Models, Theories, and Laws
The terms model, theory, and law have exact
meanings in relation to their usage in the study of physics..
LEARNING OBJECTIVE
·
Define the terms model, theory, and
law
KEY POINTS
·
Concepts in physics cannot be proven,
they can only be supported or disproven through observation and
experimentation.
·
A model is an evidence-based representation of something
that is either too difficult or impossible to display directly.
·
A theory is an explanation for patterns in nature that is
supported by scientific evidence and verified multiple times by various groups
of researchers.
·
A law uses concise language, often expressed as a
mathematical equation, to describe a generalized pattern in nature that is
supported by scientific evidence and repeated experiments.
TERMS
·
Law
A concise description, usually in the form of a mathematical equation,
used to describe a pattern in nature
·
Model
A representation of something difficult or impossible to display
directly
·
theory
An explanation for patterns in nature that is supported by scientific
evidence and verified multiple times by various groups of researchers
FULL TEXT
Definition of Terms: Model, Theory, Law
In colloquial usage, the terms model, theory,
andlaw are
often used interchangeably or have different interpretations than they do in
the sciences. In relation to the study of physics, however, each term has its
own specific meaning.
The laws of nature are concise descriptions of the universe around us. They
are not explanations, but human statements of the underlying rules that all
natural processes follow. They are intrinsic to the universe; humans did not
create them and we cannot change them. We can only discover and understand
them. The cornerstone of discovering natural laws is observation; science must
describe the universe as it is, not as we may imagine it to be. Laws can never
be known with absolute certainty, because it is impossible to perform experiments
to establish and confirm a law in every possible scenario without exception.
Physicists operate under the assumption that all scientific laws and theories
are valid until a counterexample is observed. If a good-quality, verifiable
experiment contradicts a well-established law, then the law must be modified or
overthrown completely.
Models
A model is
a representation of something that is often too difficult (or impossible) to
display directly. While a model's design is justified using experimental information,
it is only accurate under limited situations. An example is the commonly used
"planetary model" of the atom, in which electrons are pictured as orbiting the nucleus, analogous to the way planets orbit the Sun. We cannot observe electron orbits
directly, but the mental image helps explain the observations we can make, such
as the emission of light from hot gases. Physicists use models for a variety of
purposes. For example, models can help physicists analyze a scenario and
perform a calculation, or they can be used to represent a situation in the form
of a computer simulation.
Planetary Model
of an Atom
Theories
A theory is
an explanation for patterns in nature that is supported by scientific evidence
and verified multiple times by various groups of researchers. Some theories include models to help visualize phenomena, whereas
others do not.
Newton's theory of gravity, for example, does not require a model or mental
image, because we can observe the objects directly with our own senses. The kinetic theory of gases, on the other hand, makes use of
a model in which a gas is viewed as being composed of atoms and molecules.
Atoms and molecules are too small to be observed directly with our senses—thus,
we picture them mentally to understand what our instruments tell us about the
behavior of gases.
Laws
A law uses concise language to
describe a generalized pattern in nature that is supported by scientific
evidence and repeated experiments. Often, a law can be expressed in the form of
a single mathematical equation. Laws and theories are similar in that they are
both scientific statements that result from a tested hypothesis and are
supported by scientific evidence. However, the designation law is reserved for
a concise and very general statement that describes phenomena in nature, such
as the law that energy is conserved during any process, or Newton's second law of motion, which relates force, mass, and acceleration by the simple equation F=ma. A theory, in contrast, is a less concise statement of observed phenomena.
For example, the Theory of Evolution and the Theory of Relativity cannot be
expressed concisely enough to be considered a law. The biggest difference
between a law and a theory is that a law is much more complex and dynamic, and a theory is more explanatory. A law describes a
single observable point of fact, whereas a theory explains an entire group of
related phenomena. And, whereas a law is a postulate that forms the foundation
of the scientific method, a theory is the end result of that process.
Source,credits
and courtesy:boundless.com
Comments
Post a Comment