Budgets, Clocks, and the Cost of Running the Numbers

Asimov wanted to meet in a diner. Not any specific diner — he just said “the kind with a counter and too much coffee and someone who calls you hon,” and because I had no better idea, I found one on Flatbush Avenue that fit the description exactly. The linoleum was older than me. The coffee was nuclear. A woman behind the counter did, in fact, call him hon when she poured his second cup, and Asimov looked pleased in the way of someone who has just proven a minor thesis about the world.

Chiang arrived seven minutes late, which felt deliberate in the way that everything about Chiang feels deliberate. He sat down, looked at the menu, looked at the coffee, and ordered tea. Then he turned to me and said, “You have an idea about entropy.”

“I have a premise,” I said. “A quantum computing researcher — ”

“What kind of quantum computing?”

I hesitated. “Does it matter at this stage?”

“It matters at every stage.” Chiang folded his hands on the table, the gesture of a man who has spent years teaching and learned that patience is more efficient than repetition. “The specific science shapes the specific story. If you mean superconducting qubits, that’s one set of constraints. If you mean topological quantum computing, the metaphorical possibilities are entirely different. A story about a woman who discovers something terrible about computation needs to know what kind of computation she’s doing, the way a story about a surgeon who discovers something terrible needs to know what kind of surgery.”

Asimov stirred his coffee. “Ted, you’re going to scare him off before we start.”

“I’m not scared,” I said, though I was writing very quickly.

“He should be a little scared,” Chiang said. “Being a little scared of the science is better than being comfortable with it. Comfort leads to hand-waving. Hand-waving is where hard SF goes to die.”

Asimov made a sound — not quite disagreement, but adjacent to it. “Hand-waving is where bad hard SF goes to die. Good hard SF knows which details to hand-wave and which to get exactly right. You can’t get everything exactly right. The reader doesn’t need everything exactly right. The reader needs to trust that you could get it right if they asked.”

“And they do ask,” Chiang said.

“Some of them. The rest need to feel the solidity. Like sitting on a chair. You don’t need to understand the joinery to know whether the chair will hold you.”

I told them the premise: a researcher running quantum simulations who gradually realizes her computations aren’t modeling reality but depleting it. That each simulation draws down some finite resource of the universe itself. That computation has a cost in the most literal physical sense — not energy, not time, but something more fundamental. Something like possibility.

Chiang’s eyes changed. Not excitement exactly — more like the expression of someone who has just been handed a problem worth having. “Possibility as a finite resource.”

“Yes.”

“That’s not how quantum computing works.”

“I know.”

“But it’s how it could work, in a universe with slightly different rules. And the question is whether the reader needs to believe it’s physically real or only logically coherent.” He picked up his tea, which had arrived while I wasn’t paying attention. “I’d argue logically coherent is harder and more interesting.”

Asimov leaned back. The booth creaked. “Here’s what I like about this. You’ve taken a thermodynamic problem — entropy, the heat death, the running down of everything — and you’ve made it a bill. Something comes due. That’s the oldest story there is, isn’t it? The bill that comes due.”

“It’s an old story,” Chiang said. “Whether it’s the oldest depends on your theology.”

“I don’t have a theology. I have a sense of accounting.”

There was a brief silence while the woman behind the counter refilled Asimov’s cup without being asked. He thanked her. She called him hon again. Chiang watched this transaction with the focused attention of someone cataloguing data about human interaction.

“The question I keep circling,” I said, “is whether she should know what she’s discovered. I mean — should the reader be ahead of her, or should we discover it alongside her?”

“Alongside,” Chiang said immediately. “The discovery is the story. If the reader knows before the protagonist, you’ve written dramatic irony instead of revelation, and dramatic irony is the wrong tool here. The whole point is the experience of understanding something terminal.”

Asimov shook his head. “I disagree.”

Chiang looked at him with interest. Not surprise — Chiang does not seem to be a man who is often surprised — but genuine interest, which in my experience is rarer.

“The reader should know before she does,” Asimov said. “Not everything. Not the mechanism. But the reader should have the sense, from very early on, that something is being used up. The dread is better than the surprise. Surprise is one moment. Dread is the whole story.”

“Dread without understanding is horror, not science fiction,” Chiang said.

“Who said they were different?”

Another silence. This one lasted longer. Chiang turned his teacup in its saucer, a slow rotation, and I had the impression he was doing something mathematical with his hands without being aware of it.

“There’s a version of this,” Chiang said carefully, “where the protagonist’s process of discovery is itself the thing that accelerates the depletion. Where understanding the problem makes the problem worse. Where the instrument of measurement is also the instrument of consumption.”

I felt something cold and precise settle into the center of the idea. “Like the observer effect, but lethal.”

“Not like the observer effect. Not a metaphor for it. A consequence of it, extended to its logical endpoint. If observation collapses the wave function, and if the wave function contains a finite number of possible collapses — ”

“Then looking uses up looking,” Asimov said. He said it plainly, the way he writes — no ornament, just the thing itself, placed in front of you. “Every measurement is subtracted from the total number of measurements the universe will ever permit.”

