154 Science and Technology
FIND OUT MORE. Computers 190 • Design 326 • Machines 196–197
What makes the stars shine?
Why is the sky blue? How did
life start on Earth? Science
explores and tries to understand
everything in the world.
WHAT IS SCIENTIFIC METHOD?
Scientists create a theory to explain observations.
Theories are often written as equations. A good
theory makes predictions that can be tested by
further observations and experiments. A trial theory
is called a hypothesis. If its predictions are correct,
the hypothesis is supported.HOW ARE SCIENCE AND TECHNOLOGY LINKED?
Ancient technologies, such as shipbuilding, were crafts
passed on through generations. Understanding the
materials and forces used came later. Today engineers
use the discoveries and methods of science at every
stage as they solve problems and develop inventions.WHAT DO SCIENTISTS DO?
A scientist uses knowledge and a logical approach to
solve a problem or explain an observation. Scientists
use instruments to study forces, disease, and materials.
Without scientists, we would not have gone to the
Moon, discovered penicillin, or developed computers.1 BANGLADESHI PANOS STOVE
Appropriate technology fits in
with the environment and
lifestyle of the people using it.
This stove design helps people to
use less wood as fuel, which in
turn conserves forest trees.1 EXPLORATION
AND DISCOVERY
From the ocean depths to outer
space, scientists investigate the
natural world by observation
and measurement.IN THE LABORATORY 3
Scientists test their theories with
experiments in the laboratory.
This scientist is looking at
bacteria in a petri dish.SCIENCE
4 COMPUTER-AIDED DESIGN
High-speed computers solve
complex equations. Technologists
simulate (copy) the performance
of aircraft on computers to
improve designs.WHY DO SCIENTISTS PERFORM EXPERIMENTS?
An experiment is a practical test of a theory. By
performing experiments, scientists seek answers to
questions. They use measuring instruments to record
the results of their experiments as numbers.Technology is the practical application of
knowledge and skills to make tools, machines,
buildings, vehicles, and other useful things.
Technology
FIND OUT MORE. Biology 72 • Chemistry 162 • Physics 163
Bacteria culture
(growth)
in petri dishscience
,
technology