Online IELTS - IELTS trực tuyến, IELTS, TOEFL, TOEIC, IELTS online, online IELTS, luyện thi IELTS, IELTS test, test IELTS, TOEIC online, luyện thi TOEIC, học tiếng Anh online, tiếng Anh sách giáo khoa

MODEL TEST - ACADEMIC IELTS
(Time: 90 minutes)

Thời gian còn lại

Section 1

Script:

You will hear a science student enquiring about English courses at a University language centre

Student: Hi, I’ve come to ask about the English courses you run for international students.

Administrator: Oh right - I assume you’re a student at the university?

Student: Yes, I’ve just started.

Administrator: OK. Well, we’ve got a range of courses. It depends what you think you need. And how much. Urn - we can’t run everything at the same time though so. for example, in this first term we are just doing a writing course.

Student: I see. That sounds quite useful. What else is there?

Administrator: Um, some of the courses only run for single terms and we tend to focus on what students have difficulty with. That means we don’t usually do speaking courses but next term you can do listening. That’ll help you with lectures and things. Our provision is all based on what the majority of our international students need.

Student: So is everything term-based - there’s nothing that you run all year?

Administrator: Well, let’s have a look. Yes. there is a class for vocabulary and grammar every term. That’s for everybody but it’s split into three or four levels.

Student: And what about in the holidays?

Administrator: We don’t do anything during the winter or spring break but over the summer there’s just general classes because that’s what most students want - a bit of everything.

Student: OK. Quite a variety then. I’ll have a think about what I really need because I haven’t got much time. Do you have about twenty students in each class - the same as our Science seminars?

Administrator: We try to keep it at about twelve and certainly not more than fifteen. It’s important for language classes. They’re very different from your normal courses.

Student: Right - and how much are the classes?

Administrator: The rate varies depending on how many hours you attend but you shouldn’t have to pay - usually the department will fund you and even sort out which classes you need.

Student: Brilliant! It would be quite useful for me to have a certificate to take back to my country. Do you put us in for exams?

Administrator: Yes. But we don’t like them to clash with your main course exams in June, so we run them in May. That leaves you time for revision.

Student: Do I have to sign up for something now? I’m not quite sure what I want.

Administrator: Classes haven’t quite started vet so you’ve got time to decide what you do. All we insist is that you sign up before week five. That gives you about three weeks to decide.

Student: OK.

Complete the notes below. Write NO MORE THAN THREE WORDS AND/OR A NUMBER for each answer.

Courses Available

* writing in first term

* (1)….. in second term

* (2)….. throughout the year

* (3)….. during long vacation

* Class sizes: (4)….. maximum

Course costs often paid by the (5)…..

Exams available in (6)…..

Must enrol by (7)…..

week five general classes department May 7 / 7th of May 15 / fifteen listening vocabulary and grammar / vocabulary, grammar / grammar and vocabulary

(1)
(2)
(3)
(4)
(5)
(6)
(7)

Script:

Administrator: Then, when you’ve made up your mind, you need to come back here to the administration office to enrol.

Student: What do I need to bring with me when I enrol? My identity card, I guess?

Administrator: Yes, or your passport. Then you’ll be given a registration form which you’ll have to show to the teacher when you have your first class.

Student: OK. And should I ask my tutor about which classes I should do then?

Administrator: Yes, then you get a note from him and give that to the desk when you register.

Student: Can I use the computers here as well?

Administrator: Yes, you’ll be given a password when you go to your first class, so remember to bring a disk with you to save your work on as you won’t be allowed to save it on the hard drive.

Student: OK. Will I need anything else? Dictionary?

Administrator: We’ve got loads of those here that you can borrow, but you’ll need a notebook as we don’t provide paper or files.

Student: OK. Thanks.

1. Which THREE items does the student need to bring to the first class?

student identity card

notebook

registration form

dictionary

passport

note from tutor

computer disk

Explain:

Section 2

Script:

PRESENTER You’re listening to Expat News, a weekly broadcast for the English-speaking community in this great city. In today’s programme we’ll be hearing from Tom O’Hara, who’s going to tell us about all those different associations you can join. Tom.

