Here are some things to think about and do as we start the unit on
mirrors. These questions can be answered by simple experiments that will
only take a few minutes. Please do all of them.
If the mirrors in your kit look hazy, it is because there is a protective
plastic film on them. It will peel
off easily -- find an edge at a corner of the mirror. The mirrors are unbreakable
plastic, but can be scratched if treated roughly.
Admire yourself in the mirror. If you close your right eye, is
the person looking back closing their
right eye or their left?
Hold something written so that it faces the mirror
and you can see its reflection. How does a reflection of
an object differ from what you see looking directly at the object?
A corner mirror
Use two mirrors to make a simple corner mirror, by attaching
two horizontal mirrors together with a little tape hinge. Then adjust
the angle between the two mirrors until you see one complete reflection
of yourself when you look into the corner formed by the two mirrors (not
2 of you, not multiple noses, and not a partial you with no nose. When you see
one 'normal' you, that corresponds to the mirrors being at right angles
to each other). What happens to this mirror person when you
close your right eye?
Try reading text reflected
in the corner mirror.
How is this reflection
different from that produced by a single mirror?
You and a partner side by side can both look
at your reflections in the corner mirror at once.
Whose reflection is in the
center of the corner mirror?
Is a mirror more like a window (through which we can see
a funny world where they use a different alphabet), or
more
like a photograph?
To begin thinking about that question, here are some simpler ones:
If you were really nearsighted and didn't have your glasses
with you, you could still admire the Grand Canyon by taking an
instant photo of it and looking at that, close up.
Do you suppose it would work as well to hold a mirror
close to your face?
Cut a hole in a piece of paper the same shape and size as a mirror,
to make a little window you can look through.
Compare how much of the room you can see through the window to
how much you can see of the room in the mirror, holding them about
the same distance from your face (and facing opposite directions,
of course).
How is a mirror like a little window, and how is it different?
After your discussion, summarize in writing what
you have learned in the course of doing these mirror explorations.
Describe any problems you encountered, too.
All done? On to the first activity!
After your discussion, summarize in writing what
you have learned in the course of doing these mirror explorations.
Describe any problems you encountered, too.