Thursday, November 12, 2009

And There Was Light

When we flip on a light switch, wonderful things happen. In a subjective sense, our path is illuminated and objects become visible. But in a scientific sense we must explain the events in more complex terms. In our last three posts, we’ve spoken about the wonders of electromagnetic waves. We could also speak of those waves as packets of energy called photons.

White light bulbs emit thousands of different wavelengths together. The longest and shortest of them do not differ in wavelength very much. The tiny difference, however, is vitally important. A prism is able to separate the wavelengths. The longest of them (about 1/40,000 inch) impact our eyes and brain and we see “red.” We see the shortest (about 1/70,000 inch) as “violet.” The in-between wavelengths are seen as orange, yellow, green, and blue.

At the speed light travels--300,000 km/sec--trillions of these waves strike our eyes each second. When we see an object giving off red light, or appearing red, we are really seeing light which has a frequency of 430 trillion hertz (Hz). Violet colored objects emit light with a frequency of 750 trillion Hz. Other colors fall between these frequency values. Scientists use Hz to indicate the number of waves passing a given point per second. Therefore, when we observe red light or a red object, 430 trillion electromagnetic waves pass into our eyes each second.

We do not comprehend such enormous numbers. At the 1962 Seattle World’s Fair, I viewed the display of one million silver dollars. Even with that visual aid, one million was difficult to grasp. A trillion (a million million) is certainly beyond our comprehension, whether in respect to waves of light entering our eyes each second, or as a figure to quantify our national debt. Scientists have determined wavelengths and their frequency with great precision.

Visible light falls between the wavelength range described above. In our environment, there are uncountable different wavelengths longer than these; uncountable billions of wavelengths are even shorter. These longer and shorter wavelengths exist abundantly all around us, but they are all invisible to humans. Our very existence would be impossible without them.

The imagery of light in scripture is beautiful and bountiful. Science knowledge in the 21st century helps us extend our applications of such imagery. “I am the Light of the world” refers to the spiritual illumination provided by Jesus Christ and is a metaphor for salvation. The created light in Genesis enabled man to inspect the glorious works of God. Physical light often accompanied the presence of Deity.

Our current knowledge of light evokes a sense of wonder at the glory of our created order. We may visually observe the beauty and function of the physical creation and the life forms it supports, producing reverent worship. While contemplating all this, we may use human terms to exclaim simply, “God had great ideas!”