DEMO: LIGHT POLLUTION
AND SHIELDING
OBJECTIVES
ƌɄ Compare the effectiveness
of an unshielded light vs. a
shielded light.
ƌɄ Discuss ways ineffective
lighting affects our lives.
ƌɄ Come up with a simple
solution that keeps needed
lights on but directs shielded
light where needed, when
needed, and at reduced wattage
and cost, while allowing us to
better see the stars.
TIME
PROCEDURE
Optional: Begin by reading/ discussing There Once
Was a Sky Full of Stars (picture book by Bob Crelin).
Doing the Light Shielding Activity:
ƌɄ Make sure you are in a very dark room (no lights on; cover any
windows with black trash bags). Or do this demo outside at
night, away from unshielded lights.
ƌɄ To simulate an unshielded “streetlight” on a pole, unscrew the
reflector to your mini-light and turn it on in candle mode (use
the reflector end cap as a base).
ƌɄ Set up a street scene with the figurine standing on the
“ground” with the unshielded “streetlight.” Two options:
!1.
If you have a
table available,
prop open a book
(such as There
Once Was a Sky
Full of Stars) to
the page with
the desired
illustration (e.g.,
a street with light
pollution). Position the figurine in front of the open book,
on top of the city mat (or simply on top of the table) and
place the “streetlight” nearby.
!2.
Or, you can walk around with the demo
in your hands by taping the figurine to
a white paper plate (the “ground”) and
holding the flashlight (“streetlight”) on
top of the paper plate.
5-15 minutes to do the
demonstration, depending
on discussion time
MATERIALS
ƌɄ Mini-light” (such as a Mini
Maglite flashlight), to be
operated in “candle mode”
ƌɄ PVC cap or other items to act
as shields
ƌɄ City mat or white surface such
as a paper plate
ƌɄ Optional: picture book with
landscapes or city scenes, such
as There Once Was a Sky Full
of Stars by Bob Crelin
ƌɄ Optional: figurines about 1.5
inches tall
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MORE RESOURCES
Learn more about light pollution
at the GLOBE at Night website:
http://www.globeatnight.
org/learn_light.html
Find more dark-sky
activities here:
http://www.darkskiesawareness.
org/DarkSkiesRangers/
(recommended for large outdoor
groups: The Night You Hatched)
CREDITS
BACKGROUND INFORMATION
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Thanks to the National Optical
Astronomy Observatory and to
Chuck Bueter for permission to
adapt demos from these sources:
ƌɄ http://www.globeatnight.org/
dsr/Dark_Skies_Rangers_
Lessons/Demonstrating_
LightPollution&Shielding.pdf
ƌɄ http://analyzer.depaul.edu/
paperplate/lights.htm
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