DIFFUSED REFLECTION OF LIGHT 31 



If the object upon which the light falls is rough some 

 of the light is reflected, but, since the rough surface is 

 made of tiny surfaces which face in all directions, the light 

 is scattered in all directions. In the case of this experi- 

 ment we cannot see the sun in the object if it is shining 

 upon it, but we see that the object is brighter. We call 

 this scattering of light, diffused reflection. All objects 

 which give light are seen by the light which they pro- 

 duce; all other objects are seen by the light which they 

 reflect. Light is diffused by particles of dust and tiny 

 drops of water in the air which are too small to be seen. 

 The light which we receive from the sky and from clouds 

 is due to diffused reflection. Diffused light is best for 

 the eyes. 



Experiment 18. Diffused Reflection of Light. 

 Apparatus: Two blackboard erasers, glass. 

 Materials: Little milk, sheet of white paper. 



a. Darken the room except for one window through 

 which the sunshine is coming. Notice the particles of 

 dust which are shining by reflected light. Stand across 

 the room and look for the particles in the sunbeam. Can 

 you see them? Why? The sky is bright for the same 

 reason that the sunbeam appears to be bright. If there 

 were no dust in the air you could not see a sunbeam. 

 Knock two blackboard erasers together in the sunbeam 

 and tell what happens. Look at your companions' faces 

 as you do this and see if they become brighter. 



b. Put a glass of water in the sunbeam and notice 

 how it appears. Now add a drop or two of milk. What 

 color does the water become? Could you see a glass of 

 water across the room better if there were a few drops 



