IELTS Academic Reading Practice Test 432

Among the treasures of Yale University's Beinecke Rare Book and Manuscript Library is a small, battered volume that has defeated almost everyone who has tried to read it. Known as the Voynich manuscript, it consists of around 240 pages of vellum, many of them bearing careful drawings of plants, star charts and tiny figures bathing in pools. Beneath and beside the illustrations runs a dense, flowing script of unknown symbols, written from left to right in a practised hand. Nobody has established what language it records, what the pictures represent, or whether the text means anything at all.

Even without reading a line, scholars can divide the book into sections. The largest is usually called the botanical section: it contains hundreds of drawings of plants, most of which cannot be matched to any species known to science, arranged alongside short blocks of text. Then come pages of circles and stars that look astronomical or astrological, followed by a sequence of round tubs in which tiny women appear to be bathing, linked by an elaborate network of pipes. The final sections contain rows of small roots and jars, and pages of text with no pictures at all.

The writing itself has been examined with every tool available. It uses an alphabet of some twenty to thirty distinct characters, combined into words that follow consistent rules. Certain characters appear mainly at the beginnings of words, others almost only at the ends, and some pairs are common while others never occur together. Words are short, and a small number of them recur on page after page. The text is also remarkably uniform: the same statistical patterns appear in the botanical pages and in the recipes, which is odd if the sections describe different things. There are very few corrections, which some researchers find suspicious.

Some of the most patient work on the manuscript was done by William Friedman, an American cryptanalyst who had helped to break Japanese diplomatic codes during the Second World War. He and his wife Elizebeth, herself a celebrated codebreaker, studied the text for years from the 1940s onwards without success. In a paper published after his death, Friedman concluded that the book was probably an artificial language or an elaborate cipher rather than a natural language.

In 2009, researchers at the University of Arizona radiocarbon-dated small samples cut from four pages of the vellum. The results pointed to parchment made between about 1404 and 1438. Since a book cannot be older than the material it is written on, the text must have been added after that date. The finding disposed of a popular theory that the manuscript had been produced by the thirteenth-century English friar Roger Bacon. It did not settle whether the writing dates from the same period as the parchment. It might have been added decades later, using a supply of unused sheets.

A different line of inquiry comes from physicists and information theorists, who set aside meaning and ask whether the patterns in the text resemble those of real languages. In research published in 2013, Marcelo Montemurro and his colleagues applied a method used to analyse long texts and found that Voynich words cluster in ways similar to those of natural languages. Their results do not reveal what the text says, but they make the simplest explanation, that the book is meaningless nonsense, harder to sustain. Others remain cautious, noting that comparable statistics can arise from a carefully constructed hoax.

The hoax hypothesis has a determined advocate in Gordon Rugg, a computer scientist. He demonstrated that a forger could have produced page after page of convincing-looking text using a simple grid of syllables and a card with a window cut in it. His experiment showed only that the manufacture of such a document was possible, not that it happened. The demonstration has been widely cited in later discussions of the hoax theory.

The volume takes its name from Wilfrid Voynich, a book dealer born in what is now Lithuania. He acquired it in 1912 from a Jesuit college near Rome and brought it to London, where he hoped to sell it. It had not been hidden: it appears to have sat in the college's library for centuries. A letter bound into the front of the book, written in the 1660s, describes an earlier owner offering it to the scholar Athanasius Kircher. The letter adds that the manuscript had once been bought by the Holy Roman Emperor Rudolf II for a large sum, though historians have found no independent evidence for that claim.

Where does that leave the manuscript? It remains catalogued at Yale, where it has been since 1969, and high-quality digital images now allow anyone with an internet connection to study it page by page. Researchers now examine the book's materials and its history as closely as its text. Its stubborn resistance is, in a sense, the point. Whatever the book is — a private code, a lost language, a traveller's notebook or a magnificent fraud — it is a reminder of something simple. Writing preserves meaning only for those who can read it, and a few hundred pages of vellum can keep a secret for six centuries.

