The Enigma Score (50 page)

The chemists on Jubal who investigated the Presences would have found that they did not look at all like the silicon crystals used in computers, which have the fewest possible defects, but that they had very many vacancies and substitutionals – and dislocations.

This defect, dislocation, is the one that makes it possible for metals – and all metals are crystalline as they occur naturally – to be bent and deformed. Since dislocation is the only defect that ‘moves,’ it is an important one to consider in analyzing the Presences.

Figures 1 and 2 (see
page 384
) show the two types of dislocations that occur to some degree in all crystals. The first of these is called an edge dislocation (Fig. 1). It can be visualized as resulting when one makes a ‘half cut’ through a crystal and displaces the upper face perpendicular to the lower face, usually by one atomic distance. The second type of dislocation is called a screw dislocation (Fig. 2) and results from displacing the upper face perpendicular to the direction of the cut. Real dislocations are not as idealized as ‘edge’ or ‘screw’ represent them. Sometimes they form dislocation loops that wrap back on themselves, and at each point along the loop they will have varying proportions of edge and screw character. The region inside the dislocation loop is said to be ‘slipped.’ When deformed, the size of the slipped region changes. Sometimes it increases, sometimes it decreases. The amount of slipped region is proportional to the amount of energy stored in the crystal.

Dislocations represent small regions of deformation and they move in response to mechanical loading so that the deformation can migrate or extend from one region of the crystal to another. Dislocations exert forces on one another, sometimes forming stable arrays that are bound together and sometimes exerting repulsive forces that drive the dislocations apart. Energy is stored in dislocation arrays and can be released suddenly, manifested as fracture.

All of the requirements for ‘life’ can be supplied by dislocations. The storage and utilization of energy, which in biological life is accomplished through chemical means, can be provided by the interaction of dislocations, which would act as the molecules of a crystalline life form. Does this mean it could think? Is there some mechanism through which information could be stored and recalled?

Let us imagine a dislocation moving through a crystal in response to some deformation. Let us suppose that while this dislocation is moving on a straight front, it encounters two or more substitutionals. It has been observed that the substitutionals ‘pin’ the dislocation and do not allow it to move further. Between the substitutionals, however, the dislocation begins to ‘bulge,’ much as a sail bulges when pushed by the wind and pinned by the mast. When the deformation energy reaches some critical value, the dislocation can bulge no further and pinches off, wrapping back on itself and forming a dislocation loop. This loop is then free of its pins and moves forward, leaving behind a dislocation segment still pinned, which becomes the source of the next dislocation as the loading continues. This source of dislocations is called a Frank-Reed source.

From examination of the distance between dislocations generated by a Frank-Reed source, one could, in principle, reconstruct the deformation history of a crystal. Thus dislocation arrays contain information and could make up the most important component of a ‘mind’, that is the ability to store and recall information. A very elaborate and complicated array of Frank-Reed sources could operate as an anabolic path for the storage of information – not visual information, which is what we are accustomed to, but mechanical information, the entire deformation history of the crystal. The arrays would record heating and cooling, shifts in the earth, changes in the crystal’s own weight, and, very important on Jubal, sounds. Sunlight would be received only as heat and be perceived in the infrared. People and animals and climatic manifestations would be perceived by the sounds they make. Wind would be perceived as push, lightning perceived as heat and shock. The crystal would be, in fact, one enormous tactile being that could feel a wagon moving on its surface or feel a Tripsinger’s music.

How about growth? Crystal growth is also frequently dependent on dislocations. When a seed crystal is in contact with a solution or bath of the constituent atoms that make up a crystal, and when the conditions are right, a crystal will grow. Anyone with house plants has observed crystals growing on the soil surface or edges of the pot. These have grown from a seed crystal in the soil, drawing their substance from the dissolved minerals in water. In some crystals with large periods (as many as a thousand atoms), it has been discovered that in order for growth to occur, the seed crystal must contain a dislocation, usually a screw dislocation. The growth of the crystal proceeds in a spiral, reproducing the dislocation. One is confronted by a paradox: Is it the dislocation that is growing or is it the crystal? The answer depends on the reference point. To us, it is the atoms of the crystal that have reality and so, to us, it appears that the crystal is growing. However, from
within
the crystal, it is the dislocation that is real. After all, dislocations exert forces on each other and arrays of dislocations store energy, whereas the uniform structure of the crystal might seem to be no more than an ‘ether’ through which the dislocations move. Crystalline life would probably see the dislocation as growing and reproducing itself in the next generation. Regardless of how one sees the answer to this paradox, this mechanism for crystal growth serves as an analogy for DNA replication. Over many eons, those dislocations that are the most efficient at reproducing themselves will be the ones that dominate. Thus, it is possible that there could be crystalline life forms that feed on mechanical energy, store that energy in the form of dislocation arrays, and then release that energy slowly as sonic energy or more rapidly as violent, perhaps explosive, fracture.

