The higher Sun causes more hours of daylight and more intense, direct sunlight, or hotter conditions on the surface of the Earth. It is important to note that even without the tilt of the Earth, there would still be variations in temperature from one location to another, caused mainly by the curvature of the earth. Locations closer to the equator would still, on the average, be warmer than locations closer to the poles. The activities addressing this topic demonstrate and test this assertion. Solar radiation is emitted in various forms which travel at the speed of light.
Light travels through space as waves of different lengths.
Our eyes can only see radiation as visible light, but radiation also occurs as radio waves, infrared rays, ultraviolet rays, X- rays and gamma rays. Together these waves make up the electromagnetic spectrum. When the light reaches the ground it is absorbed into the grass, rocks, people, soil, etc. and becomes heat energy. With an index card, make and place a sign signifying experiment areas. Students should predict a temperature for the soil.