Full reading practice test 2

For as long as people have travelled by sea, they have needed ways of finding a safe route to the shore at night. The earliest aids were simply fires lit on hilltops or headlands, and for centuries most coastal lights remained little more than this. The most famous lighthouse of the ancient world, the Pharos of Alexandria in Egypt, was completed in the third century BCE and is thought to have been more than 100 metres tall. Although accounts of how its light worked are uncertain, it became so celebrated that the word for lighthouse in several European languages, including French phare and Italian faro, derives from its name.

For many centuries afterwards, progress was slow. Most lights were wood or coal fires burning in open iron baskets, which consumed enormous quantities of fuel and were easily obscured by their own smoke. Candles and, later, oil lamps were cleaner, but they produced a weak light that could not be seen from far out at sea. A navigator approaching a dangerous coast in poor weather could easily miss a light altogether, or mistake one light for another.

The second problem was structural. Many of the most dangerous hazards lay not on the coast but offshore, on isolated reefs and rocks where building was extraordinarily difficult. The Eddystone rocks, south of the English port of Plymouth, illustrate the challenge. The first lighthouse there, a wooden structure completed in 1698, was swept away in a great storm only five years later, and its successor was eventually destroyed by fire. The third tower, designed by the engineer John Smeaton and completed in 1759, took a different approach. Smeaton built it from blocks of granite cut so that they locked into one another and into the rock itself, and he developed a type of lime mortar that would set even under water. His tower stood for well over a century and was dismantled only because the rock beneath it was being eroded by the sea; its upper part was rebuilt on land in Plymouth, where it can still be visited.

The decisive advance in lighting came in the 1820s from the French physicist Augustin Fresnel. A conventional lens powerful enough to focus a lighthouse beam would have been impractically thick and heavy. Fresnel's solution was to divide the lens into a series of concentric rings of glass, each angled to bend the light in the same direction. The result was far thinner and lighter than a conventional lens, yet able to gather most of the light from a lamp and concentrate it into a powerful horizontal beam. Lights fitted with Fresnel lenses could be seen from much greater distances, and the design was soon adopted around the world.

Because ships could now see several lights along the same stretch of coast, it became essential to tell them apart. Engineers therefore gave each lighthouse its own signature. Some lights were fixed, while others flashed in a particular pattern, produced by rotating the lens or by moving screens around the lamp. Towers were also painted with distinctive stripes or bands so that they could be identified in daylight. Navigators carried published lists of these characteristics, which allowed them to work out their position from the pattern of a single light.

For most of their history, lighthouses depended on keepers, who lived at the station to maintain the lamp, wind the clockwork that turned the lens and keep watch through the night. On remote rock stations, keepers usually worked in small teams and spent weeks at a time away from their families. During the twentieth century, however, electricity and remote monitoring made their presence increasingly unnecessary. In the United Kingdom, the last lighthouses with resident keepers were automated in 1998.

Today, satellite navigation allows ships to establish their position with an accuracy that the keepers of the past could hardly have imagined, and some authorities have switched off lights that are no longer considered necessary. Yet many lighthouses continue to operate, since electronic systems can fail and a visible light remains a simple and reliable backup. Others have found new lives as museums, holiday accommodation or stations for monitoring weather and wildlife.

Conservation has traditionally been an exercise in careful management. Nature reserves are mown, grazed, cleared and replanted according to detailed plans designed to maintain particular habitats and the species associated with them. Over the past few decades, however, a different philosophy has gained ground. Rewilding, as it is generally known, aims to restore natural processes, such as grazing by large animals, the seasonal flooding of rivers and the natural spread of woodland, and then to step back and allow ecosystems to develop with minimal human intervention. Its advocates argue that this approach is not only cheaper in the long term but also better suited to a world in which climate change makes it impossible to keep habitats exactly as they are.

Perhaps the most frequently cited example comes from Yellowstone National Park in the United States, where grey wolves were reintroduced in 1995 after an absence of around seventy years. In the years that followed, researchers reported that the wolves had reduced the number of elk and changed where the remaining elk grazed, allowing willow and aspen trees to recover along some riverbanks. A chain of effects of this kind, in which a predator at the top of a food web influences plants several levels below, is known as a trophic cascade, and the Yellowstone story became a powerful symbol of what rewilding might achieve.

