10 pounds, and another one of us was told to pull on the other scale with a force of 30 poundsThey just couldn't do it, because of Newton's Third Law.Bill Shanks indicated that, as an important point, Newton's Third Law is still valid when the objects in question are being accelerated.

Arlyn Van Ek initiated  a discussion concerning the difference in mass and weight, in that metric spring scales are conventionally calibrated in mass units [kilograms], rather than force units [Newtons].  Somehow this led naturally to a discussion of the history of the Denver Mint.  Ann said that the Denver assay office minted gold coins for regional usage that were slightly heavier than those from, say, the Philadelphia Mint, because "g" was lower in Denver.  These privately minted coins were legally allowed until 1864, since they did not "debase" the value of standard currency.  


Bill Shanks (Joliet Central HS, Physics, Retired) Home Made Conducting Baton
made a conducting baton out of a dowel rod and handle, hooking two different light-emitting diodes [LEDs] in parallel, using current-limiting resistors and a step-down transformer to 6.5 Volts.  The circuit looked like this:

When the baton was held still, the LEDs at its tip glowed yellow, but then Bill swept it across the darkened room.  Thanks to persistence of vision, we saw alternating  green and red streaks of light produced by the diodes as first one and then the other lighted for about 1/120 sec each time.. Betty Roombos took a picture with her digital camera, and three sets of streaks were visible. Each streak was separated by small "dark regions" when the electrical potential was below the "LED flash point" of about 1 Volt.

Bill started to explain that each of the two 47 W resistors took the current passing through a different LED, but he was unable to complete this remark because his tongue got stuck inside  his cheek. Better luck next time at pulling the wool over our eyes, Bill!

Richard Goberville (Joliet Central , Physics) Garage Sale Planetary Model
Richard showed scale models of the sun and planets that he had purchased at a recent garage sale.  We took the models for the first four planets, calculated the scaled distances, and laid out the scaled distances in the hall.  Here are representative numbers:


Average Distance to Center of Sun
  Actual Scaled
Solar Surface 4.3 105 mi 0.15 m
Mercury 3.6 107 mi 12 m
Venus 6.7 107 mi 23 m
Earth 9.3 107 mi 32 m
Mars 1.4 108 mi 48 m
Jupiter 4.8 108 mi 160 m
Saturn 8.9 108 mi 300 m
Uranus 1.8 109 mi 600 m
Neptune 2.8 109 mi 950 m
Pluto 3.7 109 mi 1200 m

It was impressive to see how great the distances were compared to the sizes of the (model) planets.  Thanks, Rich.

Leticia Rodriguez (Peck School) Science Fair Projects
Leticia described what she learned at a recent in-service day concerning science projects.  She learned the following points:

She described a project involving the effect of magnets on paper clips.  The strength of the magnet can be shown to depend on the size or magnet, or the number of magnets affecting a given paper clip.  The more magnets, the greater the distance from which the paper clip can be moved.

As another example she talked about determining which of three brands of popcorn gives bigger popcorn kernels, by counting how many kernels can be fit into a container of a given size.  The more kernels, the smaller the volume per popcorn.  It is simple and convenient to draw graphs and charts to illustrate the findings, and students can begin doing this in the primary grades.

Notes taken by Porter Johnson