|HABYTIME MINI LECTURE 72: WHEN LIGHT STRIKES
METEOROLOGIST JEFF HABY
The diagram below shows 5 effects that can occur when light strikes an object. Each of these will be explained:
Reflection: This is the same type process that occurs when large objects such as a ball bounce off the wall. An example of reflection
is light striking a rain drop and the photon bounces off the object. A photon is very small thus it may penetrate the raindrop through
millions of molecules before it bounces of the nucleus of a molecule. Photons are small but nuclei are also small.
Transmission: This occurs when the photon of light penetrates all the way through an object and continues the journey after completely
going through the object. When light strikes a raindrop, due to the small size of the photons and small size of nuclei of the
molecules, the photon has a good chance of penetrating all the way through the raindrop.
Absorption: Absorption occurs when the photon strikes a nucleus of one of the molecules and transfers its energy to the molecule. This
increase of energy in the molecule can result in an electron within the molecule moving to a higher energy state. Absorption can cause
an object to warm up such as what the ground often does when the sun is out.
Refraction: Refraction is a bending of the path of light. This occurs because light slows down as it goes through an object. Light travels
at basically the speed of light in a vacuum, but slows when it travels through air and other materials. Refraction can be noticed
when looking at objects that are underwater while you are out of the water. The bending of light will distort where the object
appears to be located in the water.
Scattering: Scattering is a term to describe the variety of reflections that take place when light strikes an object. Scattering is what
makes the clear air during the daylight hours appear blue. Blue light is selectively scattered more by the air than the other colors,
thus the blue light ends of being scattered around and by the time various photons of blue light reach the ground it appears they are
originating from many different places in the sky thus the overall effect is that the air appears blue.