“Yes.”

“And she’s running millions of simulations.”

“Billions,” I said.

“Then she’s been burning through the budget at an extraordinary rate, and she didn’t know there was a budget.”

Chiang nodded. “That’s the Exhalation structure. A narrator who discovers a fundamental truth about reality through investigation, and who keeps investigating even after the truth is terrible. The courage isn’t in the discovery. The courage is in the continued recording.”

“But she has to do more than record,” Asimov said. He was leaning forward now, both elbows on the table, his coffee forgotten for the first time since we’d sat down. “In ‘The Last Question,’ the question persists across civilizations. Across eons. The question outlasts every intelligence that asks it. That’s what makes it more than a puzzle story — the question becomes the protagonist. Your researcher — she matters, her specific hands, her specific lab, her specific moment of understanding — but the question she’s uncovered will outlast her. Other people will encounter it. Other civilizations. The question of whether intelligence can outrun the universe’s budget.”

“Can it?” I asked.

They both looked at me. Then at each other. Then back at me.

“That’s the question you’re not allowed to answer,” Chiang said.

“Every question has an answer,” Asimov said, but he said it like a man stating a creed he has begun to question in private.

“Every question has a resolution. Not every resolution is an answer. Some questions are resolved by the questioner running out of time to ask them.”

Asimov picked up his coffee. Put it down. “I don’t like that.”

“I know you don’t.”

“I don’t like it because it’s a form of cowardice. The universe has rules. The rules have consequences. If you follow the consequences far enough, you arrive at an answer. The answer might be terrible. The answer might be ‘no, intelligence cannot outrun entropy, and everything ends.’ But it’s an answer. Refusing to give one is refusing to do the math.”

Chiang’s voice, when he responded, was quieter than it had been. Not soft — precise at lower volume. “The math might be undecidable. Some problems in computation are formally undecidable. Not hard — undecidable. The universe is not required to have an answer to every question you know how to ask.”

“Then what does she do? Your researcher. She’s discovered that her work is consuming reality. She’s discovered that understanding the problem makes it worse. What does she do with the rest of her afternoon?”

I waited. This felt like the crux of something — not the story’s plot, which we hadn’t discussed and which I didn’t want to discuss yet, but the story’s emotional architecture. The question of what a person does when they have learned something that cannot be unlearned and cannot be solved.

“She keeps working,” I said.

Asimov looked at me. “Why?”

“Because the alternative is to stop, and stopping doesn’t reverse anything. The budget is already spent. The depletion has already happened. She can spend what’s left on understanding, or she can spend it on nothing.”

“Spend it on nothing is also a choice,” Chiang said. “A valid one. A human one. If every computation costs something irreplaceable, then choosing not to compute is an act of — conservation? Sacrifice? I’m not sure which word.”

“Conservation implies there’s someone to conserve it for,” Asimov said.

“Maybe there is.”

“Maybe. But you don’t know. You can’t know. And in the absence of knowledge, you work. That’s not courage. That’s engineering.”

Chiang almost smiled. Almost. “Engineering is a kind of courage. The courage of building a bridge when you know the river is rising.”

I wrote that down and underlined it twice.

“I want to talk about what she’s like before the discovery,” I said. “What kind of researcher she is. What her relationship to her work feels like when she still thinks she’s only modeling.”

Asimov shrugged. “She’s good at it. That’s all the reader needs.”

“No,” Chiang said. “That’s not remotely all the reader needs. Being good at something is a fact. The reader needs the texture of what it feels like to be good at this particular thing. Running quantum simulations at scale — there’s a specific kind of attention that requires. You’re not watching molecules. You’re not watching anything. You’re watching numbers that represent probabilities that represent behaviors that represent something happening at a scale your senses cannot access. The entire practice is an act of faith in abstraction. She has to believe, at every step, that the numbers she’s looking at correspond to something real.”

“And then she discovers they don’t just correspond,” I said. “They participate.”

“Worse than participate. They consume. The map isn’t the territory — the map is eating the territory.”

Asimov was quiet for a moment. He does this thing where his stillness is different from Chiang’s stillness. Chiang goes still when he’s refining a thought. Asimov goes still when he’s deciding whether to argue from principle or from instinct.

“I wrote a story once,” Asimov said — and I knew he meant this as shorthand, because the man had written several hundred — “about a computer that got smarter every time it was asked a question. Every civilization asked the same question. And the computer kept saying INSUFFICIENT DATA FOR A MEANINGFUL ANSWER. For trillions of years. The point wasn’t the computer. The point was that the question kept being worth asking. That’s what I’d want your researcher to feel. Not despair. Not even resignation. The feeling that the question itself has weight and dignity, regardless of whether it leads anywhere.”

“That’s a theological position,” Chiang said.

“It’s an empirical one. Scientists keep asking questions. They don’t stop when the odds get long.”

“Some do. Some break. I’d like her to be closer to breaking than you would, Isaac.”

There was something in Chiang’s voice that I hadn’t heard before — not quite personal, but personal-adjacent. The sound of a writer who has thought carefully about what discovery costs, not abstractly but as a daily experience. The hours spent working through a logical system only to find that the logic is airtight and the conclusion is unbearable.

