The Walls of the Universe

by Paul Melko

  “This is a lot more fun than those video games,” Grace said, referring to the ghastly Pong-like Electrux game in the Student Union.

  “The prototype just proves that the ideas work,” John said. “Now, we have to ramp it up, so to speak.”

  “That was bad,” Grace said.

  “Grace,” John said. “I want you to build a flipper prototype. When the player presses a button, the flipper will move, about thirty degrees from here to here.” He showed her the angles with his hands. “Use a solenoid. It needs to be strong enough to launch a steel ball bearing two meters up an incline plane of ten degrees.

  “Henry, I want you to build a prototype bumper. When a ball hits a bumper, it triggers a solenoid that bounces the ball back in the opposite direction.” He drew a diagram on the chalkboard, a triangle. “The first one should be about this size, but we’ll want to be able to make any shape of bumper. I’m going to work on sound, operation, and scoring. We’ll worry about flags and other crap later.”

  “Flags?” Grace asked.

  “More ways to score points.”

  “How can you know so much about these things when I’ve never even heard of them?” Grace said.

  “I spent a lot of time playing pinball… in Vegas,” John said.

  Grace had a flipper done first, and John suspected that she had worked on it when she should have been working on her lab reports. They were all three working in the lab after dinner two days later when Grace called John over. She showed him a small red button mechanism that she held in her hand. Wires passed from it to a block of wood, where one of John’s carved wooden flippers was mounted.

  “Watch this,” she said, and pressed the button. The flipper spasmed, the block of wood jumping.

  “Wow. Kinda powerful.”

  “Yeah,” she said, smiling at the thing. She made it hop a half-dozen times.

  “Let me try,” John said. He took the button from her and pressed it, holding it down. The flipper jumped and came back to the starting position. “Is there any way to keep the flipper up while the button is depressed?”

  Grace frowned. “That wasn’t in your list of requirements, John.”

  “I’m sorry. I forgot that one. But I like this. It’s exactly what I had in mind otherwise.”

  When John looked over Henry’s shoulder to check his work, he pointedly stopped what he was doing.

  “You may want to tighten that…”

  “It’s not ready yet.”

  John shrugged and let him have his peace. Managing a team was tough work, he decided, so he returned to tracking down a quarter box and designing an underlaying physical and electrical framework. He could have used Casey’s help, but she had begged off again.

  Henry was a mechanical engineer. He’d worked in his father’s auto garage as a kid, and knew how to weld. He built a table in no time, one that opened up as John suggested so that they could easily work with the electronics underneath the table.

  “Every solenoid that clicks may need to trigger a sound and a score,” John explained.

  They built a row of bells and buzzers into the base of the thing, and a backboard that housed a small analog scoreboard. Within a week their prototype could rack up a score and emit sound when they touched various triggers on the play field.

  Two weeks later, Henry put two of Grace’s flippers into the play field and they played for an hour before the right flipper’s solenoid burned out.

  “Crappy equipment,” Grace said, pulling the mechanism out and poking at it with a soldering iron. “It worked for a while. Not bad, I say.”

  “Neat,” Henry said. “I’ll have a bumper for tomorrow. We can put it here.” He pointed to a spot next to the flipper. A wooden bumper sat there now.

  “This is coming along very nicely,” John said. “We need a ball return mechanism.” When the ball fell out the bottom of the play field, it landed in a cup. Players manually picked it up and put in the launch lane.

  Henry nodded. “I’ve got some ideas on that.”

  Grace said, “Why don’t we have two boards back-to-back for double play?”

  “What?”

  “Pinball is fun, for one person. Why not put two boards together, with a player at each end, with the goal of trying to get the ball in the other person’s drop area?”

  “Mechanical soccer,” Henry said. “Neat.”

  “That’s not traditional pinball,” John said.

  “So?” Grace said. “We don’t have to build a traditional pinball machine, do we?”

  John nodded. “I guess we don’t. We’re doing this for fun.”

  “All right.”

  The next night, they tore off the backboard and built another play field. They decreased the slope a bit.

  “You know,” Grace said, “it would be better if there were several sets of flippers; then you could pass the ball back and forth.”

  John shook his head. “Let me tell you about foosball,” he said with a laugh.

  “Yeah?”

  “Never mind.”

  The next time he came to the lab, John did so after midnight. He wanted no one to interrupt him, especially Wilson. The lab was dark and empty. John opened his lab book on his desk and scattered some experimental data around to act as cover if anyone came in. Then he turned on the spectrometer. He’d seen it on one of his casual tours of the lab: a brand-new gamma ray spectrometer from Aggison-Hewlett.

  He’d borrowed the spectrometer notes from a guy who’d taken the nuclear physics lab class the semester before. It had a simple procedure for calibrating the spectrometer, then taking and printing a spectrum.

  John calibrated it with the cesium sample, then set the device under the detector. He started it and waited.

  It took a while, but a peak began to grow. He let it sit for an hour, nervous that someone would disturb him. To occupy his mind, he started filing at a new flipper; he’d made a dozen styles for the pinball machine, and to swap them the player could simply lift off the old flipper and replace it with a new one with the same mounting.

