Save Save Save
ISPP REMINDER
September 2008
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 Chicago State University
Thursday
September 11, 2008
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 11 (Thursday) Chicago State University – Sam Bowen/Mel sabella
October Oak Park/River Forest High School – Kevin McCarron
October 10-11 (Fri – Sat) ISAAPT Illinois State, Normal, Illinois
November 8 (Saturday) CSAAPT at Naperville Crystal Lake S HS - Scott Beutlich
December 2 (Tuesday) DePaul University - Gerry Lietz /John Milton
January Elmhurst College - Mark Timko/Earl Swallow
AT OUR LAST MEETING . . .
Ruth Goehman (Museum of Science and Industry) greeted us and called the meeting to order and presented a phenomenon to start the meeting. She had assembled a wooden spool, washer and rubber band along with a wooden dowel a half centimeter in diameter and 15 cm long. The rubber band was looped around the dowel near one end of the dowel, passed through a washer and then the spool and attached at the other end with a thumbtack. Ruth wound up the rubber band by rotating the dowel and placed the device on a table surface. The spool was propelled by the dowel as it unwound the rubber band. Ruth asked if the washer was a necessary part of the design. She also suggested some other possible variations whose effects might be investigated in experiments. What about a heavier rubber band or does the longer length of the dowel rod make it go straighter? She passed around the materials for us to make our own versions as one of our free giveaway for the meeting. The other giveaway was to be from a table piled high with curious items. At the end of the meting Ruth would select numbers to chose who would have first choice at selecting an item from the table.
Gerry Lietz (DePaul University) made some
announcements. He announced the first meeting for the fall at Chicago State
University. Gerry asked if there were any new teachers. Daryl Mortenson will
be teaching at Bogan High School in September. He received a “New Teacher Bag”
from Debbie Lojkutz (Joliet West High School). Tom Senior (New Trier High School) also gave him
a copy of “Chasing the Rainbow” by Robert Greenler; foreword by Duncan T. Moore, Publisher:
Seattle: Elton-Wolf Pub., 2000. ISBN: 1586190520, which he highly recommended. We were reminded that AAPT Winter
meeting in February will be in Chicago. Tom is coordinating ISPP format like
make-and -take session. If you have any ideas get in touch with him. tomseniorphysics@yahoo.com. Ann
Brandon (Joliet West
retired) is looking for volunteer readers of a new series of PTRA manuals.
Pete Insley (Columbia College) had been playing around with the familiar toy called the “popper” $3 @ doz at Oriental Trading, a half sphere of rubber which can be partially inverted and set on a surface. Within a short time the sphere pops back to its original shape launching the popper into the air. Pete demonstrated by flexing the popper and placing it on the table. It launched itself about a meter vertically into the air. Pete asked whether it will go higher, just as high or not as high if he launched it off the tip of his finger. It clearly went higher. Can you explain this?
Pete thought he could do a quantitative estimate of the height from physical measurements of the movement and forces. He used a bathroom scale to measure the force needed to flex the popper. It took about 7 pounds on the average and moves about 2 cm as it unflexes. With a mass of 10 g it should reach a height of 6 m and not the 1 m that we observed. Pete thought that the collision with the table was not elastic. Comparing the anticipated height with the actual height Pete calculated an efficiency of 15 %. He dropped the popper from a height of I m and observed it rebounding to 15 cm., which interestingly enough seemed to match. Wow! Pete handed out poppers for us to try ourselves.
Jean Westrick (Museum of Science and Industry) introduced herself as the Manager of the Science Chicago Staff. Science Chicago, an effort spearheaded by MSI, is being billed as the world’s largest science celebration. For the next year, starting in September, the city of Chicago and the surrounding suburbs will join up to provide these communities with unique opportunities to learn about, and explore science and the scientific resources in the area. To get involved and learn more visit their web cite at http://sciencechicago.com/ It is sort of like the Science in the City Program that Paul Dolan organized last year in the Daley Plaza but bigger covering the six county area.
Paul Dolan (Northeastern Illinois University)
receives TV signals with his rabbit ear antenna. Over the weekend when we had
some severe weather he had observed a strong interference that displayed a
enough of a signal to recognize a second picture something like the interference
that comes off tall buildings. He speculated and the source of the interference
in atmospheric phenomena similar to the Aurora. Water in the air could have
acted as a reflector of electromagnetic radiation.
We discussed various TV interference phenomena: atmospheric reflection can sometime result in receiving distance stations clearly: nearby tornadoes would wipe out channel 2 reception. All these issues will be mute after Feb 17 when everyone goes digital. Sigh!
Tom Senior (New Trier High School) is asking for volunteers from the Chicago Alliances to contribute make and take projects to the winter AAPT meeting. He set up a long metal chain between two vertical poles spaced about 4 meters apart. The weight of the chain caused it to droop in the middle into the shape of a catenary. At intervals of about a meter he attached masses with varying lengths of string so that although the points of attachment where at different heights the masses more or less all lined up horizontally. Each pendulum had at least one more with the same length string. When he started one mass oscillating at one end the mass with the same length elsewhere on the catenary started to oscillate in sympathetic vibration.
We discussed the various attributes of a catenary. Tom mentioned that if you could create a catenary shaped brace by inverting the shape of his hanging chain the stress would be transferred along the length of the brace as a compression force that would make the brace very effective as a bridge support. An arch of blocks in the shape of a catenary is also very strong.
