"Heinrich Rudolf Hertz (February 22, 1857 - January 1, 1894) was the German physicist and mechanician for whom the hertz, an SI [standard international] unit, is named. In 1888, he was the first to satisfactorily demonstrate the existence of electromagnetic radiation [commonly, "EMR" in the sciences] by building an apparatus to produce and detect UHF [Ultra High Frequency] radio waves. Another of his important contributions was to the field of contact deformation and mechanics. [Contact deformation has to do with the changes imposed upon objects in collisions]."
Now the unit of measurement typically used for radio waves today reads in "Megahertz" (1 million cycles per second) or "Kilohertz," (one thousand cycles per second). The unit, 1 hertz, simply names one cycle -- reaching [or starting from] a wave top [called the peak] and then a bottom and then a new top. Picture a simple oceanic wave as it moves across the water. I used to jump over these as a child when they moved hard into shore. You get sand in your pants every time, but it's well worth the trouble. The good ones are a little further out. But watch out for the jellyfish. They may be spineless, but man can they do a number on your vacation.
When a wave builds, it reaches a top, and then a bottom, as it falls. You can even do this experiment in a bath tub with a few good floating toys, watching them rise and fall to note the wave patterns or cycles (one complete rise and then fall is one wave cycle). So one Hertz in simply one wave cycle per second. One thousand cycles in a single second then means that the waves occurs with a much higher frequency (a thousand times more often than just one Hertz). Thus, the Hertz measures wave frequency, and waves may be of higher of lower frequencies, depending on just how many highs and lows they reach in one second.
The distance from the top of the wave to its bottom can vary. Some waves in EMR are taller than others (just like people). This is called the wave "amplitude." To change the size of the wave is called "modulation." When you modulate to a higher amplitude, the cycles get bigger for each one Hertz measured.
Now if we put this altogether, we can read the dial on your radio at home. Homeschoolers, man your radios. You will notice that each radio station is either listed as AM or else FM. The first means "Amplitude modulation." And the second refers to "Frequency modulation."
You will please notice that one of these frequency bands ("band" is short for "bandwidth") comes in Kilohertz (AM) and the other in (88 to 107) Megahertz (FM). The first is categorized as medium wavelength and the second as VHF (very high frequency). UHF is the next bump up, and many Television broadcasting systems use the latter.
So here are a few questions for today to have your homeschoolers answer:
1. Who was Heinrich Hertz and why do we care?
2. Which band -- AM or FM has the higher frequency?
3. What does the word "frequency" refer to?
4. What does AM stand for?
5. What does FM stand for?
6. If you have one -- perhaps cat country 103 -- name your favorite radio station, and be sure to note its frequency on the radio dial window.
7. Find two other stations. One should be classical. The other can be news. It matters little. Now look at the dial and answer, "which has the higher frequency, and by how many Hertz"?
Teachers may need to help younger students with the math. Fine. The point is to get across the significance of just what radio waves are, and how we measure them (and why radios have such weird markings on them which need our deciphering). Also please note that all EMR is a form of light, even though most of it we do not and cannot see with our eyes.
Radio broadcasting -- in AM or FM amounts to shining a big light in all directions (by way of a helpful picture for students). These radio waves start off as generated electricity, which is attenuated (tuned) to a very specific frequency (electrical patterns of just a certain number of wave cycles each second of transmission), and then transmitted across long distances through the air (atmosphere). AM travels farther and it can "bounce" or "skip" between the ground and the upper atmosphere (ionosphere), especially at night. FM tends to be what they call "line of sight" radio transmission. It cannot make it past the hills in most cases, supposing you live in a valley.
Then your radio picks up the sounds -- the wave patterns traveling your direction -- and converts these electrical impulses into sound vibrations on a speaker. So they travel as electrical patterns and interact with your radio to become sounds. And you hear the sounds by the speaker beating out a vibration in the air, which travels to your ears -- especially if the sound vibration is rock and roll.
When you turn the dial to escape the noisy used car commercials, you are listening for electrical patterns (waves) that occur at either a higher or else lower frequency.
Early broadcast radio (as we know it) was coming into its own as late as the early 1920's, though individual operators had been at it for about two decades by then. The sinking of the titanic, for instance, was relayed around the world by radio. The Pictorial History of Radio (Irving Settel, Citadel Press, New York, 1960, p. 31) has a picture of David Sarnoff, a young Nantucket Island (MA) wireless operator, who received news of the Titanic's sinking in 1912. He looks concerned.
Radio has been a powerful tool -- the internet before the internet -- throughout its brief history, and has proved especially crucial to the speedy transfer of news around the world, and has been of great importance in the military efforts of both world wars.
In terms of biblical theology, we have the radio as men submitted in part to the light of nature, submitting to and working to understand it rules and regulations, which the sciences make every effort to quantify when possible. While its ethical laws are just as much a part of the real world -- and the sciences would not be possible except that men obey them (i.e. you shall not bear false witness against your neighbor also means "do not falsify research," and only to the extent that scientists do this is real science possible).
Thus, by borrowing upon Christian capital in the light of nature, and written more clearly, comprehensively, and particularly in the written Word of God (The Bible), even pagans are able to make great strides for furthering the better control over our environment and enable a higher standard of living for all. Without giving proper credit to the God of the Bible for their ability so to do, however, this amounts only to ideological theft, not actual borrowing.
In short, it is because of the truth that the Word of God actually describes the world as we know it, and how it came to appear as it does (and how science is even possible) that you have a radio in your homes. Because the contrary to the Christian worldview is logically impossible, because it denies the necessary preconditions for the intelligibility of radio waves and broadcasting (which depend on laws, and our knowledge of laws upon logical induction), the radio sitting in your homes amounts to another significant proof that God is faithful, speaks only the truth, and gives good gifts to men, even when they (at times) might abuse those gifts (i.e. Howard Stern and shock jocks).
Jesus is the Lord of wisdom and knowledge (Col. 3:2), and the light of nature which testifies of His goodness and glory is coming in "loud and clear" on AM and FM.
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