Trees can be a renewable source , we use them to breath , we make paper out of them , we make houses and etc.
i hope this helps
Fresnel and Fraunhofer diffraction. Fresnel diffraction is produced when light from a point source meets an obstacle, the waves are spherical and the pattern observed is a fringed image of the object. Fraunhofer diffraction occurs with plane wave-fronts with the object effectively at infinity. The pattern is in a particular direction and is a fringed image of the source.