A coastline is not a fixed line but a boundary in motion. Every wave that reaches it moves sand, gravel and pebbles a little way, and over decades the sea may remove a field or a road altogether. Coastal erosion is the name given to this removal of material, and it happens wherever the energy delivered by waves is greater than the resistance of the land. In some places the loss is dramatic, with whole cliff faces collapsing after a storm. In others it is so gradual that residents notice nothing until a path disappears over the edge. Nor does the movement always run one way: a storm may strip a beach of sand that a following summer of gentle weather partly returns.

The power of a wave depends on three things: the speed of the wind that drives it, how long that wind blows, and the distance of open water, or fetch, across which it travels. A wind of the same strength will build far larger waves in the Southern Ocean, where the fetch is thousands of kilometres, than in a narrow sea. Long waves generated by distant storms, known as swell, can reach the shore on a windless day and keep moving sediment. Storms add a further element, because low atmospheric pressure and strong onshore winds raise the sea level itself. That allows waves to attack parts of a cliff that are normally dry.

Four processes do most of the work. The first, hydraulic action, occurs when a wave drives into a crack in the rock and the air trapped inside is compressed. As the water withdraws the air expands again, and the repeated shock widens the crack. The second, abrasion, is the sandpaper effect of sediment carried by the waves, which grinds away the rock face. The third, attrition, is the wearing down of the pebbles themselves as they collide with one another, so that the debris becomes smaller and rounder. The fourth, solution, is chemical: sea water dissolves minerals in rocks such as chalk and limestone. Alternating wetting and drying, and the growth of salt crystals in pores, weaken the rock still further.

Where a cliff is made of resistant rock, the result is a distinctive sequence. Waves cut a notch at the base of the cliff, just above the level of the beach, until the rock above is left unsupported. An overhang forms and eventually collapses, and the fallen blocks lie at the foot of the cliff, absorbing wave energy for a time. The sea then breaks up the debris, removes it, and begins to cut the next notch. Repeated over thousands of years, the process leaves a gently sloping surface beneath the waves, known as a wave-cut platform.

A beach is the coast's own defence. Sand and shingle absorb wave energy, and a wide beach can protect a low-lying shore for decades while a narrow one fails within a season. Beaches are not static either: sediment is carried along the shore by longshore drift. This is the movement produced when waves approach the coast at an angle and sweep material up and along the beach face. New sediment arrives from rivers and, in some places, from the erosion of cliffs further along the coast. Dunes behind the beach store sand and release it to the shore when storms strip the upper beach. Interrupt that supply, and beaches down the coast begin to shrink.

Rock type matters as much as wave energy. A cliff of hard granite may hardly change for a century, while soft sand or clay can retreat by several metres in a year. Chalk, for instance, is porous and weak, while basalt resists both wave impact and chemical attack. Many cliffs are layered, and where a permeable rock such as sandstone rests on impermeable clay, rainwater seeps through the upper layer and lubricates the boundary beneath it. The upper mass can then slide seawards in a single movement, whatever the sea is doing at the time. How large a part groundwater plays in such failures is disputed. Some engineers treat it as decisive, others as secondary to the loss of support at the base.

Rates of erosion are usually calculated from old maps, aerial photographs and, more recently, laser surveys that record a cliff face to within a few centimetres. These records show that average figures can be misleading. A coast said to be losing half a metre a year may in fact lose nothing for a decade and then, in one winter, surrender ten metres. Forecasting precisely when a particular cliff will fail remains beyond current models. The decisive event may depend on the pattern of joints in the rock, on how much water it holds, and on the chance arrival of a storm at the worst possible moment.

Engineers have tried three broad approaches. Hard defences — sea walls, rock armour and groynes, which are barriers built across a beach — hold the sea back or trap sediment. They are expensive, and they often accelerate erosion further along the coast by depriving it of material. Soft approaches work with natural processes: beach nourishment replaces lost sand pumped from offshore, and dunes are stabilised with fencing and planting. The third option, managed realignment, means abandoning the defence of a stretch of coast and allowing the sea to reclaim it. That is cheap and creates new habitat, but it is understandably unpopular with the people who live there.