TOM Good evening. Yes, in a city with so many of its residents born outside the country, it’s hardly surprising there’s such a huge range of expatriate clubs and societies. And many of these, of course, are aimed at English speakers. So first, and perhaps most obviously, we have the sports clubs, which in some cases field teams in things like rugby and tennis that compete against clubs in other parts of the country, or even abroad. You don’t have to play at this level to have fun, though: they can be just a great way to do some exercise, and of course to get to know other people, especially if you’re new in town. The same can be said of the many hobby and interest clubs that have sprung up here: everything from landscape photography, such as the Viewfinders club in the harbour district, or Focus on the airport road, to old favourites like stamp collecting. Remember that this country has a long tradition of unusual and perhaps even eccentric societies, so there should be something for everyone: a place where you can meet people of different nationalities with the same social and/or cultural interests as you. For those who may be interested in rather more than just friendship, there’s a wide range of lively social clubs. Several singles associations organize dancing of various kinds, while for people in a real hurry there’s speed- dating, in which everyone talks to everyone else for just five minutes. Then, at the end, they decide which of them they would like to meet again by ticking their names on a list. In complete contrast to these are the many religious associations, reflecting the diversity of faith groups present in this multicultural city. Many of them, of course, have their own places of worship. Perhaps also of interest to those who’ve come here from other parts of the world are the international and cultural societies. These often provide a meeting place for people from a specific country, China for instance, and particular ethnic groups, such as Afro-Caribbeans. As in other major cities, we have here local branches of many charities with names familiar around the world. Meetings of human rights organizations like Amnesty International are held regularly in English, as are those of environmental groups such as Greenpeace. All funds raised, by the way, go to the same kinds of good cause as they do in other countries you may have lived in. Inevitably, perhaps, there are also the political clubs, often connected with a particular party and, indeed, a particular country. So we have, for example, a local association of Republicans linked to and campaigning for that party in the US, and Liberal Democrats here doing the same for their party in Britain. Finally, on a lighter note, there’s plenty to choose from in the performing arts. Whether you enjoy taking part or just watching and listening, you can take your pick from a whole range of groups. To take just a couple of examples, there’s light opera at the Memorial Hall in the city centre, or a very lively amateur theatre company in the Park district. In summer they give open-air performances of Shakespeare plays, free of charge.

Answer explanation:

1. stamp collecting: After the prompts 'hobby and interest clubs' comes the first example, 'landscape photography', and then the answer ‘stamp collecting'. Both words are needed.

2. social: After the prompt 'more than just friendship' comes the answer 'social', before the examples 'dancing' and 'speed-dating'.

3. China: You hear the prompt 'international and cultural' and then ‘China’ (followed by 'for instance').

4. charities: The examples, 'human rights organizations like Amnesty' and 'environmental groups such as Greenpeace' both come after the answer ‘charities'.

5. political: The clues come after the answer: 'party', 'campaigning' and the first example 'Republicans'.

6. Liberal Democrats: After the example 'Republicans', the speaker mentions Liberal Democrats 'doing the same for their party'. Both words are needed.

7. light opera: The word 'Finally' tells you that 17 is coming. The speaker mentions 'performing arts'. The answer is the first example. The second example is 'amateur theatre'.

Complete the table below. Write NO MORE THAN THREE WORDS for each answer.

TYPE OF CLUB OR SOCIETY	EXAMPLES
SPORTS	Rugby tennis
HOBBY/INTEREST	landscape photography (1)………
(2) ………	dancing speed-dating
RELIGIOUS
INTERNATIONAL/CULTURAL	(3) ……… Afro-Caribbean
(4) ………	human rights environmental
(5) ………	Republicans (6) ………
PERFORMING ARTS	(7) ……… amateur theatre

China stamp collecting social charities political Liberal Democrats light opera

(1)
(2)
(3)
(4)
(5)
(6)
(7)

Script:

TOM I should mention at this point that clearly some districts have a higher concentration of English- speaking clubs than others, and that certain parts of town tend to specialize in particular activities. An obvious example would be the number of water sports clubs down near the river. Whatever the number, though, they usually have one thing in common. With the exception of a few associations linked to particular countries and supported by their embassies here, in the vast majority of cases it is the individual members who fund them, so an entry fee, or a subscription, will be charged. You may be used to council-subsidized sports centres and the like in your home country, but I’m afraid that’s not the case here. Assuming you can afford it, then, you can be fairly sure that somewhere out there you’ll find a club that caters for your own particular fascination. If it’s very important to you, and you intend to spend a lot of time on it, it might even determine which district of the city you decide to live in. In the unlikely event that you really can’t find such a club, the solution is to try to persuade friends, and anyone else you meet, of the need for one. You could also use the local small ads on the Internet to suggest the idea: you’ll be amazed at just how many people share even the strangest interest. Then you can start your own.

