When you open your eyes in the morning, take a minute to thank God that you can see. We should reflect upon how good it is to have light instead of the darkness of night. The properties of light make it unique and special.
I am keenly aware of my gift of sight because of a long association with Glynn Langston, who is blind and manages our outreach to the visually impaired. In my lectures, I frequently refer to Edwin Abbott’s book Flatland to help people understand dimensions and how the spiritual is different from the physical. Glynn was born blind, so he is unable to visualize the concept of a sphere crossing a plane and leaving the outline of a circle. He has been kind about it, but my wife once said to me, “How do you expect a blind man to visualize anything!” Even those of us who can see have trouble understanding the properties of light beyond what meets the eye. Radio waves, gamma rays, X-rays, ultraviolet rays, and infra-red rays are all light!
The properties of light make it difficult to comprehend. The most general definition of light is that it is the energy released when a charge changes momentum. The bundle of energy released is called a photon, and the amount of change in momentum determines the energy of the released light. Even in the visible spectrum for humans, the different colors we see are determined by how much energy the light has. Violet has much more energy than red. Ultraviolet has more energy than violet. X-rays and gamma rays have even more energy, but they are still light. Infrared, and radio waves have lower energies than red. That is why infrared warms you and ultraviolet gives you a sunburn. It is also why radio waves can pass through the walls of your home without causing damage and gamma rays can also pass through things, but they will do significant damage.
In the creation process, there had to be special accommodations for the properties of light coming to Earth from the Sun and from outer space. The ozone layer had to be in place to absorb ultraviolet and avoid damage to life. The eyes of every living thing that uses some form of sight had to be designed to function in the part of the spectrum that fit its diet. Rattlesnakes, for example, have specialized sight organs to see in the infrared. Because they eat rodents whose bodies give off radiation in the infrared, a rattlesnake can see its prey on the darkest night. Nearly every insect sees some part of the spectrum other than the colors visible to humans. That is how a mosquito finds you and how insects navigate at night.
Not every star in the sky gives off the properties of light that are needed for life to exist. Some stars radiate in the X-ray part of the spectrum, and others radiate energies too low to be useful to life. Even our trees and shrubs require light in the green part of the visible spectrum to know when to shed their leaves in preparation for winter. In Job 38-41, God spoke to Job to show His wisdom and design and convince Job of his ignorance. Many of the designs God pointed to are connected to light. “Where is the way where light dwells, and where is the location of darkness?” (38:19) “By what process is light parted which scatters the east wind upon the earth?” (38:24) “How does the eagle seek the prey and see that which is afar off?” (39:29)
The Bible speaks of light that is not produced by the acceleration of an electric charge. The most important of these is described in Matthew 5:14-16: “You are the light of the world … let your light so shine before men that they may see your good works and glorify your Father which is in heaven.” Let those of us who are Christians not only be amazed by God’s design of the properties of light and the world in which we live, but let us also strive to be the light Jesus calls us to be.
— John N. Clayton © 2019