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ISPP REMINDER
September 2007
Dear Friends & Colleagues,
In case you haven't noticed, it's just about that time of year once again. Time to start looking over the lesson plans, dust off the books and tune up the lecture demo's. The academic year is almost upon us. Time to start thinking again about new and interesting ways to get your students excited about physics. But what can you do? You need resources! You need ideas. Where can you find it all?? ISPP!! Perhaps you already have the ideas. Perhaps you've attended a summer workshop. You're excited about it. What now? Share them with ISPP!!
OUR FIRST MEETING OF THE 2007 - 08 SEASON . . . OUR NEXT MEETING . . .
. . . is at Joliet West High School
Monday
September 10, 2007
6:30 - 9:00 p.m.
A map and directions are enclosed.
THE FREE GIVEAWAY . . .
. . . something you should find useful to excite student interest in physics - and who knows? - maybe even your own!
FUTURE MEETINGS. . .
September 10 (Monday) Joliet West High School – Debby Lojkutz/Eric Jergens
October 4 (Thursday) Loyola University – Gordon Ramsey/Maria Udo
October 12-13 (Fri – Sat) ISAAPT Lincoln Land Community College, Springfield, Illinois
November 10 (Saturday) CSAAPT at Naperville Central High School - Jan Dudzik
December 4 (Tuesday) DePaul University - Gerry Lietz /John Milton
January 9 (Wednesday) Elmhurst College - Mark Timko/Earl Swallow
AT OUR LAST MEETING . . .
Ruth
Goehmann (Museum
of Science and Industry)
greeted us and called the meeting to order and asked for a phenomenon
to start
the meeting.
Brian Sievers (Thornridge High School) explained that he saw a toy in a flea market on Maxwell Street that he thought would make a nice lab exercise. It was a small model airplane with a battery powered motor and pusher propeller mounted in the tail. The plane, a 747 jumbo jet, was tethered and flew around in a horizontal circle making a conic pendulum such that the motion of the tether subscribed a conic section. We were reminded of the battery powered personal fan that Tom Senior (New Trier High School) had adapted to the same use that he showed us at a DePaul ISPP meeting. Brian showed us a few PowerPoint slides that went through the algebra. He directs his students to time the period with stopwatches to obtain a theoretical value for the angle. Then he has them measure it with a protractor. Brian was able to get a six planes for a dollar each when he told the vendor tat he was a teacher and wanted to use them in his class. Roy Colman (CPS retired) had projected the motion onto a wall using an overhead projector to facilitate measuring the angle. Brian suggested to use batteries of different ages to vary the angles among the set-ups.
Brian had a series of views of a super well equipped ice house that was equipped with a satellite dish, TV, a wood burning stove and a microwave oven. He even had a gas powered electric generator. Surprising it did have six holes in the ice to actually fish from.
Then Brian short showed a video in which an elderly proper British couple were driving along a road. As they pulled up along side another car the lady who was in the passenger seat pulled out a second steering wheel from the back seat and pretended to be steering the car. Then she suddenly turned the wheel sharply pretending to veer into the other driver’s lane. He reacted in a panic and lost control of his vehicle spinning out. Must be British humor? Brian will share the video. Just e-mail at sievers.brian@district205.net
Gerry Lietz (DePaul University) made
some
announcements. He asked if there were any new teachers. Larissa Stanish
is
teaching at Chicago Vocational High School. She received a “New Teacher
Bag”
from Debbie Lojkutz (Joliet West High School) Paul Dolan (Northeastern Illinois
University)
asked for volunteer school to participate in Mayor Daley’s Chicago
Science
Expedition, 2007. The volunteer schools would host some kind of science
related
events following the kickoff ‘Carnival” to be held at Daley Plaza on
October 2nd.
