It was the last day before the long summer holiday known as Midsummer Break and Ida Brahma was at school sitting her terminal externals — the make-or-break examinations which would determine whether she got the career of her choice. Ida wanted to be a xenologist. There weren't many aliens on Plaka Kalada — in fact, there were none, unless you counted the Gu — and that was part of the attraction. I get to leave this mudball.
        It was now 2 pm on the third and final day of the examinations. They had already been examined on history, cosmology, chemistry, physics, ecology, biology, mathematics, history, language, economics, human relationships, nutrition, art appreciation and origami.
        "And now," said Slocum, "it's time for composition and critique."
        The worst part. You got given an individual theme, and then you had to compose a poem about it, then exchange your poem for someone else's poem and critique that. Ida's theme was "The Nebra and the Art of Conversation." So what was a Nebra? She asked her scribe. Response: there's no such thing. Okay, then. Here we go.
        I've got a tattoo on my foot.
        I call it a Nebra.
        It doesn't participate
        And that's that.
        Ida exchanged this for Pollen's hundred-line opus. Theme: "Me and my Clitoris." As Ida read through it, she felt herself getting red. She was blushing furiously by the time she had finished.
        Critique?
        I, me, my, mine — those words occurred with monotonous regularity.
        "The poet's choice of pronouns," began Ida, "indicates a jejune obsession with the self."
        And, by staying focused strictly on the pronouns, Ida managed to critique through the poem without touching on biology at all.
        "Ten minute break," said Slocum.
        Outside, they milled in the brightness of the sun.
        "You're sunburnt," said Pollen.
        "It's my hayfever," said Ida.
        Nobody was worried about their poems or critiques, since those were marked on a participation basis — if you wrote them you automatically passed. (And, logically, the reverse also applied.) And, as she intended to be a scientist, Ida wasn't worried about her weaknesses in artistic composition and critique.
        It was the next phase which mattered. The final and most important phase of the terminal externals. Answering your personal question. This was unique to you, and was specifically devised to test your aptitude for your chosen career.
        "Worried about your question?" said Dules.
        "I'm still not going to suck it, if that's what you mean," said Ida tartly. "I don't even want to look at it."
        "I was just being friendly," said Dules.
        "That's what I was afraid of," said Ida.
        "Is this relationship in trouble?" said Pollen.
        "Dules isn't looking for a relationship," said Ida. "He's looking for someone to help him out with the care and management of his clitoris. Maybe you could advise him."
        Back inside, Slocum handed out the sealed envelopes which contained their personal questions. Ida ripped hers open in a hurry.  
        "Demonstrate that the Earth is flat."
        What? But the Earth isn't flat!
        The question didn't make sense. So Ida used her scribe to check out the language, in case she was missing some nuanced ambiguity. But there was none. The key word "tanpan" — literally "undersky" — always denoted a planetary surface. And a planetary surface — the earth you stand on — is always curved.
        "The Earth can't be flat," said Ida.
        She proposed to her scribe that the Earth was flat. Her scribe rejected the notion in two seconds flat.
        "Planets are typically spherical," said the scribe. "For technical nuance, see OBLATE SPHEROID. For proofs see PROOFS. For implications see IMPLICATIONS."
        So. There you are. The Earth isn't flat. And that's that. What's more, without even bothering to look at the scribe's proofs and implications, Ida could easily write a refutation. But that wasn't what was required. If you were given a thesis, then you were supposed to support it, not refute it.
        Ida tried to see if she could see anyone else's personal questions. She could. Dules Kidikins, who wanted to be an engineer, had been told to "Explain the theoretical basis of common sense," and was already hard at work, plowing ahead with no obvious sign of effort. Pollen had been told that "The aesthetical is the ethical" and was having no trouble with that.
        Everywhere, in fact, the students were hard at work. All except Ida.
        She made eye-contact with Slocum. Noiseless in his special examination shoes, he ghosted to her side. Ida showed him the thesis she had to defend.
        "It's wrong," she said.
        Feeling hot tears pricking at her eyes. She was too tired. Too tired to have people play games with her.
