Lesson 1
Methods of Science
Focus Question
What do physicists do?
New Vocabulary
physics
scientific methods
hypothesis
model
scientific theory
scientific law
Review Vocabulary
control: a baseline test or observation used for
comparing against other results in an
experiment
Scientific Methods
• Physics is the branch of
science that studies matter,
energy and their
relationships.
• Although physicists do not
always follow a rigid set of
steps, investigations often
follow patterns called
scientific methods.
• A scientist might add new
steps, repeat some steps, or
skip steps altogether.
Scientific Methods
• Many investigations begin
when someone observes an
event in nature and
wonders why or how it
occurs. The question of
“why” or “how” is the
problem.
• Researching information
already known about a
problem helps to fine-tune
the question.
Scientific Methods
• A hypothesis is a possible
explanation for a problem
using what you know and
have observed.
• Hypotheses can be tested
by:
• Observations
• Models
• Experiments (Test the
effect of one thing on
another, using a control.)
Scientific Methods
• An important part of every
investigation is recording
observations and organizing
data into tables and graphs.
• The next step is to decide
whether the hypothesis is
supported.
• If so, the data must be
reproducible.
• If not, the hypothesis
must be reconsidered.
Models
• A model is a representation of an idea, event, structure,
or object that helps people better understand it.
• Scientists use models when an object is too large or too
small, when a process takes too much time, or when a
material is hazardous.
Why do scientists use a model to represent the atom?
Scientific Theories and Laws
• A scientific theory is an explanation of things or
events based on knowledge gained from many
observations and investigations.
• A theory is not a hypothesis; it is what a
hypothesis becomes after numerous trials
producing data that support the hypothesis.
• A theory is never permanent. It can change as new
data becomes available.
Scientific Theories and Laws
• A scientific law is a statement about what happens in
nature and seems to be true all the time.
• Laws tell you what will happen under certain
conditions, but they do not explain why or how
something happens.
Example: Gravity
• The law of gravity states that any one mass will
attract another mass.
• There are many theories that have been
proposed to explain how gravity works.
The Limitations of Science
• Science cannot explain or solve every question.
• A scientific question must be testable and verifiable.
• Questions about opinions, values, or emotions are
not scientific and cannot be tested.
The Limitations of Science
Determine if each of the following questions can be
answered by science.
•
•
•
•
•
•
How does a force change the motion of an object?
Which season is best?
How does a battery work?
Was Mark Twain a good writer?
Should we have pizza or hamburgers for lunch?
Under what conditions is energy conserved?
The Limitations of Science
Determine if each of the following questions can be
answered by science.
• How does a force change the motion of an object?
Science can answer this question because an
experiment would provide the answer.
• Which season is best? Science cannot answer this
question because it is an opinion.
• How does a battery work? Science can answer this
question because an experiment would provide
the answer.
The Limitations of Science
Determine if each of the following questions can be
answered by science.
• Was Mark Twain a good writer? Science cannot
answer this question because it is an opinion.
• Should we have pizza or hamburgers for lunch?
Science cannot answer this question because it is
an opinion.
• Under what conditions is energy conserved?
Science can answer this question because an
experiment would provide the answer.
Quiz
1. Which of the following is a physicist most likely to study?
A
the structure of cells
C
the structure of the
universe CORRECT
B
properties of
compounds
D
ecosystems
Quiz
2. Which is the most likely first step for an
investigation that follows a scientific method?
A
form a hypothesis
C
draw conclusions
B
modify the hypothesis
D
state the problem
CORRECT
Quiz
3. Which are representations of ideas, events, structures, or
objects that help people better understand them?
A
scientific laws
C
predictions
B
scientific theories
D
models
CORRECT
Quiz
4. Which is an explanation of things or events based
on knowledge gained from many investigations?
A
scientific theory
C
hypothesis
D
model
CORRECT
B
scientific law
Quiz
5. Which is a statement about what happens in
nature and seems to be true all the time?
A
scientific law
C
scientific theory
D
conclusion
CORRECT
B
hypothesis