IELTS Academic Reading Practice Test 141

In the middle of the 1990s, engineers at Ericsson's research laboratories in Lund, Sweden, were given an unusual task. The company wanted a cheap radio link that would let a mobile phone talk to a headset, a computer or a printer without any wire between them. Jaap Haartsen, a Dutch engineer at the laboratory, began the work in 1994 and is generally credited with the invention. Because no single company could turn such a link into an industry standard on its own, Ericsson approached four other firms — IBM, Intel, Nokia and Toshiba — and in 1998 the five founded the Bluetooth Special Interest Group, or SIG, to develop and publish a common specification. Version 1.0 appeared in 1999.

The name was not the product of market research. Jim Kardach, an engineer at Intel who took part in the early discussions, had been reading The Long Ships, a historical novel by Frans G. Bengtsson about Viking voyages, and proposed the name Bluetooth as a temporary codename. It referred to Harald Bluetooth, the tenth-century Danish king who united Denmark and Norway and is remembered as a unifier. The name was meant to be replaced before the product reached the market, but it proved memorable and stayed. The logo is a bind rune, a symbol that combines two runic letters, and it spells the king's initials.

Bluetooth operates in the 2.4 gigahertz band, part of the radio spectrum that most countries leave unlicensed, so that anyone may use it without asking permission. The same band is used by microwave ovens, garage-door openers and Wi-Fi, and a signal that occupied a single frequency would be drowned out. Bluetooth avoids this by frequency hopping: the radio changes channel 1,600 times a second among 79 narrow channels, so that interference from another device spoils only brief fragments of the transmission. The system was designed from the outset to consume very little power, because it had to run from the battery of a handheld telephone. A connection is normally a small network, called a piconet, in which one central device can serve up to seven active peripheral devices.

The first products appeared around 2000, and the early years were disappointing. Devices from different makers often failed to communicate, because the specification left too much to the manufacturer's discretion, and setting up a connection could take several attempts. The first devices were expensive, and many users found that a cable was quicker. Sales were slow, and some commentators concluded that a rival technology would win. Only after later versions simplified the process, and chips became cheap enough to be built into almost anything, did the technology begin to spread.

Each revision has extended what the radio can do. Version 2.0, published in 2004, increased the data rate. The largest change came in 2010, when version 4.0 introduced a second, quite separate mode of operation for devices powered by a coin cell: sensors, tags and monitors that need to send a few bytes occasionally and then sleep for minutes or hours. A fitness tracker can run for weeks in this low-energy mode. Version 5, released in 2016, offered four times the range, or twice the speed, of the previous version.

Sound has always been the most visible use. Early headsets carried a single channel of speech at low quality, and streaming music to a headset used far more power than a call. A profile agreed in the mid-2000s made stereo possible, but it still demanded a relatively high data rate, so earbuds had to be charged frequently. A newer standard, LE Audio, uses a more efficient codec called LC3, which compresses sound while preserving its quality, and earbuds therefore last longer. The same standard lets one source broadcast to many listeners at once, a facility that manufacturers are beginning to build into hearing aids, televisions and public address systems.

Because the band is shared, coexistence is a permanent concern. Later versions introduced adaptive frequency hopping, in which the radio maps the channels that nearby Wi-Fi is using and avoids them. Security has proved harder to solve. Early versions encrypted traffic with a key that could be recovered in seconds, and researchers have repeatedly found weaknesses in pairing, the procedure by which two devices agree on a key. Modern versions use stronger methods, and a connection can require both users to confirm a code displayed on the other device, which makes an unnoticed interception much harder.

Today the SIG has thousands of member companies, and billions of Bluetooth devices are shipped every year. The radio is built into phones, laptops, cars, hearing aids, locks, thermometers and industrial sensors. Part of its success is that it does so little: it is cheap, it needs no infrastructure such as a base station, and it can be added to a product for a few pence.

Its limitations are equally clear. A link that draws so little power cannot carry high-definition video, and it is not intended to. Its range is measured in tens of metres at best, and walls weaken it. It is not a substitute for Wi-Fi, which carries the heavy traffic, but a complement to it. What Bluetooth has done is to remove a specific annoyance — the cable between a device and its accessories — so thoroughly that the cable's absence is no longer noticed.