Brian Sievers (Thornridge High School) had designed
a lab exercise around the reaction of Mentos in a carbonated beverage. The
sudden release of gasses due to nucleation when micro-pored Mentos are dropped
into a soda bottle propels the liquid to amazing heights. Brian wanted to show
us his new improved Mentos tablet launcher. By the way Brian recommends Sam’s
Club cheap Dr. Thunder (67¢ @ 2 liter) diet cola Brian used copper pipe that he
sweat-soldered together with a propane torch successively reducing the diameter
of the tubing from 3/4 to mate with the bottleneck down to 1/2 and then 3/8 in.
diameters. By reducing the diameter by half he calculated from the equation of
continuity that the speed would increase by a factor of four. He achieved plume
heights of over 20 feet. He hot-glued a bottle cap with a hole drilled into it
to the 3/4 in. end. Brian loads up several Mentos and blocks the tube with a
steel ball. He holds the ball in place with a Neodymium magnet. When he is
ready to launch he merely removes the magnet and everything drops into the
bottle. The optimal number of Mentos is 5 or 6. Any more and they don’t all get
to drop in before the reaction starts.
Daryl Mortensen (Museum of Science and Industry) announced that he was looking for people with ideas for large-scale lecture demonstrations which might be worked up into possible museum displays for the Museum of Science and Industry. Daryl can be reached at (773) 947-3196 or e-mail at daryl.mortensen@msichicago.org.
John Milton (DePaul University) was looking for the PASCO album with the Galalaxy Song with words by Eric Idle of Monte Python fame. He ‘Googled’ the ‘Galaxy Song’ and got a number of hits, including a Monte Python skit on U-tube. The San Jose Astronomy Associate went so far as to produce a study telling what is accurate and what is not quite the facts presented in the lyrics.
Eileen Wild (DePaul University) told us that recent NASA infra red images of the Milky Way have given us a better idea the shape of our galaxy, which is that it is a bar galaxy. Eileen showed us a picture of the new shape, a bar with spiral arms extending from each end of the bar. Eileen wanted to use a top as an example of planetary precession and found out the Toys R Us had not carried tops in several years.
Gerry Lietz (DePaul University) highly recommends the book ‘Backyard Astronomer’s Guide’ by Terrance Dickinson and Alan Dyer. It has a lot of good information especially about what telescopes not to buy.
Mike Gallo (?) had an interesting demo. He made a ramp with a board
elevated at one end by placing it on a box. He placed a large spool on the ramp
so that it rolled on the inner core with the rims of the spool hanging over the
edges of the ramp. The spool rolled down the ramp okay but before the spool
reached the bottom of the ramp the rim contacted the table surface. Mike timed
the roll and used it to find the speed that the spool hit the bottom of the
ramp with. Then he followed the motion after the spool rolled along the table
for a short time and measured this speed. He found that the second speed was
greater. The edge of the rim was moving faster than the translation of the
rolling spool so when the rim hit the table the spool accelerated slightly.
Where did the energy come from to raise the translational speed of the spool at
the bottom of the ramp? Mike explained that 
some rotational kinetic energy was
converted to translational kinetic energy. Neat.
Mike then showed us a strange light
bulb he found that he wanted to know what it was used for. We explained that he
had a neon light. It would not light unless it had in excess of 60 volts across
the leads. Once it strikes an arc it will remain lit until the voltage drops
below 20 volts. A common application is a component of a relaxation oscillator.
This consists of a 100 volt D.C. supply with a capacitor and resistor in series
connected to it. The R and C combination should have a time constant T = RC in
the range of seconds to be able to see the results. For example, a 1 MΩ
resistance in series with a 1 µƒ capacitor would have a 1 second time constant.
The neon light is placed in parallel with the capacitor and with a 1 second
time constant would blink every second as it discharges the capacitor. Neon
lights are used as strobe lights. When connected to 60 Hz A.C. it blinks at 120
Hz. Such a light was used with a strobe pattern to adjust the speed of old
phonographs. A excited neon atom has lots of emission lines too. So, any old
apparatus that you have a question about, bring it to one of our meetings.
Someone will have seen it or will know about it.
Dan Cahille (Grays Lake Central High School)
recalled hearing that the color of a lasers spot will depend on the paper on
which the laser is shown upon. He had taped together a variety of colored
construction paper sheets. When he pointed a green laser at plane green colored
construction paper we saw just the green color reflected but other colored
paper gave different results. Pink paper changed the green laser spot to a
bright orange. He then passed out spectral glasses he loaned from Martha Lietz.
When he pointed the laser at fluorescent colored paper we saw a spectrum of
colors reflected. Dan said that he saw a similar but fainter spectrum from the
regular paper too. Researching on the web Dan found that there can be a lot of
extra intermediate transition states due to rotations and vibrations of the
atoms that will allow for a whole range of frequencies in the light emissions
besides the exciting frequency. What puzzled Dan was that some of the emitted
light contains higher frequencies, thus more energetic photons, than that of
the original laser light. How is this possible?
Then it was time for the annual John Rush Award. Ann Brandon (Joliet West 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. Dan Cahille (Grays Lake Central High School) 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 2008 - 09
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), Dan Cahille, 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
