What’s the Biggest Thing in the Universe?

What’s the biggest thing in the universe？ It sounds like a child’s question but scientists have been searching for an answer for over thirty years. Now a team led by Dr Roger Clowes from the University of Central Lancashire believe they have found it. The largest thing in the universe may be a group of seventy-three quasars. The group is so large it would take a vehicle travelling at the speed of light about four billion years to cross it （the vehicle would cross our Milky Way galaxy in just one hundred thousand light years）. It’s not surprising that this group is called the ‘huge large quasar group’ or Huge-LQG for short.

Quasars are found around enormous black holes at the centres of galaxies. Gravity pulls dust and rocks into these black holes and this causes extremely powerful explosions. These explosions mean that quasars give out some of the brightest light in the universe—sometimes one hundred times as bright as the Milky Way. They also form groups which are called large quasar groups or LQGs.

In 1991， Clowes and a colleague from Chile， Luis Campusano， discovered an enormous quasar group， the Clowes-Campusano LQG. Since then technology has improved. Clowes and his team searched for quasar groups with the help of the Sloan Digital Sky Survey （SDSS）， which produces maps of the skies. They also used computers. They finally found the Huge-LQG， which is bigger than anything else ever found in space. Clowes thinks there may be many more groups of quasars in space， although they are probably not as large as the Huge-LQG.

The Huge-LQG is so big that scientists might need to think again about some basic laws of physics. The group is three times as long and twice as wide as experts had expected. Clowes thinks we may need to start asking new questions about theories such as the Cosmological Principle， which says that laws of physics are the same everywhere in the universe.

Activity 1

Before you read， match the word to a definition.

1. billion 3. explosion 5. theory

2. cause 4. quasar 6. gravity

a. a group of stars that produce a lot of energy

b. an idea that explains why or how something happens

c. make something happen

d. a force that makes things fall， for example an apple when you drop it

e. one thousand million

f. when a bomb explodes， for example

Activity 2

1. How long has the team been looking for large objects in space？

2. Why are quasars so bright？

3. What two things did the team use to help them discover the largest quasar group？

4. Are there likely to be any groups of quasars larger than the Huge-LQG in the universe？

5. Did scientists expect to find a group of quasars of the size of the Huge-LCQ？

Activity 3

Read these sentences from the article. The expressions in bold show how we compare things：

Light from a quasar is as bright as the Milky Way.

Other quasar groups are not as large as the Huge-LQG.

The group is three times as long and twice as wide as experts had expected.

The Huge-LQG is larger than anything else ever found in space.

Quasars produce the brightest light in the universe.

Read the country facts below which tell you how large the countries are.

Then complete each sentence using the expressions in bold （above） and the correct form of the adjective large. There is also a word or phrase in brackets which you should use.

Country How large is it？ About…

Canada 10 million km2

Mexico 2 million km2

Monaco 2 km2

Russia 17 million km2

Saudi Arabia 2 million km2

Senegal 200，000 km2

Slovenia 20，000 km2

1. Senegal ________ Slovenia. （than）

2. Canada ________ Russia. （not as … as）

3. Mexico ________ Saudi Arabia. （as … as）

4. Mexico ________ Monaco. （… times as … as）

5. Russia ________ of all the countries in the world.

Activity 4

The discovery of the Huge-LQG may lead us to think again about scientific ideas. One scientist has said， ‘A good theory is one that changes every fifty years’. Do you agree？

Answers

Activity 1

1. e; 2. c; 3. f; 4. a; 5. b; 6. d

Activity 2

1. For over thirty years; 2. Because of extremely powerful explosions;

3. The Sloan Digital Sky Survey （SDSS） and computers; 4. No; 5. No

Activity 3

1. Senegal is larger than Slovenia.; 2. Canada is not as large as Russia.;

3. Mexico is as large as Saudi Arabia.; 4. Mexico is a million times as large as Monaco.;

5. Russia is the largest of all the countries in the world.