You are here: Home News Sunny science experiments

 Members and donors are our most important source of support. 

Donate Button
Membership button
 Thank you

Sign up for 



Goodsearch button 


Write a review of  
Explorit Science Center   

on Trip Advisor Logo 




Sunny science experiments

This article appeared in the April 8, 2011 edition of the Davis Enterprise.

By Liz Shenaut
Special to the Enterprise

On a bright sunny day, try the two following science experiments at home to illustrate concepts about sunlight and the Earth’s atmosphere.

Simulate the greenhouse effect in the first activity, and the effects of the ozone layer on sunlight in the second. They should take about five minutes each to set up.

Warm earth: model the greenhouse effect

You will need: two thermometers, a large lidded glass or plastic jar tall enough to hold one of the thermometers, and a few handfuls of soil.

Put the soil and one thermometer in the jar, and secure the lid. Place the jar near a window in your house in direct sunlight, and place the second thermometer next to the jar.

Observe the temperature readings on both thermometers after 30 minutes. Which did you predict would be higher? Were you right?

The jar is a model of a greenhouse, a glass or plastic enclosure for growing plants that stays warm from solar energy coming inside and getting trapped. The cooler air outside is prevented from mixing with the warm air inside.

Earth has an atmosphere of gases around it that let some energy from the sun though and onto the surface of the Earth. Much of that heat bounces back off the surface of the Earth and gets trapped by the gasses surrounding the Earth.

Greenhouse gasses are the name for the heat-absorbing gasses in the Earth’s atmosphere, and they get their name because they act like a greenhouse, keeping the Earth warm.

Although the greenhouse effect is normal, humans continue to increase the amount of one greenhouse gas in our atmosphere: carbon dioxide. This happens through deforestation and burning fossil fuels like coal and gasoline.

UV ray blocker: the ozone layer

You will need: a piece of clear plastic such as a plastic report folder, sunblock with a high SPF, a sheet of newspaper, masking tape and modeling clay.

Use your finger to coat one side of the plastic with sunblock in an even layer. Place the newspaper on a table outdoors in the sun and tape down the corners. Use walnut-sized balls of clay to support the plastic over the center of the newspaper, sunblock-side up.

You will want a ball of clay in the center of the plastic to keep it from touching the newspaper. This experiment tests the reduction of UV light, not the reduction of airflow over the newspaper.

After two hours, remove the plastic and compare the color of the newspaper in the area where the plastic was with the area around it. Which area changed color more? Why?

The ozone layer in the Earth’s atmosphere blocks some UV rays from the sun. Sunblock does the same thing. UV rays yellowed the newspaper, except in the area that was protected by the sunblock-covered plastic.

Ozone is a form of oxygen that is harmful to breathe, but is beneficial when it collects way up high in the upper atmosphere. Called the ozone layer, it protects us from UV light by stopping much of the sun’s UV light from reaching Earth.

Certain kinds of air pollution have caused a decrease in the size of the ozone layer, putting us more at risk for damage to our skin from UV rays.

These sunny science experiments are adapted from the activity book called Janice VanCleave’s Ecology for Every Kid: Easy Activities that Make Learning Science Fun. 

Coming events:

• Summer Camp Jun 13-Aug 19: More information about themes and registration can be found at  The registration deadline for the random drawing will be Friday, April 15.  Open registration will begin May 2.

• Today through May 20: If you know of someone who may be interested in volunteering as a Science Teaching Assistant during summer camp, he or she can contact Explorit’s Volunteer Coordinator, Kristin Sizemore at Applicants must be at least 12 years of age before June 13th.  Volunteer orientations will be held on May and June for accepted applicants.

Explorit Science Center’s 3141 5th St. site is the location for field trips, programs for groups, and astronomy club meetings.  It is also the hub for Explorit’s traveling programs that reach an 18-county region.  The site is open to the public for special events and to groups by reservation. For more information call (530) 756-0191 or visit

Document Actions
Personal tools