I'm the one who started this. People's comments were very helpful. Just this
morning I introduced two groups of high school teachers to the black box
exercise and it went quite well. I used plastic film cannisters for the
boxes. Your local film developers have hundreds they'd be happy to give you.
They are ideal because they are waterproof in case you want to measure
displacement, of uniform shape and nearly identical in weight. Since they
are also round they are useful for determining the shape of what's inside.
They also provide for very distinctive sounds among the various contents.
Only one item is placed in each. I provided empty cannisters and multiple
samples of what could be inside so they could construct their own black
boxes for comparative purposes. I said I would try to provide whatever
equipment they thought was necessary but waited for them to ask for a
specific item, e.g. a balance or magnet, before supplying it. If you place
such items out in advance then you give them too many ideas. Invariably one
will ask for an x-ray machine. This is a good opportunity to point out that
science is often limited by budgetary constraints and that our "grant" for
an x-ray machine was turned down. You can also turn this around and ask if
an x-ray machine would be 100% accurate given the items you have selected.
Although they worked in pairs they soon discovered that it helps to
communicate with others working on similar problems, just like real
scientists. For example, not all thought of a magnet but once one did, the
rest followed. Some of the items I used included: metal washer, penny, glass
rod, plastic coverslip, paper match, rubber band, needles of different
lengths, M&M's candy, glass beads of different sizes, a hexagonal nut, paper
clip. Some are metallic vs non-metallic and within the metallic, only some
are ferrous (magnetic). The glass rod just fit inside the container so it
rolled but barely moved lengthwise. If rolled properly the hexagonal nut
would clunk. Only one person got my favorite, the M&M. It sounds like
several other objects but if you immerse it in hot water it melts. You can
also use this exercise to demonstrate how to write a scientific paper. The
students make observations, construct a hypothesis and then test it. You can
even work in a little statistics and sampling methods. For example, do all
the glass rods or canisters weigh the same? How many should be weighed to
find the mean, what is the range of variation in their weights. I purposly
picked some items that had fairly similar weights but varied in other
properties. Get a few cannisters together and start putting things in them.
Very quickly you will come up with some good ideas!
DR. STEVEN J. WOLF
BIOLOGY DEPARTMENT
CALIFORNIA STATE UNIVERSITY, STANISLAUS
TURLOCK, CA 95382
PH. 209-667-3489, fax 209-667-3694
swolf at koko.csustan.edu, swolf at chem.csustan.eduhttp://arnica.csustan.edu/index.html