        Slocum knelt. She had never seen him kneel before. She smelt the aniseed on his breath as he lent toward her. He hesitated, as if about to say something. Then, as if thinking better of it, he stood. Pulled out one of his scratch cards. Wrote on it. Laid the card down on Ida's desk. The words on the card?
        "This is a great honor."
        Which didn't make sense, either. Ida knew full well that the examination rules permitted the supervising teacher to help out with a personal question, but Slocum hadn't done that. He'd merely left her to fry in her own juices.
        "Demonstrate that the Earth is flat."
        Well, it isn't! And that's that! I'm a scientist, and I'm not having any of this flat Earth nonsense!
        "Science," wrote Ida, furiously, "is predicated on the notion of objective truth. Two plus two equals four in any system of mathematics. Notational systems may change — base two arithmetic will process the numbers differently from base twelve arithmetic, for example — but, at the end of the day, if you have two apples and you supplement them with an additional two apples then you have four apples.
        "It is a known fact that planets are approximately spherical. This fact holds good in every realm known to the transcosmic civilization of the Zafari Jahar. To demonstrate the roundness of planets is a trivial task, one which may be experimentally demonstrated by the simple expedient of climbing a seashore hillside with a prospect of distant islands. As one gains altitude, more and more of the distant archipelago comes in view as one sees around the curvature of the planet.
        "Such an experiment is best conducted on a clear, cold day when atmospheric haze due to the presence of water moisture in the atmosphere is a at a minimum."
        So.
        So there!
        Well. Where does that get us? Nowhere. Very easy to write this stuff. But it's not what's required. You have to support the thesis, not demolish it. Demolishing it is a job for nine year olds. And supporting it? Well, you can't! It would be a heresy to science!
        "The modern science of xenology," wrote Ida, "considered as one of the communicative sciences, is predicated on the assumption that the intellects of alien species will encounter the same objective scientific basis of reality. They will find, for example, that planets are not flat but round."
        Stylistic problem: she had now used the word "predicated" twice in one essay. As Slocum had pointed out earlier in the year, there were some words of which she was far too fond. But.
        "But," muttered Ida, "that's the least of my problems."
        She considered getting up right then and there and just walking out. Walk right on out of there. A martyr to scientific truth. The undersky is not flat! It is curved, damn it! And that's that! And, what's more, every intelligent species known to our entire transcosmic civilization acknowledges that it's flat! Round, I mean!
        "Oh, bums," said Ida.
        Then looked at Slocum, to see if he was going to throw her out of the examination room for disruptive behavior. But Slocum was pointedly ignoring her. Dules Kidikins was busy illustrating his essay by drawing what looked like a schematic diagram of a transcosmic warship, and Pollen, for her part, was now sketching something which looked suspiciously like a clitoris. Only Ida was still stuck. Going down in flames. Total disaster.
        Maybe she could get a lawyer. Sue the examiners, or something. I mean, I'm a scientist — right? You can't ask me to argue something which is out-and-out contrary to science.
        What she had really expected was a scenario. You are a xenologist. You are on a new planet and you are presented with these aliens who are depicting this kind of behavior. Interpret their behavior.
        Yes, that was the kind of question she had been expecting. Not this — this anti-scientific nonsense.
        Giving up, Ida put her hands on her desk and her head on her hands. And lay there. Breathing. Respiring. Living creatures move, respire — and what else? Her brain had stopped working. She couldn't think any more.
        On the desk, an alien was moving. A real live alien creature, a hive-creature whose life was utterly remote from hers.
        It was an ant.
        A green ant.
        Ida Brahma watched the ant crawl across her desk, and observed that ants have the same number of legs on each side, a cunning arrangement designed to keep them from going round in circles for the rest of eternity.
        Thinking of legs made her think of wetas. Tama the cat regularly caught wetas, those big bulky lacquer-brown insects which looked like monstrous grasshoppers with exaggerated antennae. When Tama caught them, she would bite off the left-hand legs and would then sit watching as the insect went round in circles. And Ida would watch Tama watching.
