Environmental Engineering Reference
In-Depth Information
Science is an adventure of the human spirit. It is essentially
an artistic enterprise, stimulated largely by curiosity, served
largely by disciplined imagination, and based largely on faith
in the reasonableness, order, and beauty of the universe.
W
ARREN
W
EAVER
2-1
THE NATURE OF SCIENCE
What Is Science, and What Do
Scientists Do?
Scientists collect data, form hypotheses, and
develop theories, models, and laws about how nature
works.
Science
is an attempt to discover order in nature and
use that knowledge to make predictions about what is
likely to happen in nature. It is based on the assumption
that events in the natural world follow orderly cause
and effect patterns that can be understood through
careful observation and experimentation. Figure 2-2
summarizes the scientific process. Trace the pathways
in this figure.
The first thing scientists do is ask a question or
identify a problem to be investigated. Then they collect
scientific data,
or facts, by making observations and
measurements. They often conduct
experiments
to
study some phenomenon under known conditions.
The resulting scientific data or facts must be confirmed
by repeated observations and measurements, ideally
made by several different investigators.
The primary goal of science is not the data or
facts themselves. Instead, science seeks new ideas,
principles, or models that connect and explain certain
scientific data and predict what is likely to happen in
nature. Scientists working on a particular problem
suggest a variety of possible explanations, or
scien-
tific hypotheses,
for what they (or other scientists)
observe in nature. A scientific hypothesis is an uncon-
firmed explanation of an observed phenomenon that
can be tested by further research. To test a hypothesis,
scientists may develop a
model,
an approximate rep-
resentation or simulation of a system being studied. It
may be an actual working model, a mental model, a
pictorial model, a computer model, or a mathematical
model.
Tw o important features of the scientific process are
reproducibility
and
peer review
of results by other scien-
tists. Peers, or scientists working in the same field,
check for reproducibility by repeating and analyzing
one another's work to see if the data can be reproduced
and whether proposed hypotheses are reasonable.
Peer
review
happens when scientists publish details of the
methods they used, the results of their experiments,
and the reasoning behind their hypotheses for other
scientists to examine and criticize.
If repeated experiments or tests using models sup-
port an hypothesis, it becomes a
scientific theory:
a
highly reliable and widely accepted scientific hypothe-
sis or a related group of scientific hypotheses.
Scientific theories are not to be taken lightly.
They are
not guesses, speculations, or suggestions. Instead, they
are useful explanations of processes or natural phe-
To help us develop more sustainable societies, we
need to know about the nature of science and the mat-
ter and energy that make up the earth's living and
nonliving resources—the subjects of this chapter. It
discusses these questions:
What is science, and what do scientists do?
■
What are the basic forms of matter, and what
makes matter useful as a resource?
■
What are the major forms of energy, and what
makes energy useful as a resource?
■
What scientific law governs changes of matter
from one physical or chemical form to another?
■
What three main types of nuclear changes can mat-
ter undergo?
■
What are two scientific laws governing changes of
energy from one form to another?
■
How are the scientific laws governing changes
of matter and energy from one form to another
related to resource use and environmental
degradation?
■
KEY IDEAS
■
Scientists collect data and develop theories, mod-
els, and laws about how nature works.
■
Scientists can establish that a particular theory,
model, or law has a very high probability of being
true (sound science).
■
Matter consists of elements and compounds, which
are in turn made up of atoms, ions, or molecules.
■
When a physical or chemical change occurs, no
atoms are created or destroyed (law of conservation
of matter).
■
We cannot create or destroy energy when it is con-
verted from one form to another in a physical or
chemical change (first law of thermodynamics).
■
Whenever energy is changed from one form to an-
other, we always end up with less usable energy than
we started with (second law of thermodynamics).
■
The earth's matter and energy laws that we cannot
violate are lessons from nature about how to achieve
more sustainable societies.
