\n<\/p>\n
You know what\u2019s<\/span> great about a show like Pluribus<\/em>? It\u2019s that we don\u2019t really know what\u2019s going on, so we get to speculate. Just like real life! In case you haven\u2019t seen this show, which just finished its first season, here\u2019s a quick recap:<\/p>\n A radio transmission arrives from a planet 600 light-years away, and the message turns out to be RNA code for an alien virus. Some fool synthesizes it, and it infects almost everyone on Earth, causing them to act as one entity\u2014a hive mind with common goals, values, knowledge, everything. The show\u2019s title comes from the old US motto \u201cE pluribus unum\u201d\u2014out of many, one.<\/p>\n Only 13 people remain immune, including Carol Sturka, an ornery romance novelist who\u2019s intent on keeping her individuality, against all efforts by the collective to absorb her. We don\u2019t know for sure how the hive mind works, but it seems that the plurbs (the infected people) commune with each other unconsciously through radio waves. Talk to one of them and you talk to all of them.<\/p>\n It has advantages. For instance, there\u2019s no need to remember phone numbers. You can call any number and the same \u201cperson\u201d answers. The downside is that they\u2019re not really a person.<\/p>\n Anyway, if the radio theory is correct, how might this collective consciousness operate from a physics standpoint? Let\u2019s investigate!<\/p>\n In case you forgot (or never knew), we used to listen to music on devices called radios. There were two types of stations: AM radio with broadcast frequencies from 535 to 1,700 kilohertz (kHZ) and FM radio from 88 to 108 megahertz (MHz).<\/p>\n Now, radio waves are electromagnetic (EM) waves. That means they consist of oscillating electric and magnetic fields. In other words, they\u2019re a type of light, along with visible light, infrared, microwaves, x-rays, and so on, which differ only in frequency and wavelength. Radio waves are on one end of the EM spectrum, with the lowest frequencies and longest wavelengths. That makes them ideal for long-range communication.<\/p>\n Fine. But how do you make a radio wave? Since EM waves use changing electric fields, you can induce a wave by accelerating an electric charge. The radio station that you no longer listen to has a very large electric wire called an antenna. Electric current goes up and down the wire accelerating electrons. There\u2019s your radio wave.<\/p>\n But can a human body do this? Well \u2026 maybe? Our nervous systems are essentially electric circuits, though the \u201ccurrent\u201d consists of charged ions, not electrons. Maybe the alien civilization figured out how to harness this.<\/p>\n So if we\u2019re right, each former human is now essentially a radio transmitter and receiver. One plurb sends out a signal that is detected by others, who pass it on to others, and so on. It sounds like some kind of decentralized mesh network. But how far can one plurb transmit?<\/p>\n First, let\u2019s estimate the total power output of the transmission\u2014the amount of energy radiated per second. A person\u2019s metabolic system produces about 80 watts of power at rest, and this is used for basic functions like breathing, pumping blood, digesting food, and so on. For a plurb, let\u2019s say 10 percent of it goes into radio transmission, so that\u2019s 8 watts.<\/p>\n Let\u2019s also assume that plurbs are \u201cisotropic\u201d transmitters, meaning they emit energy in all directions equally, like in the old RKO Radio Pictures logo. As it radiates outward, that power is spread over an expanding sphere. Total power remains the same as at the source (P0<\/sub><\/strong>), but the power per area, which we call intensity<\/em> (I<\/strong>), declines. That means the power of a signal declines with distance (r). Knowing the surface area of a sphere, we can easily calculate intensity:<\/p>\n<\/div>\nWhat\u2019s a Radio Wave, and How Do You Make It?<\/h2>\n
How Far Can the Plurbs Communicate?<\/h2>\n