The Presences, because the greater part of their bulk is far underground, undoubtedly store energy from earth movement. It is not mentioned that there are any Jubal-quakes. Could the Presences be surface extensions of large or small tectonic plates, storing vast quantities of potentially destructive energy rather than using it up in earthquakes and vulcanism?

The Enigma, the ‘Mad One,’ is described as being twinned, two tines of a monstrous fork. Some crystals grow as ‘twins,’ that is, as mirror images of one another, and the plane between them is called the ‘twin boundary.’ Dislocations cannot move across surfaces, and so cannot be transmitted from one crystal to another unless they are in contact. Even when in contact the transmission of dislocations would be very poor unless certain geometric considerations are met. Thus, the Black Tower could presumably speak to the Jammers without sharing their minds. However, dislocation transmission or movement does occur across the twin boundary, and we can imagine the Enigma as a being that is actually of two minds, with each of these minds interfering with or perturbing the other.

As for the Tripsingers, what is it they do? Each Frank-Reed source has a frequency at which it vibrates, its own harmonic frequency, which may be multiple. If one were to bombard a Frank-Reed source with any other frequency, it could generate more dislocations, that is, the Frank-Reed source will operate. However, the Frank-Reed source would be absolutely transparent to its natural frequency.

If the Tripsingers simply sang in accord with the natural frequencies that were the ‘mind,’ conscious or unconscious, of the Presences, they would leave no information behind them, that is, they would not wake the Presences up. If certain sounds were ‘alertive,’ wagon wheels for example, then it would have been the Tripsinger’s job to produce complementary sounds, which, when superimposed on the wagon wheels, yielded exactly those frequencies that were transparent to the Presences. This was, obviously, quite complicated enough.

A subject of some interest might be whether talking to them when they were awake would be an easier or a more complicated matter.

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Also By Sheri S. Tepper

Land of The True Game

1.
King's Blood Four
(1983)

2.
Necromancer Nine
(1983)

3.
Wizard's Eleven
(1984)

Marianne

1.
Marianne, the Magus and the Manticore
(1985)

2.
Marianne, the Madame and the Momentary Gods
(1988)

3.
Marianne, the Matchbox and the Malachite Mouse
(1989)

Mavin Manyshaped

1.
The Song of Mavin Manyshaped
(1985)

2.
The Flight of Mavin Manyshaped
(1985)

3.
The Search of Mavin Manyshaped
(1985)

Jinian

1.
Jinian Footseer
(1985)

2.
Dervish Daughter
(1986)

3.
Jinian Star-Eye
(1986)

Ettison

1.
Blood Heritage
(1986)

2.
The Bones
(1987)

Awakeners

1.
Northshore
(1987)

2.
Southshore
(1987)

Other Novels

The Revenants
(1984)

After Long Silence
(1987)

The Gate to Women's Country
(1988)

The Enigma Score
(1989)

Grass
(1989)

Beauty
(1991)

Sideshow
(1992)

A Plague of Angels
(1993)

Shadow's End
(1994)

Gibbon's Decline and Fall
(1996)

The Family Tree
(1997)

Six Moon Dance
(1998)

Singer from the Sea
(1999)

Raising the Stones
(1990)

The Fresco
(2000)

The Visitor
(2002)

The Companions
(2003)

The Margarets
(2007)

Sheri S. Tepper (1929 – )

Sheri Stewart Tepper was born in Colorado in 1929 and is the author of a larger number of novels in the areas of science fiction, fantasy, horror and mystery, and is particularly respected for her works of feminist science fiction. Her many acclaimed novels include
The Margarets
and
Gibbon's Decline And Fall
, both shortlisted for the Arthur C. Clarke Award,
A Plague Of Angels
,
Sideshow
and
Beauty
, which was voted Best Fantasy Novel Of The Year by readers of
Locus
magazine. Her versatility is illustrated by the fact that she is one of very few writers to have titles in both the Gollancz SF and Fantasy Masterworks lists. Sheri S. Tepper lives in Santa Fe, New Mexico.

Copyright

A Gollancz eBook

Copyright © Sheri S Tepper 1989

All rights reserved.

The right of Sheri S Tepper to be identified as the author of this work has been asserted by her in accordance with the Copyright, Designs and Patents Act 1988.