IELTS Academic Reading Practice Test 127

Before 1979, listening to recorded music was for most people an activity tied to a place. A family gathered around a record player in a living room, or a driver listened to a car radio, while people walking in the street heard music only from the transistor radios carried by others. Portable cassette machines existed, but they were bulky, they weighed as much as a bag of shopping, and they were designed chiefly for recording lectures, interviews or the sound of a band rehearsing. Nobody had seriously suggested that millions of people would soon choose to walk about with loudspeakers pressed to their ears.

The idea came from Masaru Ibuka, Sony's co-founder, who was then in his late sixties. On long flights he wanted to listen to opera recordings, and the equipment available to him was too heavy and too awkward to use in an aircraft seat. He asked the company's engineers to build a small stereo cassette player that would work with lightweight headphones. Akio Morita, Sony's other co-founder, saw the device during its development and pushed it towards production. The engineering solution was to start with the Pressman, a compact cassette recorder already in Sony's catalogue, and remove everything not needed for playback: its recording circuits, its loudspeaker and much of its metal casing.

The result, the TPS-L2, went on sale in Japan on 1 July 1979 at a price of 33,000 yen. It weighed about 400 grams with its batteries and ran on two small dry cells. Morita insisted on two features that the engineers had not considered. The first was a second headphone socket, so that two people could listen at once.

The second was a button that lowered the music and switched on a tiny microphone, allowing the wearers to talk to each other without removing their headphones; Sony called it the hotline. The lightweight headphones supplied with the player were as important as the machine itself, since earlier designs had been too heavy for walking about.

Sony's own sales staff were not enthusiastic. In an era when market research was beginning to guide product decisions, researchers told the company that there was no market for a tape player that could not record, and Morita ignored them. A larger problem was the name. Sony's original plan was to call the device the Soundabout, and this was the name used when it was introduced in the United States; in Britain it was briefly sold as the Stowaway and in Sweden as the Freestyle. Only later did the company decide to use its Japanese coinage everywhere. The word sounded clumsy to English speakers, but it was at least distinctive.

Demand exceeded every forecast. Sony had planned to make 30,000 units a month and found that it could not keep up; in the first two months the entire output was sold, much of it to people in their twenties. The company was soon producing the player in several factories, and rival manufacturers in Japan and elsewhere brought out their own versions. Within a few years the personal stereo had become a familiar sight on trains, in parks and on beaches, and a new habit had appeared: choosing the music that accompanied a walk, a journey or a piece of work.

The idea had not been Morita's alone, and Sony was not the first to have it. A German-Brazilian designer named Andreas Pavel built a portable stereo cassette player he called the Stereobelt in the mid-1970s and took out patents on the concept in several countries. He approached a number of electronics firms, including Sony, without success. A long legal dispute followed the Walkman's launch, and it was settled only in the early 2000s, when Sony agreed to pay him royalties.

During the 1980s the design evolved quickly. Sony added a radio tuner, a mechanism that automatically reversed the tape at its end, remote controls mounted on the headphone cable, rechargeable batteries and circuits that boosted the bass. Special versions were built for joggers and swimmers, and the cassette mechanism was made steadily smaller and more resistant to being shaken. Professional models with better motors and metal cases were adopted by journalists, musicians and sound engineers, for whom a cassette machine that fitted in a coat pocket was a practical tool as well as a toy.

By the late 1980s the cassette Walkman faced competition from within Sony itself and from other companies. Portable compact disc players, which Sony introduced in 1984, sounded better to most listeners, though early models were larger and skipped when carried. MiniDisc players, launched in 1992, offered a recordable digital format, and in 2001 a small hard-disk player from Apple, the iPod, pointed to the future. Sales of cassette players declined steadily, and in 2010 Sony announced that it had stopped making the cassette Walkman in Japan. The brand survived on digital players.

The significance of the Walkman is easy to misread. Technically it contained little that was new: cassette tapes, headphones and miniature motors all existed before 1979. What Sony did was to combine them in a form that made a private sound world portable, and to sell that idea to a mass market. The social consequences were considerable. Music became something an individual could carry and control, and public spaces filled with people who were physically present but acoustically elsewhere. The habit of wearing headphones in the street, once considered strange, became unremarkable, and it survived the technology that created it.