  The spectrometer beeped. John examined the screen; there was a single sharp peak. He printed the spectrum, and used a ruler to figure the center of the peak. He guessed it was about 510 keV. Just one peak meant just one isotope inside, usually.

  He opened the nuclear physics book and started working through the list of elements and their gamma ray energies.

  He worked his way through the list eliminating anything with a half-life less than a year and anything with a gamma ray not within 50keV of 510. He ended up with Kr-85, which had a half-life of 10.3 years and a gamma ray of 540 keV.

  He wondered if he had calibrated the device wrong.

  John started over, and calibrated this time with a Cobalt 60 isotope, which had two distinct peaks at 1330 and 1170 keV. Again he put the device under the detector. Again he saw the same peak, and he calculated it to be at 510 keV.

  Frustrated, he put the two spectra in his backpack and walked home. Could it be that the device contained an isotope that no one here had discovered?

  The next day he wandered over to the spectrometer when someone was using it.

  “Excuse me, can you help me with something?”

  “Sure,” the guy said in a Slavic accent.

  John showed the spectrum to him, and asked, “What isotope makes a peak at 510 keV?”

  The student looked at the spectrum and said, “None. You have annihilation peak here.”

  “Annihilation peak?”

  “Sure. Gammas interact by three mechanisms…”

  “Photoelectric effect, Compton scattering, and pair production. Of course!” John laughed as he realized what he was seeing.

  “I’m Alex Cheminov, by the way,” the student said. “You know your stuff. We could make a decent nuclear physicist out of you easily enough.”

  “John Wilson,” John said, shaking hands. “I may have a few more questions. Do you mind?”

  “Not at all.”

  John rea
lized that the peak at 510 keV, really 511 keV, was from the gammas produced when a positron hit an electron and disappeared in a burst of radiation: two equal energy gammas at 511 keV. He was seeing the tail end of the pair production interaction of gamma rays in matter.

  It only happened when the gammas were highly energetic, the spontaneous breakdown of a gamma ray into an electron and positron, antimatter, as it neared a nucleus. The positron would then bounce around, slowing down until it found another electron to interact with and generate the annihilation gammas. And that was what he was seeing.

  John stopped. But the annihilation radiation was the tail end of a reaction. It was seen in addition to other methods of interaction. He should have been seeing at least one higher energy peak. But he wasn’t.

  Unless the positron wasn’t being created by pair production. Unless there was another source of the positrons. Unless there was antimatter inside the device, powering it.

  He laughed. It made sense. To move between universes required a lot of energy. And what better form was there of compact energy than antimatter? The device was powered by antimatter. It was a sound hypothesis.

  One more mystery of the device fell before the sword of science.

  “Science!” he cried, and as he was in the lab, not a single person looked up in surprise.

  John watched Casey smile, and his heart jolted. They were standing on the edge of a chasm in Old Shady Park. Water had etched a fifteen-meter jag into the bedrock, already scraped clean of topsoil by glaciers. Autumn leaves tumbled around them. Browns, reds, oranges, and yellows covered the ground.

  Casey wore no makeup. Her hair was pulled back into a ponytail. She was the most beautiful woman he had ever seen, and he hated himself for coming to desire her so. He was leaving this universe one day and would never come back.

  “Let’s go down,” she said. She caught his look. “What’s wrong? You look… pensive.”

  “I’m okay.”

  There was a stair that led them to the bottom of the gorge. The iron rail was wet, and the damp pulled the heat from John’s hand. The steps were carved into the rock but patched with cement in places. Still they were mossy, and the footing was slick.

  Casey slipped, exhaled sharply, and grabbed John’s arm. She tensed, then relaxed into him.

  “Thanks,” she said.

  “Sure.”

  The park was empty this early in the morning on a weekday. She had skipped her abnormal psychology lecture, and he had no classes on Wednesday morning. She had told him they needed to spend some quality time together.

  Something rustled in the leaves on the other side of the rail. A chipmunk raised its head to look at them, then scampered away.

  “Look!” Casey cried, before it disappeared into a hole somewhere.

  From below, the U-shaped falls seemed to close in on them. The sprinkle of water splashed in a small basin of rust-colored rock. John looked up into the falling water, past the trees, and into the cloudy sky. The moisture tickled his nose.

  “I feel claustrophobic,” Casey said.

  Her voice echoed around the carved-out cavern behind the falls. John leaped across the weakly flowing stream. Graffiti was scrawled across the rocks behind the falls. A pile of beer cans were tossed in the dry grotto. It was clearly a hangout for local kids.

  Casey hopped across the stream and joined him, hanging on to his arm.

  She looked at the garbage and said, “People are so stupid. Look at this.”

  “Yeah.”

  John walked around the cavern. The floor had been rubbed clean and smooth over the years. During heavy rains, the place would fill up.

  “Listen, John.”

  He turned. Casey was standing back a couple meters, hands in her pockets. He nodded.

  “I’m really sorry for, you know, reading your diary,” she said. “I shouldn’t have done that. It was really rude.”

