Far Horizon (Juggernaut #4)

Seven

Ellie led the way, practically skipping with excitement. Her time on Parador had opened her eyes to a world of colour and life that didn't exist on the Juggernaut outside of what farming and agriculture they could support in that strange environment.

Here on Skygarden the two worlds met. One was a clean, light and airy space station where stars were visible through the dome and the curve of a red planet cut the sky in two. The other was a cultivated parkland, warm and humid, where tall trees stretched high and broad trees spread their canopy over the plants and wildlife on the station's floor.

Sometimes they could make out the tension cables and struts which connected the floor of the two domes together.

A butterfly the size of Ellie's hand crossed their path and landed among purple flowers shaped like bells. Birds chirped and squabbled in the air above them.

They walked toward the centre of the dome. Ellie hand in had with Jayce. Nina and Malachi walking so their shoulders touched, leaning close, sharing private jokes and comments. Tila walked alone behind them. Her friends had each other, so she was the first to notice the sky.

As they moved from the edges to the centre of the garden the roof of the dome receded. In the middle, where the tallest trees grew, the dome's crown touched and become one with its counterpart at other end of the station. This flowing shape which gave the station its hourglass appearance from the outside was easily forgotten by the people within. So many plants and trees had been so carefully placed, that the funnel between the two domes was easily concealed.

But here, near the middle of the dome, it was possible to see past the treetops and to the mirror world beyond.

At the other end of the station was another garden, just like their own. The giant tree under which they stood, which had been shipped in and rooted here, had a twin which also stretched toward the neck between the domes. If you looked closely, you might see the movement of people and service vehicles underneath the distant canopy.

"That's a weird sight," said Malachi when he noticed it. "I shouldn't be able to see people when I look up."

"Or trees," said Nina.

"Is that person waving at us?" said Ellie. She waved back, just in case.

"Why did they make two domes?" said Tila. "One's enough."

They all looked at Malachi.

He waited.

"We know you already know," said Nina.

"Fine," said Malachi. "Maybe I looked it up on the ascent from Kinebar. The original plan was for a single dome, but that meant the space station would be asymmetric and they would need more anti-gravity generators to counter it. Making the station two domes meant they could reduce their power needs by adding a spin around the centre, up there." He pointed at the neck between the domes.

"Clever," said Nina. "They used centrifugal force instead of gravity."

"What's the difference?" said Ellie. "It feels just the same."

Jayce jumped up and down. "She's right."

"The difference is an object in motion stays in motion," said Malachi. "By adding the right direction of spin they saved, I don't know..., sixty to eighty per cent of the power needed for anti-gravity generators."

"It's a good thing it's spinning the right way," said Ellie.

"Is falloff the same here?" said Tila. She looked up toward the hourglass neck. Birds soared this high from the ground, surfing the thermals that moved up the dome's interior, invisible currents in the air.

Only Jayce was confused by her question. Living planet side, the inverse square law of gravity was not something he ever needed to consider. The ground was beneath him, and gravity was a constant force in one direction.

In space, with enough distance from any large mass, gravity was insignificant, and effectively absent.

But on space stations, where artificial gravity shaped the environment, and the orientation of the generators defined your horizon, and which was was up and down, falloff was something everyone considered. No artificial plate could generate the equivalent force of a planet, so the the falloff was the effective range of the gravity field. Within a few metres an artificial environment worked just like a planet, but beyond this, the falloff increased rapidly. The relationship between mass and gravity worked differently when artificially generated, in the same way that artificial light could never hold a candle, as it were, to a star.

So Tila was naturally curious about what happened above the treeline. No space station she had seen ever had this much vertical space.

The birds soared higher, crossing the centre of the neck, and then it stopped. Wings outstretched, the bird hovered in the thermals, holding it's position perfectly. Then, with a small change in position, it angled sideways as if preparing to dive back to them, but instead it moved further up. It crossed the threshold between the domes, folded its wings, and stayed there.

"Huh," said Malachi. "I guess it makes sense there would be a null area of some kind up there. There's your falloff point, Tila."

"The destructive interference zone," said Nina.

The bird tumbled in the space between the domes until it turned toward them. It shook itself and disturbed the air just enough to send it moving backward. It crossed the threshold, stretched its wings and rose away from them, falling backward toward the floor of the other dome.

"How did it learn to do that?" said Ellie. "Birds don't grow in space."

Tila watched the bird longer than the others. "If you can adapt, you can survive," she said. "And if you survive you can adapt."