Every year, millions of lithium-ion batteries reach the end of their working lives. They come from phones, laptops, power tools and, increasingly, electric vehicles, whose packs may weigh several hundred kilograms and contain thousands of individual cells. Such a pack contains lithium, cobalt, nickel, copper and aluminium, together with an electrolyte that is flammable and corrosive. Left in landfill, these materials are lost, and a battery that is crushed or short-circuited can set fire to a waste lorry or a sorting plant. Recycling is therefore both an environmental service and a source of metals that are expensive to extract from the ground.

A cell has four essential parts. The positive electrode, or cathode, is a lithium metal oxide: cobalt oxide in many phone batteries, or a blend of nickel, manganese and cobalt in those built for vehicles. The negative electrode, or anode, is graphite, a form of carbon. Between them sits the electrolyte, a lithium salt dissolved in an organic solvent, which carries lithium ions from one side to the other as the battery charges and discharges. A thin porous sheet, the separator, keeps the electrodes apart while letting ions pass. During manufacture these layers are wound or stacked and sealed, which is precisely what makes a used cell hard to take apart.

The first obstacle is not chemical but logistical. Batteries arrive mixed together, and a plant must sort them by chemistry and construction before any process can begin, because a batch of one type behaves differently from a mixture. Cells must also be discharged before handling, since a partly charged battery that is punctured can release hot gas and ignite. Regulations classify lithium batteries as dangerous goods, which restricts how they may be carried and stored. Even a single misplaced cell can spoil a load of scrap, and fires at recycling plants are a familiar hazard.

The oldest industrial approach is simply to melt the batteries. In a smelter, shredded cells are fed into a furnace at more than 1,000 °C, where plastics and electrolyte burn away and the metals are reduced. The process is robust: it accepts any mixture of chemistries, needs little sorting, and delivers cobalt, nickel and copper in a form that existing refineries can use. Its weaknesses are equally plain. It consumes a great deal of energy, and lithium, the element that gives the battery its name, ends up in the slag along with aluminium, from which it is rarely recovered. For a technology promoted as a way of conserving scarce materials, that is an awkward outcome.

Hydrometallurgy works with liquids instead. Batteries are shredded and the resulting powder, known in the industry as black mass, is dissolved in acid — usually sulphuric acid, with hydrogen peroxide to help the metals into solution. The liquor then passes through a series of stages in which solvents selectively extract cobalt, nickel and copper, and lithium is finally precipitated as lithium carbonate. Recovery rates above 90 per cent can be achieved for the main metals, and the process uses far less energy than smelting. It is, however, more sensitive to what goes into it, and it produces large volumes of liquid waste that must be treated.

A third route tries to avoid breaking the cathode down at all. In direct recycling the cathode material is separated from the rest of the cell and cleaned, but its crystal structure is left intact, so that it can be used again with little further processing. Since making a new cathode is the most energy-hungry step in battery manufacture, the savings can be considerable. The difficulty is that the method demands batteries sorted by chemistry and often by manufacturer, and a cathode that has lost some lithium during years of use must be topped up. Research centres funded by the United States Department of Energy have worked on the technique, and several companies now run pilot plants.

Whether any of this happens depends on the value of what comes out. Cobalt and nickel are expensive, so a battery rich in them is worth dismantling. Lithium iron phosphate, a chemistry widely used in buses, storage systems and cheaper cars, contains neither, and its principal metal is abundant; recycling it yields little of value, and the cost of collection and processing can exceed the return. Yet its share of the market is growing. Policy is beginning to alter the calculation. European legislation adopted in 2023 sets minimum quantities of recovered cobalt, lithium and nickel that new batteries must contain from the early 2030s, and requires each battery to carry a digital record of its chemistry and history.

