IELTS Academic Reading Practice Test 172

For most of human history, keeping clothes clean was heavy, repetitive work that consumed a large part of the week. Clothes were beaten against stones at the water's edge, scrubbed with sand or with soap made from wood ash and animal fat, and sometimes boiled in a copper. Because cloth was expensive, and making it took many hours of spinning and weaving, garments were washed far less often than we would find acceptable today. In towns, laundry was often sent to professional washerwomen who worked at public washhouses.

The first attempts to build a machine for the task appeared at the end of the eighteenth century. In 1797 an American, Nathaniel Briggs of New Hampshire, was granted a patent for a device for washing clothes, although the record of it survives only in an index damaged when the United States Patent Office burned down in 1836, so what the machine looked like is uncertain. In 1851 James King patented a machine that washed clothes inside a rotating drum, and by the 1860s several American manufacturers were selling hand-cranked washers with wooden tubs and paddles.

One of these machines was built in 1874 by William Blackstone, an Indiana businessman, who is said to have constructed it as a birthday present for his wife, who had complained about the time the family washing took. He began producing it for sale, and the company he founded went on making washing machines for decades. Yet machines of this kind still depended on human muscle: someone had to turn the handle, and the washing still had to be lifted, wrung and hung out.

Electric motors changed the calculation. In 1908 the Hurley Machine Company of Chicago introduced a machine called the Thor, designed by Alva J. Fisher, which is generally regarded as the first electric washing machine offered for sale. The motor replaced the crank, but almost everything else about the design was unchanged. Water still had to be heated on a stove and carried to the machine in buckets, and the wet clothes were passed between rollers, a device known as a wringer or mangle, to squeeze out the water. Early machines were also dangerous: belts were exposed and there was no earthing.

During the 1920s and 1930s, manufacturers turned their attention to the washing action itself. Instead of dragging clothes through water with a paddle, many machines used an agitator, a finned post that rose from the bottom of the tub and twisted the load first one way and then the other. Agitation was gentler on fabric than a paddle and cleaned more thoroughly, because the clothes were repeatedly forced through the soapy water rather than merely soaked in it. Machines became steadily cheaper.

The next step was to remove the operator from the process. In 1937 the Bendix Corporation launched a machine called the Bendix Home Laundry, which filled itself with water and then washed, emptied, rinsed and spun the clothes through a sequence controlled by a timer, with the drum turning about a horizontal axis. It was expensive and unreliable, and several years passed before machines of this kind were common in ordinary homes, but it established the pattern that automatic machines follow today. Sales of automatic and semi-automatic machines then rose rapidly in North America and Europe after the Second World War.

Two designs diverged. In North America the top-loading machine with a vertical agitator became standard, while European manufacturers concentrated on the front-loading machine, in which a horizontal drum lifts the clothes and drops them back into the water as it turns. Tumbling is gentler, and because the drum need only be partly filled, a front-loader uses considerably less water and detergent than a top-loader of similar capacity. The trade-off is a longer cycle and a door that must seal perfectly against leaks.

A modern automatic machine runs a cycle that a 1930s engineer would recognise. Clothes and detergent go into the drum, the machine fills with water at the temperature the user has selected, and the agitator or drum moves the load so that the clothes are repeatedly forced through the water. Detergent contains molecules called surfactants, which attach themselves to grease and lift it off the fibres. When the wash is finished a pump removes the dirty water, fresh water is let in for the rinse, and finally the drum spins at high speed — up to 1,600 revolutions per minute in some front-loaders — so that centrifugal force throws most of the remaining water out through holes in the drum. The faster the spin, the less drying the clothes will need afterwards.

Microprocessors added a layer of judgement. A sensor weighs the load and sets the amount of water, an optical sensor measures turbidity — how cloudy the water has become — and lengthens the wash if the clothes are very dirty, and thermostats hold the temperature steady. Brushless motors, some built directly into the drum rather than connected by a belt, have made machines quieter and more durable.

Efficiency has become the main design constraint. Heating the water accounts for most of the energy a machine uses, which is why cold-wash programmes have attracted so much attention, and why regulations introduced in Europe and North America from the 1990s onwards pushed manufacturers towards machines that use less water and electricity. A further problem has only recently been recognised: washing releases tiny plastic fibres from synthetic fabrics into waste water, and filters designed to capture them are now being tested.

