Kirk Vandermeer was a connoisseur of aged food. At first I thought he might be a nut-job survivalist preparing for the next flood. He explained that an ex-girlfriend who worked at the Human Nutrition Lab had turned him on to food that was past its sell-by date. The girlfriend had dumped him, which was why he lived out of his office, and he decided to conduct his own culinary experiments.

"The flavor evolves," he said. "Like very slow cooking. Just avoid botulism."

Most of his stock was relatively fresh, bought from Hugo's or the Walmart discount aisles. Some of the older tins had gone quite pungent, becoming an acquired taste or perhaps a test of courage. My dad had talked fondly of surstrmming, fermented herring, from his trip back to Sweden. I miss the tuna and sardines though.

We ate, slept, and sat holed up in Witmer Hall for the second day. Kirk had opened his undergrad physics text on the desk. I remember the bright yellow USED sticker on the red binding. I reread Leiber's Swords Against Wizardry since it was lying around. But no one came for us.

"I think I should get my stuff," I said later that day, feeling antsy.

Kirk didn't look up from the textbook. "They probably won't be after you."

"Yeah. Must have better things to do," I said. "Like looking for a lunatic with a sword . . ."

Kirk slammed the book closed. "Stay away from the supermarkets. Those will be getting ugly."

So I hiked from the loading dock into the crazy changed world toward the graduate apartments. Hand-printed signs warned people to stay home and not enter main campus grounds by order of the provost. The university cops were taking their duties to heart. So I skirted into the residential neighborhood to trek west. For all the strangeness, it was quiet as dusk settled. Most folks hunkered inside, staying warm. The lucky houses had wood smoke drifting from chimneys or old fuel oil furnaces that didn't need electricity. The frats and sororities all had fireplaces. I crossed the English Coulee near the deserted dorms. Some pedestrians, wrapped more tightly than the previous days, waved at me in anonymity provided by scarves and knit caps. I kept my hood low. Overall there was a stoic sense of wait and see. Hadn't we just survived a major catastrophe? At least the water wasn't rising and nothing had burned down. The government or someone else would be here soon to sort things out. Sure. You betcha.

DAY 3.

GRADUATE HOUSING AND WITMER HALL, UND.

I returned the next morning with a duffel bag and large rucksack full of everything I could scrounge that might be useful. That meant my stereo system, television, and computer were left behind in the furnished apartment. I retrieved camping gear, my kitchen cutlery, blankets and towels, a bottle of vodka, and the other contents of my freezer. I also grabbed my Redwing work boots, my articulated knee brace, and my pouch of gaming dice. Even a valid excuse to not write on the dissertation made me feel guilty.

I had cut across campus, but everyone else seemed to obey the warning signs. We were a law-abiding people, mostly. I didn't see anyone else among the redbrick buildings, but carried a camp hatchet just in case. I banged on the steel loading dock door to have Kirk let me in. I dumped my load in his office.

"I'm working through Halliday and Resnick."

At his desk, Kirk flipped the aging beige pages. He looked haggard, dark shadows under his eyes and dark stubble on his chin.

"So far dynamics seems to be unchanged. Gravitation, too."

"Did you do the ball drop?"

I hated that lab exercise as a TA for Physics I. The spring-loaded apparatus that launched a ball bearing horizontally and dropped another one straight down must have been sixty years old. If I never had to do that experiment again, I'd be perfectly happy.

"Raided the teaching lab and did pendulum measurements. The timing works out."

Kirk held up a self-winding Seiko dive watch, fat against his slender wrist. "Also looked at the orbits of Mars and Venus. Took the telescope to the roof while you were gone last night. Good viewing without sodium streetlights. But it might be a while before anything changes at that scale."

"Very systematic." I blinked at the morning sunlight that was warming the cold room. "I wonder if the sun is still working."

"Fusion? That's beyond the scope of this course." Kirk smiled and his bloodshot eyes glittered with a strange enthusiasm. "But I'll check the spectral lines if I can locate the correct filters."

"It'll be years before we see dimming." I remember solving the stat-mech problems to determine how long a photon took to escape from the core to the chromosphere. Eight years or something. Then it would really get cold for everyone. No more North Dakota bragging rights.

Kirk nodded. "Now's our chance to make a real impact. To understand what's happened."

I found a cheap solar-powered calculator on the desk and picked it up on the off chance it might work. It didn't. I tossed the useless calculator onto the desk.

"Calculators on the fritz . . . what did they use before? Slide rules and log tables? Isn't that what Dr. Soonpa uses?"

"We chose this path," Kirk admonished. "We chose understanding the universe over an easy life. If we hadn't, we'd be down on South Padre Island right now with the rest of the spring break partiers, getting drunk."

"And meeting women."

"Drunken women," he said with disdain.

"Your point?" I leered down at him and he finally laughed.

DAY 4.

WITMER HALL.

"First we should check Boyle's Law."

Kirk led me to the roof through the service stairway. He had his katana tucked into his belt.

"Which one is that again?" I asked, a bit sheepish. "An ideal gas?"

"The product of pressure and volume of a gas remain constant," Kirk said. "Remember pushing the Duster? There was no compression from the engine. Strange, don't you think?"