Choose the correct answer.

1. In this city, clubs and societies are mainly paid for by

individual members

embassies of other countries

the city council

Explain:
individual members: The speaker mentions 'a few associations supported by the embassies' but then states 'in the vast majority of cases it is the individual members who fund them', so this is the correct answer, not 'Council-subsidized sports centres' are in listeners' home countries. .

2. Finding the right club might influence your choice of

city

friends

district

Explain:
district: The prompt is 'find a club'. The speaker says 'it might even determine which district of the city you decide to live in', so “district” is correct, not “city”. The speaker mentions persuading 'friends' of the need for a club, but doesn't mention choosing 'friends'. “friends” is therefore also wrong. .

3. What should you do if the right club does not exist?

join one in another town

set one up yourself

find one on the Internet

Explain:
set one up yourself: The keys words are 'Then you can start your own! Although he says “use the small local ads on the internet; this is "to suggest the idea; not to join an existing club, so choice “find one on the Internet” is wrong. He does not suggest joining one in another town as stated in choice “join one in another town”.

Section 3

Script:

Student: I’m interested in entering your Business Administration program, and I’d like some information on how to apply. I’m a little concerned because I’ve been out of school for a number of years.

Advisor: That could actually work to your advantage. It’s possible to get academic credit for work experience, if that experience is related to courses in our program.

Student: I’ve been working in business for several years. How would I get academic credit for that?

Advisor: First, you’ll need to read the university catalog to see if any of the course descriptions match your specific job experience. For example, if you’ve worked in accounting, you may be able to get credit for an accounting course.

Student: So then what would I do?

Advisor: You would write a summary of your work experience, relating it to specific courses we offer. Submit that to the Admissions Office with a letter from your work supervisor confirming your experience.

Complete the information below. Write NO MORE THAN TWO WORDS for each answer.

How to get academic credit for work experience

First, read the (1)......... Find courses that match your work experience. Then write (2)......... of your work experience. Submit that together with a letter from your (3)......... to the university admissions office.

a summary university catalog work supervisor

(1)
(2)
(3)

Section 4

Script:

STUDENT: Well, my group has been doing a project on how household waste is recycled in Britain.

We were quite shocked to discover that only 9% of people here in the UK make an effort to recycle their household waste. This is a lower figure than in most other European countries, and needs to increase dramatically in the next few years if the government is going to meet its recycling targets.

The agreed targets for the UK mean that by 2008 we must reduce our carbon dioxide emissions by 12.5%, compared with 1990. And recycling can help to achieve that goal, in two main ways: the production of recycled glass and paper uses much less energy than producing them from virgin materials, and also recycling reduces greenhouse gas emissions from landfill sites and incineration plants.

As part of our project, we carried out a survey of people in the street, and the thing that came up over and over again is that people don’t think it's easy enough to recycle their waste. One problem is that there aren’t enough ‘drop-off’ sites, that is, the places where the public are supposed to take their waste.

We also discovered that waste that’s collected from householders is taken to places called ‘bring banks’, for sorting and baling into loads. One problem here is taking out everything that shouldn’t have been placed in the recycling containers: people put all sorts of things into bottle banks, like plastic bags and even broken umbrellas. All this has to be removed by hand. Another difficulty is that toughened glass used for cooking doesn’t fully melt at the temperature required for other glass, and so that also has to be picked out by hand.

Glass is easy to recycle because it can be reused over and over again without becoming weaker. Two million tons of glass is thrown away each year, that is, seven billion bottles and jars; but only 500,000 tons of that is collected and recycled.

Complete the sentences below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

cooking incineration plants 12.5% / 12.5 percent drop-off 500,000

HOUSEHOLD WASTE RECYCLING

- By 2008, carbon dioxide emissions need to be lower than in 1990.

- Recycling saves energy and reduces emissions from landfill sites and .

- People say that one problem is a lack of ‘ ′ sites for household waste. At the "bring banks′, household waste is sorted and unsuitable items removed.

- Glass designed to be utilised for cannot be recycled with other types of glass.

- In the UK, tons of glass is recycled each year.

