Relativity (31 page)

Inside the dark pit of a migraine, Mark remembered things. Things he couldn't erase, memories he'd suppressed. Bright flashes of old feelings: the claustrophobic confinement of a cell; the monotony of endless white walls, white floors, and white ceilings; the humiliation of sweeping the dull concrete floors of the prison block. Ticking clocks, empty hours, infinite days. Cheek pressed against a cinderblock wall, his hands pinned to his back. Mark was never a religious person, but sometimes he dropped down to his knees and prayed those memories would go away.

He'd need to wait until it was dark before he dared venture up the road to the shops. Even though Mark was a grown man, in some ways he still couldn't take care of himself. Ethan seemed to ground him, though. For the first time in years, Mark felt like himself. He didn't have to follow orders or be at another's command; he didn't feel trapped. His son appreciated him. Something flickered behind Ethan's eyes as he hung on to Mark's every word.

It was still a surprise to see him suddenly appear at his door.

“Ethan, what are you doing here?”

The boy was carrying a heavy backpack. “I'm on school holidays. Are you busy?”

“I was just going to the shops.”

“Can I come?” Ethan smiled.

Mark noticed how perfect his son's teeth were. “Yeah, all right,” he said, massaging his temples.

“What's wrong?”

“Just have a little headache.”

“How come?”

Ethan asked a lot of questions. He asked questions about physics, about how the stars were formed and if time travel were possible, how you might make a wormhole. Thankfully, he'd stopped asking personal questions. It was for the best: Mark's past was a vortex. Nobody ever went down there.

“What are you going to buy?” Ethan asked as they entered the supermarket.

“Aspirin.” The migraine had intensified. Brutal supermarket fluorescence made it worse. He closed his eyes for a moment. It always reminded him of prison, this bright artificial light.

Ethan picked up a basket. “What's your favorite food?”

Mark opened his eyes again. “I don't think I've been asked that question for a while,” he said. He stopped to think about it for a second. “Mexican food, I think.”

“Me too! Have you ever been to Mexico?”

“No, I haven't.”

Ethan looked over at the breakfast cereals. “Me neither. Maybe we could go together one day?”

Mark didn't even stop to consider how realistic the possibility of that was. “Definitely.”

“I know how to make fajitas,” Ethan said. “I could make them for you.” He took a kit in his hands and started to read the back of the yellow box. “We need chicken breast and some vegetables and maybe cheese.”

Mark followed him to the next aisle. His vision was clouded by scintillating scotoma; he couldn't focus from one moment to the next.

“Can you help?” Ethan asked, trying to reach the sour cream.

Mark grabbed it from the top shelf.

“What's that?” The boy leaned in. He touched Mark's upper arm, lifted up his T-shirt and poked his skin.

The tattoo. Mark put his hand over it, covering its lines. “The problem with tattoos is you can't get rid of them.”

Ethan stepped back. “Did you get it in prison?”

“No,” Mark said quickly. “I got it a very long time ago.”

“It looks like—” Ethan pushed his father's hand off the tattoo and took a moment to inspect it. That tattoo had been on his skin for almost thirteen years; the black ink had faded to navy blue, the crisp lines softer now, where the pigment bled into his flesh.

“It's an equation,” Ethan said, excited. “It's E=mc
²
. But what does that mean?”

“Well, c is the speed of light,” Mark began. “And—”

“No, I know that.
E
is energy,
m
is mass. I mean, what does it mean? When adults get tattoos they usually mean something. Why do you have a tattoo of that? What does it stand for?”

Mark pulled his sleeve down. “Nothing. It doesn't stand for anything.”

“So you just really like Einstein's mass equals energy equivalence equation?”

“It's silly, really. I got this tattoo when you were born. It's us. You were the product of us. E=mc
²
—E for Ethan, M for Mark, C for Claire. She was my constant.” Mark trailed off. “Not anymore.”

Ethan looked away.

Mark wondered what he was thinking. He'd said too much. The boy was only twelve; he wouldn't understand. That stupid tattoo. It reminded him there'd been so much optimism once. Before other things forced themselves in the way, Mark believed their little family could survive anything.

