Chapter 1 Notes:
Section 1 What Is Earth Science?
Section 1 Objectives
1. Describe two cultures that contributed to modern scientific study.
2. Name the four main branches of Earth science.
3. Discuss how Earth scientists help us understand the world around us.
The Scientific Study of Earth
• Earth science the scientific study of Earth and the universe around it
• Earth science assumes that the causes of natural events, or
phenomena, can be discovered through observation and
experimentation.
Branches of Earth Science
• Most Earth scientists specialize in one of four major areas of study:
the solid Earth, the oceans, the atmosphere, and the universe beyond
Earth.
Geology
• geology the scientific study of the origin, history, and structure of
Earth and the processes that shape Earth
• Geology includes many specialized fields of study, such as the study
of earthquakes or volcanoes, exploration for natural resources such as
coal and oil, and the study of Earth’s history through the study of
rocks and fossils.
Oceanography
• oceanography the scientific study of the ocean, including the
properties and movement of ocean water, the characteristics of the
ocean floor, and the organisms that live in the ocean
• Like geology, oceanography includes specialized fields. Some
oceanographers study ocean water. Others study waves, tides, and
ocean currents. Still others study the ocean floor or the organisms that
live in the oceans.
Meteorology
• meteorology the scientific study of Earth’s atmosphere, especially in
relation to weather and climate
• Using satellites, radar, and other technologies, meteorologists study
the atmospheric conditions that produce weather. They may use this
information to prepare weather forecasts.
• Some meteorologists study climate, the patterns of weather that occur
over long periods of time.
Astronomy
• astronomy the scientific study of the universe
• Astronomy is one of the oldest branches of Earth science.
• Modern astronomers use Earth-based and space-based telescopes, as
well as other instruments, to study the sun, the moon, the planets, and
the universe.
Environmental Science
• Environmental science is a relatively new field of Earth science that
involves the study of the ways in which humans interact with their
environment.
• Environmental scientists study many issues, such as the use of natural
resources, pollution, and the health of plant and animal species on
Earth.
The Importance of Earth Science
• Natural forces not only shape Earth but also affect life on Earth. By
understanding how natural forces shape our environment, Earth
scientists can better predict potential disasters and help save lives and
property.
• The work of Earth scientists helps us understand our place in the
universe.
• The study of Earth science can help people gain access to Earth’s
resources, and Earth scientists also strive to help people use those
resources wisely.
Section 2 Science as a Process
Section 2 Objectives:
1. Explain how science is different from other forms of human
endeavor.
2. Identify the steps that make up scientific methods.
3. Analyze how scientific thought changes as new information is
collected.
4. Explain how science affects society.
Behavior of Natural Systems
• The goal of science is to explain natural phenomena.
• Scientists ask questions about natural events and then work to answer
those questions through experiments and examination.
• Everybody does pretty much the same thing whenever they are trying
to solve a problem.
Assumptions that Scientists Make:
• Scientists start with the assumption that nature is understandable.
• Scientists also expect that similar forces in a similar situation will
cause similar results.
• Scientists also expect that nature is predictable, which means that the
future behavior of natural forces can be anticipated.
Scientific Methods
• Over time, the scientific community has developed organized and
logical approaches to scientific research. These approaches are
known as scientific methods.
• Scientific methods are not a set of sequential steps that scientists
always follow. Rather these methods are guidelines to scientific
problem solving.
Ask a Question
• observation the process of obtaining information by using the
senses; the information obtained by using the senses
• Scientific investigations often start with observations.
• Observations commonly lead to questions.
• Simple questions have fueled years of scientific research and have
been investigated through scientific methods.
Form a Hypothesis
• hypothesis an idea or explanation that is based on observation and
that can be tested
• Once a question has been asked and basic information has been
gathered, a scientist may propose a tentative answer, which is also
known as a hypothesis.
• Most hypotheses are based on known facts about similar events.
Test the Hypothesis
• After a hypothesis is proposed, it is commonly tested by performing
experiments. An experiment is a procedure that is carried out
according to certain guidelines.
• independent variable in an experiment, the factor that is deliberately
manipulated
• dependent variable in an experiment, the factor that changes as a
result of one or more other factors (the independent variables)
Controlled Experiments
• Type of experiment that limits the number of observed variablesYou only focus and record the results of one changing aspect.
• Usually consists of two experimental groups used to compare to each
other.
Important Aspects of Controlled Experiments
• Variable: factor that affects an experiment.
• Constant: factor that does NOT change between two experimental
groups.
• Independent variable & Dependent variable.
• Experimental group: Experimental set up that contains the
independent variable.
• Control group: Experimental setup that does not contain the
independent variable. Used as a standard for comparison to the
experimental group.
Draw Conclusions
• After many experiments and observations, a scientist may reach
conclusions about his or her hypothesis.
• If the hypothesis fits the known facts, it may be accepted as true.
• If the experimental results differ from what was expected, the
hypothesis is changed or discarded.
• The results of scientific inquiry may lead to new knowledge and new
methods of inquiry that further scientific aims.
Scientific Measurements and Analysis
• Measurement is the comparison of some aspect of an object or event
with a standard unit.
• Scientists around the world can compare and analyze each other’s
measurements because scientists use a common system of
measurements called the International System of Units, or SI.
Accuracy and Precision
• Accuracy refers to how close a measurement is to the true value of
the thing being measured.
• Precision is the exactness of the measurement.
Error
• Error is an expression of the amount of imprecision or variation in a
set of measurements.
• Error is commonly expressed as percentage error or as a confidence
interval.
Observations and Models
• In Earth science, using controlled experiments to test hypotheses is
often impossible.
• When experiments are impossible, scientists make additional
observations to gather evidence.
• The hypothesis is then tested by examining how well the hypothesis
fits or explains all of the known evidence.
• Scientists also use models to simulate conditions in the natural world.
• A model is a description, representation, or imitation of an object,
system, process, or concept.
• Scientists use several types of models, including physical models,
graphical models, conceptual models, mathematical models, and
computer models.
Acceptance of Scientific Ideas
• Scientific understanding moves forward through the work of many
scientists, who build on the research of the generations of scientists
before them.
• When scientists reach a conclusion, they introduce their findings to
the scientific community.
• Scientific Ideas must be accepted by the scientific community of
experts in that field before it should be shared/explained to the public.
Publication of Results and Conclusions
• Scientists commonly present the results of their work in scientific
journals or at professional meetings.
Peer Review
• Scientists follow an ethical code that states that only valid
experimental results should be published.
• To reduce bias, scientists submit their ideas to other scientists for
peer review.
• peer review the process in which experts in a given field examine the
results and conclusions of a scientist’s study before that study is
accepted for publication
Formulating a Theory
• When an idea has undergone much testing and reaches general
acceptance, that idea may help form a theory.
• theory the explanation for some phenomenon that is based on
observation, experimentation, and reasoning; that is supported by a
large quantity of evidence; and that does not conflict with any
existing experimental results or observations
• A scientific law is a general statement that explains how the natural
world behaves under certain conditions and for which no exceptions
have been found.
• Theories and scientific laws can be changed if conflicting
information
is discovered in the future.