“Right. A deeply submerged submarine. ELF waves are very long, and therefore the transmissions are very slow. But they can penetrate anything. Thus, their only practical use is to contact submerged submarines that can’t be contacted by normal means.”
“Right. Can ELF waves screw up my cell phone?”
He chuckled again. “No. These waves are so far off the chart, they wouldn’t interfere with any other radio waves, microwaves, or anything we currently use on a day-to-day basis.”
Kate said to him, “So, these ELF transmissions are letter codes.”
“Correct.”
“And they can only be picked up by submarines?”
“Well, they can be picked up by anyone with an ELF receiver. But unless you know the code, which changes often, it would be meaningless. All you’d hear would be transmitted pulses, which are the letters in encrypted form. From what I understand, a three-letter code is the most common.”
Kate asked, “And that tells the people on the sub everything they need to know?”
“Usually, it just tells them that they need to establish normal radio communication.” He explained, “An ELF transmission is called a bell ringer. It’s to alert a submarine commander that a situation is developing, and he needs to do something to get in touch. But sometimes the three-letter code is self-explanatory. For instance, it could mean ‘Surface’ or ‘Proceed to location A,’ which is a predesignated grid coordinate. Follow?”
Kate replied, “I think so.”
“You can’t use ELF for long, chatty messages. It can take half an hour for the signal to reach the sub. And I should point out that the submarine can’t send an ELF signal or message. It can only receive one.”
I said, “Like, ‘Don’t call us, we’ll call you.’”
“Correct.”
Kate asked, “Why can’t a sub send an ELF message?”
“The transmitter and antenna need to be on land. I can explain that later. But meanwhile, if a submarine needs to reply to this one-way message, or if the sub commander needs more data, then the sub would need to get near an underwater hydro-acoustic station-if there’s time-or would need to get near the surface and send up a communication buoy to reply or get more information via VLF, or these days via satellite, or other means.”
I inquired, “What do you mean, ‘If there’s time’?”
“Well, for instance, if the other side has already launched ICBMs against us, then there’s no time to establish normal radio communication, because by the time the sub receives an ELF signal, which, as I said, can take thirty minutes, all forms of communication in the U.S. have already been vaporized, and the atomic war is all but over.” He explained, “If that’s what’s happening on the surface, then the submarines receive the last and only ELF message they will ever get-a three-letter code that means… well, ‘Fire away.’”
Kate looked a bit worried, but Commander Nasseff had good news. “ELF waves are not affected by thermonuclear explosions.”
I said, “Thank God for that. But let me ask you-what if the guy sending the atomic-launch code sends the wrong letters? Like, he means to type in XYZ, which means ‘lunch break,’ but he screws up and types in XYV, which means ‘Launch your nukes’?”
Commander Nasseff replied with a little amusement in his voice, “That can’t happen.”
“Why not? Look at the e-mails you get.”
“I mean,” he explained patiently, “there are safeguards, and all orders to launch need to be verified.”
“By who? By the time the sub gets the order a half hour after it’s sent, as you just said, there’s no one left to verify anything.”
“This is true. But rest assured that can’t happen.”
“Why not? I mean, you’re talking about three measly letters. Like those monkeys typing King Lear.”
“For your information, a three-letter code will yield 17,576 possible letter combinations in the English language alphabet. The Russian alphabet, with thirty-three letters, will yield 35,937 different codes.” He explained, “Thirty-three, times thirty-three, times thirty-three equals 35,937. So, what are the chances that a naval radio operator could mistakenly send the code to the submarine fleet to launch their missiles at their predesignated targets?”
Considering the fact that if something could go wrong, it would, I thought the chances seemed pretty good. I said, “Maybe we should use the Russian alphabet. You know? More letters. Less chance of starting a nuclear war by accident.”
He found that funny and said to me, “Actually, if you want to know more than you need to know, whoever transmits the message needs to send it as a repeating, error-correcting code, followed by another three-letter verification code. No one can screw that up by accident.”
I asked the obvious and more pertinent question, “How about on purpose? Like some nut who wants to start an atomic war?”
He thought about that and replied, “As I said, the codes change frequently.”
“But if someone had the code-”
“I can’t imagine that any unauthorized person could get the initiating codes and the verification codes, plus getting the current encrypting protocols. Also, the computer encryption software is sophisticated beyond anything you can imagine.” He added, “You shouldn’t worry about things like that.”
I thought of Bain Madox and wanted to say to Commander Nasseff, “You should.”
Kate asked, “And there is no other possible application for this means of communication? I mean, no other use for ELF waves other than military?”
“Well, that was true. But I’ve heard that since the end of the Cold War, the Russian ELF transmitter has been used for geophysical research. Swords into plowshares.” He explained, “The ELF waves can penetrate deep into the Earth’s crust and can therefore be used for electromagnetic sounding and monitoring. For instance, seismic research. Earthquake predictions and things of that sort. But I don’t know much about that.”
Kate said, “So, theoretically, someone outside the military could send an ELF transmission. Like scientists.”
“Theoretically, but there are only three ELF transmitters in the whole world, and they’re all owned by the military.” He added, “We have two, they have the other.”
Kate thought about that, then asked, “I see… but theoretically… is this top secret, or is it unlawful to build such a transmitter?”
“I don’t know about unlawful, and there’s nothing top secret about the technology or the physics behind it. The actual problem is that an ELF transmitting station can be expensive to build, and it has no practical application outside of contacting submarines or, recently, in limited geophysical research.”
I didn’t think that Bain Madox was interested in geophysical research, but he might be, so I asked, “Can these ELF waves detect oil deposits?”
“I would think so.”
“So, geologists could use them to find oil.”
“Theoretically, but ELF stations can only be built in a few places in the world.”
Kate inquired, “Why is that?”
“Well, now that we’re talking about the actual transmitter itself, let me explain that. You asked why a submarine can’t send an ELF message. One reason is that an ELF transmitter can only be located on land in an area that has very low ground conductivity. And there are only a few places on the planet where this geological condition exists.”
I asked, of course, “And where is that?”
“Well, one is where the Russian transmitter, called Zevs, is located-northwest of Murmansk, up near the Arctic Circle. Another place where these necessary conditions exist is here in the U.S. Our two transmitters are the Wisconsin Transmitter Facility-WTF-and the Michigan Transmitter Facility-MTF, and they both share the same geological formation called the Laurentian Shield.”
“And that’s it?”
“Well, that’s it for existing ELF transmitters. But the Brits almost built one during the Cold War for the Royal Navy at a suitable location called Glengarry Forest in Scotland. But for a variety of political and practical reasons, the idea was scrapped.”