Timeline Trivia

By: Jim Virkler; ©2009

One of my pastimes is personal family genealogical research. I enjoy pinpointing family events and connecting them with people and dates in history. Which family life spans overlapped those of famous people? Who was living when certain historic events occurred? What family member was alive, for example, when a certain scientific discovery was made?

My maternal grandfather was born just before the Civil War and died a few weeks after my birth. He was alive, therefore, in 1864 when brilliant physicist James Clerk Maxwell (1831-1879) developed his famous theory of electromagnetism which unified many observations of scientists who lived in previous decades.

Maxwell’s theory explained waves of electric and magnetic energy traveling at right angles to each other and to their direction of travel. I asked my students to imagine a tiny “package” of magnetism, the invisible force surrounding their childhood magnetic toys which attracted or repelled each other. They also imagined “packages” of electric force which, when pulsing through a copper wire, could deflect the needle of a nearby compass. By this, students were able to visualize the intrinsic relationship between electricity and magnetism.

The students needed to imagine these “packages” racing off through space. Through his equations, Maxwell calculated that the speed of these “packages” (waves) should be about 300,000 km/sec (186,000 mi/sec). Since light was known to travel at that speed, he correctly theorized that light was an electromagnetic wave. And he predicted that scientists would later be able to generate them artificially. Radio waves were first produced by Heinrich Hertz in 1886.

How are these waves produced? Another giant of science was J.J. Thomson (1856-1940). He was alive until 1940, several years after my birth. In 1897, this Nobel Prize winner discovered electrons: tiny negatively-charged particles present in all matter. In the late 19th century, Thomson and others realized that when electric or magnetic fields change position, or oscillate, electromagnetic waves are generated. As the atoms in all the objects around us vibrate constantly with kinetic energy, the electrons in them also oscillate. What is the result? The electrons and the magnetic fields around them also oscillate. Electromagnetic waves are produced.

My grandfather raised his older children on the prairies of Oklahoma during the late 19th century. His older children knew nothing of radio, microwaves, infra-red, the electromagnetic nature of visible light, ultraviolet, X-rays, and gamma rays. Discoveries and applications of electromagnetic waves were in their infancy. And yet, they feared God deeply. With respect to our fear of God, what impact does our present knowledge have on us?

http://jasscience.blogspot.com/2009/11/timeline-trivia.html

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