Free Survey Ship by Marion Zimmer Bradley

the window and said, “Right.” Formally, they exchanged places. Teague said, “Are we going to keep on Greenwich Time for the whole voyage? Hours, days . .. weeks, months, years — they don't make much sense out here. Anyhow, as we approach light-speed, there'll be changes . . . it's not as if we could keep the clock set for what time it is back in dear old Greenwich of whatever!”
    Peake said, turning his back on the vista of stars — that was Ravi's responsibility for the next twelve hours — “We have to keep a 24 hour ship's day, or something near it. For circadian rhythms. God alone knows what light-speeds and zero gravity will do to our body rhythms. But we have to try and keep them as stable as we can, and for the next few months it won't matter much.”
    “The ship's already on Universal Solar,” Ravi said, looking at a small tell-tale at the very center of the ceiling of the Bridge; the seats swivelled through a full circular rotation — so they could be turned to any angle, though they would lock at whatever angle the sitter chose. The tell-tale displayed, in smooth-flowing liquid crystal digital numbers the time by what was called Universal Solar, or sometimes only true time; a kind of reckoning in seconds from the pulses of energy, elapsed time from the original Big Bang; true time, so-
    called, measured the exact age of the known Universe.
    “But Universal Solar is clumsy,” said Peake, looking at the long stream of numbers which measured time, in seconds, from the beginning of the universe,
    “Clumsy!” Moira said, disbelieving, and Ching said, “How can anything as precise as that be clumsy?”
    “Because,” Peake said, good-naturedly, “by the time you read all that off, in seconds, it's some other time already. I suggest we keep Greenwich Time just to figure out when our shifts begin and end, and when we're going to meet for those daily music sessions Fontana, or was it Moira, thought were so important.”
    Looking at the long, ever-changing stream of numbers on the tell-tale, they all, one by one, agreed to that. Greenwich Time would become a kind of biological time-clock for them; Ching's flying fingers programmed, into the computer, a sequence of “elapsed time, in hours and days, from leaving the space station,” basing it on 24-hour days, of which this — they all agreed — was Day One. Years calculated in Earth reckoning, Anno Domini, a religio-political reckoning, they all agreed, had no meaning for them. Day One became the day they had been skylifted, first to the Space Station, then to the Ship; and by that reckoning, when Ravi took his first shift, it became noon of Day One. Peake would go on-shift again at Midnight, which they would call the first moment of Day Two.
    “And we have been aboard for four hours,” Ching said, “and my biological rhythms are beginning to tell me that it's dinner-time. Is there any reason we have to stay in the Bridge, or must one of us be here to tend the machines at all times? And what will that do to our theory that we all ought to meet once a day?”
    Moira made a final finicky adjustment to a sail, a great triangular translucency blotting out a third of the
     stars, From the lenticular window she could see that the ship was rotating on its own axis as it moved against the stars. They seemed to be standing still, now, without the reference points of Space Station and Earth, and when she shut her eyes, the DeMag units told her that “down” was the floor of the Bridge, and the lenticular window was straight before her; but when she looked out to the small slow spin of the ship around them, the other shaped modules that came into view and were obscured again, themselves obscuring nearby stars, she felt a trace of vertigo, her inner ear channels rebelled, and she wondered how she could manage to swallow against this queasiness. She shut her eyes and the Bridge settled into homey normal up-and-down. Stability again.
    “Nobody has to be