Childrens Illustrated Encyclopedia

455

A glass rod in a

beaker of water

looks bent

because light

waves travel

slower through

water than

through air.

Biology

Chemistry

Earth

Physics

Rocks and minerals

Find out more

ThERE aRE many foRms of sCiEnCE, and together the sciences seek

to understand the nature and behavior of the universe and everything in it.

science comes from the Latin word for “to know.” scientists find out what

they want to know by practical methods. They observe, take measurements,

make experiments, and write down the results. There are four main categories

(types) of science: natural sciences, physical sciences, technological sciences,

and social sciences. natural sciences include the life sciences, such as biology

and botany, and Earth sciences, such as geology. Physical sciences include

physics and chemistry. Technological science includes engineering and uses

information discovered by scientists to make or build things in the real

world. social sciences study people and include anthropology

and psychology. all the

sciences depend on

mathematics.

sCiEnTifiC mEThod

scientific method involves

using observation and

hypothesis (theory) to

explain things and then

testing these theories

with experiments. To be

sure that their results are

accurate, scientists always

follow strict rules when

making an experiment.

in an experiment only the

conditions under test

must change, everything

else must be kept the

same. in this way,

differences in the results

should only be caused by

the experimenter’s

deliberate changes.

LifE sCiEnCEs

any of the sciences that study

living things is called a life science.

Biology is the study of life

of all kinds, botany is the

study of plants, and

zoology is the study of

animals. Because

animal and plant life

depend on each other,

scientists also study them

together Ecology is the

study of the relationships

between living things of

all kinds and how they

fit in with and affect

their environments.

EaRTh sCiEnCEs

Geography and geology are Earth sciences.

Earth scientists study the structure of our

planet and the way it changes. The study

of rocks and fossils can tell us a lot about

the way the planet and its life have evolved.

since Earth is a living planet, the Earth

sciences are linked to

the life sciences.

soCiaL sCiEnCEs

The sciences that study people are called social sciences.

There are various kinds. anthropology is the study of the life

and culture of the whole of humanity. sociology studies the

way humans behave together in groups; it looks at how

families work, how society is made up, what makes it change,

and how the changes affect people. Psychology is also a social

science, but it looks at how people behave as individuals.

PhysiCs

Physics is the

study of matter

and energy and

how they work

together. Because

there are many different kinds of

matter and forms of energy, there

are many different branches of

physics. optics, for example, looks

at the different way light waves can

behave. for instance, they travel at

different speeds through space, air,

glass, or water.

Science

More salt is added to the

water until the salt no

longer dissolves but

sinks to the bottom of

the jar. This is called

the saturation point.

A measured amount of salt

is mixed in to a measured

amount of water.

Shoot grows up

toward the sun.

Geologists study rocks

and crystals.

Bean shoot

Roots absorb water

and nutrients.

A simple experiment

to find out how much

salt can be dissolved

in water

Cyanotrichite

Chrysocolla

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