The Andromeda Strain - Crichton Michael - Страница 30

In theory it was simple, but in practice the reading of spectrometrograms was complex and difficult. No one in this Wildfire laboratory was trained to do it well. Thus results were fed directly into a computer, which performed the analysis. Because of the sensitivity of the computer, rough percentage compositions could also be determined.

Burton placed the first chip, from the black rock, onto the vaporizer and pressed the button. There was a single bright burst of intensely hot light; he turned away, avoiding the brightness, and then put the second chip onto the lamp. Already, he knew, the computer was analyzing the light from the first chip.

He repeated the process with the green fleck, and then checked the time. The computer was now scanning the self-developing photographic plates, which were ready for viewing in seconds. But the scan itself would take two hours- die electric eye was very slow.

Once the scan was completed, the computer would analyze results and print the data within five seconds.

The wall clock told him it was now 1500 hours- three in the afternoon. He suddenly realized he was tired. He punched in instructions to the computer to wake him when analysis was finished. Then he went off to bed.

In another room, Leavitt was carefully feeding similar chips into a different machine, an amino-acid analyzer. As he did so, he smiled slightly to himself, for he could remember how it had been in the old days, before AA analysis was automatic.

In the early fifties, the analysis of amino acids in a protein might take weeks, or even months. Sometimes it took years. Now it took hours- or at the very most, a day- and it was fully automatic.

Amino acids were the building blocks of proteins. There were twenty-four known amino acids, each composed of a half-dozen molecules of carbon, hydrogen, oxygen, and nitrogen. Proteins were made by stringing these amino acids together in a line, like a freight train. The order of stringing determined the nature of the protein- whether it was insulin, hemoglobin, or growth hormone. All proteins were composed of the same freight cars, the same units. Some proteins had more of one kind of car than another, or in a different order. But that was the only difference. The same amino acids, the same freight cars, existed in human proteins and flea proteins.

That fact had taken approximately twenty years to discover.

But what controlled the order of amino acids in the protein? The answer turned out to be DNA, the genetic-coding substance, which acted like a switching manager in a freightyard.

That particular fact had taken another twenty years to discover.

But then once the amino acids were strung together, they began to twist and coil upon themselves; the analogy became closer to a snake than a train. The manner of coiling was determined by the order of acids, and was quite specific: a protein had to be coiled in a certain way, and no other, or it failed to function.

Another ten years.

Rather odd, Leavitt thought. Hundreds of laboratories, thousands of workers throughout the world, all bent on discovering such essentially simple facts. It had all taken years and years, decades of patient effort.

And now there was this machine. The machine would not, of course, give the precise order of amino acids. But it would give a rough percentage composition: so much valine, so much arginine, so much cystine and proline and leucine. And that, in turn, would give a great deal of information.

Yet it was a shot in the dark, this machine. Because they had no reason to believe that either the rock or the green organism was composed even partially of proteins. True, every living thing on earth had at least some proteins- but that didn't mean life elsewhere had to have it.

For a moment, he tried to imagine life without proteins. It was almost impossible: on earth, proteins were part of the cell wall, and comprised all the enzymes known to man. And life without enzymes? Was that possible?

He recalled the remark of George Thompson, the British biochemist, who had called enzymes "the matchmakers of life." It was true; enzymes acted as catalysts for all chemical reactions, by providing a surface for two molecules to come together and react upon. There were hundreds of thousands, perhaps millions, of enzymes, each existing solely to aid a single chemical reaction. Without enzymes, there could be no chemical reactions.

Without chemical reactions, there could be no life.

Or could there?

It was a long-standing problem. Early in planning Wildfire, the question had been posed: How do you study a form of life totally unlike any you know? How would you even know it was alive?

This was not an academic matter. Biology, as George Wald had said, was a unique science because it could not define its subject matter. Nobody had a definition for life. Nobody knew what it was, really. The old definitions- an organism that showed ingestion, excretion, metabolism, reproduction, and so on- were worthless. One could always find exceptions.

The group had finally concluded that energy conversion was the hallmark of life. All living organisms in some way took in energy- as food, or sunlight- and converted it to another form of energy, and put it to use. (Viruses were the exception to this rule, but the group was prepared to define viruses as nonliving.)

