You know what’s great about a show like Pluribus? It’s that we don’t really know what’s going on, so we get to speculate. Just like real life! In case you haven’t seen this show, which just finished its first season, here’s a quick recap:
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—a hive mind with common goals, values, knowledge, everything. The show’s title comes from the old US motto “E pluribus unum”—out of many, one.
Only 13 people remain immune, including Carol Sturka, an ornery romance novelist who’s intent on keeping her individuality, against all efforts by the collective to absorb her. We don’t 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.
It has advantages. For instance, there’s no need to remember phone numbers. You can call any number and the same “person” answers. The downside is that they’re not really a person.
Anyway, if the radio theory is correct, how might this collective consciousness operate from a physics standpoint? Let’s investigate!
What’s a Radio Wave and How Do You Make It?
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).
Now, radio waves are electromagnetic (EM) waves. That means they consist of oscillating electric and magnetic fields. In other words, they’re 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.
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’s your radio wave.
But can a human body do this? Well … maybe? Our nervous systems are essentially electric circuits, though the “current” consists of charged ions, not electrons. Maybe the alien civilization figured out how to harness this.
How Far Can the Plurbs Communicate?
So if we’re 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, etc. It sounds like some kind of decentralized mesh network. But how far can one plurb transmit?
First, let’s estimate the total power output of the transmission—the amount of energy radiated per second. A person’s 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’s say 10 percent of it goes into radio transmission, so that’s 8 watts.
Let’s also assume that plurbs are “isotropic” 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), but the power per area, which we call intensity (I), declines. That means the power of a signal declines with distance (r). Knowing the surface area of a sphere, we can easily calculate intensity:
Finally, we need a minimum detection level. What’s the weakest signal that a plurb can receive? I’m just going to grab a value out of the air and say they can detect radio at an intensity of 1 microwatt per square meter.
So now, putting these two things together, we can solve for the maximum communication range, which is 798 meters (about half a mile). Oh sure, maybe they can detect much lower intensities, but we’d still be looking at a distance of less than 20 miles or so. Astronauts in orbit would be totally at loose ends. Even camping trips could be dicey.
Could You Hear the Plurb Radio Transmissions?
So if everyone around you is basically a radio tower, would you hear their communications? No, because we don’t hear radio waves. Remember, radio emissions are a type of light. But around 1900, humans invented radio receivers that turn radio waves into electric pulses, which then jiggle a magnetic speaker back and forth, creating ripples of air pressure. Those are sound waves.
At one point, another uninfected human scanning through the dial on a shortwave radio notices some activity on a particular frequency: 8,613 kHz. All others are silent. Could this be the channel for plurb-to-plurb communication? If we converted the radio waves to sound waves would we hear something?
Unfortunately no. Humans can only detect sounds from 20 Hz to 20 kHz, and this channel is way beyond that range. But wait! Then how do real-world radio stations send music to radios at even higher frequencies? I’m glad you asked, because this is pretty cool.
There are two basic tricks—our old AM and FM. AM stands for amplitude modulation. Amplitude is the height, or intensity, of a wave at its peak (or the depth at its trough). The idea is that you have some carrier wave frequency, which is what people turn their radio dial to. For example, the legendary Chicago station WLS, which brought rock ’n roll to Middle America in the early ’60s, was at 890 on the AM dial, so its carrier frequency was 890 kHz.
Then what you do is modulate the amplitude of that carrier wave, so that the changes in amplitude actually encode the audio signal. For a single tone, it might look something like this, where the blue squiggly line is the high-frequency carrier wave, and the red wave is the lower-frequency audio signal as decoded by your radio.
For FM radio, it’s not the amplitude of the carrier wave that changes but the frequency. It doesn’t look as cool, but here is a plot of a blue carrier wave with the resulting red audio signal.
Those are two of the ways that audio signals are carried over radio waves. But it doesn’t seem like these methods would work to connect the hive mind of plurbs, as they aren’t speaking through sound but rather something like a mesh Wi-Fi network. But wait! There’s another way to send data via radio waves: by using digital values.
Imagine that your radio signal changes from a value of 0 to 1 and back over a very short time interval. Basically you’re repeatedly turning the power on and off. You can turn this into a binary number where an amplitude of 1 is the binary value 1 and 0 is of course zero. These binary numbers can then be turned into any kind of data. I guess you could even share thoughts and feelings with the rest of the hive. Here’s what it would look like:
Now for the cool part. If the rate at which the values switch between 0 and 1 is less than 15 kHz, a normal human could hear this as some type of audio signal. So maybe the Plurbs are digital.
What About a Faraday Cage?
I have no idea where the show is going in season 2, but if Carol is looking for a way to de-plurb a human, like her “chaperone,” Zosia, I’d recommend a Faraday cage. What’s that, you ask? A Faraday cage is a metal container that prevents the detection of electromagnetic signals.
There are a few things to know. First, people say these containers block EM waves, but they don’t. What they do is produce another electromagnetic wave that cancels the first one. Recall that metals are electric conductors. That’s because they have electrons that aren’t bound to particular atoms and can move around freely.
When an EM wave encounters a metal, the electric part of the wave exerts a force on these electrons and causes them to accelerate. Oh hey! Remember, we said accelerating charges create EM waves? It turns out these induced EM waves have amplitudes that are opposite to the incident waves, so they mostly offset. It’s kind of the same idea as noise-canceling headphones.
Would it be hard to build Faraday cages to shut down the hive mind? Not at all. Even simple chicken wire would work. It turns out that a Faraday cage with holes works just fine, so long as the holes are much smaller than the wavelength of the incident wave. Well, like we said, radio waves are long. An 8.6-MHz signal would have a wavelength of 35 meters, so this would do the trick. Yep, you heard it here first: Expect chicken wire in season 2.
That’s all for now. And may we just add, we hope this article made you happy. All we want is for you to be happy …
The post How Does the Hive Mind Work in ‘Pluribus? appeared first on Wired.