        Actually, it revulsed her, watching those wetas going round and round in helpless circles. But horror is an unscientific emotion. You cannot know unless you look. "More mistakes are made by not looking than by not knowing" — an indispensable axiom of every discipline from medical science to xenology. Since Ida was going to be a xenologist, she had to cultivate the ability to contemplate objective reality steadily, even when that reality included Tama the cat, and the truth of what cats did to wetas.
        Ida watched the ant.
        Is it happy? What does happiness mean to an ant? At least it has all its legs. Is that sufficient grounds for happiness? And, speaking of legs — how many legs do ants have? It is an insect — right? Well, then — how many legs do insects have? Can't remember. But you're supposed to be a scientist! How many? Quick! Six? Eight? Not sure ...
        And the ant was too small and too rapid in its motions for her to count its legs conveniently, unless she killed it first. But a living ant was more interesting than a dead ant. Besides, she should cultivate the ability to study living organisms, despite the attendant difficulties. After all, as a xenologist she wanted to study real live aliens, preferably aliens in the best of health.
        Ida put a finger in front of her ant. It ran up the finger, paused, thought inscrutable ant-thoughts to itself, then fled back to the desktop.          
        How many colors did ants come in? There were green ants, red ants and black ants, and maybe there were also brown ants, she seemed to remember that it was brown ants which had eaten the butterfly pupa she had tried to hatch the year before. This green ant looked like it belonged on the grass rather than on a school desk. It looked out of place. So, for that matter, did Ida. The wooden desk was far too small for her. It was ridiculous to be sitting at a desk so small, playing at child, when she was 19 years of age and the size of a small elephant. Despite statistical evidence to the contrary, Ida firmly believed that the last generation of Settlers must have been smaller (certainly her mother was smaller). And it was an incontestable fact that they had generally left school
earlier.
        Ida studied her living ant. Then, seeing it was about to escape over the side of the desk, she drew a circle round it with her finger, trapping it inside a ring of human scent. It hit the invisible scent-wall, paused, waved its antennae, then started to backtrack and sidetrack. Randomly? Or according to some set of ant-world heuristics?
        By now Ida had her nose right down at ant level, researching ants. Her ant-sample was small — a sample of one — but she was determined to extract from it all the information she could. Ants are green. They have bodies divided into three segments. When ants are moving, running backwards and forwards over a wooden desk inscribed with the graffiti of the last three generations, it can be incredibly difficult to count their legs.
        Finally, the scent barrier weakened. Or the ant decided to cross it anyway. The creature zibby-zibbied across the magic invisible circle drawn by Ida's finger, and, before she could stop it, it vanished over the side of the desk. Over the side of the -
        The world.
        Its flat world.
        The ant has just walked over the edge of the world, which is flat. A flat desk. But it sits on a round planet. Why is the desk flat if the planet is spherical?
        Sitting up and opening her eyes, Ida looked around the room. A flat room. When she had been little, and Lon Tray Pan's new high school had been under construction, she had seen a man with a spirit level checking the floor for flatness. A carpenter's spirit level is an engineering instrument designed for a technical discipline which assumes a flat planet.
        Crystallizing lightning.
        She was hot, hotter than embarrassment, and the white light was crystallizing in all directions, refashioning the nature of reality.           
        At just that moment, the bell rang, signaling the end of the terminal externals. The students rose, noisily, handed in their papers and departed.
        "Ida!" said Pollen.
        Ida paid no attention. She sat there, totally calm, waiting until the classroom was empty but for her and Slocum.
        "I apply for a grant of extra time," said Ida, using the formal language mandated by law.
        "Granted," said Slocum.
        Then Ida bent to her paper. Scanned what she had already written. Science is objective, blah blah. The undersky is round. We can prove this by experiment. Continuation word? However.
        "However, such notions of objective scientific truth must always be tempered by a regard for the applicable level of description. Therefore, while it is certainly true that a planet is, on the macrocosmic level of description, an approximately spherical entity, the ant which walks from one side of a table to the other is experiencing a planet which, for all intents and purposes, is effectively flat.