For the next meeting, Leavitt was asked to prepare a rebuttal to the definition. He pondered it for a week, and returned with three objects: a swatch of black cloth, a watch, and a piece of granite. He set them down before the group and said, "Gentleman, I give you three living things."

He then challenged the team to prove that they were not living. He placed the black cloth in the sunlight; it became warm. This, he announced, was an example of energy conversion-radiant energy to heat.

It was objected that this was merely passive energy absorption, not conversion. It was also objected that the conversion, if it could be called that, was not purposeful. It served no function.

"How do you know it is not purposeful?" Leavitt had demanded.

They then turned to the watch. Leavitt pointed to the radium dial, which glowed in the dark. Decay was taking place, and light was being produced.

The men argued that this was merely release of potential energy held in unstable electron levels. But there was growing confusion; Leavitt was making his point.

Finally, they came to the granite. "This is alive," Leavitt said. "It is living, breathing, walking, and talking. Only we cannot see it, because it is happening too slowly. Rock has a lifespan of three billion years. We have a lifespan of sixty or seventy years. We cannot see what is happening to this rock for the same reason that we cannot make out the tune on a record being played at the rate of one revolution every century. And the rock, for its part, is not even aware of our existence because we are alive for only a brief instant of its lifespan. To it, we are like flashes in the dark."

He held up his watch.

His point was clear enough, and they revised their thinking in one important respect. They conceded that it was possible that they might not be able to analyze certain life forms. It was possible that they might not be able to make the slightest headway, the least beginning, in such an analysis.

But Leavitt's concerns extended beyond this, to the general problem of action in uncertainty. He recalled reading Talbert Gregson's "Planning the Unplanned" with close attention, poring over the complex mathematical models the author had devised to analyze the problem. It was Gregson's conviction that:

All decisions involving uncertainty fall within two distinct categories- those with contingencies, and those without. The latter are distinctly more difficult to deal with.

Most decisions, and nearly all human interaction, can be incorporated into a contingencies model. For example, a President may start a war, a man may sell his business, or divorce his wife. Such an action will produce a reaction; the number of reactions is infinite but the number of probable reactions is manageably small. Before making a decision, an individual can predict various reactions, and he can assess his original, or primary-mode, decision more effectively.

But there is also a category which cannot be analyzed by contingencies. This category involves events and situations which are absolutely unpredictable, not merely disasters of all sorts, but those also including rare moments Of discovery and insight, such as those which produced the laser, or penicillin. Because these moments are unpredictable, they cannot be planned for in any logical manner. The mathematics are wholly unsatisfactory.

We may only take comfort in the fact that such situations, for ill or for good, are exceedingly rare.

Jeremy Stone, working with infinite patience, took a flake of the green material and dropped it into molten plastic. The plastic was the size and shape of a medicine capsule. He waited until the flake was firmly imbedded, and poured more plastic over it. He then transferred the plastic pill to the curing room.

Stone envied the others their mechanized routines. The preparation of samples for electron microscopy was still a delicate task requiring skilled human hands; the preparation of a good sample was as demanding a, craft as that ever practiced by an artisan- and took almost as long to learn. Stone had worked for five years before he became proficient at it.

The plastic was cured in a special high-speed processing unit, but it would still take five hours to harden to proper consistency. The curing room would maintain a constant temperature of 61 deg C. with a relative humidity of 10 per cent.

Once the plastic was hardened, he would scrape it away, and then flake off a small bit of green with a microtome. This would go into the electron microscope. The flake would have to be of the right thickness and size, a small round shaving 1,500 angstroms in depth, no more.

Only then could he look at the green stuff, whatever it was, at sixty thousand diameters magnification.

That, he thought, would be interesting.

In general, Stone believed the work was going well. They were making fine progress, moving forward in several promising lines of inquiry. But most important, they had time. There was no rush, no panic, no need to fear.

The bomb had been dropped on Piedmont. That would destroy airborne organisms, and neutralize the source of infection. Wildfire was the only place that any further infection could spread from, and Wildfire was specifically designed to prevent that. Should isolation be broken in the lab, the areas that were contaminated would automatically seal off. Within a half-second, sliding airtight doors would close, producing a new configuration for the lab.