Now the only constants he believed in were mathematical, scientific: the gravitational constant
G
, Planck's constant
h
, the electric constant
ke
, and the elementary charge
e
. These were, for Mark, the only things that he could rely on to be universally true. Nothing else was truly constant—not family, not people, not love. Not even himself.

Ethan tapped Mark's shoulder. “You wouldn't happen to know anything about Einstein's field equations, would you?”

Ω

ACCORDING TO HIS CALCULATIONS,
Ethan needed to be back home in one hour and fifty-two minutes. Mum was working late—another ballet opening but he wasn't allowed to come—and the show finished at 8:30 p.m. Ethan and Mark finished eating dinner and were watching television. The fajitas were a little overcooked but his father hadn't really noticed. In fact, he hadn't noticed much. Mark seemed agitated and upset, massaging his forehead and shutting his eyes. Ethan hoped he hadn't done anything to annoy him.

Ethan looked around the house; it was massive and unfriendly. Even though it was full of stuff—old family pictures in dusty golden frames, glass paperweights trapping butterflies, faded portraits of frowning saints—it felt empty and abandoned. More like a museum, not like a home.

The long corridors asphyxiated light; Ethan couldn't even see the other end of the hall. Whispers and creaks echoed from behind closed doors, like secrets and ghosts hid inside locked rooms. Ethan stared at the family photographs, curious about the people who'd lived here once. His grandparents, both dead. Their unfamiliar faces made him ache for his own home.

“It's getting late,” Ethan said.

Mark opened his eyes. “You're right. I'd give you a lift but I don't think I'm in any state to drive. But I don't want you to catch the bus home alone at this hour. How about I give you some money for a taxi?”

“I'm not allowed. Mum says never get in cars with people you don't know.”

“Even taxi drivers?”

Ethan was wringing his hands. “I've never caught a taxi alone. And I don't want to break any other rules. Maybe you could ride in the taxi with me?” His voice shook a little; he didn't know why.

Mark nodded. “Sure, I could do that.”

Ω

THE TAXI DROVE
from Sydney's east to its west: climbing up to Edgecliff's peak where the darkening city horizon shifted to dusk; through the Bayswater tunnel and into the neon reds and pinks of Kings Cross; weaving around the traffic-choked blocks of the CBD where pedestrians jaywalked, stumbling off the pavement at busy intersections; past Chinatown's flickering signs for noodle houses and light-flooded frozen yogurt shops; briefly stopping behind swarms of blue and gray buses collecting passengers at Railway Square.

“Dad, did you study at UTS?” Ethan asked as the taxi drove past the tower.

“Nope, Sydney Uni.” Mark pointed toward Broadway.

“Oh yeah? Physics Road.” Ethan stared out the window. Mark obviously hadn't heard. Ethan had never called him Dad before; he'd never actually called anyone Dad. It felt nice to hold that word in his mouth—Dad—the cluck of the syllable rolling effortlessly off his tongue.

He changed the subject. “Is there such a thing as the opposite of a black hole?”

“Sort of. Some people call that a white hole,” Mark said. “Whatever black holes do, white holes do in reverse. But they've never been observed. In fact, there's only been one proposed white hole singularity in the history of the universe. At the heart of the Big Bang.”

They drove along Parramatta Road, past the gas station and antique furniture warehouse.

Ethan sat up straight. “But they're not totally impossible?”

“White holes don't agree with the second law of thermodynamics. Entropy is supposed to increase over time, but in a white hole the entropy is low.”

“Oh,” Ethan said, sinking back into the seat. “That sucks.”

“But the second law of thermodynamics only applies to closed systems. To balance out the entropy problem, a white hole could draw its energy from somewhere outside the system. But that would require an awful lot of energy.”

“What if you borrowed lots of energy but paid it back quickly? Then do you think it's possible to make a traversable wormhole with a black hole and a white—”

The brakes squeaked as the taxi stopped in front of the house.

Mark stared. “This is where you live?”