        "Furthermore, the carpenter who makes the table makes no allowances for the curvature of the local planet. He — I write this on the backwater planet of Plaka Kalada, where tables are actually made by real carpenters, who are typically male — assumes a flat surface. And the table, when made, sits in a house which is designed and built by an architect and a builder who assume, for the practical purposes of the work that they are doing, that the Earth is indeed flat.
        "There exists, then, an obvious intellectual tension between the objective realities perceived at the macrocosmic level of description and the countervailing realities which exist at alternative levels of description. It may readily be argued that this tension will be encountered by all intelligent entities, and may be factored into our abstract model of what it means to be an intelligent entity living in a physical universe.
        "All this raises obvious questions about exactly what constitutes objective reality. In what sense is the spherical planet orbited by the cosmonaut more or less objective than the flat planet which the ant and the carpenter, equally, find underfoot? Depending on what level of description is specified, it is possible to argue that both are equally valid.
        "To draw an analogy, depending on the level of description which is specified, a table may be thought of as a largely empty void inhabited by the interplay of impersonal physical forces — here we are describing, of course, the subatomic level of description — or, at an entirely different yet scientifically equally valid level of description, as a cultural artefact indicative of certain historical and social trends. The anthropologist who describes a family gathering around the kitchen table is a scientist, yet, for the purposes of doing science at his level of description, ignores entirely the nature of the table at the sub-atomic level of description."
        At some point, the sky began to darken, and the lights came on automatically in the inhabited room.
        "All scientific analysis has a purpose," wrote Ida. "If there is a mismatch between the purpose and the level of description, then error will result."
        It sounded good. But she was not quite sure what she meant by it. She had the most frustrating sense of being on the edge of something huge, but not quite being able to take the next step. She tugged at her hair, angrily, but failed to break loose the necessary idea. Well — what are you going to do? Give up? You can't write all night, you know. It's physically impossible.
        Stalled, Ida sat there through the slow-motion cataclysm of the sunset. Evening. And Tama the cat would be wanting to go outside, to hunt. The cat! And that stupid man -
        "In contributing to a debate on the environmental depredations perpetrated by cats," wrote Ida, silently appalled by the pretentiousness of her own language, but unwilling to pause to reframe her thoughts into simpler, more workmanlike prose, "one scientist wrote that it was legitimate to incarcerate cats in the confines of the family home because, as a time-budget analysis shows, they spend most of their time doing nothing.
        "Here is an obvious example of an error consequent upon a mismatch between purpose and level of description. The gross statistical measure of the time expended on an activity is taken to be an indicator of the psychological significance of the activity, so the performance of nothing is taken as being, to the cat, more significant than the performance of other cat activities, such as hunting, courting, chasing rats, demolishing wetas, watching TV, sharpening claws, tearing up the carpet, playing computer games, reading comic books or waging war."
        That lapse into whimsy was juvenile, and she knew it. But it would take a lot of thinking to recast her thought into more severe, academically acceptable terms — to suppress the exuberant child in herself. Later. For the moment, press on, press on.
        "However, most animals, including humans, spend most of their time apparently doing nothing, as the most cursory study of time-budget analysis will show. One analysis of academic computer usage, for example, showed that the most common activity outwardly amounted to no more than sitting unmoving in a state of apparent paralysis.        
        "There is an obvious problem here for the science of xenology. Assuming that our purpose is to facilitate harmonious interactions between humans and other races, our level of description has to be that at which the alien race forms its value judgments. To do that, we have to internally locate ourselves in the consciousness of the alien. We cannot assess the value the cat places on the evening hunt by brute statistical analysis."
        At two in the morning, Ida's mother brought her hot soup, which she ate automatically, without really noticing what she was eating. She was deep in the problem of locating oneself in an alien consciousness, and was writing about an extreme example of the alien: the shark, that utterly alien creature which is oblivious of our ethical universe, and which has not even the first glimmering of the nature of our world of value judgments.
        As the night wore on, Ida worked more and more slowly. A lot of her time was spent just sitting, staring, in a half-trance. At other times, new ideas came so quickly that she was buoyed up by the rush of them, intoxicated, drunkenly delirious with a combination of extreme fatigue and inspiration.
