Seveneves - Страница 50

Her eyes opened as a thought came to her: maybe this was the source known as the Space Troll. That term had originated with Rufus, who had first mentioned it several days ago: Have you heard from the Space Troll yet? It was his name for a transmitter that he had begun picking up recently, and it matched what Dinah was hearing now.

She ejected herself from the bag, turned up the volume on the receiver, and listened while pulling on a T-shirt and some drawstring pants. The signal sounded as if it was coming in from a home-brew transmitter. The owner had a sketchy understanding of the practices and etiquette of the CW (Morse code — using) radio world. His dots and dashes were perfectly formed, and came rapidly, as much as proving that he was using a computer keyboard and an app that automatically converted keystrokes into Morse. He was sending out a lot of QRKs and QRNs, which were queries about the strength of his own signal and the degree to which it was being interfered with. So, he seemed a little insecure about the quality of his equipment.

According to Rufus, as soon as you started transmitting back to the Space Troll he would shoot back a spate of QRSes, meaning “please transmit more slowly,” further proof that he was a novice using a computer keyboard to form the groups, but not very good at deciphering what came back. He transmitted on one frequency only, which was the one that Rufus had, until a year ago, generally used to contact Dinah. This had become known to the Internet in the wake of a human interest story about the MacQuarie family, and so for a few weeks it had been damned near unusable as every CW ham on the planet had tried to use it to contact Dinah. Then word had gotten around that the MacQuaries père et fille weren’t using it anymore and it had gone pretty silent, except for a few people who apparently hadn’t gotten the memo, such as the Space Troll. Anyway, Rufus had gone back to monitoring that frequency again and Dinah was now doing likewise. She had not personally heard any transmissions from the Space Troll. This was not remarkable. Her antenna was nothing compared to the one that Rufus had installed above his mine, and her receiver was something out of a fifth-grade science project. Except when Izzy was passing over his meridian, she and Rufus would naturally “hear” different stations.

According to Rufus, having a conversation with the Space Troll required patience or a sense of humor. The fact that novice hams were screwing around on the radio, which would have driven Rufus into a spasm of righteous fury a few years ago, now just seemed like a sign of the times. Of course people were getting interested in amateur radio; the Internet was expected to go down as soon as the Hard Rain started. And of course many of them were novices.

When they finally did begin an intelligible conversation, Rufus would send QTH, which meant “where are you?” and would get back QET. This was an unofficial Q code, a sort of corny joke meaning “not on planet Earth.”

And that was why Rufus called this guy the Space Troll. Because, among other oddities, he didn’t have a call sign, or at least didn’t use one. The signal she was hearing now was QRA QET, repeated every few seconds; it meant, basically, “Hello, this is E.T., is anyone listening?”

Dinah generally kept the transmit side of her rig turned off when not in use. She turned it on now, but kept her hand well clear of the brass telegraph key. Lurking and listening were harmless, but as soon as she touched that thing, the Space Troll would hear an answering beep, and then she might never be rid of him. More likely, though, was that the Space Troll would give up after a while. Then she could transmit to Rufus, who’d be coming up over the horizon in a few minutes, and let him know that she too had heard from the mysterious “extraterrestrial.” It would be good for a laugh, and a few minutes’ distraction. Her father sounded like he could use some of both.

It had long since become obvious that he and a number of his mining industry friends had mounted a serious operation to prepare for an extended stay beneath the surface of the Earth. They were hardly the only ones to think that way; people were digging holes in the ground all over the world. Most of them would be dead within hours or days of the beginning of the Hard Rain. Constructing an underground complex that could sustain itself for thousands of years was an operation of which few, if any, organizations were capable. Most of those were governmental or military. But if any private group could do it, it was Rufus and his network. The sorts of questions he had been asking her for the last two years left nothing to the imagination. To the extent that the experts on Izzy knew anything about long-term sustainability of artificial ecosystems, Rufus now knew it too.

