Page 3 - Principles of Applied Engineering

8 Chapter 1 EnginEEring as a DisCiplinE

fact that material and energy cannot be created or destroyed; therefore, we need to be
mindful of our consumption of natural resources.
Benefiting the Human Race: Through an engineer’s work, he or she is meeting a par-
ticular need. Whether the need in question is relieving poverty in a disadvantaged
region of the nation or delivering a quality surround-sound experience in a family’s
home theater, the process is fundamentally the same. Our modern lives can be attrib-
uted to the work of engineers through the centuries.
design Design Process: Of all the terms in the definition, design lies at the heart of the engi-
neering profession. In order to benefit the human race in a tangible way, we need to
undergo a process that takes an idea and implements it physically. The process in ques-
design process tion is called the design process, an iterative series of steps engineers use to arrive at
the solution to a problem.
Throughout this text, we will delve into the field of engineering and the manner in
which an engineer goes about meeting the technological challenges of this century –
design.

1.2 The hisTorical DevelopmenT of engineering

When did technology actually begin? People often think of our times as technological
times and earlier eras as “ before technology.” In fact, people have always used technol-
ogy. Recall that technology is simply using the knowledge we have to create things that
people need. Because our knowledge has grown, technology has grown with it—from
the simple spears and grinding stones of our earliest ancestors to the complex machin-
ery and systems of today.
Much of our history has been defined by the materials that people used in a par-
ticular era. They used these materials to make tools that helped them carry out every-
day tasks. The names of these materials have given us a way to classify historical
periods. Three important periods of early history are the Stone Age, the Bronze Age,
and the Iron Age.

stone age

Stone Age The Stone Age, the period during which people used stone to make tools, lasted for
almost 1 million years—from about 1 million b.c. to about 3000 b.c. (Other common
materials used during this time were bones and wood.)
During this period, people lived very different lives from ours. Early humans used
stone, bone, and wood to make axes, spears, scrapers, and even tools for starting a fire.
They used the bow for hunting animals. They made needles from bone and used them
to sew clothing from animal skins.
During the Stone Age, there were few villages. Most people lived nomadic lives,
wandering from place to place. They hunted animals and gathered plants, fruits, seeds,
and roots for food. They used fire for cooking meat and for protection from wild ani-
mals. When they had used up food sources in an area, they moved to a new location.
The pace of technological change was very slow.

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