Elementary Mathematics-Science SMILE Meeting
25 January 2000
Notes Prepared by Earl Zwicker

...we met according to subject, Biology/Chemistry or Mathematics/Physics, with elementary and high school teachers mixed. So here's what happened!

Biology/Chemistry

Pat Riley (Lincoln Park HS) got two volunteers to come up to the table in front of us. There were two large beakers standing, one (A) nearly full of a colored solution, the other (B) nearly empty. Each volunteer was given a small beaker of the same size. One was to scoop up as much solution from A as possible and dump it into B, while the other volunteer scooped as much solution from B as possible and dump it into A. They synchronized their dumping. It became apparent that the liquid volumes in A and B became more and more equal as the process proceeded. A dynamic equilibrium was being reached!

A similar exercise involved our standing and sitting (mechanical equilibrium approached). Then water and sugar mixed until no more dissolved. But some sugar molecules are still dissolving while others are crystallizing out on surfaces of the undissolved sugar. Great ways to make dynamic equilibrium "real!"

Chuck Buzek (Spry School) gave a SMILE pep talk on the phenomenological method of teaching science. Then he gave a counter-intuitive example. He passed out balloons, had us each add a couple of drops of vanilla extract, and then inflate them. Could we smell the vanilla through the balloon? Yes! We did! Much discussion followed to explain this - involving sizes of molecules, temperature effects...Wow!

Karlene Joseph (Lane Tech HS) reached in her pocket, pulled out 46 pennies and gave 2 to each pair of us. We pairs each flipped the 2 pennies ten times, and recorded the number of times we got 2 heads, 2 tails, or 1 head & 1 tail. Then she had each pair of us report the results, and listed them on the board. Individual reports varied significantly, but when Karlene had us get the totals in each category, the ratios of 2H/total, 2T/total, (H+T)/total respectively were: 1.22, 1.00, 2.05 - close to 1, 1, 2. She then applied the concept to genetics. Given two genes, B and b, and - using a square "grid" - she showed that one gets 25% BB, 25% bb, and 50% Bb, or 1,1,2. How clear a somewhat abstract idea can be made by starting with a concrete analogy! Great, Karlene!

Math/Physics

Bill Colson (Morgan Park HS) opened with an amusing collection of cartoons, each showing something that was not scientifically accurate. Ignorance or satire? Shows why "Americans need more Science." Informative fun!

Fred Schaal (Lane Tech HS) tied a porcelain cup to one end of a string and a key to the other end. Then he placed small blanket on the floor - so the cup might not break if it should fall. Facing us, he held a pencil in his right hand, hung the string over the pencil next to the cup, and then held the key at the other end with the string stretched out horizontally. Question: What will happen when I release the key? We made several different guesses at the outcome: cup will fall and strike the blanket (floor), etc. And then Fred released the key. The cup began its fall toward the floor, but the key fell also, swinging in an arc toward the cup, speeding up rapidly and finally wrapping the string several times around the pencil. Friction beween string and pencil then brought things to rest, the cup not reaching the floor at all! Each time asking us to predict what would happen, Fred asked us what would happen to the final height of the cup above the floor if he used 2 keys? ...3 keys?...more? It turned out that the more keys, the greater the height! Conservation of angular momentum was invoked in the physics explanation. Very nice!

Arlyn Van Ek (Iliana Christian HS) (handout- electrostatics lab experiments) showed us a beautiful set of logically-connected experiments with static electricity. He made a form of electroscope from a foam cup (inverted on the table as a stand), an elbow straw attached with tape to the cup, then bent horizontally with a piece of tape hung vertically down. Arlyn then stuck a piece of tape (Scotch Magic, about 2 -3 in long) on the table, then stuck another piece of top of that piece. He was careful to fold and stick a short section at the end of each piece back on itself to act as a "handle." Then he stripped the top piece from the bottom piece, and brought it near the electroscope tape - and the two tapes bent toward each other - an attractive force! There was much more, including determining charge sign using a detector (handout) made from a film can and FET. A most striking effect occurred when Arlyn ran a stream of water from the faucet, and brought the charged tape near the stream: the stream of water actually bent and curved toward the tape! He thanked Bill Shanks and Ann Brandon for having given him these ideas in earlier meetings. Arlyn, thank you!

Carl Martikean (Wallace School, Gary) told us about the 4 foot, 8.5 inch gauge of the railroad, and the size of English roadways. It turns out this was the "standard width" of the rear ends of two horses! Reasonable - when you think about it. And an amusing story about bureaucrats. Informative fun!

Janet Sheard (4th,West School, Glencoe) (Handout) got 5 volunteers to do 5 science experiments, with 5 of us in each of 5 groups.

• Bill Blunk did the ramp (inclined plane wrapped around a pencil) - also a screw!
• Ann Brandon did levers (done with pencils and books).
• Alma White did second class levers (toothpicks and your hand).
• Carl Martikean did inertia (glass, index card and clothespin).
• Earnest Garrison did the helicopter (paper and scissors).
Wonderful, hands-on science - low cost! Great, Janet!