Meyer, Bay Area Project ASTRO astronomer
students, or for that matter most people, have had little or no
experience looking through a good amateur or professional telescope.
However, many people have seen very colorful images of the planets,
containing a wealth of details. For many people, their first view
of a planet through a telescope can be quite disappointing, since
they only see at first glance a small white spot. The eye is an
excellent, perhaps unmatched detector of subtle, extremely low contrast
details, but the mind of the observer must be ready and willing
to perceive such low-level sensory input. Like listening for very
faint sounds or smelling the differences between wines, this may
require concentration and perhaps also some training or practice.
As an attempt to provide a little of such training, with Mary's
permission and help I conducted the following activity.
hardboiled egg (with a green dot on one side) per student
empty egg carton per small group
identification worksheets as illustrated in Figure A
beam projector, spotlight, or flashlights
hard boiled egg was provided to each student. A worksheet was also
provided, which contained four outlines of the shape of an egg as
viewed from two opposite sides, and as viewed end on, namely two
circles. The students were asked to carefully inspect their eggs,
looking for any distinctive features on the sides or on the ends
that they could draw on their worksheets. The goal for each student
was to find features on the egg that they could draw on their "egg
identification sheet", such that someone else would be able to match
the egg to the drawing, and therefore determine the original "owner"
of the egg. The overhead beam projector and a spotlight were made
available for close inspection of eggs under lighting that brings
out very subtle features (bumps, valleys, grooves, spots, cracks).
I noticed a few students started to just make random dots to represent
a speckled or rough appearance, and the class was reminded to concentrate
on trying to make accurate drawings of a few distinctive features.
Many of the students were able to find quite subtle and distinguishing
features, and reasonably accurately represent their appearance and
location on their worksheets.
class had been divided into groups of 4 or 5. When all of the students
in a group had finished their drawings, their eggs were placed in
an egg carton, their drawings collected, and then the eggs and drawings
were passed on to another group of the same size. The two groups
might swap eggs and drawings, or several groups might be involved
in transfer of sets. A group receives a carton of eggs and a set
of drawings, and then attempts to match up the drawings and the
eggs. When they think they have established which drawings represent
which eggs, they write the names from the drawings in the egg carton,
placing the egg in its assigned spot. Finally the carton containing
proposed identifications is returned for verification. In this case,
about half of the identifications were correct.
this I reviewed the motivation for this exercise - to learn how
to see, describe and draw faint or subtle features on an object
which is thought of by most people as having a smooth, featureless
surface. I concluded by telling the students that I hoped they would
understand when the time did come to look through a telescope and
I asked them to "Remember the egg!"