Britannica Student Encyclopedia - 2010

time in order to sow their crops and reap

their harvests. These people were the

first astronomers.

The most influential ancient astronomer

was Ptolemy of Alexandria in Egypt. He

lived in the AD 100s. He developed the

idea that Earth occupies the center of

the universe. He thought that the other

objects revolved around Earth. Most

people believed this idea of Ptolemy’s

for more than a thousand years.

In 1543Nicolaus Copernicus published a

revolutionary new theory.He believed

that Earth and the other planets revolve

around the sun. Copernicus was criticized

because he challenged Ptolemy’s theory.

Galileo Galilei, a great Italian scientist

and astronomer, supported Copernicus’

theory with his observations.

Later astronomers made new discoveries

that also supported Copernicus’ idea. In

the early 1600s Johannes Kepler

explained how the planets travel around

the sun. In 1687 Isaac Newton learned

about gravitation and motion. His work

reinforced Kepler’s laws. Today astrono-

Astronomers study everything

they can see or detect in the sky.

Some astronomers study the

oddly shaped clouds of gas and

dust called nebulas.

Chinese

astronomers

noticed an

explosion in

the sky on July

4, 1054. This

was a supernova,

or the

explosion of a

star. Its

remains can

be seen today

in the Crab

Nebula.

BRITANNICA STUDENT ENCYCLOPEDIA Astronomy 215

 

mers know that Copernicus was correct.

But there are still many questions about

the universe. Astronomers continue to

try to answer those questions.

..More to explore

Solar System • Telescope • Universe

Asuncion

Population

(2006

estimate), city,

519,361;

(2007

estimate), urban

area,

1,870,000

Asuncion is the capital of Paraguay, a

country in South America. It is Paraguay’s

largest city. Asuncion is located

on the Paraguay River. From the city’s

port, ships can travel to the Atlantic

Ocean.

Asuncion processes and ships much of

the food grown throughout Paraguay.

Factories in the city also process cotton

and make cloth, shoes, and tobacco

products. The government employs

many people in Asuncion. Others work

in service industries such as health care,

tourism, and trade.

The Guarani Indians moved into the

area hundreds of years ago. In the 1500s

people from Spain settled among the

Guarani and created a colony. The Spanish

named the city Asuncion in 1537.

Paraguay became independent from

Spain in 1811. Asuncion then became

Paraguay’s capital. During a war in the

late 1800s Brazil took control of Asuncion.

But the city was returned to Paraguay

about 10 years later.

..More to explore

Paraguay

Athapaskan

The Athapaskan (or Athabascan) were a

large group of Native American tribes

who spoke similar languages. They traditionally

lived in northwestern North

The presidential palace in Asuncion is

brightly lit at night.

An Athapaskan child shows his drawings of

reindeer.

216 Asuncion BRITANNICA STUDENT ENCYCLOPEDIA

 

America. Before 1400 some Athapaskans,

including the Navajo and the

Apache, moved to what is now the

southwestern United States. Others

migrated to the Great Plains or the

Pacific coast. Today the name Athapaskan

is usually used for tribes who stayed

in northern Canada and Alaska. They

include the Chipewyan, the Han, and

the Kutchin.

The Athapaskan lived in forests in areas

with long, snowy winters. They fished

and hunted for animals such as deer,

moose, rabbits, and squirrels. They

prized the reindeer for its skin and fur as

well as its meat. The Athapaskan also

gathered plants.

Living in such a cold environment, the

Athapaskan spent most of the year in a

constant search for food. They traveled

in small family groups. While hunting

they lived in portable, cone-shaped

dwellings that resembled the tepees

made by Plains Indians. They used

dogsleds to carry their belongings over

snow and ice.

For many years only a few French,

English, and Russian fur traders entered

Athapaskan lands. In the late 1800s

many more people arrived in search of

gold. The newcomers brought change,

but traditional ways survived. In the late

20th century more than 40,000 Athapaskan

lived in Alaska and northern

Canada, where they are called Dene.

#More to explore

Apache • Chipewyan • Native

Americans • Navajo • Plains Indians

Athena

In ancient Greek mythology Athena was

the goddess of war, wisdom, and handicrafts.

She was one of the 12 gods

believed to live on Mount Olympus. She

is associated with the Roman goddess

BRITANNICA STUDENT ENCYCLOPEDIA Athena 217

 

Minerva because they shared many of

the same characteristics. Athena’s symbols

were the olive tree, which represents

peace, and the owl, which represents

wisdom.

According to legend, Athena was the

favorite daughter of Zeus, the chief god.

She was said to have sprung from his

head fully grown and clothed in a suit of

armor. Like Zeus, Athena wore the aegis,

which was a magical breastplate fringed

with snakes. It produced thunderbolts

when shaken.

Athena was very different from the war

god Ares, who was a powerful fighter.

Athena used her great wisdom to advise

soldiers during wartime. She believed

that war should be used only to protect

people and to provide justice. In addition,

she was known for inventing the