Script:

Oddly enough, half the glass that’s collected is green, and a lot of that is imported, so more green glass is recycled than the UK needs. As a result, new uses are being developed for recycled glass, particularly green glass, for example in fibreglass manufacture and water filtration. A company called CLF Aggregates makes a product for roads, and 30% of the material is crushed glass. For recycling paper, Britain comes second in Europe with 40%, behind Germany’s amazing 70%.

When recycling started, there were quality problems, so it was difficult to use recycled paper in office printers. But these problems have now been solved, and Martin’s, based in South London, produces a range of office stationery which is 100% recycled, costs the same as normal paper and is of equally high quality.

But this high quality comes at a cost in terms of the waste produced during the process. Over a third of the waste paper that comes in can’t be used in the recycled paper, leaving the question of what to do with it. One firm, Papersave, currently sells this to farmers as a soil conditioner, though this practice will soon be banned because of transport costs and the smell, and the company is looking into the possibility of alternative uses.

Plastic causes problems, because there are so many different types of plastic in use today, and each one has to be dealt with differently. Pacrite recycles all sorts of things, from bottles to car bumpers, and one of its most successful activities is recycling plastic bottles to make containers which are used all over the country to collect waste.

The Save-a-Cup scheme was set up by the vending and plastics industries to recycle as many as possible of the three-and-a-half billion polystyrene cups used each year. At the moment 500 million polycups are collected, processed and sold on to other businesses, such as Waterford, which turns the cups into pencils, and Johnson & Jones, a Welsh-based firm, which has developed a wide variety of items, including business cards.

Well, to sum up, there seems to be plenty of research going on into how to re-use materials, but the biggest problem is getting people to think about recycling instead of throwing things away. At least doing the research made us much more careful.

Complete the table below. Write NO MORE THAN THREE WORDS for each answer.

Companies working with recycled materials
Material	Company	Product that the company manufactures
glass	CLF Aggregates	material used for making (1)...................
paper	Martin’s	office stationery
paper	Papersave	(2)................... for use on farms
plastic	Pacrite	(3) ................... for collecting waste
	Waterford	(4) ...................
	Johnson & Jones	(5) ...................

soil conditioner roads business cards pencils containers

(1)
(2)
(3)
(4)
(5)

Passage 1

BAKELITE

The birth of modern plastics

In 1907, Leo Hendrick Baekeland, a Belgian scientist working in New York, discovered and patented a revolutionary new synthetic material. His invention, which he named 'Bakelite', was of enormous technological importance, and effectively launched the modern plastics industry.

The term 'plastic' comes from the Greek plassein, meaning ‘to mould’. Some plastics are derived from natural sources, some are semi-synthetic (the result of chemical action on a natural substance), and some are entirely synthetic, that is, chemically engineered from the constituents of coal or oil. Some are 'thermoplastic', which means that, like candlewax, they melt when heated and can then be reshaped. Others are 'thermosetting': like eggs, they cannot revert to their original viscous state, and their shape is thus fixed for ever. Bakelite had the distinction of being the first totally synthetic thermosetting plastic.

The history of today's plastics begins with the discovery of a series of semi-synthetic thermoplastic materials in the mid-nineteenth century. The impetus behind the development of these early plastics was generated by a number of factors - immense technological progress in the domain of chemistry, coupled with wider cultural changes, and the pragmatic need to find acceptable substitutes for dwindling supplies of ‘luxury’ materials such as tortoiseshell and ivory.

Baekeland's interest in plastics began in 1885 when, as a young chemistry student in Belgium, he embarked on research into phenolic resins, the group of sticky substances produced when phenol (carbolic acid) combines with an aldehyde (a volatile fluid similar to alcohol). He soon abandoned the subject, however, only returning to it some years later. By 1905 he was a wealthy New Yorker, having recently made his fortune with the invention of a new photographic paper. While Baekeland had been busily amassing dollars, some advances had been made in the development of plastics. The years 1899 and 1900 had seen the patenting of the first semi-synthetic thermosetting material that could be manufactured on an industrial scale. In purely scientific terms, Baekeland's major contribution to the field is not so much the actual discovery of the material to which he gave his name, but rather the method by which a reaction between phenol and formaldehyde could be controlled, thus making possible its preparation on a commercial basis. On 13 July 1907, Baekeland took out his famous patent describing this preparation, the essential features of which are still in use today.