The properties of an ordinary material — how it conducts electricity, how it bends light, how it carries sound — are decided by the atoms it is made of and the way those atoms are bonded. A metamaterial works differently. Its unusual behaviour comes not from its chemistry but from its structure: from an arrangement of tiny components, repeated in a regular pattern, that is designed to interact with a particular kind of wave. The components must be smaller than the wavelength of the wave concerned, so that the wave passes through many of them in a single oscillation; the material then behaves as a continuous medium with properties that no natural substance possesses. The prefix comes from the Greek word for 'beyond'.

The idea attracted wide attention because of a strange prediction about light. When light passes from air into glass it bends, because it travels more slowly in the denser medium; this behaviour is described by a quantity called the refractive index, which is positive for every natural material. In the 1990s the physicist John Pendry, working at Imperial College London, calculated that an artificial structure containing conducting loops and wires could, at certain frequencies, produce a negative refractive index, bending light the 'wrong' way. In 2000 a team led by David Smith at the University of California, San Diego, built such a structure for microwaves, using rings of copper on a circuit board. The result was quickly confirmed by other laboratories.

The mechanism is a matter of resonance. Each tiny element behaves like a miniature electrical circuit that responds to the passing wave. The metal loops in Smith's material resonated with the magnetic part of the microwave field, while the thin wires responded to its electric part. Because the elements are so much smaller than the wavelength, the wave does not see them individually; it experiences an average effect, as though it were travelling through a substance whose properties can be designed. The price of the trick is that resonances work strongly only over a narrow range of frequencies, a limitation that has shaped almost everything built since.

The best-known application of these ideas is cloaking. In 2006 Pendry and colleagues published a mathematical method, known as transformation optics, for calculating what kind of material would steer waves around a region of space and return them to their original paths on the far side, leaving no trace. Smith's group built a working version for microwaves within months. The device was a set of concentric rings, and it did hide a small object from microwave detectors. The demonstration captured the public imagination; the reality was more modest than the headlines. The cloak worked at a single frequency, hid the object only from an observer outside it, and itself cast a noticeable shadow.

Other limitations are just as stubborn. Metamaterials made from metal elements absorb some of the energy passing through them, so images and signals weaken. Low-loss designs using dielectrics are an active field of research. Fabricating structures a few tens of nanometres across, as visible light requires, is expensive and slow, and making them in three dimensions, at a scale larger than a few centimetres, is harder still. Most laboratory demonstrations are flat, two-dimensional patterns, and their behaviour changes sharply if the wave arrives at an angle. A material that works beautifully at one frequency may do nothing at all at its neighbour.

Commercial products have nevertheless appeared. The first markets were in radio frequencies, where the structures are large enough to manufacture cheaply. Metamaterial layers are used to make antennas for mobile phones, satellite terminals and radar smaller, flatter or more directional, and to improve the performance of base stations and wireless links. Flat lenses, known as metalenses, pattern their surfaces with pillars of varying size to focus light without the bulk and curvature of conventional glass, and they are now found in some miniature cameras and sensors. Similar patterns are also being studied for radar-absorbing surfaces and for shields that protect sensitive electronics from interference.

Sound and mechanical force can be manipulated in the same way. Acoustic metamaterials, built from repeated cavities or membranes, can block low-frequency noise far better than ordinary insulation of the same thickness, and they can bend sound around an object in a way that resembles the microwave cloak. Mechanical metamaterials with carefully shaped lattice structures can be stiff in one direction and soft in another, or expand sideways when pulled, the opposite of ordinary behaviour. Engineers are examining such structures for packaging that absorbs impact and for components that must combine lightness with strength. Some researchers have even studied the ground itself, calculating how rows of holes or trees might deflect the surface waves produced by an earthquake.

The most promising direction of travel is away from materials with fixed properties. A passive metamaterial does one thing; a programmable one contains switches, diodes or other components whose behaviour can be changed electronically, so that its response to a wave can be tuned from moment to moment. Such surfaces could steer a communications beam towards a moving user without any mechanical movement. Designers increasingly use machine-learning methods to search for structures with a desired response, because the number of possible geometries is vast. Whether these efforts will produce materials that work across a wide band of frequencies, at optical wavelengths and in large sheets is still an open question.