Every year the world generates more digital information than the year before, and almost all of it is kept on magnetic disks or tape. These media are cheap and fast, but they are not durable. A hard disk left unused for a decade may not start again, and tape must be copied every few years onto a fresh cartridge. For information that must be kept for centuries — scientific records, legal archives, films, the output of genome sequencing — this is an uncomfortable arrangement, and it has prompted interest in a much older storage medium: DNA.

DNA carries information in the sequence of four chemical bases, conventionally written as A, C, G and T. A digital file is first converted into a string of ones and zeros; each pair of bits is then mapped to one of the four bases, and the resulting sequence is divided into short fragments. Each fragment is built by a chemical process that adds bases one at a time, and because the fragments are made separately, millions of distinct sequences can be produced at once. The DNA is then dried and stored in a small tube. To read the data back, the fragments are decoded by a sequencing machine, which reports the order of the bases, and a computer translates that order into binary code again.

The idea is not new. In 1988 the artist Joe Davis encoded a small graphic into the DNA of a bacterium, and by the 2010s molecular biologists had begun to take the possibility seriously. In 2012 a team led by George Church at Harvard encoded a book of about 53,000 words, together with illustrations and a short computer program, into DNA and read it back with few errors. A year later Nick Goldman and Ewan Birney stored a collection that included Shakespeare's sonnets, a photograph, a sound recording and a scientific paper. These demonstrations involved only a few megabytes, but they showed that the principle worked.

The main engineering problem is accuracy. Chemical synthesis occasionally fails to add the intended base, and sequencing machines make mistakes of their own. The solution is borrowed from computing: redundant information and error-correcting codes, which allow the original sequence to be reconstructed even when parts of it are wrong or missing. The codes used on CDs and in spacecraft are adapted for the purpose. In 2017 Yaniv Erlich and Dina Zielinski described a scheme they called DNA Fountain, which packaged the data in a way that made recovery reliable, and used it to store and then perfectly recover more than two megabytes of files.

Random access is the second problem. An archive is of little use if reading one document means reading everything, and a DNA archive contains millions of fragments mixed together in one tube. The answer is to attach short standard sequences, known as primers, to the ends of each fragment belonging to a particular file, and to use the polymerase chain reaction, a standard laboratory technique, to make millions of copies of just those fragments. In 2018 researchers at Microsoft and the University of Washington showed that individual files could be retrieved in this way without disturbing the rest.

Cost remains the decisive obstacle. Reading DNA has become dramatically cheaper: the price of sequencing a human genome has fallen from billions of dollars to a few hundred, a rate of improvement that outstrips Moore's law. Writing DNA has not followed the same curve. Synthesis is a slow, sequential chemical process, and although the cost per base has fallen, it is still far higher than the cost of storing the same information on tape. For the moment, therefore, DNA is economic only for material that is worth a great deal and must be kept for a very long time.

Even if the cost fell, DNA is unlikely to replace the disk inside a laptop. Writing is slow, retrieving a file takes hours or days rather than milliseconds, and data cannot easily be edited once written; a correction means synthesising and adding a new fragment. For these reasons those working on the technology describe it as a medium for archival storage — the deep, cold end of the market, where data is written once, read rarely and must survive for decades or centuries. The theoretical density is extraordinary: a single gram of DNA can in principle hold hundreds of terabytes, so a national archive could fit in a drawer.

Research is now concentrated on synthesis. Instead of building chains of bases with the conventional chemical method, several groups are experimenting with enzymes that add bases to a growing strand, which may eventually allow DNA to be written far faster and at lower cost. Others have persuaded living cells to copy designed sequences as they divide, or to hold data in the genome of a bacterium. The software company Microsoft and the biotechnology firm Twist Bioscience have worked together on the practical details of an end-to-end system, and standards for encoding and describing DNA files are being discussed.

