"All right, all right, time and space have a discrete atomic structure at the Planck scale. So what?"
Rusk sighed. The conversation had taken on an interminable plod, and her coffee, barely potable to begin with, had gotten cold. She sipped at it miserably, hoping Shairp would notice. He didn't.
"So time isn't a vacuum, it's a physical medium with attendant physical laws, and a particle traveling through time is subject to those laws." He was grinding his teeth. "But what kind of particle? What if the local physics of time were determined by the kind of particle traveling through them?
"Think of the particles as passengers. Some passengers get first class, all the amenities; others get steerage, because it's what they can afford. It's all the same ship, but they travel differently because they're treated differently.
"The current quantum theory of gravity suggests a revision, if not a revival, of the æther, but a blanket medium doesn't explain the behavior of particles at the Planck scale unless the physics react according to the class of the passenger."
"Pass the pot." Rusk held out her hand. Shairp leaned back in his folding chair to grab the carafe. "I realize you're trying to make this easy on me, but I'm not a physicist. I don't even understand why you're trying to explain this to me, unless it's some ham-handed attempt at making a pass." She poured herself a warm-up and gave the carafe back. "Is that the idea? Club me over the head with your brains and take me back to your cave? Because it's not working."
"I'm trying to tell you Tipler lied to me, to detour my line of research so he could get funding for his own. The cylinder was our project. Ours!" Shairp pulled a pack of Chesterfields from the carton in the mini fridge. "Someone in defense got to him."
Rusk stood and stretched, her sweater riding up. "Leave me out of your office gossip. I'm here to make sure Dr. Tipler gets the proof he needs for appropriations. More money means more research, and that means you, too."
Shairp held the unlit cigarette in the corner of his mouth with a disbelieving grimace. "I say some idiot wants to weaponize time travel and you roll your eyes."
Rusk scratched her stomach. "Lab coats are patriots too."
"Unbelievable. Unfuckingbelieveable." He took the cigarette from his mouth and ran his fingers through his hair, his head down.
Rusk looked at him, seeming to weigh something, then sat back down. "So what was your point about the particles?"
Shairp didn't look at her. "He said we couldn't aim. I thought we could, depending on the type of particle. I wanted to try projecting a continuous stream of information at a specific point in spacetime as a kind of probe. My idea was to hook the projection up to a quantum computer, see if the stream went both ways, if maybe the computer could read the stream and interact with the information received."
The suggestion seem to intrigue Rusk. "A time traveler AI."
Shairp shook his head. "But he said it was impossible. Wanted to bombard a region and see if he could induce a historical pattern instead. Which sounded reasonable, at first. Only now it resembles a bombing campaign." He waved at the map of the Kiev Oblast on the wall. Red strings ran from pushpins in Lelyov, Chernobyl, and Pripyat, leading off into the layers of paper surrounding the map; movie stills of 'Stalker' next to photographs of Andrei Tarkovsky sick in bed, the radiation index of Pripyat and chapter excerpts from 'Roadside Picnic' by Boris and Arkady Strugatsky, the unpublicized nuclear disaster in Chelyabinsk in 1957 and the Zone of Exclusion now known as Chernobyl.
Shairp looked up at Rusk, his eyes wet. "I think I helped win the Cold War."