Anatomy Lecture Notes – Unit 0
Section 0.1 Course and Instructor Introduction (see class syllabus)
Section 0.2 The Scientific Method and
Hypothesis Testing
I. The Nature of
Science
A. What is
science?
1. Science is the total collection of knowledge gained by man's observation of the physical
universe.
2. It tries to answer the questions
"how" and "why."
3. It is a logical way of problem solving.
B. Two main types
of science
1. Pure
science - studying things for the sake of gaining knowledge; new discoveries.
2. Applied
science - the use of pure science in practical ways (technology).
C. Limitations of Science
1. Cannot
make value judgments.
2. Cannot
prove something doesn't exist (universal negative).
3.
Scientific investigation is as limited as the instruments we use.
D. Scientific Statements
1. Facts -
things that are observable and indisputable.
2. Data -
any piece of information; usually gained through experimentation.
3. Laws -
statements that describe patterns in nature with no known exceptions.
4. Theories
- explanations usually based on evidence (may be wrong).
5. Models -
man-made ideas to help us visualize scientific concepts.
E. The Scientific Method
The scientific method is the process of trying to construct an accurate representation of the world. The scientific method attempts to minimize the influence of bias or prejudice in the experimenter when testing a hypothesis or a theory. By having a repeatable process, other people can check our results, and understand how we came about them. The scientific method has seven steps
1. Observe the situation
2. Ask a question
3. Turn that question into a testable hypothesis
4. Predict the outcome of your experiment
5. Perform your experiment
6. Analyze the results
7. Evaluate your hypothesis
While the scientific method is divided into steps, the key element is testing the hypothesis. In other words, can you prove that you are wrong? We’ll go more into this during the rest of the course, as the best way to learn the scientific method is by doing it.
F. Hypotheses, Models, and Theories
A hypothesis is a proposal intended to explain
certain facts or observations.
A model is a simplified description of a complex entity or process.
A scientific theory is a model or idea that has undergone testing from careful observations and can be used to make a variety of predictions of what will happen under different circumstances.
G. Scientific Experimentation
1. An experiment is a controlled test to find the answer to a question.
2. Only one condition in an experiment is changed at a time.
a. The conditions that affect the outcome are called variables.
b. Independent Variable - the one changed by the experimenter.
c. Dependent Variable - the condition that changes because of the independent variable.
3. Factors in experiments that do not change are called constants.
4. Experiments have two parts:
a. Control group - group under normal conditions (nothing unusual done to it).
b. Experimental group - the test group in which variables are changed.
5. Good observational skills are important (this includes being able to measure accurately).
6. The goal of an experiment is to predict what might happen in similar situations.
READ CARGO CULT SCIENCE ARTICLE AND ANSWER QUESTIONS
Section 0.3 An Introduction to the Measures of
Earth Science
Systems of
Measurement
Why do we need a measurement system? When experiments are performed there are almost always some observations where questions like "how fast", "how far", or "how much" must be answered. The only way to answer these questions is through measuring. Because of this, numbers in science will always have "units". These units are just as important as the numbers when communicating observations. Never write a number without its units.
Standards
A "standard" is something that is used as a comparison for measuring.
Two things are important for any standard:
1) The standard must be available for everyone to use when checking measurements. This means a standard should be something in nature that is the same all over the earth.
2) The standard must never vary.
The English System of
Measurement is commonly used as the day to day system in the
It might be alright to use the English System when
communicating with others in the
The International
System of Measurement - SI is commonly called the
metric system in the
Know these SI units:
Meter - unit of length
Kilogram - unit of mass
Liter - unit of volume
Celsius degrees - unit of temperature
Second - unit of time
Know these SI prefixes:
Mega - 1 000 000
Kilo - 1 000
Centi - 0.01
Milli - 0.001
Derived units are combinations of basic units. Volume units are combinations of length units. This makes volume a derived unit. Density is another derived unit that will be used in this class. Density is found by dividing mass by volume and is usually expressed in grams per cubic centimeter.
Using the Metric System is difficult only because:
You have grown up using the English System.
When you use the Metric System, your mind is comparing it to the English System.
There are exact conversion factors that can be used to change units in one system to units in the other. We will not stress conversion between the systems in this class. All our measurements will be done using SI units. The table below might help you begin to visualize the size of the units of the metric system.
An approximate comparison of the two
systems:
|
English System |
Metric System |
|
1 yard |
0.9 meter |
|
1 mile |
1.5 kilometer |
|
1 pound |
0.5 kilogram |
|
1 quart |
~1 liter |