Achieve IELTS test 4
Reading Passage 3
You should spend about 20 minutes
on Question 27-40, which are based on Reading Passage 3
The First
Antigravity Machine?
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It was one of the biggest science stories since
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 name 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 -1960 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 Müller and Johannes Bednorz, who first demonstrated it
in the 1980s. but according to Podkletnov, the dic 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 in dependent 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 he 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 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 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.
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Questions 27-30
Label the diagram below.
Choose NO MORE THAN TWO WORDS from
the passage for each answer.
Write your answers in boxes 27-30 on
your answer sheet.
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Questions 31-35
Classify the following findings as
belonging to
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A. Podkletnov
B. Tohuku University
C. Modanese
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Write the correct letter A, B, or C
in boxes 31-35 on your answer sheet.
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31
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The experiment only works if the equipment
moves in a particular direction
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32
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Varying
amounts of weight are lost as a result of the test
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33
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Gravity could be absorbed by a magnetic
field
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34
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Superconductive
material seems to screen an object from gravity
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35
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Weight loss occurs when the equipment
rotates at speeds reaching 13,000 rpm
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Questions
36-40
Do the
following statements agree with information given in Reading Passage 3?
in
boxes 36-40 on your answer sheet, write
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TRUE
FALSE
NOT
GIVEN
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if the
statement agrees with the information
if the
statement contradicts the information
if there
is no information on this
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36
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Podkletnov
won a prize for his initial work on superconductive substances
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37
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A chance
observation led Podkletnov to experiment with gravity blocking
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38
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Einstein
challenged earlier experiments on antigravity
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39
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Modanese
suffered professionally after following up Podkletnov’a findings
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40
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An
aircraft company announced that it had replicated Podkletnov’s results.
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ANSWER
KEY
27
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(sensitive) balance
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34
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A
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28
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5,000/ five thousand rpm/ revolutions per
minute
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35
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B
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29
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liquid
nitrogen
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36
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FALSE
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30
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glass tube
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37
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TRUE
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31
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B
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38
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NOT
GIVEN
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32
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A
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39
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TRUE
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33
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C
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40
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FALSE
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