Distracted by thinking about Rufus and his mine, Dinah became aware that the Space Troll’s transmission had changed. Instead of the familiar QRA QET, it now began with QSO, which in this context meant “can you communicate with. .?” This was followed by an unfamiliar call sign, which she didn’t recognize as such because it was so long: a string of digits and letters that didn’t follow any of the standard conventions for radio call signs.

The third time this transmission was repeated, she wrote it down: twelve characters in all, a basically random assortment of digits and letters. But she did notice that all the letters were in the range A through F. Which was a strong hint that this was a number expressed in hexadecimal notation: a system typically used by computer programmers.

The fact that it had twelve digits was also a clue. The network chips used by almost all computer systems had unique addresses in that format: twelve hexadecimal digits.

And here was where Dinah got a weird feeling on the back of her neck, because the first few digits in that string looked familiar to her. Network interface chips were produced in large batches, with unique addresses assigned to each chip in sequence. So, just as all Fords rolling off the assembly line in a given week might have serial numbers beginning with the same few characters, all the network chips in a given batch would start with the same few hex digits. Some of Dinah’s chips were cheap off-the-shelf hardware made for terrestrial use, but she also had some rad-hard ones, which she hoarded in a shielded box in a drawer beneath her workstation.

She opened that drawer, pulled out that box, and took out a little green PC board, about the size of a stick of gum, with an assortment of chips mounted to it. Printed in white capital letters directly on the board was its MAC address. And its first half-dozen digits matched those in the transmission coming from the Space Troll.

She reached for the key and coded in QSO, meaning, in this context, “yes, I can communicate with. .” and then keyed in the full MAC address of the little board in her hand — different from the one in the original transmission. It was a way of saying, “no, I can’t communicate with the one you mentioned, but I can communicate with this other one.”

QSB, came the answer back. “Your signals are fading.” Then QTX 46, which she guessed meant something like “Will you be available on this frequency forty-six minutes from now?” As anyone on Izzy would understand, this meant “I will call you back when you have orbited around to the other side of the planet.”

QTX 46, she answered back. “Yes.”

They were passing over the terminator, currently dividing the Pacific into a day side and a night side.

WHO THE HELL ARE YOU TALKING TO?

This was a transmission from Rufus, loud and clear. She looked out the window to see the West Coast of North America creeping over the horizon toward them, identifiable as a pattern of lights delineating the conurbations of the Fraser Delta, Puget Sound, the Columbia River, San Francisco Bay. Which meant that Alaska had line of sight to Izzy.

“Knock knock!” came the voice of Dubois Harris through the curtain. He’d been waiting there a long time.

“Come in,” Dinah said, and keyed back a brief transmission to Rufus making a joke about the Space Troll and telling him she would be in touch later. She checked the world clock app on her computer screen. It was shortly before dot 7, therefore 7:00 A.M. in London, therefore ten in the evening for Rufus in Alaska.

A somewhat distracted and scattered conversation followed, Dinah trying to maintain a train of thought with Doob while fielding sporadic, peremptory interruptions from Rufus. “Something kinda weird just happened on the radio,” she said. “Do you want a drink? It’s evening for you, right?”

“I pretty much always want one,” Doob said. “Let’s not worry about it. What’s up?”

Dinah related the story. Doob looked distracted at first, perhaps because of all the ham radio jargon, but focused when she showed him the MAC addresses.

“The simplest explanation,” he pointed out, “is that it’s a troll, just messing with you.”

“But how would a troll know those MAC addresses? We don’t give those out — we don’t want our robots getting hacked from the ground.”

“The PR people have come through here, haven’t they? Taking pictures of you and your robot lab. Mightn’t it be the case that a picture got snapped when you had that box open, and some of those PC boards visible?”

“There’s no gravity in here, Doob. I can’t leave things lying around on my desk.”

“Because,” Doob said, “obviously what’s going on here is that someone wants to talk to you through a private channel—”