Paul thought that the ISPP group might populate a booth for the
Carnival with a
few favorite demos’ similar to the ISPP meeting format. Anyone
interested in
participating should get in touch with Paul P-Dolan@neiu.edu
or Mike Lach Mlach@cps.k12.il.us
Pete
Insley
(Columbia College) has his students
cut an 8 x 8 square out of paper. Cut off a 3 x 8 rectangle and then
cut that
into two triangles by cutting across the diagonal. Take the remaining 5
x 8
rectangle and cut it into two identical pieces by marking off a 3 inch
length
along one 8 inch side and a 5 inch length along the other 8 inch side
and then
cut along a line joining the two points. He had already cut the
appropriate
pieces from card stock and attached magnets to each piece so he could
mount
them on a metallic board. He arranged the pieces into a square on a
conveniently located steel door to show us how the square would look
assembled.
Then Pete, to our amazement, rearranged the pieces into a 5 x 13
rectangle (see
picture). A square area of 64 square inches had become a rectangular
area of 65
square inches right before our eyes. Where did the extra square inch
come from?
We figured it out. Can you?
Paul Dolan (Northeastern Illinois
University)
was playing around with two lenticular lenses which were a free give
away from
the May ISPP meeting at Northwestern University. Art Schmidt had passed
out
lenticular lenses he bought on-line
(http://www.3dphotopro.com/lenses.html) and
several pictures which when placed under the lens would show multiple
images as
the observer’s angle of viewing changed. Art used the process to show
multiple
pictures but one might also show motion or produce 3 D pictures.
A lenticular lens is a sheet of transparent plastic that has a series of bumps molded into one side. Each bump is a half cylinder which acts as a one-dimensional convergent lens. The bumps are very narrow (1/16th of an inch) but span the width of the sheet. The special pictures are made by taking two or more images and interlacing them in thin stripes alternating from picture to picture. Paul had made transparencies of one of the pictures Art had supplied to see if he could project the multiple images effect. He recalled that the thin stripes had to be exactly the width of the lenticular lens and that the Xerox process does not reproduce dimensions exactly. The results were of mixed success. Paul had better results with a professionally done picture of an actress, Jessica Alba which he got from Art. As he rotated the orientation of the lenticular picture on the stage of the overhead projector the image alternately appeared and disappeared as it did when viewed normally.
Paul noted that
overlapping two
lenses produced a moiré pattern. The pattern was similar to what he was
able to
produce by overlapping two Freznel lenses. He demonstrated the pattern
with two
Ferznel lenses he obtained from the American Science Center for a few
dollars
each.
Tom Senior (New Trier High School) built a modification to the typical stomp rocket launcher that launches a drinking straw projectile with a puff of air. He noted that it was hard to get consistent results stomping the same each time. He found that he could use a syringe to produce a reproducible puff of air. One could pre-select a particular volume in the syringe to experiment with the range. The top end of the straw was sealed using a piece of clay or as he does, a 1/4-inch steel shoot (sling shot ammo 200 for $4.29 at local hardware stores). He passed out a rough plan. His launcher had an adjustable launch angle. A quarter inch O.D. straw fit nicely in the piece of plumbing pipe that had a quarter inch I.D. If you wanted fins on your rocket you would need to find a projectile that fit the O.D. of the pipe. Tom Suggested creating the rocket tube by wrapping a spiral of paper around the outside of the launcher tube and gluing fins and a nose cone to it.
Gordon Ramsey (Loyola University)
reported an
error in the solution that he handed out at the last meeting to show
distribution of static charge on the vane of an electroscope in
equilibrium
which came up as the result of a demo from the meeting previous to
that. Gordon
solved the problem first assuming a constant charge density on the
moveable
vane and obtained the solution that was a quadratic in cos q. The solution is cos q ≈ [(Mg)/{4klFlM}] where lF and lM are the
charge
densities for the fixed and moveable vanes respectively. One can also
solve the
problem for a varying charge density but it is much more complicated.
The
typical charge density for masses of the electroscope pieces he found
was
around 10-5 C/m.
Gerry Lietz (DePaul University)
showed us a
book “Physics Demonstrations” by Julien Clinton Sprott (ISBN
0-299-21580-6. Dr.
Sprott is a renowned Lecturer and Demonstrator from the University of
Wisconsin. For many years he had a wildly popular Demo Show that he put
on with
several standing room only performances on a weekend in mid February.
