Relativity (45 page)

His son had taught him that science was revision. Recognizing errors and setting them straight. That physics was full of paradoxes and duality, always at odds with our intuition. Because in a cosmic accident, Mark had done one great thing, made his mark. He'd released some positive energy into the universe—Ethan. And now they were quantum entangled. Like a spaceship spinning out of control, Mark had spiraled out of orbit but Ethan would be his ground control, carefully guiding him home.

The lights in the cabin dimmed. I forgive you, his son had said. Mark had often wondered if on hearing those words, he'd feel some kind of release. Finally stop punishing himself. Taste the sweetness of reprieve. But he still felt none of those things; he was just as weighed down as ever.

For the last twelve years, Mark's guilt had strangled him silently; he was like a helpless tree choking in the tight grip of a Moreton Bay fig. However, admitting to hurting his son—saying it out loud—felt like taking his first gasp for air. It gave Mark oxygen. Before now, he believed he'd always be moored by anchors of regret.

But maybe Ethan was right about time travel: we can't change what's already happened, but we can still change the future. His son's forgiveness had loosened something; it allowed Mark to uncover some dormant strength. That eventually he might untangle the knots that kept him tethered to the past. That one day Mark would be strong enough to lift those heavy anchors, cast out into the future, and finally forgive himself for his mistake.

Ω

ETHAN MET ALISON
by the rotunda at Observatory Hill Park. He walked quickly up the hill, feeling the muscles in his shins stretch with the sloping incline, and stopped to turn around. Below him was a field of color: green and yellow and orange. Summer was almost over and the season's palette was changing. A scattering of golden leaves peppered the ground.

From up there, Ethan saw all of Sydney: the sandstone city, the turquoise harbor, the pointed gleam of skyscrapers, the Rocks, the Harbor Bridge. A path intersected the huge lawn, cutting it into four sections. It made Ethan think of the cerebral cortex, the different grassy areas of each green lobe. Frontal, parietal, occipital, and temporal lawns.

“Ethan!” Alison shouted, waving. Her hair had grown back around her ear, covering her surgery scar. Ethan's head was still a little patchy. She wore a purple dress with a frilly hem, which bounced as she walked up the hill, and carried a bunch of multicolored helium balloons in her hand.

“What's with the balloons?”

Alison looked up at them, strings taut as they blew in the wind. “Duh,” she said. “They're for you.”

Ethan took the bunch in his hand. There were seven balloons—red, orange, yellow, green, blue, indigo, and violet—just like wavelengths of the electromagnetic spectrum. A rainbow. He tied them to the bench.

Alison pointed to Ethan's plastic bag. “What's in there?”

“Quark.”

“Your dead rabbit?”

Ethan nodded.

“Yuck,” she said. “Why'd you bring him with you?”

“He's been in the freezer. But I wanted to bury him here, in this park. Do you think we could dig a hole?”

“What? Here?” Alison looked down at the grass beneath her feet. “I'm pretty sure we're not allowed to do that.”

Ethan frowned. “Why not?”

“Because I think the park belongs to the Queen.”

“She's in England. She won't know.”

Alison shrugged. “I guess not.”

They started to dig a hole together, in the shadow of the colossal Moreton Bay fig tree and its tangled roots, using white plastic teaspoons. Digging with spoons was more difficult than Ethan expected. Maybe he should have brought a shovel.

“I have dirt under my fingernails.” Alison frowned.

When the hole was deep enough for the shoebox coffin, Ethan gently lowered Quark into the soil.

“What do we do next?”

Alison waved good-bye to the shoebox. “You need to give a eulogy. That's a speech.”

“Good-bye, Quark.” Ethan scratched his head. “You were named after an elementary particle and a fundamental constituent of matter, postulated as building blocks of hadrons. But you were so much more than that. You were a rabbit who liked to eat biscuits, and my very best pet. I'm sorry you didn't survive my botched attempt at time travel. But thank you for saving my life.”

Alison coughed.

“And thanks to Alison for saving my life too.”

“You know what?” she said brightly. “Maybe Quark did survive. Maybe he's the one who successfully went backward in time. He could be the leader of bunnies in Ancient Rome or something.”

Ethan kicked the pile of dirt back over the hole, covering the shoebox. “I hope so. That would be a much happier ending to the story than spending the rest of eternity being dead in a box. Like what happened to Schrödinger's cat.”

Alison gave him a confused look. She placed a bunch of handpicked flowers on top of Quark's grave. “When do you go back to school? I start next Wednesday.”

“Me too. But guess what? I'm going to uni as well.”

“You're too young to go to uni.”

“I know, but the physics department invited me to go to some cosmology lectures. Only if I can pass the mathematics requirements but it looks pretty easy. I'm a genius, remember?”

“Yeah, whatever. Your shoelaces are undone.”

Ethan untied the balloons from the bench. He'd sat here once with his father, on that exact seat, and eaten a cheeseburger. Fed the ibises. Talked about physics. He looked at his watch and then at the sky. High above the horizon, in the east, Ethan could see the moon. He pointed. “Look!”

Alison shielded her face with her hand. “It's a funny shape. And it's daytime. I thought the moon only came out at night.”

“Right now, it's a waxing gibbous moon so it rises earlier. But the shape of the moon is always the same, what changes is the reflected light. Even when we can't see it, the moon's still always there. Sometimes it's full and bright and sometimes it's covered in shadows. And because the moon is tidally locked to Earth, we never see its dark side.”

A strong gust of wind stole the strings from Ethan's grip and suddenly the helium balloons were carried away by the breeze.