Antarctica has no permanent residents, no economy and no government. It is governed instead by a treaty signed in 1959 by twelve countries, which reserves the continent for peaceful purposes and for scientific research. Dozens more countries have joined that agreement since, and decisions under it are taken by consensus. The treaty has no expiry date.

For most of the twentieth century almost nobody went there for pleasure. That has changed. Each southern summer now brings tens of thousands of visitors, almost all of them on cruise ships sailing from South America. Ships also leave from Australia and New Zealand, though in much smaller numbers. The question of whether the continent should remain effectively closed to mass tourism has become a live one.

Tourism in Antarctica is not unregulated, though the regulation is unusual. The 1991 Environmental Protocol to the treaty, which came into force in 1998, designates the continent as a natural reserve devoted to peace and science and prohibits mining. It says little about tourism specifically. In practice the industry polices itself through an association of operators, formed in 1991, which sets rules on landings, ship sizes and wildlife. Ships carrying more than 500 passengers, for example, do not make landings. The absence of an explicit cap on numbers is, I think, the most important gap in the present arrangements.

Conservation biologists who work on penguins and seabirds point out that the continent is vast. Visitors, however, are concentrated in a small number of landing sites, mostly along the Antarctic Peninsula. Repeated visits to the same colony during the breeding season can disturb nesting birds, and the mud and seeds carried on boots and clothing offer a well-documented route for introduced species. The industry replies that its guidelines on site visits, group sizes and boot cleaning were written to address these risks.

Tour operators make a different case. They argue that the number of people who actually set foot on the continent each year is tiny compared with any other tourist destination, and that the fees those visitors pay help to fund the treaty system. More importantly, they say, visitors return home as advocates. Someone who has seen a glacier calve or a colony of emperor penguins is more likely to support the costly science and diplomacy that keep Antarctica intact. Restrictions that made access harder, in this view, would reduce the constituency for protection rather than enlarge it. The claim is plausible, though it is hard to test.

Some of the governments that make decisions under the treaty take a less relaxed view. They note that visitor numbers have risen quickly and that no agreed limit exists on how many ships or passengers may come. They also worry about the concentration of traffic: if a ship gets into trouble in a remote area, the rescue effort draws on resources that national Antarctic programmes would rather spend on science. A few have argued for a binding cap on numbers, or for a charge on every passenger to pay for monitoring and clean-up.

Economists approach the question differently. Antarctica has the character of a common resource: nobody owns it, access is open in principle, and the costs of crowding fall on everyone rather than on the operator who causes them. Several economists have proposed that access be auctioned, so that the price of a berth reflects the scarcity of the experience rather than merely the cost of providing it. Others object that an auction would simply hand the continent to whoever is richest, and that the value of Antarctica lies less in what visitors pay than in what scientists can learn from it. That objection seems to me decisive.

Legal scholars add a complication that is rarely mentioned in the brochures. The Environmental Protocol can be reviewed fifty years after it came into force, which means that from 2048 a member state may request a review conference, and that the ban on mining could in principle be reopened. Nobody expects a rush to drill. But the existence of that date gives decisions about tourism a wider significance. Whatever rules are settled now will shape how the continent is treated when that settlement comes under strain.

Researchers who study polar tourism for a living tend to be sceptical of the loudest warnings. Their surveys suggest that the industry's own rules are followed more closely than those governing many other forms of travel. They add that the greatest pressures on Antarctic wildlife come not from visitors but from the warming of the Southern Ocean and from fishing for krill and toothfish. Those pressures, they note, cannot be managed by asking visitors to clean their boots. On this view, tourism is a visible target that distracts attention from less photogenic problems.

My own position is that the middle course is right, but that it needs firmer limits than it now has. Mass tourism in the ordinary sense — large ships disgorging thousands of passengers, hotels, roads, permanent infrastructure — should remain prohibited. The treaty's environmental rules should be strengthened to make sure that it stays that way. Small-scale, ship-based, land-light tourism, by contrast, does little measurable harm and a great deal of good. Its continuation should depend on visitor numbers being capped. Landings would need to be spread across more sites than the handful that now receive most of the traffic. A levy on every passenger should pay for the monitoring that the industry makes necessary.