The book
documented many familiar demos. It also included two CD’s showing
videos of
demonstrations. Gerry recommended it highly for new teachers. For years
Gerry
had used Tesla coils in demonstrations. He drew a circuit of a Tesla
coil. The
tuned circuit resonated at 100Khz at very high voltages. Gerry related
how one
can cause a fluorescent light to light in the high voltage field. Gerry
wondered why one doesn’t get a shock when holding the bulb. He had
thought it
was due to some skin effect but a calculation revealed that the skin
depth
would be several centimeters. Gerry learned from the book that the
frequency
was so high that our nerves just don’t respond to it. Gerry recently
had a
pacemaker installed. He was warned not to get close to a Tesla coil or
a Van De
Graff and to his surprise, no magnet fields greater than 10 Gauss. He
wondered
why they couldn’t shield effectively against magnetic fields. As it
turns they
change the settings on the pacemaker using a magnet. Brian Sievers
related how
he avoids shock from charging himself in the winter and touching a
doorknob by
using the sharp point of a key to discharge himself painlessly. Why
does this
work?
Gerry pulled out a huge roll of Pepsi bottle labels from Australia that read “Low Joule Cola” instead of the local “diet” cola. The roll was left over from a free giveaway from the demonstration show they put on for the August 1994 AAPT meeting at Notre Dame. John Milton has CD’s of the show. A friend of Gerry’s wife worked at the Pepsi bottling company and was able to get the labels in lieu of actual cans that his sister had originally seen on a trip to Australia.
Ruth Goehmann (Museum of Science and Industry) passed around card glasses like the 3-D polarized glasses she has given away at passed meetings. She turned down the room lights and lit up a string of Christmas lights. She directed us to look through the glasses at the point lights. Each light turned into a snowflake. Other glasses displayed snowmen. The images could be projected by pointing a laser beam through the lens. We wondered how they worked. She also had some that were diffraction gratings.
Then it
was time for the annual John
Rush Award. Earl Zwicker (IIT retired) explained
the history of the award. The John
Rush award is given to one of our members for exciting ideas and 'phun'
contributions to the group. John taught for many years at Eisenhower
High
School in Blue Island, and coined the word 'pneumenon', a new phenomena
that
you haven't experienced. On the first day of class John would
show his
students a strange contraption and challenged them to discover what it
was. Then Gordon Ramsey (Loyola University)
announced this year's winner. Ruth
Goehmann (Museum
of
Science and Industry) came up to receive the award and clamped the
'pneumenon'
to the table to peel the traditional apple. Submitted by Arthur Schmidt
For any information regarding ISPP contact Gerry Lietz at DePaul University, Physics Department, 2219 N. Kenmore Chi. IL 60614 phone: 773-325-7333 e-mail glietz@depaul.edu. ISPP home page: http://condor.depaul.edu/~glietz/ispp/ispp.html
BRING FRIENDS BRING IDEAS! ! SEE YOU THERE! ! !
Debby Lojkutz/Eric Jergens Art Schmidt Ann Brandon
Kevin McCarron Pete Insley Paul Dolan/Joe Hemanek
Gerry Lietz/John Milton Ruth Goehmann Mike Kash
Tom Senior Earl Swallow Van Bistrow/ Dennis Gordon
Gordon Ramsey Roy Coleman Earl Zwicker
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
During 2007 - 08
Coordinators: Paul Dolan
Gerry Lietz
Earl Zwicker
ISPP Authors: Gerry Lietz Data Base Managers: Roy Coleman
Art Schmidt Earl Zwicker
John Milton
Pete Insley
Photographers: Paul Dolan Treasurers: Ann Brandon
Art Schmidt Peter Insley
Gerry Lietz
John Milton
Earl Zwicker
Special Events Committee:
Physics Day - Ann Brandon, Roy Coleman, (Co-Chairs)
John Rush Award - Gordon Ramsey, Nate Unterman (chair), Ruth Goehmann, Bill Blunk (ex-officio)
Harald Jensen Award - Keith Bellof (chair), Martha Lietz, Ann Brandon
Annual Tri - Physics Meeting - Bruce Illingworth, Gerry Lietz
National Bridge Building Committee - Carlo Segre
New Member Committee – Kevin McCarron (coordinator), Ann Brandon, Pete Insley, John Milton