The original patent outlined a three-stage process, in which phenol and formaldehyde (from wood or coal) were initially combined under vacuum inside a large egg-shaped kettle. The result was a resin known as Novalak, which became soluble and malleable when heated. The resin was allowed to cool in shallow trays until it hardened, and then broken up and ground into powder. Other substances were then introduced: including fillers, such as wood flour, asbestos or cotton, which increase strength and moisture resistance, catalysts (substances to speed up the reaction between two chemicals without joining to either) and hexa, a compound of ammonia and formaldehyde which supplied the additional formaldehyde necessary to form a thermosetting resin. This resin was then left to cool and harden, and ground up a second time. The resulting granular powder was raw Bakelite, ready to be made into a vast range of manufactured objects. In the last stage, the heated Bakelite was poured into a hollow mould of the required shape and subjected to extreme heat and pressure, thereby 'setting' its form for life.

The design of Bakelite objects, everything from earrings to television sets, was governed to a large extent by the technical requirements of the moulding process. The object could not be designed so that it was locked into the mould and therefore difficult to extract. A common general rule was that objects should taper towards the deepest part of the mould, and if necessary the product was moulded in separate pieces. Moulds had to be carefully designed so that the molten Bakelite would flow evenly and completely into the mould. Sharp corners proved impractical and were thus avoided, giving rise to the smooth, 'streamlined' style popular in the 1930s. The thickness of the walls of the mould was also crucial- thick walls took longer to cool and harden, a factor which had to be considered by the designer in order to make the most efficient use of machines.

Baekeland's invention, although treated with disdain m its early years, went on to enjoy an unparalleled popularity which lasted throughout the first half of the twentieth century. It became the wonder product of the new world of industrial expansion - 'the material of a thousand uses'. Being both non-porous and heat-resistant, Bakelite kitchen goods were promoted as being germ-free and sterilisable. Electrical manufacturers seized on its insulating properties, and consumers everywhere relished its dazzling array of shades, delighted that they were now, at last, no longer restricted to the wood tones and drab browns of the pre-plastic era. It then fell from favour again during the 1950s, and was despised and destroyed in vast quantities. Recently, however, it has been experiencing something of a renaissance, with renewed demand for original Bakelite objects in the collectors' marketplace, and museums, societies and dedicated individuals once again appreciating the style and originality of this innovative material.

Complete the summary. Choose ONE WORD ONLY from the passage for each answer.

candlewax chemistry synthetic

Some plastics behave in a similar way to in that they melt under heat and can be moulded into new forms. Bakelite was unique because it was the first material to be both entirely in origin, and thermosetting.

There were several reasons for the research into plastics in the nineteenth century, among them the great advances that had been made in the field of and the search for alternatives to natural resources like ivory.

Complete the flow-chart. Choose ONE WORD ONLY from the passage for each answer.

raw pressure fillers hexa Novalak

(1)
(2)
(3)
(4)
(5)

Passage 2

WHALE STRANDINGS

Why do whales leave the ocean and become stuck on beaches?

When the last stranded whale of a group eventually dies, the story does not end there. A team of researchers begins to investigate, collecting skin samples for instance, recording anything that could help them answer the crucial question: why? Theories abound, some more convincing than others. In recent years, navy sonar has been accused of causing certain whales to strand. It is known that noise pollution from offshore industry, shipping and sonar can impair underwater communication, but can it really drive whales onto our beaches?

In 1998, researchers at the Pelagos Cetacean Research Institute, a Greek non-profit scientific group, linked whale strandings with low- frequency sonar tests being carried out by the North Atlantic Treaty Organisation (NATO). They recorded the stranding of 12 Cuvier’s beaked whales over 38.2 kilometres of coastline. NATO later admitted it had been testing new sonar technology in the same area at the time as the strandings had occurred. ‘Mass’ whale strandings involve four or more animals. Typically they all wash ashore together, but in mass atypical strandings (such as the one in Greece), the whales don't strand as a group; they are scattered over a larger area.

For humans, hearing a sudden loud noise might prove frightening, but it does not induce mass fatality. For whales, on the other hand, there is a theory on how sonar can kill. The noise can surprise the animal, causing it to swim too quickly to the surface. The result is decompression sickness, a hazard human divers know all too well. If a diver ascends too quickly from a high-pressure underwater environment to a lower-pressure one, gases dissolved in blood and tissue expand and form bubbles. The bubbles block the flow of blood to vital organs, and can ultimately lead to death.