Whether the technology will succeed commercially is uncertain. The density and durability of DNA are unmatched, but so is the cost of writing it, and archives are conservative institutions that change their methods slowly. The most likely outcome, most researchers agree, is not a single storage technology but a hierarchy: fast disks for the data in daily use, tape or optical media for the rest, and DNA for the small fraction of material that must be preserved for the very long term. That fraction is small, but it is not trivial.

A loot box is a simple piece of design. A player pays a small sum — a pound or two, or a bundle of in-game currency bought with real money — and receives a sealed container. What is inside has already been decided by a random number generator, and the player discovers only afterwards whether the contents are common, rare or extremely rare. The items are usually cosmetic: a costume for an avatar, a coloured finish on a weapon, an animation that plays when a goal is scored. In some games they are not cosmetic at all, because the players inside a pack go straight into a competitive team.

The economics explain why publishers defend the mechanic so firmly. Most players never spend a penny; a small minority spend heavily, and the revenue depends on that minority. Designers therefore have a reason to make the rarest items desirable and the odds hard to interpret. Because a box costs about as much as a cup of coffee, spending is spread across many small decisions rather than one purchase, and the total is easy to misjudge.

Three features are usually said to define gambling: a stake, an outcome decided by chance, and a prize of value. A loot box supplies the first two beyond dispute. The argument is about the third. Publishers maintain that the contents belong to them, cannot be sold, and vanish when the servers close; on that view the player has bought a licence to a picture, not a prize. Critics reply that value is whatever people will pay for, and that on grey markets these objects change hands for real money. The law, though, tends to ask whether the operator offers a cash return, and on that narrow test most loot boxes fall outside it.

The best-known evidence appeared in 2018, when two psychologists at the University of York surveyed several thousand players and found that the more people spent on loot boxes, the higher they scored on a standard measure of problem gambling. The result has been repeated in different countries and age groups, and reviews of the literature describe an association that is consistent and moderate in size. It could be that chance-based spending draws young people towards gambling, or that those already disposed to gamble are drawn to loot boxes, or that both reflect a third trait such as impulsiveness. Longitudinal studies, which follow the same individuals over time, suggest that influence runs in both directions.

The concern is sharpest where children are involved. Loot boxes appear in games rated suitable for players of seven or twelve, and a child using a parent's payment card can spend without any grasp of what a random reward is worth. The same mechanic sits in free-to-play titles on a phone, where the barrier to a first purchase is almost nil. Whatever courts decide about adults, the proposition that a ten-year-old should not be invited to gamble for a picture of a footballer is not a difficult one.

Some regulators have acted. In 2018 the Belgian Gaming Commission concluded that paid loot boxes in several popular games amounted to a game of chance, which Belgian law permits only under a licence the publishers did not hold. Rather than apply for one, the companies removed the paid boxes from Belgian versions of their games. The decision was blunt, and by European standards unusually quick.

The Netherlands reached a different destination by a different route. Its gambling authority ruled in 2018 that certain loot boxes breached national law and began enforcement action. One publisher fought the decision through the courts, and in 2022 the country's highest administrative court accepted its central argument: the packs were an integral part of a larger game of skill, not a separate game of chance. Two neighbouring countries were left with opposite rules, and the case showed how much turns on technical legal definitions.

The industry has preferred to regulate itself, and it has made concessions. Platform holders announced in 2019 that games offering paid random items on their consoles would have to disclose the odds. In 2020 the European age-rating system PEGI introduced a label warning that a game contains paid random items, and its North American counterpart did the same. Publishers cite such measures as proof that legislation is unnecessary. Critics answer that a warning does not limit spending and that the odds for the most desirable items are often so long that knowing them changes nothing. Governments have wavered as well: in 2022 the British government declined to legislate, preferring to wait for evidence.

In my view the regulators who have hesitated are asking the wrong question. The legal test of a prize was designed for lotteries and betting shops, where money is the only thing at stake; it is a poor guide to a market in which children spend on chance and receive something that feels valuable and is traded for money elsewhere. The sensible response is not a blanket ban but a graduated one: odds disclosed in plain language, spending limits and age checks on accounts held by minors, and a licence for games that combine random rewards with competitive advantage. Self-regulation has had a decade to show what it can do, and it has produced labels and odds pages without reducing spending.