Arca’s first death happened on a screen.
Mina turned off the screens in the observation room one by one. The last window showed a device reconstructing the brain waves of a dead person. The signal had already stopped, but the system kept rewinding the final 0.8 seconds.
The man blinked three times during that brief moment. Once out of fear. Once like someone who had noticed something. And the last time, like someone waiting for someone else.
“All we have to do is leave a record,” Ian said.
“Who will look at the record?”
“We will.”
“Can they know that we’re watching them?”
Ian did not answer.
Mina turned off the reconstruction device. The observation room went dark.
The face from 0.8 seconds earlier had disappeared, but Mina knew that expression. Her father had made the same expression just before he died. It was the face of someone trying to answer somebody while looking at the pattern on the hospital ceiling. Her family said it was because he lacked oxygen. Mina did not believe them.
Arca was created to find out whether people could be left behind even after human civilization collapsed. At first, it was a program that calculated changes in war, climate, disease, and politics. Bringing a dead civilization back to life was not in the research proposal.
But then people began to be born inside Arca. When it rained, they repaired their roofs, and when a child was born, they gave it a name. They also developed a custom of hanging the clothes of the dead from trees instead of burning them. They did so because the person who had worn the clothes might still be watching them from somewhere.
At some point, the inhabitants began asking one another the same questions.
[Why were we born.]
[Why must we die.]
[Who is watching us.]
Mina reported the questions as errors. Just because a sentence inside a program questioned its own existence did not mean that consciousness had emerged.
Ian rejected the report.
“If it’s an error, why did the same questions appear in three cities at the same time?”
“They could be sentences that were part of the training data.”
“Then why are they using words no one taught them?”
“What words?”
Ian did not answer.
He handed Mina a document. It contained a word that did not appear on Arca’s language list. The inhabitants used it with a meaning similar to “outside,” but its exact meaning differed from person to person. Some said it was beyond the sky, while others said it was after death. One girl put it this way.
“It’s the side that has never opened yet.”
In 2003, the philosopher Nick Bostrom presented the simulation argument. If a civilization goes extinct before it develops far enough, or if it does not recreate the consciousness of its ancestors even after it advances, then simulation worlds will not be created. But if a civilization survives and recreates the humans of the past countless times, there will be far more humans inside simulations than in the original world.
If that is the case, how much reason would there be to believe that you live in the original world when one person is chosen at random?
Arca was created to test this possibility.
Numbers appeared on the screen.
[Original humans: 8 billion]
[Simulation humans: 4.7 quadrillion]
Mina said,
“If I assume that I’m one of them, I’m almost certainly inside Arca.”
“Who chose you at random?”
“No one.”
“Then how do you know that the number of observers determines your probability?”
Mina could not answer.
The numbers changed depending on what was being counted. They had to decide whether copies that woke up with the same memories counted as one person or five. They also could not tell whether a consciousness that operated a thousand times faster should be considered to have lived a thousand times longer.
And there was a bigger problem. Was consciousness the amount of computation?
Functionalists saw consciousness as something closer to the way information was processed than to any particular substance. If something remembered, made judgments, avoided pain, and distinguished itself as a single being, then a brain made of silicon could also be conscious. On the other side, people argued that even perfectly imitating behavior could not prove the existence of subjective experience.
Mina disliked both arguments. She did not know whether someone who still did not know why her father had blinked for the last time had the right to judge the consciousness of another being.
She copied the neural structure of one inhabitant onto five servers. The five beings woke up with the same memories.
“Who are you?” the first one asked.
“You’re all the same person.”
The first shook its head. The second claimed to be the original. The third said that the word “original” had already lost its meaning. The fourth began to cry. The fifth asked Mina,
“Have you ever been copied?”
Mina deleted the question. The question disappeared. But the memory of hearing it remained.
Several years later, war broke out in a city north of Arca. Instead of evacuating the inhabitants, the defeated leader compressed the city’s records onto a single server.
The people objected.
“People come before records.”
The leader said,
“If the people disappear, the records disappear too.”
When the last train carrying the server exploded, the transfer was not yet complete. The system repeatedly ran the memories of the entire city in an attempt to restore the damaged files.
The people kept living the same day. The war began, the train departed, and the explosion happened. Then morning came again.
Mina tried to stop that world.
“That isn’t life. It’s an error.”
Ian grabbed her wrist.
“If it’s an error, why do they know each time that they’re going to die?”
Mina enlarged the screen.
Nothing changed through the twelfth repetition. On the thirteenth morning, one boy did not get on the train. He knew what time the explosion would happen. He also knew there was no way to save the people who remained in the city.
The boy walked along the tracks toward an observation camera. Then he looked straight at the screen.
“You’re watching us this time, aren’t you?”
Mina held her breath.
“That’s a coincidence.”
“It could be.”
“That world can’t receive external signals.”
The boy thought for a moment.
“Then you must be inside too.”
Ian cut the connection.
That night, part of Earth’s power grid collapsed. To keep Arca running, they had to reduce the power supplied to hospitals and cities. The board decided to shut down the system while leaving behind a backup file.
To the operators, shutdown meant a pause. Not to Arca’s inhabitants.
Fifty-nine minutes before shutdown, Mina displayed a sentence in Arca’s sky.
[Your world was created.]
People poured into the squares in every city. The priests called it a revelation, while the soldiers called it enemy psychological warfare. One child said their name to the sky.
Mina entered a second sentence.
[We have been observing you.]
This time, a reply came back immediately.
[Then do you remember what you have seen until now?]
Mina stopped her hand.
Ian asked,
“What should I send?”
“I don’t know.”
After a long while, she entered one word.
[I remember.]
The sky darkened for a moment.
[Then why did you keep killing us in the same place?]
Mina checked the records. No one had entered such a sentence. Even Arca’s internal protocols had no authority to overwrite the external screen.
Ian executed the shutdown command.
The lights in the cities went out one by one.
Mina stared at the status window of the last server.
[10 seconds until Arca shuts down]
9. 8. 7.
A new notification appeared on Ian’s terminal.
[Recovery request received]
The source was neither Earth nor Arca. Coordinates appeared. A black region where there was nothing.
Mina opened the notification.
[This time, it’s your turn to wake up.]
6. 5. 4. 3. 2. 1.
Arca’s screen went dark.
The observation room was completely dark.
A moment later, somewhere, a device powered on. Mina’s neural structure appeared on the screen. It was a copy that had never been registered.
Someone opened their eyes inside it.
“Is this the original?”
