Children explore light and heat as different components of the Sun’s energy.
Some children may observe that it is warmer and lighter during the day than it is at night — so light and heat from our Sun do not seem to be different things. Others may remember that it can be cold on a sunny day, so it may seem they are different. Invite them to test these two different ideas.
Give three small sheets of black poster board to each group. Have them set one aside and use the others to draw and cut out two shapes about three inches across. Be creative — make planets, handprints, or other shapes.
Show them the photosensitive paper and explain that this paper darkens when exposed to light. In a few minutes, they will go outside, get a piece of this paper, and tape their shapes to it.
Before going outside, have the children place several strips of tape around the edges of their shapes as well as the piece of black poster board, in preparation for taping them to the photo paper outside. (The black side of multicolored boards should be the side exposed to the Sun).
Invite them to take their shapes outside and prepare to act quickly.
Distribute the photosensitive paper. Have them very quickly take the photo paper, tape the shapes on it — a few on each side — then tape the black poster board over one half of the photo paper, including one of the shapes. Wait two minutes and then remove the board and shapes.
As the groups finish have them discuss and record their results.
For each group of 3 or 4 children:
Connections to the National Science Standard(s)
Standards A,B,&D(grades 5–8): Communicate an understanding through scientific investigation that the Sun’s energy arrives as light with a range of wavelengths, including visible light and infrared radiation, and two ways in which light interacts with matter are by transmission and absorption.
Standards A, B&D (grades 9–12): Understands through scientific investigation and effectively communicates that light waves have energy and can transfer energy when they interact with matter. Understands that our Sun is the major external source of energy.