The Twin Paradox

Nobody can hear you scream in the vacuum of space, or so they say. I know this to be true, as I know that panic depletes oxygen, that liquid water is required to support life, and that my life suddenly makes no sense now that we’re apart. Sound is just vibrating air, and there’s no air outside. No atmosphere. No “they” to say anything anymore.

Maybe only twins need the sound of someone else breathing nearby to feel grounded, to feel safe. I knew I was giving up that ground when I left. I knew our plan like the shape of our hands tracing constellations against the sky. But after all our careful calculations, how did I underestimate the impact of missing you?

MISSION STATS

• DATE: 3.16.2055
• SPEED: 40,100 MPH
• DISTANCE FROM EARTH: 512,393 MILES
• HEART RATE: 78 BPM
• OUTSIDE DECIBEL LEVEL: 0

I’m recording this message to keep my mind off of the cool inertia of the cryosleep drugs slowly seeping into my IV. Every time we simulated this at home, I slipped into a dreamless, peaceful sleep that felt endless and instant at the same time. But now, having passed the moon, having confirmed our trajectory, I should be ready for the long nap. I can feel it like a thousand little hands trying to drag me under, into an inky black nothingness and I… I don’t want to go. The drugs are having a reverse effect. The stress response has my heart rate up. So, I’m whispering to you across the universe like we used to whisper through our bunkbeds at bedtime… because… I’m terrified. I know I’m not supposed to fight it. But I also know that keeping my mind active can keep the sleep at bay for a while. So I found something in the databanks of the research module — an Atlas Obscura. Have you looked at one in a while? It’s so much more beautiful than I remembered. A 3D map of space beyond the Heliosphere with symbols for the habitable moons of Saturn, including, of course, our Enceladus. Blue lines outline the subsurface ocean. Yellow dots mark the hydrothermal vents. Orange for the geysers of organic compounds. Black where they crack through glacial ice. I wonder if my residential pod will have a view of the meltwater waves. They say it’s like swimming in champagne. The subaqueous volcanic activity dissolves gases and sparkles the water like Perrier. I know you’ll see me up here. That’s why we fell in love with this moon in the first place.

Enceladus, brightest crystalline surface in the galaxy. Perfect for future astronauts afraid of the dark, and now the gateway for all direct fusion transport to the Outer Rim. But when this map was charted, mid 20th century, only the most basic data was logged in the margins: Enceladus: Type: Icy moon. Orbital period: 32.9 hours. Diameter: 504 kilometers. Surface temperature: -330F. Conditions: Liquid water; organic molecules, carbon, hydrogen, nitrogen, oxygen. Life.

MISSION STATS

• DATE: 3.16.2055
• SPEED: 41,037 MPH
• DISTANCE FROM EARTH: 590,521 MILES
• HEART RATE: 70 BPM
• OUTSIDE DECIBEL LEVEL: 0

Sound familiar? Bio-Genesis 101. What did they teach us? Life on Earth began in darkness on the ocean floor. In the absence of sunlight, bathing in warm salt water for 4 billion years, the ocean crust spewed plumes of molecular hydrogen. You called it candy for microbes. You’re brilliant, you know? Everyone’s always said so, but it’s true. You’re one of kind, except no one but me could ever really see that. It was never fair that half the kudos went to me. Identical twins feel like one thing. One soul, two people. I know we agreed to this experiment. We dreamt of it, studied for it, kept its secrets safe. Given the risks, it was better for the family—the genius astrophysicist stays home so the reckless astronaut can roam. You fell in love, put down roots. I joined a band and failed up.

I hope there’ll be some solace for everyone, seeing both of our faces in yours. But when I get back… if I get back… we won’t be mistaken for one thing anymore, will we? Thanks to the Twin Paradox, time dilation and a round trip of nearly a billion miles, I’ll be about a decade younger.

Einstein had his constant, the speed of light. He measured all of astrophysics against it. The faster we travel, the slower time passes. But as I hurtle toward Enceladus at 200,000 meters per second, I am streaking away from my constant, my twin, against whom I measure all things. We arrived in this universe together and the thought of being out of sync with you puts a black hole-sized pit in my stomach. I miss home. I miss weather, color, coffee, conversation. I thought the silence would break my heart, but it’s not even that poetic. It’s not quite quiet. There’s the constant hiss of the air recycling. The random clanks and clicks and beeps and whirring of a system reminding me that there’s basically a sheet of tinfoil between me and all that emptiness. The nature recordings you sent help a little, but hearing the cicadas buzzing and the hot summer wind through the trees of our forest, without feeling it on my face makes my heart ache and pound like a fist against the inside of my ribcage… Oh god I’m in a cage.