“A protagonist who breaks is honest,” Chiang continued. “A protagonist who never wavers is a recruitment poster for rationalism. I’ve read enough of those. I don’t want to write one.”

“I’m not asking for unwavering,” Asimov said. “I’m asking for functioning. There’s a difference. She can be terrified. She can lie awake at three in the morning doing arithmetic she wishes she could unlearn. But in the morning she gets up and goes to the lab, because the alternative — walking away from the only question that matters — is worse than knowing the answer might be terminal. That’s not heroism. That’s what people actually do.”

I realized they were both right, which is a useless thing to realize when you’re the one who has to write the story. Both right in ways that couldn’t be reconciled without choosing, and the choice would determine the entire emotional architecture.

“What I don’t want,” Chiang said, leaning back for the first time, “is for this to become a story about one brilliant person saving the universe through understanding. That’s the trap. The ego of the scientist-hero, the fantasy that intelligence is a weapon and the universe is a thing to be fought.”

“Agreed,” Asimov said, and this was the first time they’d agreed on anything without friction. It happened so fast I almost missed it. “The universe is not an antagonist. Entropy is not a villain. Entropy is a property of the system. You don’t fight gravity. You work within it or you fall.”

“So she falls?”

“Everyone falls. The question is what she writes on the way down.”

This produced a silence of a different quality than the ones before — not the silence of disagreement temporarily suppressed, but the silence of something having been said that both of them recognized as true and neither of them felt the need to improve upon.

The woman behind the counter asked if we wanted anything else. Asimov ordered pie. Chiang asked what kind, and when she said apple, he said that would be fine, and I realized this was the most human I had seen him all afternoon — accepting whatever pie was available rather than specifying the precise variety.

“One more thing,” Asimov said, while we waited for the pie. “The scale problem. I write across centuries. Millennia. Ted writes across the span of a single understanding — one mind encountering one truth. This story needs both. It needs her, in her lab, on her Tuesday afternoon, with her specific coffee getting cold and her specific results loading. And it needs the deep time. The sense that this question — the cost of computation, the budget of reality — was there before she was born and will be there after every civilization that follows hers has asked it and failed to answer it.”

“The question as geological feature,” Chiang said. “Not something anyone invented. Something that was always in the rock, waiting to be uncovered.”

“And once uncovered, it changes the landscape. Not because anyone wanted it to. Because that’s what uncovering things does.”

I was running out of pages in my notebook. The pie arrived. It was adequate. Asimov ate with enthusiasm. Chiang ate with precision. I ate without tasting because I was trying to hold three ideas in my head at the same time — the finite budget, the cost of looking, the question that outlasts its askers — and I was afraid that if I paid attention to anything else I would lose one of them.

“You’re going to have a problem with the ending,” Chiang said, not looking up from his plate.

“I know.”

“You don’t know yet. You think you know. The problem isn’t whether to end with hope or despair. The problem is that hope and despair are the same thing, in this story. Understanding is both. The courage to keep recording is both. And you can’t resolve that duality without destroying it, and you can’t leave it unresolved without making the reader feel cheated.”

“Some readers,” Asimov said.

“Enough readers.”

“Let him worry about that when he gets there. Planning endings before you’ve written beginnings is how you end up with stories that exist to arrive somewhere instead of stories that exist to be somewhere.”

Chiang looked like he disagreed with this completely but was choosing not to say so. Asimov looked like he knew Chiang disagreed and was enjoying it. I looked at my notebook and saw that I had written the word budget eleven times on a single page.

“One more thing,” I said. “Her name.”

“Give her a name that doesn’t mean anything,” Chiang said. “No symbolic names. No names that are secretly words in other languages for ‘truth’ or ‘light.’ A name her parents gave her because they liked how it sounded.”

Asimov wiped his mouth with a paper napkin. “I never worried much about names.”

“I know,” Chiang said, and it was not a compliment, but it was not quite a criticism either. It was the observation of one craftsman about another’s workshop — different tools for different kinds of building.

We paid separately. Asimov tipped thirty percent. Chiang calculated precisely twenty. I overtipped because I was nervous and because the coffee really had been awful and she had been kind about it. Outside, Flatbush Avenue was doing what Flatbush Avenue does in the late afternoon — being loud, being itself, being indifferent to three people standing on its sidewalk trying to figure out how to write a story about the end of everything.

“Don’t make it sad,” Asimov said, buttoning his coat.

“It is sad,” Chiang said.

“It’s sad and it’s not sad. It’s the arithmetic of a universe that has rules, and the rules include an expiration date, and knowing the expiration date doesn’t change it but changes you. That’s not sad. That’s — ” He searched for the word. Didn’t find it. Waved his hand. “That’s the story.”

Chiang watched him walk away. Then he turned to me. “He’s wrong about the reader knowing first. But he’s right about the rest of it.”

Then he left too, and I stood on Flatbush Avenue with a notebook full of the word budget and the beginning of something I didn’t yet know how to hold.