...And We Will Have Snow

Chapter 7: Marian

The introductory meeting adjourned. Everyone had lots of questions, but Tengri said they should consult the individual experts, not him. Naga immediately corralled Dema, and dragged her off along with Rosita to show her Marian's facility. Cern left with Ryan, who was suggesting they go see Jack and get a look at the power plant. Juan and Kore (or was it Sedna?) stayed behind to talk with Tengri a bit more.

"You got Tengri's vision," Naga said to Dema, "So you know how central the biology project is to the plan. Juan and I've been working with Rosita and Marian since we got here, and I'd love to try to explain the whole system to you, but Marian can do it much better."

They had left the main house, and crossed a wide yard to a building that looked like it was part barn and part greenhouse. Inside, Dema inhaled the rich aroma of growing things, and looked up between the rows of the many-tiered structure to see warm light filtering down through the glass roof.

"It's not really glass," said Rosita, "It's a much more durable polycarbonate, although it has the same greenhouse properties."

Naga had rounded up Marian, who shook Dema's hand warmly in welcome.

Dema said, "I hope this isn't too much of an interruption."

"Not at all," Marian replied, "I'm always happy to talk about what we're doing here. Where shall I start?" She looked at both Naga and Dema.

"Better start with the basics," Dema said. "I'm sure my forensic biology studies left a lot of holes, and I've forgotten most of it anyway."

"Okay. But please forgive me if I get too professorial or too carried away. I live and dream all this." She waved an arm at their surroundings. "Stop me any time if you have questions." She paused for a moment, then began.

"Biological systems are made up of four essential elements: carbon, hydrogen, oxygen and nitrogen. Each of these elements has a cycle by which it moves through the system. The movement is driven by energy flows and energy exchanges. These four cycles are intricately interwoven and interdependent, with energy flowing back and forth between them as it moves down the energy gradient."

As she spoke, Marian began to walk slowly between the tiers of plants. "Natural systems have evolved to utilize the naturally occurring energy flows. The most obvious source is solar, but there are also earth-thermal flows and subsidiary flows of air and water; atmospheric, oceanic and riverine." She made sweeping gestures toward the tiers with her arms and hands, as if tracing some of the flows she spoke of.

"These flows carry all four elements in the forms of water (H2O), carbon dioxide, free oxygen and free nitrogen. Of these, the flow of nitrogen is the most problematic, and because of that perhaps the most miraculous."

Dema's eyebrows perked up in curiosity at that. Naga and Rosita smiled, they knew where this was going.

"Together the four elements I named form the amino acids, along with several other elements that give some of them their special characteristics. The amino acids are the building blocks of life, and they all can and do form naturally, even in outer space." 

There was another little look of surprise from Dema.

"But for life to develop and evolve as it has on earth, there must be concentrated energy flows to enable and create organization, construction of increasingly complex physical entities, natural design. Crucial to this process is the ability of nitrogen to combine with either hydrogen or oxygen, or both, capturing energy as it does so. But atmospheric nitrogen, N2, is very stable, effectively inert. It doesn't spontaneously become 'fixed' into any of its compound forms, except occasionally in lightning strikes, or geothermal events such as volcanic eruptions."

Marian paused and scanned her little audience. "You're probably wondering what that has to do with our little aquaponics system. What I'm describing is the biosphere, and what we are developing here is a biosphere in miniature. Shall I continue?" Heads nodded, so she went on.

"You probably know that the most abundant atmospheric gases, nitrogen and oxygen, are both only poorly soluble in water. This is a kind of miracle in itself, as it means that the presence of water helps restrain oxidation reactions that would make life impossible.

"The miracle of nitrogen is that, although it is even less soluble in water than oxygen, early bacteria developed the ability to 'fix' it in the form of ammonia, NH3, which is highly soluble. From that form it can be oxidized into nitrites and nitrates. All three forms are essential to biological processes.

"What's amazing is that it takes energy to make ammonia, and those bacteria were able to learn this trick, tapping into whatever energy gradients were available. First geothermal, eventually solar. Here it is electrical, converted to heat or light as needed."

Dema was nodding her understanding. This was at least vaguely familiar from her science training. It was also familiar in the shaman sense, from the deep biological awareness she thought of as her link to Gaia.

Marian continued. "So. Now we have complete life systems, the global biosphere. And we also have farms for growing food so people can tap into those systems and live off of them. But these farms rely mostly on the natural cycles to do the work. Farming evolved with little real understanding of the four cycles. Especially the nitrogen one. Farmers figured out long ago that rotating crops was good for the soil, but they didn't really know why until recently. Many crops deplete the nitrogen in the soil. Some crops put it back.

"When this became understood, artificial fertilizer was invented, to replace the depleted nitrogen without rotating crops. Industrial farming began. But the understanding was incomplete. Too much ammonia is a bad thing, worse than too little. The excess began poisoning the environment, even to the extent of creating 'dead zones' in the oceans where rivers dump it. This happens because the nitrates stimulate the growth of algae and cause huge algal blooms, which paradoxically deplete the oxygen so fish and other sea animals that normally eat the algae can't survive.

"More recently we have begun to learn that there can be a similar problem with the carbon cycle. Plants thrive on carbon dioxide. Add a little extra and they grow more lush. But add too much and it becomes toxic to the plants. In between, there's a condition where the plants, responding to an abundance of carbon dioxide, grow so lush so fast that they outstrip their ability to extract essential nutrients and minerals from the soil. Although more lush they may be less nutritious. So a proper balance is important.

"Now, at last, we are beginning to understand all this. We can design aquaponic farm systems with all four cycles in mind. That is, in theory. In practice, it's a very complex undertaking. The tendency is to oversimplify it, and then supplement it artificially to keep it in some rough balance. To replace industrial farming with industrial aquaponics.

"Our challenge here is to design a complete, self-sustaining system independent of outside resources. Our ideal is to design a farm that would work on a spaceship, and feed the whole crew indefinitely."