After that, they got in the habit of talking from time to time. He always had to work to draw her out, but it was interesting work. And when the dry season came, in the fall helionequinox, and he started going out sailing again from the little harbor Alpha, he asked her haltingly if she would like to join him, and they stuttered their way through a deeply awkward interaction, which resulted in her going out with him the next nice day, sailing in one of the lab’s many little catamarans.

When day sailing, Sax stayed in the little bay called the Florentine, southeast of the peninsula, where Ravi Fjord widened but before it became Hydroates Bay. This was where Sax had learned to sail, and where he still felt best acquainted with the winds and currents. On longer trips he had explored the delta of fjords and bays at the bottom end of the Marineris system, and three or four times he had sailed up the eastern side of the Chryse Gulf, all the way to Mawrth Fjord and along the Sinai Peninsula.

On this special day, however, he confined himself to the Florentine. The wind was from the south, and Sax tacked down into it, enlisting Bao’s help at every change of tack. Neither of them said much. Finally, to get things started, Sax was forced to ask about physics. They talked about the ways in which strings constituted the very fabric of space-time itself, rather than being replacements for points in some absolute abstract grid.

Thinking it over, Sax said, “Do you ever worry that work on a realm so far beyond the reach of experiment will turn out to be a kind of house of cards — knocked over by some simple discrepancy in the math, or some later different theory that does the job better, or is more confirmable?”

“No,” Bao said. “Something so beautiful as this has to be true.”

“Hmm,” Sax said, glancing at her. “I must admit I’d rather have something solid crop up. Something like Einstein’s Mercury — a known discrepancy in the previous theory, which the new theory resolves.”

“Some people would say that the missing shadow matter fills that bill.”

“Possibly.”

She laughed. “You need more, I can see. Perhaps some kind of thing we can do.”

“Not necessarily,” Sax said. “Although it would be nice, of course. Convincing, I mean. If something were better understood, so that we could manipulate it better. Like the plasmas in fusion reactors.” This was an ongoing problem in another lab at Da Vinci.

“Plasmas might very well be better understood if you modeled them as having patterns imposed by spin networks.”

“Really?”

“I think so.”

She closed her eyes — as if she could see it all written down, on the inside of her eyelids. Everything in the world. Sax felt a piercing stab of envy, of — loss. He had always wanted that kind of insight; and there it was, right in the boat beside him. Genius was a strange thing to witness.

“Do you think this theory will mean the end of physics?” he asked.

“Oh no. Although we might work out the fundamentals. You know, the basic laws. That might be possible, sure. But then every level of emergence above that creates its own problems. Taneev’s work only scratches the surface there. It’s like chess — we might learn all the rules, but still not be able to play very well because of emergent properties. Like, you know, pieces are stronger if they’re out in the center of the board. That’s not in the rules, it’s a result of all the rules put together.”

“Like weather.”

“Yes. We already understand atoms better than weather. The interactions of the elements are too complex to follow.”

“There’s holonomy. Study of whole systems.”

“But it’s just a bunch of speculation at this point. The start of a science, if it turns out to work.”

“And so plasmas, though?”

“Those are very homogeneous. There’s only a very few factors involved, so it might be amenable to spin-network analysis.”

“You should talk to the fusion group about that.”

“Yes?” She looked surprised.

“Yes.”

Then a hard gust hit, and they spent a few minutes watching the boat respond, the mast sucking in sails with a bit of humming until they were reset, and running across the strengthening breeze, into the sun. Light flaked off the fine black hair gathered at the back of Bao’s neck; beyond that, the sea cliffs of Da Vinci. Networks, trembling at the touch of the sun — no. He could not see it, with eyes open or closed.

Cautiously he said, “Do you ever wonder about being, you know. Being one of the first great women mathematicians?”

She looked startled, then turned her head away. She had thought about it, he saw. “The atoms in a plasma move in patterns that are big fractals of the spin-network patterns,” she said.

Sax nodded, asked more questions about that. It seemed possible to him that she would be able to help Da Vinci’s fusion group with the problems they were having engineering a lightweight fusion apparatus. “Have you ever done any engineering? Or physics?”

Affronted: “I am a physicist.”

“Well, a mathematical physicist. I was thinking of the engineering side.”

“Physics is physics.”

“True.”

Only once more did he push, and this time indirectly. “When did you first learn math?”

“My mom gave me quadratic equations at four, and all kinds of math games. She was a statistician, very keen about it all.”

“And the Dorsa Brevia schools… .”

She shrugged. “They were fair. Math was mostly something I did by reading, and correspondence with the department in Sabishii.”

“I see.”

And they went back to talking about the new results from CERN; about weather; about the sailboat’s ability to point to within a few degrees of the wind. And then the following week she went out with him again, on one of his walks on the peninsula’s sea cliffs. It was a great pleasure to show her a bit of the tundra. And over time, taking him through it step-by-step, she managed to convince him that they were perhaps coming close to understanding what was happening at the Planck level. A truly amazing thing, he thought, to intuit this level, and then make the speculations and deductions necessary to flesh it out and understand it, creating a very complex powerful physics, for a realm that was so very small, so very far beyond the senses. Awe-inspiring, really. The fabric of reality. Although both of them agreed that just as with all earlier theories, many fundamental questions were left unanswered. It was inevitable. So that they could lie side by side in the grass in the sun, staring as deeply into the petals of a tundra flower as ever one could, and no matter what was happening at the Planck level, in the here and now the petals glowed blue in the light with a quite mysterious power to catch the eye.

Actually, lying on the grass made it clear how much the permafrost was melting. And the melt lay on a hardpan of still-frozen ground, so that the surface became saturated and boggy. When Sax stood up, his ventral side chilled instantly in the breeze. He spread his arms to the sunlight. Photon rain, vibrating across the spin networks. In many regions heat exhaust from nuclear power plants was being directed down into capillary galleries in the permafrost, he told Bao as they walked back to the rover. This was causing trouble in some wet areas, which were tending to saturate at the surface. The land melting, so to speak. Instant wetlands. A very active biome, in fact. Though the Reds objected. But most of the land that would have been affected by permafrost melt was now under the North Sea anyway. What little remained above the sea was to be treasured as swamps and marshes.

The rest of the hydrosphere was almost equally transformative of the surface. It couldn’t be helped; water was a very effective carver of rock, hard though it was to believe when watching a gossamer waterfall drift down a sea cliff, turning to white mist long before it hit the ocean. Then again there was the sight of the massive giant howler waves, battering the cliffs so hard that the ground shook underfoot. A few million years of that and those cliffs would be significantly eroded.