WordNet
n. a theory that explains scientific observations; "scientific theories must be falsifiable"
Wikipedia
A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed, preferably using a written, pre-defined, protocol of observations and experiments. Scientific theories are the most reliable, rigorous, and comprehensive form of scientific knowledge.
It is important to note that the definition of a "scientific theory" (often ambiguously contracted to "theory" for the sake of brevity, including in this page) as used in the disciplines of science is significantly different from, and in contrast to, the common vernacular usage of the word "theory". As used in everyday non-scientific speech, "theory" implies that something is an unsubstantiated and speculative guess, conjecture, idea, or, hypothesis; such a usage is the opposite of the word 'theory' in science. These different usages are comparable to the differing, and often opposing, usages of the term " prediction" in science (less ambiguously called a "scientific prediction") versus "prediction" in vernacular speech, denoting a mere hope.
The strength of a scientific theory is related to the diversity of phenomena it can explain, and to its elegance and simplicity (see Occam's razor). As additional scientific evidence is gathered, a scientific theory may be rejected or modified if it does not fit the new empirical findings; in such circumstances, a more accurate theory is then desired. In certain cases, the less-accurate unmodified scientific theory can still be treated as a theory if it is useful (due to its sheer simplicity) as an approximation under specific conditions (e.g., Newton's laws of motion as an approximation to special relativity at velocities that are small relative to the speed of light).
Scientific theories are testable and make falsifiable predictions. They describe the causal elements responsible for a particular natural phenomenon, and are used to explain and predict aspects of the physical universe or specific areas of inquiry (e.g., electricity, chemistry, astronomy). Scientists use theories as a foundation to gain further scientific knowledge, as well as to accomplish goals such as inventing technology or curing disease.
As with most, if not all, forms of scientific knowledge, scientific theories are both deductive and inductive in nature and aim for predictive power and explanatory capability.
Usage examples of "scientific theory".
On the one hand, we have seen that there is a way out of the impasse into which modern scientific theory has got itself as a result of the lack of a justifiable concept of force, and that this way is the one shown by Reid and travelled by Goethe.
And could I in doing so avoid the naive positivism which is how most of us as working scientists go about our day-to-day labours, but instead set this account of my own laboratory practice into the richer and more complex context which the present-day philosophy, politics and sociology of science have revealed as framing scientific theory and experiment?
The scientific doubt of Descartes and the scientific theory of Newton might convince a reasonable man, but for all that, life was still much the same.
Imagine that there is a new scientific theory that warns of an impending crisis, and points to a way out.
What scientific theory could be built up on proofs from its first conception?
In order to talk about the nature of the universe and to discuss questions such as whether it has a beginning or an end, you have to be clear about what a scientific theory is.
Publicity, fame, and accolades could only make a scientific theory popular.
The objection raised by Julian Huxley and others was that female whims were not legitimate foundations for a truly scientific theory.
The savage tribes described by Frazer had a far more scientific theory.