IELTS Academic Reading Practice Test 86

People have kept wild animals for thousands of years. Rulers in Egypt, China and Mesoamerica used them to show wealth and power. Travelling shows brought strange beasts to European audiences. The modern zoo, however, is largely a product of the eighteenth and nineteenth centuries. In that period royal collections were changed into scientific and educational institutions. Since then people have debated how much zoos should focus on entertainment, research and conservation.

One of the oldest surviving zoos is the imperial menagerie at Schönbrunn in Vienna. It was founded in 1752 as a private collection for the Habsburg family, but from 1779 the public was admitted on certain days. The Zoological Society of London, established in 1826, opened London Zoo two years later with the stated intention of keeping animals for scientific study; admission to the general public began in 1847. These institutions were soon followed by others in Europe and North America. By the end of the nineteenth century, the zoo had become a familiar feature of major cities.

From the beginning, the conditions in which animals were kept often showed limited knowledge of their needs. Many early exhibits were little more than concrete enclosures with iron bars. They were designed to allow visitors to see the animals clearly rather than to satisfy the animals' own requirements. As knowledge of animal behaviour grew during the twentieth century, zoos were criticised for providing too little space, stimulation or social contact. The public slowly began to expect zoos to be places of care rather than mere curiosity.

A more fundamental change came from the conservation movement. By the middle of the twentieth century, several species had become extinct in the wild or were close to disappearing. Zoos began to cooperate in breeding them. The concept of the studbook, a record of the ancestry of every individual in a captive population, had originated earlier. From the 1960s onward, international bodies used studbooks to avoid inbreeding and to manage rare animals as shared populations. In the 1980s, American zoos formalised this approach through Species Survival Plans. These plans coordinate breeding among accredited zoos according to genetic and demographic goals.

Captive breeding has produced some celebrated recoveries. The Arabian oryx was hunted to extinction in the wild by the early 1970s. But animals from several zoos were bred successfully, and beginning in 1982 oryx were returned to reserves in Oman and later elsewhere. The black-footed ferret, thought extinct until a small population was found in Wyoming in 1981, was saved when the remaining animals were captured and bred in specialised facilities. Their descendants have since been released on the North American prairie. The California condor also passed through a severe bottleneck: all remaining wild birds were captured by the late 1980s. Captive-bred birds are now flying again over California, Arizona and Utah, though their long-term future remains dependent on human management.

Such reintroductions are only possible if animals retain the behaviours needed for survival. Animals born in zoos may not learn how to hunt, avoid predators or migrate. Pre-release training and long-term monitoring are therefore essential. Nevertheless, reintroductions have shown that captive populations can act as a reserve, or insurance, against extinction in the wild. For many species, the remaining wild habitat is now too small or too fragmented to support a viable population without help.

Modern accredited zoos devote considerable resources to enrichment, which aims to give captive animals choices and opportunities to perform natural behaviour. Enclosures are designed around natural features. Social groups are arranged to reflect wild structures, and keepers hide food or use puzzles to encourage feeding and exploration. Many zoos also run education programmes. They argue that direct contact with live animals can produce lasting concern for conservation that films alone cannot match.

Critics reply that no amount of enrichment can make up for the loss of freedom and autonomy experienced by a wild animal. Even well-run zoos keep species whose needs cannot be met in captivity. Some studies have reported signs of stress in wide-ranging animals such as elephants and polar bears kept in confined spaces. Defenders of zoos accept that earlier institutions sometimes failed. But they point to accreditation systems and legal standards that now govern enclosure size, veterinary care and the movement of animals between collections. The dispute has become more prominent as public attitudes towards animals have changed.

The debate is not simply about individual animals. Zoos now present themselves as conservation organisations, and many direct part of their income to field projects that protect habitat, combat poaching and support local communities. Whether this justifies keeping animals in captivity is disputed. But there is little doubt that zoos have contributed to the survival of a number of species that would otherwise have vanished. They will also play a role as wildlife populations continue to decline.

