The name comes from the Latin albedo, which means ‘whiteness’. The albedo effect refers to the fact that light surfaces reflect more heat than dark ones. So, the lighter a surface, the greater its albedo, meaning it reflects more heat and light, and absorbs less. In this activity, we are going to use thermometers to test whether white or reflective materials absorbs more or less heat than black or dark ones.

Activity steps

1. Make sure that both thermometers are at room temperature.
2. Note the temperature of each thermometer.
3. Place one thermometer under the white or reflective material and the other under the black one.
4. Put the thermometers covered by the material under the light source, making sure that they are the same distance away.
5. Keep the thermometers there for 15 minutes.
6. Note the new temperature of each thermometer.

Questions

1. Which colour absorbed more heat energy?
2. Which colour reflected more heat energy?
3. Which colour represents the ice and which one represents the water?
4. How does the ice help to keep the Arctic cool?
5. If there is less ice, what could happen to the temperature of the Arctic Ocean?

• Piece of white or reflective material, such as felt or aluminum foil
• Piece of black material, such as felt
• 2 thermometers
• Heat source such as a lamp (a traditional light bulb will work much better than an energy-saving one, this is because energy saving bulbs are designed to give out less waste heat)

Expected results

The thermometer under the white material should have a smaller temperature rise.

Misconceptions

Students often think that black ‘attracts’ more heat. This is not the case. Black materials do not pull energy towards them, they absorb more of the energy that hits their surfaces. They also release more of the energy that is inside them.

Students often think that ice keeps the Arctic cold by ‘giving out cold’. There is no such thing as ‘cold’. This is a pretty complex bit of science, but simply, imagine two objects of the same material. One is ‘hot’ and one is ‘cold’. The hot one has more energy than the cold one. So the heat energy moves from the hot one to the cold one. If you have two ‘cold’ objects, the heat will move to which ever one is colder.

The ice helps maintain the temperature in the Arctic by reflecting vast amounts of the heat energy that hits it.