The humans said I must keep a written diary of this expedition, which I complained was ridiculous, since all I am is a living, breathing diary. But what if I died? they asked. I never think in those terms, since when I die the nonredundant parts of my memory will be passed to my successor. But in fact I might be physically obliterated out here, something that has not happened to a member of my family for 4362 ares. A certain amount of knowledge was lost that day, unrecoverable. So I have to agree with them, and am writing this down, though it is unutterably slow and imprecise, and includes the labor of translation, since we have no written language.

English is their language, so I will use it, though French and Russian are easier for me to speak, since they have more sounds like our own.

Not speaking my own language depresses me. Snowbird is missing her “white” language, too, perhaps more than I miss mine; theirs is prettier, if less accurate. The consensus language we’re constrained to use lacks both qualities. And English is unspeakable. Namir, my favorite human here, can converse with me in Japanese, which is the most pleasant human language I know.

This is the first of May, 2088, the last day when our clocks and calendars will be the same as those on Earth and Mars. When we reach turnaround, halfway to our target, it will be August 13, 2091, on the ship, but back on Earth it will be July 2, 2100, almost nine years later. They say this is because of general relativity, though it makes no sense to me. They say our clocks run faster because we are moving, and although I know it’s true, it also makes no sense to me. Snowbird seems to understand it somewhat. She told me that little t, which is our time, is equal to c over a times the hyperbolic cosine of a over c times Earth time, which is big T. I suppose it’s true, but all I have to do is remember it. I think if I had to understand it, my brain would overheat and explode.

We have been accelerating for eight hours, and I think it will be eight years before I get used to it, if ever. It is like carrying more than your own weight on your back. The instant it started, I had to shit. That’s an impolite word, for some reason, but is the closest human word to what we do. I went as fast as I could, which was slowly, into our living area, to the patch of dirt we use for recycling our toxins. Snowbird was already there, being younger and stronger, but she respected my seniority and allowed me to step in first. The extra gravity did accelerate the process, which is the only good thing I can say about it.