To make spectroscopes, copy these figures onto
opaque paper or cardboard and cut them out.
Dark construction paper works well. Cut on the
continuous lines, including the small slit, but
don't cut on dotted lines. Cut the slit with
straight edges carefully, so as to let through
some light, about 0.5 mm wide. You can cut it
wider, and then form a narrow slit by the gap
between two pieces of opaque tape.
Now choose a data or music CD that you don't
want as a CD, such as those you get unsolicited
in the mail, and cut it into wedges using a pair
of stout scissors. You can get about 16 useful
wedges out of one CD to use as diffraction
gratings. Attach a wedge of CD where indicated
by the dotted outline, on the side of the paper
that will become the inside (usually the
unprinted side). Make sure the iridescent shiny
side is exposed, but cover the mirror-like part at
the narrow point with tape or glued on paper as
shown. Fold on the other dotted lines to make
a little box with the CD piece inside on the
bottom. Glue or tape edges closed (a to a, b to
b, etc.) so that they don't leak light, but do not
cover the slit. You can tape g and h less
thoroughly so the back can be opened to look at
or readjust the diffraction grating (CD piece).
Now point the slit at a light, and look through the
hole at the CD. Try looking at an incandescent
light bulb, and then at a fluorescent light bulb.
Try other light sources, but DO NOT LOOK AT
THE SUN! A bright spectrum of sunlight can be
seen if you look in the general direction of a
window. Look at light reflected off of colored
paper. What happens if you widen the slit?
to light
look this
direction
tolight
lookthis
direction
piece of CD to inside,
shiny side showing.
cutslit
e
c
a
a
c
ef
d
b
b
d
f
c1999
Cover
with
Tape
Attach
g
h
ghto light
look this
direction
tolight
lookthis
direction
piece of CD to inside,
shiny side showing.
cutslit
e
c
a
a
c
e
f
d
b
b
d
f
c1999
Attach
g
h
gh
Cover
with
Tape
"Science of Stuff" Spectroscopes c 1999 Alan Schwabacher
UWM Chemistry
www.uwm.edu/~awschwab/specweb.htm
UWM
Chemistry
mini
spectroscope
UWM
Chemistry
mini
spectroscope