IELTSwithJurabek

PASSAGE 2

Read the text and answer questions 14-26

WHAT IS AN UNFAIR ADVANTAGE IN SPORT?

Olympic athletes increasingly depend on technology to help them win - but is that fair?

14 What happened to the Australian athlete Ron Clarke in the 10,000 metres at the Mexico City Olympics of 1968 is now virtually forgotten, though at the time it was headline news. Clarke was the greatest distance runner in history; he had broken more world records than anybody else. But in front of 55,000 horrified spectators, the event went disastrously wrong. In the third lap, one runner keeled over and with six laps to go, two more were carried away. Yet the race was being conducted at a relatively leisurely speed: the halfway time was the slowest since the Paris Olympics of 1924. With two laps to go, Clarke was in the leading pack. "I had never felt better in a race," he says. But suddenly he too began to struggle, and as the frontrunners moved up a gear, a gap opened up. Clarke remembers nothing of his last lap which he ran in 90 seconds. "Normally I would run it in 64," he explains. He stumbled across the line in sixth place and collapsed. He was administered oxygen and stretchered off the track.

15 Mexico City is surrounded by mountains and is over 2,240 metres above sea level. That the altitude would have an impact on the Games was predicted. Clarke had raised the issue himself, but had been told by the Australian sports authorities that complaining was regarded as bad sportsmanship. As it turned out, he had good reason to do so. Clearly, the link between athletic performance and altitude needed further investigation.

16 Although there were few standout performances in distance running at the Mexico Games, they marked a turning point: the start of an astonishing record of success by east Africans. While Clarke lay crumpled in a heap, runners from Kenya and Ethiopia were celebrating their gold and silver medals. The record books confirm how entrenched this pattern has become. The names of the seven fastest men in history over 5,000 metres are all from either Kenya or Ethiopia. Between 1997 and 2011 the 10,000 metres men's world record was smashed five times, each time by a Kenyan or an Ethiopian. While there is a complex mix of explanations for the preeminence of east Africans, one factor is surely that many of these athletes have lived most of their lives in thin air.

17 At high altitudes, a number of physiological alterations occur, most importantly, more red blood cells and haemoglobin are produced. This increases the capacity of the blood to carry oxygen, which feeds the muscles and gives an advantage to athletes when they return to sea level. However, it is impossible to train with the same level of intensity in the mountains. As a result, the consensus is that the optimum approach to athletic preparation is: Live High, Train Low (LHTL). Yet that has obvious practical drawbacks. Not many people live in the mountains and those who do would prefer not to spend several hours each day driving up and down winding treacherous roads.

18 That is where the altitude tent - sometimes called the hypoxic tent - comes in. Around two decades ago, two different scientists had the same exciting thought. If they could artificially control the atmosphere within a confined space, they could simulate the effects of high altitude and save an athlete at sea level from the time and expense of travelling to higher ground. Altitude tents have improved over the years and are much cheaper too. They are also perfectly lawful. Five years ago when the tents were investigated by Wada, the World Anti Doping Agency, it was ruled that they did not violate the spirit of distance running. It is now routine for athletes to sleep in them in preparation for an event.

19 However, it is not the case that all new technologies gain approval. In 2008, a staggering 105 world records were broken in swimming, the vast majority achieved by competitors wearing the new Speedo LZR Racer suit. These suits use a high-tech fabric tested in Nasa's wind tunnels, which reduces drag and improves buoyancy. The LZR was initially sanctioned by Fina, the international swimming body. But as better suits were produced by Speedo and other manufacturers, and more records were broken, they became increasingly controversial. In a 2009 ruling, Fina changed its mind, banning all suits made with this high-tech fabric.

20 Going faster, higher, stronger is integral to the logic of athletics in general, and the Olympics in particular. Athletes believe they need records all the time. And the only way they can achieve records is by improving the clothing, the kit, the training, the nutrition, all to identify minute distinctions between people of 0.0001 of a second. But when a new technology is invented, the relevant sports authority has to consider whether to embrace or reject it. In some cases, athletes are granted permission to use the technology; in others, it is banned. But whatever the outcome, rulings should not appear arbitrary: arguments have to be examined and weighed and the rules of logic ought to apply in every case.

