Tag Archives: spectrum

I like radio.

In fact, I’m fascinated by the entire electromagnetic spectrum. Some consider it overreach to include direct current, like the electricity produced by a battery, but the AC electricity that powers most homes and offices definitely belongs. AC power oscillates, changing direction and then back again in some approximation of a sine wave.

For most AC power in America, this occurs 60 times per second. For years, this was to as 60 cycles per second until the late 1960s when it was changed to “Hertz” (Hz). This name change was to honor Heinrich Hertz, the German physicist who proved the existence of electromagnetic waves. Unfortunately, since Hertz had been dead since 1894, we was totally unaware of the honor. Perhaps the living physicists put their sliderules and partied to songs like John Mellencamp’s Hertz so Good. [I know the song was recorded at least ten years later, but physicists are not big partiers, so it may have taken them a while to pull things together.]

There are radio waves as low as 3 – 30 Hz, referred to as “Extremely Low Frequency,” but most of us don’t notice them until somewhere around the AM Broadcast band. The spectrum continues through shortwave, or high frequency (HF), very high frequency (VHF), which includes television*, FM radio, and aircraft communication. Ultra high frequency (UHF) include a number of other radio services, including cell phones. Microwaves, which are useful for radar and reheating leftovers start around 1 gigahertz (GHz) up to about 40 GHz, are next.

Going up. Next stop includes infrared through ultraviolet; smack dab in the middle is visible light. I think it’s safe to say that visible light was the first segment of the electromagnetic spectrum to which humans were aware. In fact, to many people, “spectrum” is what you see with a prism or in a rainbow.

Once you get above ultraviolet, there are X-rays and Gamma Rays, which have the ability to pass through matter and create an image that can be recorded. However, they also have an additional characteristic—they become ionizing, which means that they can change the electrical charges in matter. Ionizing radiation can cause cells to mutate. While comic book storylines propose that mutations result in superpowers, that’s just a STORYline. In actuality most mutations are bad; however, bad mutations can be useful, if applied to a confined area, such as a cancerous tumor. When the cancerous cells mutate, they often die.

To the best of my knowledge, the only thing above gamma rays are cosmic rays, but who knows what remains to be discovered.

Don’t touch that dial. I’ll be back soon with even more.

* I find it disappointing that many people do not know that with a simple indoor antenna your HD flatscreen smart television will receive the local television stations without cable. Picture quality is almost always better, because the signal doesn’t have to be compressed the way it is for cable. In addition, when television switched from analog to digital, they each ended up with three channels that fit in the same bandwidth as the old analog system. Since it’s “use it or lose it,” the other two channels tend to rely on shows that are far less expensive—so you may find Soupy Sales or Mr. Ed. Finally, since a smart TV connects to the internet through your wireless router, you can still access Netflix, Amazon, etc., all without the television being connected to the cable.