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Written in the stars. Retell the text using the following word combinations. Popular Information. Read the information on dark energy and highlight the key points in writing
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Written in the stars
" Some say the world will end in fire, some say in ice... "
What will be the final destiny of the Universe? Probably it will end in ice, if we are to believe this year's Nobel Laureates in Physics. They have studied several dozen exploding stars, called supernovae, and discovered that the Universe is expanding at an ever-accelerating rate. The discovery came as a complete surprise even to the Laureates themselves.
In 1998, cosmology was shaken at its foundations as two research teams presented their findings. Headed by Saul Perlmutter, one of the teams had set to work in 1988. Brian Schmidt headed another team, launched at the end of 1994, where Adam Riess was to play a crucial role.
The research teams raced to map the Universe by locating the most distant supernovae. More sophisticated telescopes on the ground and in space, as well as more powerful computers and new digital imaging sensors (CCD, Nobel Prize in Physics in 2009), opened the possibility in the 1990s to add more pieces to the cosmological puzzle.
The teams used a particular kind of supernova, called type Ia supernova. It is an explosion of an old compact star that is as heavy as the Sun but as small as the Earth. A single such supernova can emit as much light as a whole galaxy. All in all, the two research teams found over 50 distant supernovae whose light was weaker than expected — this was a sign that the expansion of the Universe was accelerating. The potential pitfalls had been numerous, and the scientists found reassurance in the fact that both groups had reached the same astonishing conclusion.
For almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. However, the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up the Universe will end in ice.
The acceleration is thought to be driven by dark energy, but what that dark energy is remains an enigma — perhaps the greatest in physics today. What is known is that dark energy constitutes about three quarters of the Universe. Therefore the findings of the 2011 Nobel Laureates in Physics have helped to unveil a Universe that to a large extent is unknown to science. And everything is possible again.
(http: //www. nobelprize. org/nobel_prizes/physics/laureates/2011/press. html)
Answer the questions to the text:
1) What is the final destiny of the Universe according to 2011’s Nobel Laureates in Physics?
2) What discovery made them make their conclusions?
3) What was the original aim of their research? What kind of equipment was engaged to achieve it?
4) What is supernova and why did the researchers use it as the object of the study?
5) What surprising results did they obtain?
6) What is the generally accepted theory of the origin of the Universe?
7) What is the driving force of the acceleration of the Universe and how much of the Universe does it constitute?
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Retell the text using the following word combinations
to study several dozen exploding stars (supernovae), to expand at an ever-accelerating rate, to come as a complete surprise to smb, to be shaken at its foundations(cosmology), to present findings, to set to work, to play a crucial role, to locate the most distant supernovae, open the possibility, to add more pieces to the cosmological puzzle, to use a particular kind of supernova, to emit as much light as a whole galaxy, all in all, numerous potential pitfalls, to find reassurance in the fact that…, to reach the same astonishing conclusion, to remain an enigma, an astounding discovery, to unveil the Universe, unknown to a large extent to science
Popular Information
Read the information on dark energy and highlight the key points in writing
So what is it that is speeding up the Universe? It is called dark energy and is a challenge for physics, a riddle that no one has managed to solve yet. Several ideas have been proposed. The simplest is to reintroduce Einstein’s cosmological constant, which he once rejected. At that time, he inserted the cosmological constant as an anti-gravitational force to counter the gravitational force of matter and thus create a static Universe. Today, the cosmological constant instead appears to make the expansion of the Universe accelerate.
The cosmological constant is, of course, constant, and as such does not change over time. So dark energy becomes dominant when matter, and thus its gravity, gets diluted due to expansion of the Universe over billions of years. According to scientists, that would account for why the cosmological constant entered the scene so late in the history of the Universe, only five to six billion years ago. At about that time, the gravitational force of matter had weakened enough in relation to the cosmological constant. Until then, the expansion of the Universe had been decelerating.
The cosmological constant could have its source in the vacuum, empty space that, according to quantum physics, is never completely empty. Instead, the vacuum is a bubbling quantum soup where virtual particles of matter and antimatter pop in and out of existence and give rise to energy. However, the simplest estimation for the amount of dark energy does not correspond at all to the amount that has been measured in space, which is about 10120times larger (1 followed by 120 zeros). This constitutes a gigantic and still unexplained gap between theory and observation — on all the beaches of the world there are no more than 1020 (1 followed by 20 zeros) grains of sand.
It may be that the dark energy is not constant after all. Perhaps it changes over time. Perhaps an unknown force field only occasionally generates dark energy. In physics there are many such force fields that collectively go by the name quintessence, after the Greek name for the fifth element. Quintessence could speed up the Universe, but only sometimes. That would make it impossible to foresee the fate of the Universe.
Whatever dark energy is, it seems to be here to stay. It fits very well in the cosmological puzzle that physicists and astronomers have been working on for a long time. According to current consensus, about three quarters of the Universe consist of dark energy. The rest is matter. But the regular matter, the stuff that galaxies, stars, humans and flowers are made of, is only five percent of the Universe. The remaining matter is called dark matter and is so far hidden from us.
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The dark matter is yet another mystery in our largely unknown cosmos. Like dark energy, dark matter is invisible. So we know both only by their effects — one is pushing, the other one is pulling. They only have the adjective “dark” in common.
Therefore the findings of the 2011 Nobel Laureates in Physics have helped to unveil a Universe that is to 95% unknown to science.
(http: //www. nobelprize. org/nobel_prizes/physics/laureates/2011/public. html)
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