PASSAGE 3

Read the text and answer questions 27-40

THEORIES OF PLANET FORMATION QUESTIONED

A. The traditional view of astronomy has been that planets form slowly as material congeals within the disk of gas, dust and ice known to surround young stars. First, gravity gathers together bits of dust that merge to form boulder-sized bodies, which themselves coalesce into bigger and bigger objects. In about a million years, these form rocky planets like Earth and Mars. Over the next few million years, gas from the disk settles around some of these solid bodies and they grow far larger, becoming giants like gaseous Saturn and Jupiter. This theory of planet formation is known as the core-accretion model. However, several astronomers now say that this model for making planets may not be entirely correct.

B. These astronomers have devised an alternative theory in which planets as massive as Jupiter, whether orbiting our sun or a distant star, would form completely within a few hundred years, rather than millions of years as previously believed. Both theories for planet formation start with the same reservoir of planet-making materials. The spinning cloud of gas, dust and ice rapidly fattens into disk-like shapes known as proto-planetary disks; and, as time goes by, gravity causes material in these disks to clump into planet-sized objects. However, it is the speed of the clustering, and the size of the initial clumps, that provide the disparity in the two models for planet formation.

C. According to the core-accretion model, the making of Jupiter required the initial formation of a solid core five to ten times Earth's mass. It would have taken about a million years to achieve this. Most astronomers believe that the large core then had enough gravity to attract a huge amount of gas from the proto-planetary disk to create a planet of the massive proportions of Jupiter. In this core-accretion model, these gas giants may take as long as ten million years to form.

D. That is several million years too long in the opinion of Lucio Mayer of Zurich University. Direct telescope sightings suggest that the proto-planetary disks do not last more than about seven million years, and studies of the environment in which stars form suggest that many disks may evaporate in much less time. Mayer asserts that most stars in the Milky Way form in dense clouds of gas, dust and ice. Their temperatures are very intense and the ultraviolet light they send into space can evaporate a proto-planetary disk in less than 100,000 years. In the core-accretion model, that is not enough time for a Jupiter-like planet to form.

E. Recent computer simulations show that when individual stars form, the gravitational pull between them can result in the outer gaseous parts of the proto-planetary disks being destroyed in 100,000 years or less. Thus, Thomas Quinn of the University of Washington concludes that if a gas giant planet cannot form quickly, it will probably never form. He also asserts that if the core-accretion model is correct, gas giant planets like Jupiter should be rare. However, since 1995, astronomers have found more than one hundred planets as large as Jupiter outside our solar system.

F. Quinn and his colleagues recently analyzed the standard core-accretion model of planet formation and investigated whether giant planets could form quickly. They looked at the work of Gerard Kuiper who, in the 1950s, proposed that they could. Alan P Boss of the Carnegie Institute did more extensive work on the subject in the late 1980s. Using computer simulations, he was surprised to find that gravity could cause a proto-planetary disk, after a few orbits of its parent star, to break into clumps as big as an average-sized planet. The clumps would continue to pull in gas, ice and dust. This is called the gravitational-instability model of planet formation.

G. Recent calculations have suggested that many of the solid bodies that might be the rocky core for Jupiter-size planets in the traditional theory would spin into the parent star before the massive planet could form. Moreover, further analysis has shown that other effects could also cause a proto-planetary disk to become unstable and split into large fragments. For instance, within the disk, electrically charged material might accumulate, leading to fragmentation of the disk. Or a powerful gravitational disturbance, such as the pull of a star passing nearby, could produce instability in the proto-planetary disk.

H. Nevertheless, the gravitational-instability model has problems of its own, as it is mathematically complicated and requires sophisticated computer use. Therefore, no one has studied the simulations long enough to establish conclusively that the model allows for the formation of massive planets.

I. In response, Mayer says that he and his team have described the results of an extensive simulation based on the gravitational-instability model. They spent two years refining calculations to track what would happen to a proto-planetary disk over one thousand years, which is more than any other simulation had done. In addition, over a decade previously Mayer and his team had made simulations of the formation and evolution of galaxies. In doing this, they had already developed a fast computer code that could run in parallel on machines with hundreds of processors, and this knowledge assisted them in investigating their gravitational-instability theory.