We stepped onto the flat asphalt and tar-lined roof. It was a sunny day and well into the mid-forties, so the remaining snow created puddles. I noticed a dusty Weber grill with a broken wheel and beat-up lawn furniture in an empty patch of roof next to the air handling enclosure. The department's eight-inch Schmidt-Cassegrain telescope was on a tripod next to the chaise longue. The piston and cylinder experiment for demonstrating hydraulics to the education majors sat by the grill.

"What do you need me for?" I asked.

"You need to confirm my methods and results, so I know I'm not going schizoid."

Kirk set his sword on the chair and knelt by the hydraulic experiment: two clear Plexiglas cylinders, one half the diameter of the other. Fancy plungers with gaskets and handle grips were inserted in the cylinders and tubing ran between them. Two dial pressure gauges poked out the side of both. He pressed gently on the fat plunger and the skinny plunger rose up slowly as air transferred through the connecting tube. The needles on the gauges barely registered.

"Now you try. Give it a real shove."

"I'll probably break it." I leaned over and gripped the plunger. Then I shoved it down with all my strength. A momentary resistance vanished and the volume in the fat cylinder decreased without corresponding movement from the skinny plunger.

"There must be a leak."

We repeated the experiment several times. I couldn't find the leak. The rubber gaskets were sealed. But sudden pressure change much above one atmosphere seemed to bleed off. For the first time in a long time, I felt scared, because I really didn't understand.

"How did this happen?"

"It's not the overall pressure. It's the delta, the rate of change of pressure. I wonder if there would be any sonic booms?"

"No, not just the experiment. Everything. How did this happen? Why doesn't anything work? What changed?"

"One question at a time." Kirk, seeing my face, switched topic.

He glanced up at the large water tower to the south, past the geology building. "We should collect fresh water while there's still pressure in the pipes. We might be here a while."

"How long? I'm worried about my folks," I said.

That was mostly true. My dad would be fine, except come deer season if guns really weren't working. My mom would have a harder time if she didn't get her soaps.

"Are you going to walk forty miles with that knee?" Kirk asked, mockingly.

His mother was in Houston, fourteen hundred miles away.

I shut up.

DAY 5.

WITMER HALL.

The next day on the roof, we got a metal piston in a fitted barrel, once used to compress ceramic powder samples for Dr. Soonpa, and a propane torch for brazing pipe fittings. The small green propane cylinder still held gas, supporting the change in pressure hypothesis. The piston didn't have a gauge, so we piled graduated weights on the top. We heated the piston with a few millimeters of water trapped inside. Kirk removed mass after mass, waiting for the piston to move. The temperature was high, above boiling, but no expansion.

Kirk took the last ten-gram weight off the piston top. "A tea kettle might whistle, but not much else. Good-bye Industrial Revolution."

"Is mass no longer conserved?"

I quenched the small torch. PV = nRT was a law. Had Avogadro's number changed with temperature? How could it? It was just a number and supposed to be constant.

As the cylinder cooled, the piston slowly sucked down. Kirk pulled the piston out with a vacuum pop as it released.

"It's as if all the hot molecules just escaped."

We repeated the same experiment several times, varying the added water, the heating time, everything we could think of. The same results, a dramatically irreversible process.

"Maybe it's a bubble universe, a brane, that's enveloped our region of space," I proposed.

Branes were the big thing in theoretical physics. A separation between universes had slipped somehow.

Kirk scoffed.

"A brane wouldn't be permeable to physical matter. Otherwise there would be mass diffusion and no separation of universes."

"Okay, maybe another fundamental force has frozen out of a cooling universe? Like the electro-weak did."

"Doesn't match with observables and it's not testable." Kirk rubbed his moustache with a finger. "It's like Maxwell's demon has taken control."

"And Maxwell's demon is testable?" I asked.

Maxwell's demon was a thought experiment. In the 1800s, James Clerk Maxwell proposed an imp gatekeeper between two containers that would allow only hot molecules from one container to the next. Eventually all the hot molecules would be in the same side, circumventing the randomizing chaos of entropy. I forget what Maxwell's point was, but there was no real demon.

Kirk just rubbed his moustache and gave a sly smile. "You'll see."

I wanted to smack the smug right off Kirk's face.

DAY 6.

WITMER AND STARCHER HALLS.

The Simplot plant sent its reek of rotting potatoes as the early thaw settled in. I could barely stand to be on the roof with the wind coming from the north, but the warm sunshine was too enticing. I scratched my itchy stubble and then the ruff of hair on the back of my head. I had stopped shaving. The last thing I needed was a nick to go septic and then die from the infection.

The fires in town started the previous nights. Smoke and flames from various neighborhoods near the river on the Minnesota side. There was no one to put them out. One week without power or gasoline or guns and civilization was starting to crumble. But when people started to feel hungry and frightened and abandoned, what could be expected? I guess I was lucky, having fallen in with Kirk. We had begun rationing the food.

"We can't stay up here forever." I leaned over the Weber grill. The last of my frozen hamburger patties stored in the disappearing snow sizzled on the grate. I flipped them with Kirk's long Williams-Sonoma grilling spatula with serrated edges and solid steel handle. I liked the heft of the spatula, but Kirk complained about it being too heavy. So I cooked. I put the lid on the grill to dampen the smoke.