alerted Harry; he was so intrigued that he went back and looked, much to the consternation of the trailing apparatchik. She shooed Harry back into the herd with a sour look on her face. Harry, on the other hand, was grinning like a fool. “A Gehaar,” he said. “It was eating a buffalo wing when I looked in. Disgusting. ” Then he giggled. The Gehaar were one of the first intelligent aliens humans encountered, in the days before the Colonial Union established its monopoly on space travel. Nice enough people, but they ate by injecting their food with acid from dozens of thin head tentacles and then noisily slurping the resulting goop into an orifice. Messy.
Harry didn’t care. He’d spotted his first live alien.
Our meander reached its conclusion as we approached a holding bay with the words “Henry Hudson/CDF Recruits” glowing from a flight display. Our group gratefully took seats while our apparatchiks went to talk with some other Colonials waiting by the shuttle gate door. Harry, who was clearly showing a tendency toward curiosity, wandered over to the bay window to look at our ship. Jesse and I wearily got up and followed him. A small informational monitor at the window helped us find it among the other traffic.
The Henry Hudson was not actually docked at the gate, of course; it’s hard to make a hundred-thousand-metric-ton interstellar spacecraft move daintily in tandem with a revolving space station. As with the colony transports, it maintained a reasonable distance while supplies, passengers and crew were transported back and forth by rather more manageable shuttles and barges. The Hudson itself was stationed a few miles out and above the station, not the massive, unesthetically functional spoked-wheel design of the colony transports, but sleeker, flatter and, importantly, not at all cylindrical or wheel-shaped. I mentioned this to Harry, who nodded. “Full-time artificial gravity,” he said. “And stable over a large field. Very impressive.”
“I thought we were using artificial gravity on the way up,” Jesse said.
“We were,” Harry said. “The beanstalk platform’s gravity generators were increasing their output the higher up we went.”
“So what’s so different about a spaceship using artificial gravity?” Jesse asked.
“It’s just extremely difficult,” Harry said. “It takes an enormous amount of energy to create a gravitational field, and the amount of energy you have to put out increases exponentially with the radius of the field. They probably cheated by creating multiple, smaller fields instead of one larger field. But even that way, creating the fields in our beanstalk platform probably took more energy than it took to light your hometown for a month.”
“I don’t know about that,” Jesse said. “I’m from San Antonio.”
“Fine. His hometown, then,” Harry said, jerking a thumb toward me. “Point is, it’s an incredibly wasteful use of energy, and in most situations where artificial gravity is required, it’s simpler and much less expensive just to create a wheel, spin it and let that stick people and things to the inside rim. Once you’ve spun up, you only need to put minimal additional energy into the system to compensate for friction. As opposed to creating an artificial gravity field, which needs a constant and significant output of energy.”
He pointed to the Henry Hudson. “Look, there’s a shuttle next to the Hudson. Using that as a scale, I’m guessing the Hudson is 800 feet long, 200 feet wide and about 150 feet deep. Creating a single artificial gravity field around that baby would definitely dim the lights in San Antonio. Even multiple fields would be an amazing drain on power. So either they have a power source that can keep the gravity on and still run all the ship’s other systems, like propulsion and life support, or they’ve found a new, low-energy way to create gravity.”
“It’s probably not cheap,” I said, and pointed to a colony