The scene is familiar in most large cities: a rider on a bicycle, a large insulated bag on the back, waiting outside a restaurant for an order to be ready. Behind that rider stands a company that owns no restaurants, employs no cooks and owns no vehicles, yet decides who works, when and for how much. The rise of what is usually called the gig economy has produced a heated argument, and much of that argument seems to me to be conducted at cross purposes. The trouble is not that people disagree about the facts. It is that gig work is treated as a single thing when it covers at least three quite different kinds of work.

The word itself is older than the technology. Jazz musicians have long spoken of a gig for a single engagement, paid at the end of the night, and the term spread into other casual trades. What changed after the financial crisis of 2008 was the arrival of smartphone applications that could match a person who wanted a task done with a person willing to do it, and take a commission. Companies such as Uber, founded in 2009, and a crowd of delivery and household-service platforms grew quickly. Today the label covers a lawyer advising a client abroad through a freelance website, a consultant on a six-month contract and a rider paid by the delivery. Their circumstances have almost nothing in common.

The case for these arrangements rests mainly on flexibility. A student can earn between lectures; a parent can work while a child is at school and stop in the holidays; someone in a region with few employers can find paid work on a phone. Surveys of platform workers in a number of countries have repeatedly found that a majority value the ability to choose their hours, and many use the income to supplement a main job or a pension. Customers gain too: services arrive quickly and, in transport and delivery, often cheaply, because the platforms have lowered the cost of connecting the two sides of a market.

The case against is equally substantial, and it is not really about flexibility. It is about dependence without protection. A rider who works for one application, in a city where that application controls most of the orders, is not running a small business: the platform sets the price of each delivery, decides which jobs are offered to whom and monitors performance through a rating system. Poor ratings, or an algorithm's judgement that demand is low, can end a person's income without a hearing. Meanwhile the costs of the work — the bicycle, the phone, the insurance — are borne by the worker, and so are the risks of injury and of a quiet week.

The legal question is whether such people are employees, entitled to a minimum wage, holiday pay and protection against dismissal, or independent contractors, entitled to none of these. Courts have answered it differently. In 2021 the Supreme Court of the United Kingdom ruled that a group of drivers were workers for the purposes of minimum wage and holiday pay, because the company set their fares and controlled their work. In California, a law passed in 2019 applied a similar test and was then largely reversed by a referendum the following year. The lesson is that the outcome turns on how much control the platform exercises, not on what the contract calls the relationship.

That is where I think the argument should be settled. The label matters less than the reality of control, and the reality can be examined. If a company fixes prices, allocates work, penalises workers through ratings and forbids them from serving rivals, then it is directing the work, whatever the wording of the agreement. A genuinely independent freelancer, who sets a price, refuses a job without penalty and serves several clients, is in a different position and should be treated differently.

Nor is flexibility the fragile flower that some commentators suggest. Minimum rates for waiting time, insurance against injury and a right to appeal against removal do not prevent a platform from offering short shifts; they decide who pays when work is scarce or a rider is hurt. Several companies that once insisted such rules would destroy their business have continued to operate in cities that imposed them, adjusting their prices rather than closing down.

There is a fair objection, which I acknowledge: badly designed rules can shut out the very people the gig economy has helped, particularly those who cannot commit to fixed hours. A law requiring every worker to be on a roster with guaranteed weekly hours would exclude many of them. That is an argument for careful design, however, not for doing nothing.

My own view is that the technology is not the problem, and blaming the application is a distraction. Smartphones have made it cheap to match supply and demand, and that is a genuine gain. What has gone wrong is that the gains have been distributed upwards while the risks have been pushed down to individuals who can least afford them. The remedy is transparency about how work is allocated and how ratings are used, a legal test based on control, and benefits — sick pay, injury cover, pension contributions — that follow a person from one engagement to the next rather than being tied to a single employer. None of this is technologically difficult. It is politically difficult, which is a different matter.