Plausible as this seems, it is still a theory and based on our more comprehensive knowledge of land-based animals. For this reason, some scientists are wary. Whale expert Karen Evans is one such scientist. Another is Rosemary Gales, a leading expert on whale strandings. She says sonar technology cannot always be blamed for mass strandings. "It’s a case-by-case situation. Whales have been stranding for a very long time - pre-sonar.” And when 80% of all Australian whale strandings occur around Tasmania, Gales and her team must continue in the search for answers.

When animals beach next to each other at the same time, the most common cause has nothing to do with humans at all. "They're highly social creatures,” says Gales. "When they mass strand - it’s complete panic and chaos. If one of the group strands and sounds the alarm, others will try to swim to its aid, and become stuck themselves.”

Activities such as sonar testing can hint at when a stranding may occur, but if conservationists are to reduce the number of strandings, or improve rescue operations, they need information on where strandings are likely to occur as well. With this in mind, Ralph James, physicist at the University of Western Australia in Perth, thinks he may have discovered why whales turn up only on some beaches. In 1986 he went to Augusta, Western Australia, where more than 100 false killer whales had beached. “I found out from chatting to the locals that whales had been stranding there for decades. So I asked myself, what is it about this beach?” From this question that James pondered over 20 years ago, grew the university's Whale Stranding Analysis Project. Data has since revealed that all mass strandings around Australia occur on gently sloping sandy beaches, some with inclines of less than 0.5%. For whale species that depend on an echolocation system to navigate, this kind of beach spells disaster. Usually, as they swim, they make clicking noises, and the resulting sound waves are reflected in an echo and travel back to them. Flowever, these just fade out on shallow beaches, so the whale doesn’t hear an echo and it crashes onto the shore.

But that is not all. Physics, it appears, can help with the when as well as the where. The ocean is full of bubbles. Larger ones rise quickly to the surface and disappear, whilst smaller ones - called microbubbles - can last for days. It is these that absorb whale 'clicks! "Rough weather generates more bubbles than usual,” James adds. So, during and after a storm, echolocating whales are essentially swimming blind.

Last year was a bad one for strandings in Australia. Can we predict if this - or any other year - will be any better? Some scientists believe we can. They have found trends which could be used to forecast ‘bad years’ for strandings in the future. In 2005, a survey by Klaus Vanselow and Klaus Ricklefs of sperm whale strandings in the North Sea even found a correlation between these and the sunspot cycle, and suggested that changes in the Earth’s magnetic field might be involved. But others are sceptical. “Their study was interesting ... but the analyses they used were flawed on a number of levels,” says Evans. In the same year, she co-authored a study on. Australian strandings that uncovered a completely different trend. “We analysed data from 1920 to 2002 ... and observed a clear periodicity in the number of whales stranded each year that coincides with a major climatic cycle.” To put it more simply, she says, in the years when strong westerly and southerly winds bring cool water rich in nutrients closer to the Australia coast, there is an increase in the number of fish. The whales follow.

So what causes mass strandings? “It's probably many different components,” says James. And he is probably right. But the point is we now know what many of those components are.

Choose NO MORE THAN TWO WORDS from the passage for each answer.

skin/ skin samples noise/ noise pollution sperm/ sperm wales/ sperm whale around Tasmania/ Tasmania

What do researchers often take from the bodies of whales?

What do some industries and shipping create that is harmful to whales?

In which geographical region do most whale strandings in Australia happen?

Which kind of whale was the subject of a study in the North Sea?

Label the diagram below. Choose NO MORE THAN TWO WORDS from the passage for each answer.

sound waves microbubbles nutrients blood

(1)
(2)
(3)
(4)

Passage 3

The First Antigravity Machine?

It was one of the biggest science stories of the 1990s. Even now, the facts behind it remain hotly disputed. And small wonder, for if the claims made for the small disc, the focus of the controversy, are true, it may be possible to break through one of the great barriers in the scientific world and control the most potent of cosmic forces: gravity. Huge innovations in flight and space travel could arise from that.

