Environmental Engineering Reference
In-Depth Information
that is, by running mathematical models on high-
speed computers to analyze the interactions of many
variables without having to carry out traditional con-
trolled experiments.
Scientists use critical thinking skills (p. 3) and logi-
cal thinking to develop and evaluate scientific ideas.
But scientists also try to come up with new and cre-
ative ideas to explain some of the things they observe
in nature. According to physicist Albert Einstein, how-
ever, “There is no completely logical way to a new sci-
entific idea.” Intuition, imagination, and creativity are
as important in science as they are in poetry, art, music,
and other great adventures of the human spirit, as re-
flected by Warren Weaver's quotation found at the
opening of this chapter.
Royal Society, which attempt to summarize consensus
among experts in key areas of science.
Junk Science
Junk science is untested ideas presented as sound
science.
Junk science
consists of scientific results or hypotheses
that are presented as sound science but have not under-
gone the rigors of peer review. Two problems arise in
uncovering junk science. First, some scientists, politi-
cians, and other analysts label as junk science any sci-
ence that does not support or further their particular
agenda. Second, reporters and journalists sometimes
mislead their audiences by presenting sound or consen-
sus science along with a quote from a scientist in the
field who disagrees with the consensus view or from
someone who is not an expert in the field. Such attempts
to give a false sense of balance or fairness can mislead
the public into distrusting well-established sound sci-
ence. See the Guest Essay on environmental reporting
by Andrew C. Revkin on the website for this chapter.
Here are some critical thinking questions you can
use to uncover junk science.
How Valid Are the Results of Science?
Scientists try to establish that a particular theory or
law has a very high probability of being true.
Scientists try to do two major things.
First,
they dis-
prove things.
Second,
they establish that a particular
theory or law has a very high probability or degree of
certainty of being true. Ultimately, like scholars in any
field, scientists cannot prove their theories and laws
are
absolutely
true.
Although it may be extremely low, some degree of
uncertainty is always present for any scientific theory,
model, or law. Most scientists rarely say something
like, “Cigarettes cause lung cancer.” Rather, they might
say, “Overwhelming evidence from thousands of stud-
ies indicates that there is a significant relationship be-
tween cigarette smoking and lung cancer.”
■
How reliable are the sources making a particular
claim? Do they have a hidden agenda? Are they ex-
perts in this field? What is their source of funding?
■
Do the conclusions follow logically from the
observations?
■
Has the claim been verified by impartial peer
review?
■
How does the claim compare with the consensus
view of experts in this field?
Frontier Science and Sound Science
Scientific results fall into two categories: those that
have not been confirmed (frontier science) and those
that have been well tested and widely accepted
(sound science).
News reports often focus on two things: so-called sci-
entific breakthroughs, and disputes between scientists
over the validity of preliminary and untested data and
hypotheses. These preliminary results, called
frontier
science,
are often controversial because they have not
been widely tested and accepted. At the frontier stage,
it is normal and healthy for reputable scientists to dis-
agree about the meaning and accuracy of data and the
validity of various hypotheses.
By contrast,
sound science
(also known as
con-
sensus science
) consists of data, theories, and laws
that are widely accepted by scientists who are consid-
ered experts in the field. The results of sound science
are based on a self-correcting process of open peer re-
view. To find out what scientists generally agree on,
you can seek out reports by scientific bodies such as
the U.S. National Academy of Sciences and the British
2-2
MATTER
Elements and Compounds
Matter exists in chemical forms as elements and
compounds.
Matter
is anything that has mass (the amount of mate-
rial in an object) and takes up space. Scientists classify
matter as existing in various levels of organization
(Figure 2-3). Chapter 3 gives details about the five lev-
els of matter that make up the realm of ecology.
Matter is found in two chemical forms. One is
ele-
ments:
the distinctive building blocks of matter that
make up every material substance. The other consists
of
compounds:
two or more different elements held to-
gether in fixed proportions by attractive forces called
chemical bonds.
To simplify things, chemists represent each ele-
ment by a one- or two-letter symbol. Examples used in
this topic are hydrogen (H), carbon (C), oxygen (O), ni-
trogen (N), phosphorus (P), sulfur (S), chlorine (Cl),