“Oh no,” he said. “I let them go.”

As they watched the balloons drift over the park and up into the sky, Ethan felt heavy. He thought about his mum and his dad, how his universe had expanded. Then he thought back to his father's words. There's too much gravity. It was everywhere. Even though the balloons floated high above them now, eventually they'd burst or deflate. Helium might leak until the balloons fell out of the sky; the heat of the sun might pop them. Gravity would get them in the end. Falling was inevitable.

Now Ethan understood. Phrases like “the gravity of the situation” made sense, and he realized why—when things were difficult—they were called heavy or weighty.

Gravity.

Ethan couldn't see it with his brain anymore, but he felt it everywhere.

Ω

GRAVITY MAKES TEARS
run down our faces, and our chests heave and sink. It's the reason we drop to the ground and yell out our hurt. It can be paralytic, leaving us heavy in our beds, unable to rise and face the day. Gravity plays tricks on us: distorts space and time, bends the light. But gravity keeps our feet on the floor and stops us from floating far away into the atmosphere, disappearing into outer space. Because gravity doesn't just pull us down—it also pushes us up.

Gravitation shapes the universe. Forms tides, heats planetary cores. It's why fragments of matter clump together into planets and moons, why stars cluster into vast, rippling galaxies. Earth isn't going to crash into the sun, the moon won't collide with Earth—gravity keeps them safely in orbit. It always attracts and never repels; it brings the planets back.

Gravity is insistent. It firmly stands its ground. We never stop accelerating toward the center of the Earth at 9.8m/s
²
. That curvature in the fabric of space-time is a phenomenon we experience every day, an invisible experience we all have in common.

None of us are weightless. Gravity extends to infinity.

And when stronger forces threaten to pull us apart, it's the weakest force that unites us. Gravity binds us together.

T
hank you to my exceptional agent, Karolina Sutton, for championing
Relativity
from its first draft and offering the best advice at every juncture. I'm also grateful to my amazing international agents: Melissa Pimentel and everyone at Curtis Brown UK; Pippa Masson and all at Curtis Brown Australia; and Alexandra Machinist and all at ICM.

Enormous thanks to my phenomenal editors, Cate Blake and Karen Kosztolnyik—this book is infinitely stronger because of your magical brains. Thanks also to Ben Ball, Lou Ryan, Laura Thomas, Josh Durham, Rhian Davies, Heidi McCourt, Alysha Farry, and everyone at Penguin Australia, as well as Nikki Lusk and Emma Schwarcz for your sharp eyes. Further thanks to Jennifer Bergstrom, Becky Prager, Louise Burke, Carolyn Reidy, Meagan Harris, Jennifer Robinson, Jennifer Long, Liz Psaltis, Lisa Litwack, and all at Gallery Books, and Sarah Castleton, Grace Vincent, Kate Doran, Rachel Wilkie and everyone at Corsair.

To everyone who read
Relativity
in its various shapes over the years—Marcus Forsythe, Mark Scano, Adrienne Xu, Karen Riley, Jack Boag, Eliza Sarlos, Tim Willox, Eva Husson, Margot Watts, James Goodman-Stephens, Liv Hambrett, Geoff Orton, Josephine Rowe, Sofija Stefanovic, Elmo Keep, Dan Ducrou, Eva Schonstein, Luke Gerzina, and anyone else I've missed—thank you for your generosity and encouragement. Adrian Fernand, your drive and intelligent feedback always pushed me to work harder and dig deeper—thank you for being my partner in crime. A million thanks to Sam Thorp, who had confidence in my writing before I ever did and helped me find Schrödinger's cat. I'm especially grateful to Brendan Gallagher, Angela Bennetts, and Amy Gray for your insightful help. Most of all, my heartfelt thanks to Alison Fairley.

For your physics expertise, thank you, Paul Gregory and Joseph Roche. I'm indebted to Stewart Saunders, Chris John Bell, and Jeanne North for guidance with all things neuroscience and medical, and to Rhoderic Chung. Thanks, Benjamin Law, Renee Senogles, Kelly Fagan, Romy Ash, Emily Maguire, Nam Le, Christos Tsiolkas, Dominic Knight, and Sophie Cunningham for your sage advice.

Writing this book would have been impossible without help from my Faber Academy crew: Amy Hoskin, Damien Gibson, Simon Murphy, Richard Reeves, Richard Skinner, and Steve Watson. Special thanks to each of you for all the years of priceless editorial advice, friendship, solidarity, and support.

Thank you to my parents—to my mother, Josephine Barcelon, for always encouraging me to read, and to my father, Michael Hayes, for always encouraging me to write. Extra thanks to Dad for pointing out constellations at our star-watching stone and showing me the moon. Thank you to Nerida and Robert for your continued support, and to my grandparents Marie Thérèse, Amparo, Francis Daniel, and José. And Claudia, Hose, Peter, Froukje, and Harry—you guys are the best.

Finally, a googolplexian of thanks to my son and husband for their boundless love and patience. Julian, you inspire me every moment of every day—thank you for teaching me how to tell stories and showing me how to write this one. You are my light and my constant;
Relativity
is my ode to you. And David, your unwavering belief and infinite kindness have sustained me through the brightest and darkest moments. I'll never be able to thank you enough for giving me time and space, and the universe.

Every year, thousands of infants across the world are injured or killed by abusive head trauma caused by violent shaking. These injuries and deaths are 100 percent preventable. This book is dedicated to all the families affected by shaken baby syndrome and in memory of those babies who didn't survive.