The most promising changes may come before a battery is ever used. Designers are being urged to think about dismantling: cells that can be unscrewed rather than glued, labels that state the chemistry, and fewer composite materials that cannot be separated. In the laboratory, researchers are testing gentler chemistry, including organic acids and biological methods in which bacteria or fungi leach metals from shredded powder, a technique borrowed from mining. These are slow and still far from commercial scale, and the economics of a plant built to handle one chemistry can be wrecked by a change of fashion in battery design. Designing for recycling may prove more effective than any single process, because a battery built to be taken apart is cheaper for whoever recycles it.

Few features of the early internet were celebrated as enthusiastically as the freedom to speak under a made-up name. Handles on bulletin boards and forums allowed people to ask questions they would never put to a neighbour, and to argue about politics without risking their jobs. That freedom is now under pressure. Several governments have proposed or introduced rules requiring platforms to establish who their users really are, and some companies have done so without being asked. In this article I argue that neither of the simple positions is defensible: anonymity should remain the default, but it cannot be unconditional.

Anonymity has been part of online life from the beginning, and not by accident. The design of the early network made it hard to know who was at the other end, and the culture that grew up around it treated pseudonyms as normal. People used them for harmless reasons — a memorable name, a fresh start — but also for serious ones. A person who has been stalked can join a support forum without being found. A junior employee can report misconduct. A teenager can ask about a subject that would embarrass them at school.

The strongest case for anonymity is that those who need it most are often those least able to speak without it. Victims of domestic abuse, whistleblowers inside large organisations, members of persecuted minorities and people seeking information about a health condition they do not wish to disclose all depend on being able to speak without their name attached. Political criticism belongs in the same category. A government that can identify everyone who has mocked it, or every official who has leaked a document, has gained a power that no government should have. In each of these cases the protection is not a luxury but the condition that makes speech possible.

Against this, the case for identification is easy to state and hard to answer. A great deal of online cruelty is committed by people who would not say the same things to a face. The psychologist John Suler coined the term online disinhibition effect to describe how invisibility and the absence of immediate consequences loosen the restraints that normally govern behaviour. Harassment campaigns, racist abuse aimed at athletes, fraud and deliberate disinformation are all made easier when the person responsible cannot be traced. The cost of removing anonymity, on this view, is small set against the misery it would prevent.

The evidence is less obliging. South Korea introduced a requirement in 2007 for large websites to verify the real names of people posting comments, and abandoned it five years later, after its constitutional court found that it had failed to reduce malicious comments and had discouraged legitimate expression. That is one country's experience, and it should not be treated as a law of nature. Yet it points to a difficulty that runs through the whole debate: the people who write abusive messages are rarely the ones deterred by rules, while the people deterred are the cautious and the vulnerable.

Abuse is also not confined to anonymous accounts. It flourishes on platforms where users post under their real names, and journalists who have traced abusive accounts have often found that the writers made little attempt to hide who they were. The problem, in other words, is not simply the absence of a name. It lies in the economics of platforms that are rewarded for engagement, in moderation that is slow or absent, and in a legal environment in which the person targeted usually has to pay for the pursuit. Removing anonymity would not by itself remove the abuse.

This is why the distinction that matters is not between anonymity and identification but between public and private identification. A marketplace may reasonably insist that a seller prove who they are to the company before taking payment, while allowing them to trade under a shop name. The user's fellow readers would still see a pseudonym; only the platform, and where necessary the police acting on a lawful request, would know the name behind it. Such checks are defensible where money changes hands and the risk of fraud is real; they are not defensible where the speech in question is political.

Even this arrangement carries risks that its advocates underplay. Verification systems require everyone to possess a passport, a phone registered in their own name or a bank account, and those without such documents — the young, the poor, some migrants — would be shut out. A database linking real names to pseudonyms is a target worth attacking, and any system must therefore hold as little personal data as possible. Authentication also fails in practice, since a determined user can borrow another person's identity, as any parent who has watched a child pass an age check knows.

So what should be done? Anonymity should be the presumption, and it should be defended as such; but a presumption is not a right to immunity. Platforms that profit from public conversation should be obliged to act on abuse quickly and to keep the identity data they hold to a minimum. Where money changes hands, or where a user's age matters, checking identity privately is defensible. Beyond that, the burden should fall on those who wish to identify others to explain why they need to know, and on the rest of us to defend the principle that a name is not a condition of being heard.