Ethan looked at the narrow entrance of his front gate and suddenly felt embarrassed. It was bigger than other places they'd lived—a castle compared to their studio apartment back when he was still in preschool—but it wasn't fancy like the Woollahra house. Ethan saw his home through his father's eyes. “We have a garden out the back,” he said. “Quark is scared of the garden, though.”

The taxi's engine was still running, headlights illuminating the quiet street. Another car pulled up behind them and beeped its horn. Inside the dark house, someone switched on a light.

Ethan's stomach sank. “Oh no. Mum.”

“She's home? I can come inside with you. Do you want me to talk to her?”

“No, that'd just make it worse.” Ethan slowly opened the door and climbed out of the taxi.

Mark held the car door ajar with his hand. “Ethan, you can call me later if you'd like.”

“Thanks, Dad.”

Mark's face stiffened and he blinked. That time Ethan knew that he'd noticed; that time he'd definitely heard.

Ω

INSIDE THE HOUSE,
Mum sat on Ethan's bed. Her eyes were blank and she looked like a ghost in the half-lit room. Ethan felt truly scared of his mum for the first time. Other times—when he'd been badly behaved, hadn't done well at school, a couple of occasions when he'd disappointed her—Ethan was scolded. But she'd never been scary. Now there was an absence in his mum's eyes that terrified him. He couldn't tell how angry she was; her face gave him no hints.

“Mum?” He felt himself shrink back into his body. His limbs grew shorter, his rib cage narrowed, his internal organs contracted. “Mum, I'm really sorry.”

“I missed a phone call this afternoon at work. So I opened up my recent call history. And I was surprised to see several phone calls on that list that I didn't make myself.”

Ethan knew where this was going. “Mum, I can explain—”

She cut him off. “When I saw who the calls were made to, I became quite concerned. I came straight home so I could talk to you about it. But you weren't home when I got back. I had no idea where you were! And it was getting later and later. Do you think maybe I was worried out of my mind, Ethan?” Mum didn't wait for a reply. “I was going to call the police. I came into your bedroom trying to see if you'd left any clues about where you might be, a note or something. And then I found this.” A crumpled piece of paper was in her hand. She unfolded it, offering it to Ethan. The letter from Dad.

“Mum, it's not what you—”

She spoke over him. “Is that where you went tonight? To see him?”

All Ethan could do was give a small nod.

“I see,” she said, her voice flat. “Thank you for being honest with me.”

“That's it?” Ethan searched her face. He needed her to explode, to cry, to behave like his mum. But all she did was give him a stony stare. “Am I in trouble? Am I grounded?”

“No, you're not. You've just really hurt my feelings, Ethan. And the thing that hurts the most,” Mum said, taking a small breath, “is that you hid this from me. For how long? Weeks? Months? You knew your father was back but you never said a word. Since when do we keep secrets like that from each other?”

Now Ethan was hurt. “Mum, you kept a really big secret from me. And you didn't tell me he was in Sydney when you knew.”

She closed her eyes. “Ethan, that's very different. I was trying to protect you.”

“He isn't going to hurt me. He isn't dangerous.”

It was the truth. They'd met twice now—had spent precisely six and a quarter hours together—and Ethan knew that his father wasn't a dangerous man. He was gentle and generous. Always explaining things to Ethan, just wanting him to learn. Mark knew so much about everything—physics, music, architecture. He was like an audio guide; he made life a museum. Ethan could take him anywhere and he'd explain anything.

Mum wasn't like that. She didn't know the answers to Ethan's questions—what happens at an event horizon, what's the escape velocity of Mars? They were universes apart. She lived behind a force field. But his father, in the space of six and a quarter hours, had allowed Ethan to totally enter his world.

“He's my dad,” Ethan said.

“I'm your mother!”

“But you lied to me about him. And you made my father leave.”

“Ethan, that's not true. You had a serious brain injury; it's much more complicated than that. You almost died.”

“But I didn't die. I'm fine. Better than fine. Dr. Saunders said my brain injury gave me a special gift.” Ethan held his chest high. “I can see physics. Nobody else can do that. Just my brain. Dr. Saunders said so. Only me. I'm special.”