  John shrugged. He didn’t want to talk about it and had hoped that she had forgotten all about it.

  “I mean it,” she pushed. “I am sorry.”

  John nodded.

  “Don’t you accept my apology?” she said.

  “Yeah, yeah, I do.”

  John was worried she’d keep at him, but she seemed satisfied with his reply.

  “So, are you ready to meet my parents again?”

  “Huh?”

  “For Thanksgiving. You’re coming for dinner.”

  The holiday was only a few weeks away.

  “Casey, I don’t think-”

  “John, you have to. They want to meet you again, especially since they never liked Jack so much.”

  John sighed.

  “No, I won’t be able to go,” John said firmly.

  “Where else will you be going? You don’t have family.”

  “The Rayburns will have me.”

  “You’re not even related!”

  John’s face flushed, but instead of yelling back, he said quietly, “I don’t want to go to your parents’ house. I don’t want to spend Thanksgiving with you and them.”

  Casey’s retort died in her mouth. “You don’t-?”

  “No. I’m busy with pinball stuff.”

  “Pinball stuff?”

  “Yeah.”

  “You have got to be kidding! You’d rather spend time with your friends on that stupid game than with me?”

  “I thought you were a part of it?”

  She rolled her eyes.

  “If I wasn’t I’d never see you. It’s either the pinball machine or whatever you have locked in that box.”

  “Hey!” John cried. He hadn’t realized she knew about the box.

  “It’s like I’m not even a part of the important stuff in your life,” she said. “It’s like you keep everyone at arm’s length.”

  “That’s not true!”

  “Then what’s in the box?”

  John didn’t answer.

  “What?”

  “It’s not important,” he said. “Casey, I’m new at this. I’ve never had… I’ve never been this close before.”

  “You’re not that close now!” she cried. Tears were falling down her face.

  “I’ve never done this before!” John replied. “I don’t want to hurt you or make you angry or hide important things from you. But-”

  “But you do.”

  “Casey, don’t be unfair to me!”

  “Me unfair to you?” She forced a sharp laugh. “I’m your girlfriend, remember? We’re supposed to share things. Be together. For holidays and things.”

  “Fine, I’ll go to your parents’ for Thanksgiving.”

  “Too late. The offer is null and void!”

  “Don’t be petty!”

  “Don’t cave just because I cried. You should have wanted to come.” Her cheeks were bright red.

  “Stop playing games!” John cried. “Stop pressuring me! I have a say in what we do, don’t I? If I don’t want to go to Thanksgiving dinner, I shouldn’t have to!” A point that had been inconsequential was now a bone of contention.

  “You think-” She stopped herself. “John. It doesn’t matter. You don’t have to come to Thanksgiving.”

  She turned away, stepping over the stream into the open.

  “Casey.”

  She walked down the path parallel to the stream.

  “Casey.” John ran after her. He grabbed her arm. “This is silly,” he said. “I want to come to your parents’ house. I do. I don’t know why I said I didn’t. It’s just stupid of me.”

  She wiped snot from her nose on her sleeve. “Yeah, that’s true.”

  “You didn’t have to agree so fast,” John said with a smile.

  “I think I did.”

  John slipped his hand in hers and they walked the length of the trail in silence.

  The prototype was ready three weeks later, a complete head-to-head pinball game, with a digital scoring system, various bumpers, and six sets of flippers per player.

  John won the first ten matches, mo
stly because he knew how to work the flippers while the others couldn’t get the hang of catching and holding the ball. But Henry learned fast, and he was the first to beat John.

  “And there was much rejoicing,” Grace said when Henry scored the game point.

  “Whose side are you on?”

  “Not yours.”

  The flurry of bells and screaming could be heard throughout the lab, and before long a grad student wandered by and asked to join in. He dropped in a quarter, and when John heard the clink of the coin in the money bucket he caught Grace’s eye and smiled.

  Henry kicked his ass in two minutes.

  The next night they had ten people there. The third night it was standing room only in the lab. That weekend they had the first tournament. Henry won against John in the finals, ten to nine.

  It was a smash success. So much so that John decided they would try the next step. He should have known better; he should have remembered his ultimate goal was to understand the device. Instead he was caught up in the idea of the pinball machine and didn’t realize what he was about to do.

  Seeing the bars in the light of the day was like seeing a news anchor without his or her makeup and cue cards. The places smelled of stale beer and echoed their footsteps as they entered. John and Casey stopped in a small bar called Woodman’s not far from campus, which had a video game and a couple of pool tables. John and Casey had been there once. John was always surprised not to be carded going into bars, but the drinking age in this universe was eighteen.

  “We’re looking for the manager.”

  A guy was hauling a keg of beer up a conveyor belt from the basement through a hatch in the floor. He said, “In the office. Past the bathrooms.”

  Casey followed John down the hall to a door marked: “Authorized Persons.” John knocked and a rough voice answered, “What do ya want?”

  John pushed the door open onto a cramped office. A balding man sat behind a desk, smoking a cigarette.

  He looked up at them and said, “I ain’t sponsoring any homecoming float.”