Factoring Humanity

But no; the spheres weren’t planets. Nor were they twin suns. Rather, she felt sure, they were realms — specific spaces, but not really solid. What she’d first taken to be lakes reflecting sunlight on the surface of one of them were in fact tunnels right through, revealing the multicolored maelstrom that made up the backdrop to everything.

Heather found that her throat was dry. She swallowed with effort, trying to calm herself, trying to think.

If the construct had really folded into a hypercube, then she was perhaps now in a four-dimensional universe. That could explain why objects disappeared if she didn’t look at them directly — they were slipping not just left and right out of her field of view, but ana and kata as well.

Heather was stunned, shell-shocked, unsure of what to do next. Try to fly up to the orb above? Down to the one below, perhaps taking a journey through one of the tunnels that permeated it? Or move ahead to the maelstrom?

But soon her choice was made for her. Without her exerting any effort, she seemed to be floating up toward the overhead sphere — or, perhaps, the sphere was coming down toward her. She couldn’t tell if the breeze she felt was due to her own movement or was just the air-circulation system inside the construct.

As she floated upward, she was startled to see what looked like a mouth open upon the sphere above her and a long, iridescent snake shoot out of it and drop down past her, connecting with the sphere below, where it was promptly swallowed by another mouth. As she continued her ascent, two more snakes made the downward journey from above, and one leaped up past her from the lower sphere to the upper one.

Although they were unlike anything she’d ever seen before, she felt sure, somehow, that the spheres and snakes were organic — they had the look of biology, the slick wetness of life, the irregularities of something grown rather than manufactured. But whether they were separate life forms or just organs within a bigger creature, she had no way to tell. The maelstrom backdrop might be the far reaches of space — or some sort of containing membrane.

Her heart was still hammering; the idea that some or all of this was alive frightened her. And as she got closer to the surface of the upper sphere, she could see that it was gently expanding and contracting — either pumping or breathing. The dimensions were fantastic; assuming that she was still 164 centimeters tall, the sphere must be dozens, if not hundreds, of kilometers across. But then again, perhaps she’d shrunk to a tiny fraction of her original size and was now on some fantastic voyage through the anatomy of a Centaur.

Indeed, perhaps that was the purpose! Many SETI researchers had suggested that actual, physical travel between stars would always be impractical. Perhaps the Centaurs had merely sent a detailed record of what they were like inside so that humans could reconstruct one of them from local material.

She continued to rise higher and higher — which made her think about gravity. She had a sense of up and down, and she felt as though she were moving to a greater altitude. But if she were truly weightless, then such sensations had no real meaning.

Up or down? Rising or falling?

Perspectives. Perceptions.

In a class on the psychology of perception years ago, Heather had been introduced to the Necker cube: twelve lines making up the skeletal view of a cube, as seen from an angle:

[Picture C]

If you stared at it long enough, it seemed to bounce between being a cube angling off toward the upper left and one angling toward the lower right, each square panel popping between being the one in the foreground and the one in the background.

She closed her eyes, and -

— and after a second, saw the inside of the construct. That method wouldn’t do to reorient herself. She opened her eyes, but the same sphere seemed to be overhead. So instead, she pulled in her focus, looking at an imaginary object only centimeters in front of her nose. The background became blurry. After a few seconds, she let her eyes relax, returning to infinity focus.

And indeed, her perspective had now flipped. The closest sphere now appeared to be beneath her feet. She rather suspected that with an effort of will, she could make it appear to her left or right, or front or back, or -

Or kata or ana?

If her mind could only deal with three pairs of directions at once, and if there really were four to choose from here, then she simply was failing to see one of the pairs. But surely there was no absolute hierarchy, no sense in which length had any more claim to being the first dimension than did height or depth.

She defocused her eyes again and tried to clear her mind.

When she refocused, everything was the same.

She tried once more, this time also blinking her eyes but making sure not to keep them closed long enough to switch back to the interior of the construct.

And then the blurry background did seem to shift -

And she refocused once more.