Page 153 of Project Hail Mary

He opens the top and points to a couple of hinged rods.“Control these from outside. Gather sample. Seal you device. Open my device. Have sample. Do human science with sample.”

“Smart,” I say. “Thanks.”

He gets back to work.

I lie in my bunk. There are a bunch of things I want to do, but I need to take it slow. I can’t risk another “stupid day” like yesterday. I almost ruined the sample and killed Rocky. I’m smart enough now to know I’m stupid. That’s progress.

“Computer: coffee!”

After a minute, the arms hand me a cup of java.

“Hey,” I say, sipping my coffee. “How come you and I hear the same sounds?”

He keeps working on the armatures inside his device.“Useful trait. Both evolve. Not surprising.”

“Yeah, but why the same frequencies? Why don’t you hear much higher frequencies than I can? Or much lower?”

“I do hear much higher frequency and much lower frequency.”

Didn’t know that. But I should have figured that was the case. It’s an Eridian’s primary sensory input. Of course he’ll have a wider range than I do. That still leaves one unanswered question, though.

“Okay, but why is there overlap? Why don’t you and I hear completely different frequency ranges?”

He puts the tool in one of his hands down, which leaves two hands still plugging away on his device. With the newly free hand, he scrapes his workbench.“You hear this, question?”

“Yes.”

“That is sound of predator approaching you. That is sound of prey running away. Sound of object touching object very important. Evolve to hear.”

“Ah! Yes.”

It’s obvious now that he points it out. Voices, instruments, birdcalls, whatever—they can all be wildly different sounds. But the sound of objects colliding isn’t going to have much variance from planet to planet. If I bang two rocks together on Earth, they’re going to make the same noise as if I bang them together on Erid. So we’re all selected-for by being able to hear it.

“Better question,”he says.“Why we think same speed, question?”

I shift over to lie on my side. “We don’t think at the same speed. You do math way faster than I can. And you can remember things perfectly. Humans can’t do that. Eridians are smarter.”

He grabs a new tool with his free hand and gets back to tinkering.“Math is not thinking. Math is procedure. Memory is not thinking. Memory is storage. Thinking is thinking. Problem, solution. You and me think same speed. Why, question?”

“Hmm.”

I ponder it for a while. It’s a really good question. How come Rocky isn’t a thousand times smarter than me? Or a thousand times dumber?

“Well…I have a theory for why we’re about the same intelligence. Maybe.”

“Explain.”

“Intelligence evolves to gives us an advantage over the other animals on our planet. But evolution is lazy. Once a problem is solved, the trait stops evolving. So you and me, we’re both just intelligent enough to be smarter than our planet’s other animals.”

“We are much much smarter than animals.”

“We’re as smart as evolution made us. So we’re the minimum intelligence needed to ensure we can dominate our planets.”

He thinks it over.“I accept this. Still not explain why Earth intelligence evolve same level as Erid intelligence.”

“Our intelligence is based on the animals’ intelligences. So what is animal intelligence based on? How smart do animals have to be?”

“Smart enough to identify threat or prey in time to act.”