The James Webb Space Telescope is often described as a time machine, because it is designed to observe light that has travelled for most of the history of the universe. Its instruments are tuned to infrared wavelengths, which are better able than visible light to pass through cosmic dust and to reveal objects whose light has been stretched by the expansion of space. The telescope is the result of more than two decades of development and a partnership between the space agencies of the United States, Europe and Canada.

The heart of Webb is its primary mirror, which is far larger than any previous space telescope mirror. It measures about 6.5 metres across and is made up of 18 separate hexagonal segments, each covered with a thin layer of gold to improve reflection at infrared wavelengths. Because no existing rocket could carry a mirror of this size as a single piece, the segments were folded for launch and unfolded remotely once the telescope was in space, a process that required extraordinary precision.

Webb was launched on 25 December 2021 from French Guiana aboard an Ariane 5 rocket. Over the following month it travelled to its operating position known as the second Lagrange point, or L2, roughly 1.5 million kilometres from Earth on the side opposite the Sun. At this point the gravitational pulls of the Earth and the Sun balance the telescope's orbital motion, allowing it to keep its position while using relatively little fuel. Because it orbits the Sun rather than the Earth, it can maintain a stable thermal environment.

To observe extremely faint infrared radiation, Webb must be kept extremely cold, and its most visible piece of equipment is therefore a five-layer sunshield. Each layer is made from a plastic film coated with aluminium, and the shield is about the size of a tennis court when fully deployed. The layers are separated so that heat radiates out between them, reducing the temperature on the cold side to around 40 degrees above absolute zero. This passive cooling allows the telescope's optics and most of its instruments to work without heavy refrigerators.

Webb carries four main science instruments. The Near Infrared Camera, or NIRCam, is the primary image-making camera, while the Near Infrared Spectrograph dissects light into its component wavelengths to reveal the chemical composition and motion of distant objects. The Mid-Infrared Instrument, contributed by a European consortium and NASA's Jet Propulsion Laboratory, operates at longer wavelengths and must be cooled even further by an active cryocooler. A fourth system, made up of the Near Infrared Imager and Slitless Spectrograph and the Fine Guidance Sensor, supports both imaging and pointing.

One of Webb's main goals is to study the first galaxies that formed after the Big Bang. Because light from those objects has been travelling for more than thirteen billion years, it arrives at the telescope as infrared radiation. In its first year of operation the telescope detected galaxies whose light appears to come from a time only a few hundred million years after the Big Bang, earlier than any previous telescope had reached. These observations are beginning to show how the earliest stars and black holes formed.

Webb is also transforming the study of planets beyond our solar system. By watching as an exoplanet passes in front of its star, the telescope can measure the tiny change in starlight and identify gases in the planet's atmosphere. In 2022 it detected carbon dioxide outside the solar system for the first time, and it has since revealed water vapour, sulphur dioxide and other chemicals around planets orbiting distant stars. Such measurements help astronomers assess whether a world might have conditions suitable for life.

The telescope has not been without difficulties. Its journey from proposal to launch involved delays and cost increases, and after launch its mirror was struck by several micrometeoroids, though engineers report that the damage is small and manageable. Scientists have also had to learn how to interpret the unexpectedly sharp data that Webb returns, as many established models of early galaxies have required adjustment. Despite these difficulties, most astronomers agree that Webb has opened a new era in space astronomy.

Webb is expected to operate for at least a decade, and its supply of fuel, which is used for station-keeping, will determine its ultimate lifetime. Astronomers from around the world compete for observing time through a peer-review process, and the data are made public in archives after a short proprietary period. The telescope's observations are expected to complement those of future missions, including studies of gravitational waves and the search for signs of life on nearby planets.

