So his clock is intuitive for me to read. And it works like an odometer. “ℓ” is clearly their 0. From that, I know that “I” is 1, “V” is 2, “λ” is 3, “+” is 4, and “V” is 5. What about 6 through 9? They don’t exist. After “V” we go back to “ℓ.” Eridians use base six.

Of all the things I teach my students, numerical bases are the hardest to make them truly understand. There’s nothing special about the number 10. We have ten unique digits because we have ten fingers. Simple as that. Rockies have three fingers per hand and I guess they only like to use two hands when counting (they probably keep the other three feet/hands on the ground to stay steady). So they have six fingers to work with.

“I like you, Rocky! You’re a genius!”

And he is! With this simple act, Rocky showed me:

• How Eridian numbers work (base six)
• How Eridian numbers are written (ℓ, I, V, λ,+, V)
• How Eridians read information (left to right)
• How long an Eridian second is

I hold up a finger and rush back into the ship to get my stopwatch. I come back and time Rocky’s clock. I start the timer just as the third rotor changes state. The right rotor continues clicking over every two seconds or so, and every six steps, the next rotor advances one. This is going to take a while, but I want as accurate a count as possible. It takes around a minute and a half for the third rotor to move just one step. I can expect to be at this for ten minutes or so. But I plan to watch the whole time.

Rocky gets bored. At least, I think that’s what happens. He starts fidgeting, and then lets the clock float in place near the divider wall. Then he wanders around his side of the tunnel. I’m not sure if he’s doing anything in particular. He opens a door leading into his ship, begins to climb through, and then stops. He seems to think it over, then changes his mind. He closes the door. He doesn’t want to leave while I’m still here. After all, I might do or say something interesting.

“♪♪♩,” he says.

“I know, I know,” I say. I hold up a finger.

He holds up his finger, then returns to slowly bouncing from wall to wall. Zero-g pacing.

Finally, the third rotor completes a full lap and I stop my timer. Total time: 511.0 seconds. I don’t have a calculator, and I’m too excited to go back into the ship to get one. I pull out a pen and do long division on the palm of my other hand. One Eridian second is 2.366 Earth seconds.

I circle the answer on my palm and stare at it. I add a few exclamation points nearby because I feel like they’re warranted.