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Radio Waves

From wireless telegraphs to 5G data, the modern world runs on radio waves.

In the electromagnetic spectrum, radio waves are the lowest frequency & longest wave length waves available. The name “radio” doesn’t mean the waves are just for radios, it comes from the idea to “radiate energy” and the waves are used for lots of things. Wireless telegraphs, TV broadcasts, walkie talkies, radar, GPS, wireless routers, bluetooth, your mobile phone data – it’s all radio waves.

The existence of radio waves were proposed in 1867 by James Maxwell, but it took twenty years until 1887 for Heinrich Hertz to first demonstrate them (and because of this the hertz unit of measurement was named for him). The potential of radio waves was first realized by Guglielmo Marconi who used them to create wireless telegraphs. Marconi’s invention allowed people to send messages wirelessly through the air (which won him the 1909 Nobel Prize in physics). His invention is also one half of the very good Erik Larson book Thunderstruck.

Radio waves sit on the far end of the electromagnetic spectrum.

The Wave

We can send & receive data through the air thanks to transmitters & receivers. A transmitter antenna will send out a radio wave, modifying the wave form as need be. Then a receiver antenna will take the wave and process it as information. In the modern world most of that information is converted into binary ones & zeros as data.

Rather than sending out a consistent steady wave (which wouldn’t be very useful), transmitters modulate waves in various ways. You can modulate a wave’s amplitude as well as its frequency (which, incidentally, is why we have AM and FM radio – amplitude modulation and frequency modulation). You can also change where you begin & end a wave’s phase. This can create thousands of combinations, each of which can mean combinations of binary data. Using this complicated system of changing wave types we can have lots of devices sending & receiving information in relatively close proximity to one another. This is perhaps best demonstrated in the prolific use of mobile phones.

Cellular data (and the 5G boogeyman)

Mobile phones interact with antennas to send & receive data using radio waves. Each antenna covers a certain territory (a cell), but they are all working together (a network) – hence “cellular network”. Early mobile car phones had very few antenna to interact with so, once you left one’s area, you lost service. As mobile phones became popular in the 1990s more complex cellular networks with many towers were created.

5G is the fifth generation of the technology that runs these cellular networks. The challenge for 5G is to give even more devices even faster information. Part of how it does this is through an increase in the number of antennas. It also uses a wider range of wave frequencies. 5G uses radio waves but it also uses higher frequency microwaves (millimeter waves) to send more information, faster, across short distances. To do this the millimeter waves use smaller network cells, with more antennas, closer to the ground than the typical radio waves use.

As 5G was arrived out so too did the conspiracy theories.

The rollout of 5G began in 2019 and with it came the conspiracy theories. Some people claimed 5G weakens our immune systems leaving us vulnerable to viruses (such as COVID-19). Others claimed Covid was caused by 5G waves or that the Covid vaccines contained secret microchips that would be controlled by 5G. There are also conspiracy theories that 5G causes cancer and specifically because of the millimeter microwaves. None of this is true.

The waves used in 5G are non-ionizing waves (meaning they do not remove electrons from atoms or damage human cells). Ionizing radiation is found on the other end of the electromagnetic spectrum beyond visible light. Ultraviolet, X-rays, and gamma rays will damage your cells, radio waves and microwaves do not. The waves used in 5G can’t penetrate your skin and no credible study has found them to be dangerous to humans. Alcoholic drinks and processed meats have higher likelihoods of causing cancer than 5G.

A really great explanation of how modern cellular networks operate.

A crash-course on 5G data.

Sea Monsters on Maps

The rise and fall of map sea monsters

Between the Middle Ages and the Renaissance exotic sea creatures were sometimes included in the watery regions of world maps. Many of the monsters were hybrid creatures – the top half was some land animal combined with the bottom half of a fish. This was in keeping with a long held idea from the ancient Greeks that anything on land had an aquatic counterpart in the sea. Sea rams, sea elephants, sea pigs, sea humans were all real possibilities. Over the centuries as explorers and traders traveled further abroad, they brought back tales of other strange creatures from around the oceans. Some of these beasts turned out to be real animals (such as whales) but others were just mistaken identity or entirely fictional stories. Either way, they ended up in maps.

Two kinds of maps

Generally speaking there were two kinds of maps in use during the Middle Ages and the Renaissance: nautical maps and general maps of the world (mappae mundi). Nautical maps were more utilitarian and typically did not include sea monsters as it cost extra to include them and the illustrations were generally not very useful when sailing a ship. As such, most of the maps that included sea monsters were world maps for home use to learn about the world beyond your home town/city and the possible dangers at the borders of our knowledge.

Sea monsters were frequently found at the edges of the map which showed that the world beyond what had been mapped was unknown & possibly dangerous. They illustrated in a real sense the wonders of the world. They were also a way to hide gaps in the cartographer’s knowledge by taking up space with big animal illustrations (rather than big empty areas). Sea monsters also helped the marketability of these maps which was good for business.

A detail of a 1587 map of Iceland by Abraham Ortelius

A detail from the 1539 *Carta Marina* by Olaus Magnus

Another detail from the 1539 *Carta Marina* by Olaus Magnus

Eventually, the more sailors traveled the oceans the further out on maps the sea monsters were pushed. By the end of the 16th century much more of the globe had been explored & documented. The scientific knowledge of the flora & fauna of the world had grown and started to disprove some of these sea monsters. The more we learned, the unknown corners of the world in which to place these fantastical monsters eventually disappeared. By the 17th century instead of sea monsters on the margins there were illustrations of whales, other real life animals, or ships. This left us with more accurate, if a bit less interesting, maps of the seas.

Added info: Some sea monsters were included with ulterior motives. It is believed that Olaus Magnus’s 1539 map of Scandinavia included sea monsters in the Norwegian Sea to scare away potential foreign fisherman, and thereby protect the waters for the local fishing industry. A very Scooby Doo villain plan.

For more sea monsters, check out Chet Van Duzer’s Sea Monsters on Medieval and Renaissance Maps.