The first gravity-blocking system to be taken seriously by scientists appeared in a laboratory in Tampere University of Technology, Finland. A Russian scientist named Dr Evgeny Podkletnov created a disc 275mm across, made from a substance which combined copper, barium and the ‘rare Earth metal’ called yttrium, which is known to be a high-temperature superconductor (a substance that conducts electricity without resistance). When chilled with liquid nitrogen at -196° C (a high temperature compared with other superconductors), this material loses all its electrical resistance, and can levitate (lift) in a magnetic field. That may seem amazing for a ceramic-like material - and it won a Nobel Prize for the scientists, Karl Muller and Johannes Bednorz, who first demonstrated it in the 1980s. But according to Podkletnov, the disc had another far more astounding property.

In 1992, while experimenting with rotating superconductors, Podkletnov noticed that pipe-smoke from a nearby researcher was drifting into a vertical column above the spinning disc. Intrigued by this phenomenon, he decided to devise an experiment to investigate further. A superconductive disc, surrounded by liquid nitrogen was magnetically levitated and rotated at high speed - up to 5,000 revolutions per minute (rpm) in a magnetic field. An object was suspended from a sensitive balance above the disc. It was enclosed in a glass tube to shield it from any effects of air currents. During the course of a series of tests, Podkletnov was able to observe that the object lost a variable amount of weight from less than 0.5 percent to 2 percent of its total weight. This effect was noted with a range of materials from ceramics to wood. The effect was slight, yet the implications were revolutionary: the disc appeared to be partly shielding the object from the gravitational pull of the Earth.

This was just the start, claimed Podkletnov. While far short of the 100 percent reduction in weight needed to send astronauts into space, for example, it was infinitely greater than the amount predicted by the best theory of gravity currently in existence: Einstein’s theory of general relativity (GR), published in 1905. According to Einstein, gravity is not some kind of ‘force field’, like magnetism, which can - in principle at least - be screened out. Instead, GR views gravity as a distortion in the very fabric of space and time, that permeates the whole cosmos. As such, any claim to have shielded objects from gravity is to defy Einstein himself.

Podkletnov’s claims were subjected to intense scrutiny when he submitted them for publication. The UK Institute of Physics had Podkletnov’s paper checked by three independent referees, but none could find a fatal flaw. His research was set to appear in the respected Journal of Physics D when events took an unexpected turn. The claims were leaked to the media, sparking world-wide coverage of his apparent breakthrough. Then Podkletnov suddenly withdrew the paper from publication and refused to talk to the press.

Rumours began to circulate of unknown backers demanding silence until the device had been fully patented. But for many scientists the strange events were all too familiar. Podkletnov was just the latest in a long line of people to have made claims about defying gravity. Most of these have come from madcap inventors, with bizarre devices - often with some kind of spinning disc. But occasionally, respectable academics have made such claims as well.

One instance of this occurred in the late 1980s when scientists at Tohoku University, Japan, made headlines with research suggesting that apparatus, known as a gyroscope, lost 0.01 percent of its weight when spinning at up to 13,000 rpm. Oddly the effect only appeared if the gyroscope was spinning anticlockwise - raising suspicions that some mechanical peculiarity was to blame. Attempts by scientists at the University of Colorado to replicate the effect failed.

Then Professor Giovanni Modanese, an Italian theoretical physicist, became interested. He had read an earlier paper by Podkletnov, hinting at a connection between superconductivity and gravity shielding. Modanese wondered if the magnetic fields surrounding the superconductive disc might somehow assimilate part of the gravitational field under it. He published some calculations based on his idea in 1995 - and soon discovered that taking ‘antigravity’ seriously was a career-limiting move.

The revelations about Podkletnov’s antigravity research led to reports of major corporations setting up their own studies. In 2000, the UK defence contractor BAE Systems was said to have launched ‘Project Greenglow’ to investigate Podkletnov’s gravity shield effect. Then it emerged that the US aircraft builder Boeing was also investigating, suggesting it too had an interest in the effect. Groups in other countries were also rumoured to be carrying out studies. Yet not one of the teams has reported confirmation of the original findings. Some projects have been wound up without producing results either way. So for the time being, it seems that the dream of controlling gravity will remain precisely that.

Label the diagram below. Choose NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage for each answer.

sensitive balance / balance liquid nitrogen 5,000 rpm / five thousand rpm /5,000 revolutions per minute / five revolutions per minute glass tube

(1)
(2)
(3)
(4)

Score: 0/10

SCORE AGAIN NEXT

No.

Date

Right Score

Total Score

elearn site

PARTNERS

NEWS