Meanwhile, the hot blood is too hot for any biological material to survive inside—it boils the water inside. This is handy for sterilizing incoming food of pathogens, by the way.

But in order for his worker cells to service any part of the hot-blood system, the system has to be cooled to ambient levels. And when that happens, the Eridian can’t use muscles at all. And that’s why Eridians sleep.

They don’t “sleep” like a human does. They’re legitimately paralyzed. And the brain, also being maintained, has no conscious function during that period. A sleeping Eridian can’t wake up.

That’s why they keep an eye on each other when they sleep. Someone has to keep you safe. Probably dates back to caveman (cave-Eridian?) days, and now it’s just a social norm.

As amazed as I am at all that, to Rocky it’s a boring topic. Meanwhile, he’s utterly shocked and amazed by humanity.

“You hear light, question?” Rocky says. (He puts a little quaver on the first note of his sentence when he’s surprised or impressed.)

“Yes. I hear light.”

While we chat, he uses his many hands to assemble some complicated-looking piece of equipment. It’s almost as big as he is. I recognize several parts on it as things he’s been repairing these past few days. He can hold a conversation and work on delicate machinery at the same time. I think Eridians are much better at doing multiple tasks than humans are.

“How, question?” he asks. “How can you hear light, question?”

I point to my eyes. “These are special body parts that focus and detect light. They send the information to my brain.”

“Light gives you information, question? Enough information to understand room, question?”

“Yes. Light gives information to humans like sound gives information to Eridians.”

A thought occurs to him. He stops working on his device entirely. “You hear light from space, question? You hear stars, planets, asteroids, question?”

“Yes.”

“Amaze. What about sound, question? You can hear sound.”

I point to my ears. “I hear sound with these. How do you hear sound?”

He gestures all over his carapace and arms. “Everywhere. Tiny receptors on outer shell. All report back to brain. Like touch.”

So his whole body is a microphone. His brain must be doing some serious processing. It has to know the exact position of the body, sense the time difference between sound hitting different parts of it… man, that’s interesting. But hey, my brain gives me an entire 3-D model of my surroundings just from two eyeballs. Sensory input is really impressive across the board.

“I can’t hear as well as you,” I say. “Without light, I can’t understand the room. I can hear you talk, but no more.”

He points to the divider. “This is wall.”

“This is a special wall. Light passes through this wall.”