MISSION STATS

• DATE: 3.16.2055
• SPEED: 41,781 MPH
• DISTANCE FROM EARTH: 601,324 MILES
• HEART RATE: 90 BPM
• OUTSIDE DECIBEL LEVEL: 0

Breathe with me. Let me imagine you here, breathing with me. When we were children we knew how to listen to the sky. The moon whispered, the planets whirred, the stars plinked like an infinity of pizzicato strings. We lay on our backs in the cool summer grass and spoke the names of constellations, invoking their magic. Time was a simple, fluid thing that puddled up around the present as we played. We didn’t think of space as silent, or stars as primordial, any more than we thought of ourselves as fleeting sentient forms in the incomprehensible vastness of spacetime. The night sky was simply our refuge when the world shut down and we fell under the protection of its sentinels.

By starlight we discovered the ancient glacial erratic that had deposited Ice Age boulders in our backyard. You read to me from the Book of Prehistoric Life, about a time when the oceans iced over and great beasts crossed continents on a land bridge between frozen seas. Humans followed the animals, hunting them for food, sheltering in the strength of their bones and the warmth of their skins. I feel like I’m inside a great beast now, like I slid down its slick glass throat and tucked myself neatly in its cold metal belly.

You’re probably up late, hearing this message at Mission Control alone at your station. One of the only reasons I thought I could handle this trip was that we’d only have a 83-minute signal delay. Eighty-three minutes until you get this message. Eighty-three more until I hear your response. Eighty-three minutes sounds like nothing, but if I let this unnatural sleep slip into my mind, it’s eight years to splashdown. Eight years in this Juliet-like sleep. “God knows when we shall meet again. I have a faint cold fear thrills through my veins, that almost freezes up the heat of life.” Act 4, scene three. It’s getting to me— “What if this mixture do not work at all? There's a fearful point! Shall I not, then, be stifled in the vault, to whose foul mouth no healthsome air breathes in, and there die strangled ere my Enceladus comes?” It’s too much. The darkness, the endless hush like cotton in my ears. We’re both scientists. We theorize, analyze, predict. We try to understand. I’ve left our Earth and all its creatures, but I’m having an animal response I can’t shake now. PTSD breathing. Inhale for four. Hold for seven. Exhale for eight.

MISSION STATS

• DATE: 3.16.2055
• SPEED: 42,002 MPH
• DISTANCE FROM EARTH: 638,041 MILES
• HEART RATE: 145 BPM
• OUTSIDE DECIBEL LEVEL: 0

I keep reminding myself of our last conversation. Replaying it on a tiny loop, like the tiny vibrating loops this whole universe is made of. We’re all just sound expressed in another form, aren’t we? Maybe that’s why silence feels so wrong. Breathe with me. “It will happen without warning. Sometimes, you can see further in the dark. We will be unprepared. Sometimes, you can see further in the dark. Sometimes.” What is time anymore anyway? I feel like I’m being stretched on the event horizon of my own personal black hole. Spaghettified by my fear. I remember spaghetti. That time we threw it on the floor as babies. Side by side. How do I have access to that memory?

MISSION STATS

• DATE: 3.16.2055
• SPEED: 42,067 MPH
• DISTANCE FROM EARTH: 638,204 MILES
• HEART RATE: 201 BPM
• OUTSIDE DECIBEL LEVEL: 0

This is wrong. I want to pull out all these drips and tubes and electrodes. I don’t want to go. This is fight or flight. Intellectually, I know that… But I’m only realizing, hundreds of thousands of miles into the grey matter of the universe, that my brain doesn’t know the difference between this and dying. All our memories are flashing, not before my eyes, but in my ears. I can hear the thunder of that superstorm that swallowed the electric grid and blacked out the city when we were seven. The songs we sang out the moonroof of your car after graduation. The crunch of gravel in the driveway. The chirp of frogs in the pond. The sizzle of eggs in my favorite square pan. The scream of your espresso machine splitting the quiet of the morning.

It’s so quiet now. I can’t breathe… Every exhale wants to erupt… I need to get out of here… To throw open the airlock… If I could just hear your voice… I need to screa– What was that sound?! I don’t understa– It sounds like it’s coming from outside…

MISSION STATS

• DATE: 3.16.2055
• SPEED: 42,138 MPH
• DISTANCE FROM EARTH: 638,279 MILES
• HEART RATE: 215 BPM

• OUTSIDE DECIBEL LEVEL: 89 DBS

How could there be sound outside? Nyx… Is that you?