        "One problem with the whole notion of finding the right level at which to describe the behaviors of an alien race," she wrote, finally, "is that, if alien behavior echoes human behavior, we may find the internal world-view of aliens to be partial, erratic, and irrational. Or, at least, alarmingly elastic.
        "In the case of humans, for instance, we have no standard frame of reference for assessing the significance even of so gross an act as murder. While it is generally agreed that an individual who murders twelve others is a pathological monster, a governmental regime which kills twelve may yet be thought of as restrained, even benign. Similarly, while the looter who trashes the family home excites our urgent anger, the large-scale fraud which impoverishes our community via the wholesale looting of a trading bank or similar may, because of its remoteness, its complexity and its scale, leave us bored and indifferent.
        "In a sense, we are like the shark. The personal and immediate we sense of a certainty, but our grasp of the wider world is partial at best, and we all too easily find ourselves blandly indifferent. How then are we, partial and imperfect creatures that we are, to shape tools with which to accurately analyse the needs, desires and motives of alien races?"
        She had ended with a question, not an answer. Never mind. She had the rest of her life in which to seek for an answer.
        The short summer night — which had been, nevertheless, the longest night of her life — was over. The rotation of the tilted planet was bringing her in view of the primary once again: the sun was rising. And, as the sun rose, Ida finally handed in her paper.
        Slocum took the paper, expressionlessly.
        And Ida went home.
        Nobody had sat up to wait for her. She was not a child any more: she was an adult. And, exhausted and vulnerable, she was in half a mind to be upset by this.
        "Grow up," said Ida.
        You are a scientist, or you are going to be. And that means you will do what is necessary to pursue your idea, even if it means working all night.
        So, rejecting the temptations of an emotional outburst, Ida brewed coffee in the kitchen. She poured the hot coffee into her favorite glass mug. It was Terzalura coffee, and its blue was not the ordinary blue of the ordinary sky, but a deeper, richer, lapis lazuli blue.
        As Ida waited for the blue of her coffee to cool toward drinkability, it happened that she glanced out of the kitchen window. She looked down the driveway and across Lon Tray Pan road to the fields beyond. And it happened that she saw a tree.
        And the tree was suddenly there, real, roots reaching down, branches reaching up, trunk extending. Height, width, depth. Existing as itself. And its existence was more than her perception of its existence.
        "What am I seeing?" said Ida.
        There was no distortion of the image. She was not hallucinating. She was seeing a tree: no more and no less. She was not seeing singing dandelions dancing with a purple octopus, or anything eccentric like that. Just a tree.
        A real tree.
        We are not real to the shark. And, probably, the weta dissected by Tama the cat is not real to the cat. To the shark, as to the cat, the exterior world is a set of contingencies to be coped with. The world is known and experienced to the extent to which it offers or demands the experience of interaction.
        But what Ida was seeing, now, was the external reality of the tree. The independent completeness of the tree. And this was difficult to put into words because -
        "Because it is a mystical experience," said Ida.
        And, as if that act of analysis broke a spell, the moment was over. The tree was no longer the emblematic trigger of mystical experience. Instead, it was merely a contingency, an aspect of the view which impinged on her field of sight.
        "All this mystical stuff," said Ida, putting a testing thumb to the side of her coffee mug. "It's probably got something to do with the clitoris."
        The coffee was cool enough. Ida took it out on the balcony, and drank. It was cold out on the balcony. Cold? This was summer. It was her body which was cold, not the day.
        Ida set her coffee down on the rail of the balcony and shoved her hands into her pockets to shelter them from the cold, Ida found something there. One of Slocum's scratch cards. She pulled it out and read the message.
        "This is a great honor."
        Yes. Yes, it is. It is. It was. She had been given a task designed not for a child but for a young adult. And she had succeeded. She had faced a long night of endurance and it had ended with a mystical vision in the dawn. She had completed a rite of passage, and had entered a new world much larger than that of green ants and wetas and Tama the cat.
        And, overwhelmed by a sense of having been through far too much far too fast, Ida suddenly broke into tears. And wept. Then, done with weeping, finished her coffee, and finally did the sensible adult thing and went inside to sleep.