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ISPP REMINDER

March, 2008

OUR NEXT MEETING. . .

. . . is at Chicago State University

Wednesday
March 12
6:30 - 9:00 p.m.

A note from our host, Mel Sabella: “We will be meeting in the new academic library in the auditorium on the 4^th floor. Parking is available in any of the lots not marked reserved. Unfortunately, I was not able to get the passes as last year - so it will cost people $4 to park.”

Future Meetings and Events

Physics Northwest	Wheeling H.S.	March 5 (Wed)	Raeghan Graessle
ISPP	Chicago State University	Mar 12 (Wed)	Mel Sabella
	Lake Forest College	Apr 1 (Tue)	Scott Schappe/Nathan Mueggenburg
	Northwestern University	May 5 (Mon)	Art Schmidt
	MSI or Columbia College	June 3 or 10 (Tue)	Ruth Goehmann or Pete Insley
CSAAPT	Harper College (Click here for information)	Mar 15 (Sat)	Invited Speaker: Randy Knight
Physics Day	Great America	May 8 (Thu)	AnnBrandon/Roy Coleman

At our last meeting...

…at Northeastern Illinois University, Paul Dolan welcomed us with his liquid nitrogen demonstration. He froze a banana, some grapes, and an onion in a knee high sock. Then he passed the sock around so we could thump the banana and touch the grape. The onion broke up in a satisfactory manner. The banana was less satisfying.

Announcements:
In February 2009 the AAPT will hold its national meeting in downtown Chicago. It’s time to start talking it up a little to see if we can get some time off to go.

In Summer 2009 the annual summer meeting will be in Ann Arbor, MI, a short drive away. Start thinking of an exciting demo for the show, but don’t hurt yourself. <

The results of the 2008 Chicago Regional Bridge Building Contest held February 5, 2008 at Illinois Institute of Technology. Congratulations to all the winners, particularly the top two in each region who will be participating in the 2008 International Contest on April 26.

City of Chicago Region
C.J. Hughes	- Payton College Preparatory
Kelly Corcoran	- St. Ignatius College Prep
North Suburban Chicago Region
Jonathan Gray	- Wheaton Warrenville South High School
Evan Binkerd	- Wheaton Warrenville South High School
South Suburban Chicago Region
Brian Sarniak	- Lincoln-Way Central High School
Bernadette Bajzek	- Tinley Park High School

Tom Senior (New Trier High School) brought a 2-liter clear pop bottle containing about .5 liter of staple pieces he got from the copy center at his school. It seems modern copiers have a long piece of wire that the staples are cut from and sometimes pieces are left over. The machine is cleaned out regularly and they are thrown away. The pieces looked pretty uniform to me; all about 1cm long. Tom had various neodymium magnets that he held to the outside of the bottle. The staple pieces would be attracted to the magnet and form interesting patterns showing the shapes of the magnetic fields. Tom said a good source for magnets is Allelectronics (www.allelectronics.com)

Johan Tabora (Northside Prep High School) brought his laptop and showed us a program called “RockSim” in which you can simulate building a model rocket and then check out your rocket in cyberspace. He’s had students do this and then he got some money to order rocket kits so they can build the rockets to their own specs and fly them in a contest. It looked like fun. Johan was looking for some more ideas of how physics principles could be inserted into the project. If you have any ideas for him send them to jtabora@northsideprep.org. Someone suggested using the graphs he got from RockSim and have the students calculate areas and slopes and discuss the principles involved in the area or slope. Pretty clever I thought.

Gerry Lietz (DePaul University) passed out a letter to the editor he found in the Tribune auto section discussing hydrogen as an alternate fuel. The general conclusion is that when considering an energy source a person should also consider all the energy used to produce that source and where all the energy goes when it is used by that source. Shipping pre-use and pollution post-use are also costs. A free lunch requires a sufficiently large number of dumpsters.

Roy Coleman (CPS retired) put an old joke on the board:

Then Ann Brandon (Joliet West High School, retired) and Gordon Ramsey (Loyola University) combined for this one I hadn’t seen before:
It’s a Volkswagen pulling a mobile ohm with a current license plate attached.
And IR = V. I enjoyed this one and intend to use it somewhere.

Ann also added:

Ohm is where the heart is. Always good for Valentine’s Day!

Pete Insley (Columbia College Chicago) brought 50 or so multimeters to give away. They were welcomed.

Paul Dolan (Northeastern Illinois University) then pulled out a series of giveaways, including:
1. NEIU ball point pens
2. Some 12-pin liquid crystal displays that lit up when exposed to static charges

3. About 100 celts (rattlebacks) (from Educational Innovations). We then had a short discussion of the celts. Some said you could change their properties by sticking a weight crosswise on the back of the celt changing its moment of inertia. I took a couple to try it out. [Google “rattleback” to see several links that describe the physics of the rattleback.]

4. A roll of Chinese yen (also from Educational Innovations). They are made of aluminum and are about the size of a nickel. Paul floated one in a clear cup of water; it was held up by surface tension. They recommend using a bent paper clip to hold the coin. Balance the coin on the clip and then dip the clip into the water. The coin should float free. The coin clearly floats below the surface of the water because of Archimedes Principle. It was easy to see and a little surprising.

We brought out the niobium magnets near the coin and it did not attract it but when we waved the magnet over the coin the magnet caused the coin to move because of the induced currents in the coin formed by the changing magnetic field. I got a few coins to try that myself.

Finally we brought a charged rod (actually a charged Styrofoam cup) near the coin and it repelled !??

Actually the rod attracted the water under the rod causing it to lift slightly and the coin slid down the ramp caused by the slant of the water.

It was another very enjoyable meeting and I also got a chance to meet Johan from Northside Prep and talk to some old friends. Try it yourself.

Reported by Pete Insley