Loneliness is often confused with being alone, but the two are not the same. Loneliness is a subjective state: it arises when a person perceives that the quality or quantity of their social relationships falls short of what they need or expect. A person can be surrounded by colleagues and relatives and still feel profoundly lonely, while another person who lives alone may feel entirely content. This distinction is not merely academic, because it determines both how the problem is measured and how it should be addressed.

Researchers therefore distinguish between objective social isolation, which refers to the number and frequency of social contacts, and perceived social isolation, which is the emotional experience of loneliness. Surveys repeatedly show that the relationship between the two is only moderate. Some highly sociable people report intense loneliness, while some individuals with very few contacts do not. This disconnect can frustrate both health professionals and the people they try to help. Because loneliness is rooted in perception, it cannot be inferred reliably from a person's living arrangements or the size of their friendship network, and this makes it difficult to identify those most at risk.

There is now strong evidence that severe and prolonged loneliness is harmful. Large population studies have associated it with an increased risk of cardiovascular disease, depression, disturbed sleep and a weakened immune response, as well as with an elevated chance of dying earlier. Some analyses have compared the size of the mortality risk to that associated with smoking or obesity. These findings do not prove that loneliness directly causes ill health, since lonely people may also experience poverty, disability or poor nutrition, but the association appears robust after such factors are taken into account. Loneliness may also affect health behaviours, as isolated individuals may exercise less or seek medical help later.

Why loneliness should be physically damaging is a matter of ongoing research. One influential explanation is evolutionary: because humans evolved in groups, being separated from the group may have activated a threat response that prepared the body for danger. In the short term this response may promote self-protection, but when it becomes chronic it can keep stress hormones elevated, increase inflammation and interfere with sleep. In this view, loneliness is not only an unpleasant feeling but a signal that one's social environment has become unsafe.

The causes of the apparent rise in loneliness are disputed. Some commentators blame social media and smartphones, arguing that online interaction replaces deeper face-to-face relationships. Others point to longer working hours, the decline of stable neighbourhoods, the movement of families across cities, and the growing number of people who live alone. The evidence suggests that the effects of technology depend heavily on how it is used: people who use digital tools mainly to arrange contact with friends often report benefits, whereas those who scroll passively or compare themselves with others may feel worse. Age differences complicate the picture further.

I would argue that loneliness is best understood as an interaction between individual psychology and social conditions, rather than as a disease that strikes randomly. Because it is subjective, it can be reduced by changing how people think about their relationships, but because it is also shaped by the availability of meaningful contact, it cannot be solved by therapy alone. Communities with poor public transport, a lack of shared spaces or precarious work create conditions in which loneliness thrives, however resilient their residents may be. Loneliness is therefore neither a purely personal failing nor an inevitable feature of modern life.

Intervention studies offer some guidance. Teaching social skills and simply arranging more contact, for example through befriending schemes, have produced modest results. More consistent improvements have come from cognitive behavioural therapy, which helps people identify and challenge beliefs such as the idea that others are unfriendly or that one is not worth knowing. This suggests that tackling chronic loneliness may require not so much forcing people into social situations as changing the interpretations that make those situations feel threatening or unfulfilling.

The most promising approach, in my view, combines such psychological work with changes in the physical and social environment. Community centres, age-friendly housing, reliable public transport and workplaces that permit reasonable hours are all part of a serious response. We should also accept that solitude is not always a problem. Many people choose periods of solitude for reflection or creative work, and there is no reason to treat this as a condition requiring treatment. The goal should be to ensure that people have access to connection when they want it, and support when chronic loneliness becomes damaging. Some countries, including the United Kingdom and Japan, have gone further by appointing ministers for loneliness to coordinate services.

Loneliness has been called an epidemic, but the word may mislead. It suggests a uniform disease spreading in the same way everywhere, whereas loneliness has many forms and causes. Occasional loneliness is a normal human experience, and even useful if it prompts us to reconnect with others. The danger arises when it becomes chronic and is accompanied by a sense of having no one to turn to. Recognising that distinction would, I believe, lead to a more humane and effective response.