1-1: What is Physics?
Objectives:
•
•
•
Identify activities and fields that involve the major areas within physics
Describe the process of the scientific method
Describe the role of models and diagrams in physics
Standards:
•
P1.1, P1.2
Assessments:
•
•
Read the section
Define all vocabulary for this section
We can’t control Earth’s
motion, but we have
learned the rules by which it
moves. The study of
nature’s rules is what this
book is about.
Understanding these rules
adds richness to the way we
see our world.
What is Physics?
• Physics is the study of the physical world.
• You are using physics everyday of your life,
you may not realize it but most of the things
we do everyday involve physics.
• Anything that deals with temperature, size,
motion, position, shape, or color involves
physics.
Physics is about the nature of basic things such as
motion, forces, energy, matter, heat, sound, light,
and the composition of atoms.
1.1 The Basic Science—Physics
The study of science branches into the study of living things and
nonliving things.
• The life sciences include biology, zoology, and botany.
• The physical sciences include geology, astronomy, chemistry,
and physics.
1.1 The Basic Science—Physics
You can understand other sciences much better if you first
understand physics.
• Physics is the most basic of all the sciences.
• Chemistry is about how matter is put together.
• Biology is still more complex and involves matter that is
alive.
Areas within Physics
•
Mechanics
– Motion and its causes
•
•
Falling objects, friction, weight, spinning objects
Thermodynamics
– Heat and temperature
•
•
Melting and freezing processes, engines, refrigerators
Vibrations and wave phenomena
– Specific types of repetitive motions
•
•
Springs, pendulums, sound
Optics
– Light
•
•
Mirrors, lenses, color, astronomy
Electromagnetism
– Electricity, magnetism, and light
•
•
Electrical charge, circuitry, permanent magnets, electromagnets
Relativity
– Particles moving at any speed, including very high speeds
•
•
Particle collisions, particle accelerators, nuclear energy
Quantum mechanics
– Behavior of submicroscopic particles
•
The atom and its parts
The Scientific Method
• In science we need to question things around
us!
1. Make observations.
2. Formulate and objectively test hypothesis by
experiments.
3. Interpret results and revise the hypothesis if
necessary.
4. State conclusions in a form that can be evaluated
by others.
1.1 Scientific Methods
Scientific methods generally include some, if
not all, of the following:
1. Recognize a problem.
2. Make an educated guess—a hypothesis—about the
answer.
3. Predict the consequences of the hypothesis.
4. Perform experiments to test predictions.
5. Formulate the simplest general rule that organizes
the main ingredients: hypothesis, prediction, and
experimental outcome.
Models and the scientific method
• Models are ways to show the structure or
workings of an object, system, or concept.
• Use models that describe only part of reality
– Isolate what you need to know.
– Draw a diagram that includes only the relevant
information
– Disregard irrelevant information
– Simplify the surroundings
• Wind resistance, water resistance, etc…
1.1 Scientific Methods
Scientific methods are extremely effective in gaining, organizing,
and applying new knowledge.
The scientific method is often credited to the Italian physicist
Galileo Galilei (a.) and the English philosopher Francis Bacon (b.).
Models and the scientific method
• Models can help build hypotheses
– A hypothesis is a reasonable explanation for an
observation.
– Models can be used to show how a hypothesis can
be tested.
Models and the scientific method
• Models help guide experimental design
– Models can be used to actually do the experiment
or demonstration.
– A key part of using models and doing experiments
is to have a controlled experiment.
• A controlled experiment is an experiment involving
manipulation on a single variable or factor.
Models and the scientific method
• Using models will help to prove a hypothesis.
Either true or false.
• Some models may not end up in the same
results as others. In this case the hypothesis
needs to be tested many more times.
• A conclusion is valid only if it can be verified
by other people
1.1 Scientific Methods
Although the scientific method is popular, it is not the universal
key to discoveries and advances in science.
• Trial and error, experimentation without guessing, and
accidental discovery account for much of the progress in
science.
• The success of science has more to do with an attitude of
inquiry, experimentation, and humility than with a
particular method.
1.1 The Scientific Attitude
In science, a fact is a close agreement by competent
observers who make a series of observations of the
same phenomenon.
A scientific hypothesis is an educated guess that is not
fully accepted until demonstrated by experiment.
When hypotheses about the relationship among
natural quantities are tested over and over again and
not contradicted, they may become laws or principles.
1.1 The Scientific Attitude
Scientists must accept their findings even when they would like
them to be different. They must distinguish between what they
see and what they wish to see.
1.1 The Scientific Attitude
Scientific Theories
A scientific theory is a synthesis of a large body of
information that encompasses well-tested and verified
hypotheses about certain aspects of the natural world.
1.1 The Scientific Attitude
The theories of science evolve as they go
through stages of redefinition and
refinement.
• The refinement of theories is a
strength of science, not a
weakness.
• More important than defending
beliefs is improving upon them.
• Better hypotheses are made by
those who are honest in the face of
experimental evidence.