More recent research has complicated this picture. Some ecologists argue that the recovery of trees was patchier than early reports suggested, and that other factors, including drought, hunting by people outside the park and the growing numbers of other predators such as bears, also affected elk populations. Separating the effect of a single species from everything else that is changing in a large ecosystem is extremely difficult, and there is still no consensus on how much of the change can be attributed to wolves. Few scientists dispute that the wolves have had some effect; the disagreement concerns its size and consistency.

In densely populated regions such as much of Europe, rewilding projects usually operate on a smaller scale and with less dramatic species. On some former farmland, for example, landowners have removed internal fences, stopped using fertilisers and introduced hardy breeds of cattle, ponies and pigs as substitutes for the wild grazing animals that once shaped the landscape. The results can be striking: scrub, wetland and grassland form a shifting patchwork, and some declining species of birds and insects have returned in numbers that surprised even the projects' organisers.

Rewilding nonetheless remains controversial. Farmers and rural communities sometimes see it as a threat to their livelihoods and to landscapes that have been shaped by agriculture for centuries. The return of predators raises understandable fears for livestock, while taking land out of farming may be viewed as a loss of food production. Some conservationists also worry that a hands-off approach could harm species that depend on particular managed habitats, such as certain meadow flowers that disappear if grassland is no longer cut or grazed.

In response, many practitioners now describe rewilding as a spectrum rather than a single method. At one end lies the reintroduction of large predators across vast areas; at the other, modest measures such as allowing a straightened river to meander again or leaving part of a farm unmanaged. What unites these projects is a shift in emphasis from controlling outcomes to restoring processes. Whether that shift can deliver lasting benefits at the scale required, and whether it can win the support of the people who live alongside it, are questions that only time and careful monitoring will answer.

It has become one of the most repeated claims of the digital age: that human attention spans are shrinking, and that we can now concentrate for less time than a goldfish. The figure usually quoted, eight seconds, has appeared in newspapers, conference talks and training courses around the world. Yet attempts to trace it to its source have found no study that actually measured it, and psychologists who study attention have pointed out that the idea of a single attention span, measurable in seconds, makes little sense in the first place.

The difficulty lies partly in what the term is taken to mean. Researchers distinguish between several kinds of attention: the ability to sustain focus on a monotonous task, the ability to select relevant information while ignoring distractions, and the ability to switch efficiently between tasks. These capacities are measured in different ways, and performance on each depends heavily on the task, the person's motivation and how tired they are. Someone who abandons a dull article after a few seconds may concentrate for hours on a video game, a novel or a difficult piece of music. To speak of a fixed span is therefore to confuse a property of the person with a property of the situation.

None of this means that digital technology has no effect on how we attend. There is reasonable evidence that people switch between tasks very frequently when working on computers, and that interruptions, whether they come from notifications or from our own impulse to check something, carry a cost: after switching, it takes time to re-engage fully with the original task, and errors become more likely. What is far less clear is whether these habits have produced any lasting change in our underlying capacity to concentrate. A person who checks their phone every few minutes may simply be responding to an environment designed to capture their attention, rather than suffering from a diminished ability to focus.

This distinction matters, because it shapes the remedies we choose. If the problem were a decline in capacity, the solution might lie in training programmes intended to strengthen concentration, of which there is no shortage on the market. The evidence that such programmes improve attention in everyday life, as opposed to performance on the particular exercises they contain, is, however, weak. If, on the other hand, the problem lies largely in our surroundings, the more effective responses are environmental: turning off notifications, setting aside periods free of interruption, and designing workplaces and classrooms that make sustained focus easier rather than harder.

It is worth asking why the myth has proved so durable. Part of the answer is that it confirms a widespread intuition. Many people do feel more distracted than they used to, and a precise-sounding statistic lends that feeling an air of scientific authority, while the comparison with a goldfish supplies a memorable image. There is also a long tradition of anxiety about new media: similar fears were expressed about cheap novels, radio and television, each of which was accused in its time of eroding the public's capacity for serious thought. This is not to dismiss present concerns, but it should make us cautious about assuming that, this time, the damage is permanent.

The more useful question, then, is not how many seconds we can concentrate for, but under what conditions we concentrate well. Framed in this way, the issue becomes one that individuals, employers and educators can do something about. A myth that tells us our minds have been irreversibly damaged invites resignation; an accurate account of how attention responds to its environment invites change.