10. Solar S’Mores
Solar energy is the energy given off by the sun.
When light energy is absorbed by objects it is changed to heat energy.
Dark-colored objects absorb more light and store more heat from sunlight.
Solar energy is often called “radiant energy.”
Solar energy is produced by nuclear fusion reactions within the sun.
Solar energy does not pollute
Dark-colored objects absorb more light and store more heat from sunlight than light-colored objects.
Light-colored objects appear light to us because they are reflecting
more of the light that hits them rather than absorbing it. Objects
appear to be black when they absorb all wavelengths of light that hit
4 graham crackers
16 mini marshmallows
2 plain milk chocolate candy bars
8”x11” glass baking pan
A clear glass lid for the baking pan
Pair your class into teams of two people (or more). Each team needs a set of the above materials.
This is an outdoor experiment. Need to have a place in direct sunlight
(no shade) and where animals won’t come by to eat the ingredients or
disturb the pan! Use your thermometer to see what
temperature it is outside. You need to do this experiment when it is
at least 85-degrees. If it isn’t hot enough outside, wait for a warmer
Procedures and Activity:
Share the following questions:
Can you cook food outdoors?
What makes food cook or things melt outside?
How can we use the sun’s energy to help us in our lives?
Welcome a discussion about “cooking” outside. Think about how we melt
marshmallows over a bonfire, heat a hot dog on a stick over a fire,
sear and cook the inside of a hamburger on a grill. Then think about
what makes the melting, warming, and cooking happen – heat.
Talk about what happens when we are in sunlight. Share how the heat
from the sun can be used for cooking, melting, and warming food.
May also share ideas and experiences with solar cooking, solar heating, and solar-powered cars.
Put four graham crackers side by side in the bottom of the glass baking pan.
Place a chocolate bar on top of two of the graham crackers.
Put 8 mini-marshmallows on top of the other two graham crackers.
Cover the baking pan with the clear glass lid.
Put the pan out in an area where it will get full sunlight – no shade!
Let the pan just sit there until the chocolate bars and marshmallows melt.
To make a S’More, put one chocolate and one marshmallow graham cracker
together to make a sandwich. You should have two sandwiches. Enjoy!
Were we able to make S’Mores using sun energy instead of a bonfire?
Talk about what really happened. Review how the sun gives off radiant
energy. Share ideas about the ways in which objects absorb light
energy and it is changed into heat energy. Talk about dark colors and
objects and how they absorb and store more heat.
You might repeat this experiment, but this time try
lining the glass baking pan with aluminum foil and black construction
paper. See if the marshmallows and chocolate melt faster than they did
in the plain glass pan. If our hunch is right, and dark paper absorbs
more sunlight and heat, we should find out the S’Mores melt faster than
in the plain glass pan.
Try putting the two halves of the S’Mores sandwiches together before
you put the dish out in the sun. See what happens. Does it take
longer for the marshmallows and chocolate to melt? Why? It may be
that the top graham cracker is sort of like a roof of a house. It
shades the chocolate and marshmallow inside. This means that it will
take longer for things to melt because the top graham cracker is
absorbing much of the sun’s heat.
Read about NASA’s idea of Solar S’Mores. As a result of the solar
maximum, every 11 years the Earth’s atmosphere “puffs up” like a marshmallow over a campfire, leading to extra
drag on Earth-orbiting satellites.
Have you noticed how different the temperature can be on a hot day when
you are standing out in the direct sun instead of standing under the
shade of a tree or awning? People who have houses that are under lots
of shady trees will find that their homes stay cooler on hot days than
those sitting out in the direct sun. Farmers are careful to be sure
that their animals have shady areas available, too, on hot summer
days. Can you think of other times when we use what we know about the
sun and shade to help us out?
Explore people in your community who are using solar energy or are
developing and selling products that use solar energy. Invite them to
come and share their research and products.
How do we apply what we know about dark colors absorbing and storing
more solar heat than light ones? Think about houses and buildings in
hot and desert kinds of places. Often, people use stucco and light
colors so less heat from the sun is stored. When you go outside on a
cold and sunny winter’s day, you will be warmer if you wear darker
clothing because it will absorb more sunlight. Or, on hot and sunny
summer days, we are smart to wear light-colored clothing outdoors.