you know what a theory in science is? so not just a theory....
(from wikipedia)
Definitions from scientific organizations
The United States National Academy of Sciences defines scientific theories as follows:The formal scientific definition of "theory" is quite different from the everyday meaning of the word. It refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence. Many scientific theories are so well established that no new evidence is likely to alter them substantially. For example, no new evidence will demonstrate that the Earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the Earth is not divided into solid plates that have moved over geological timescales (the theory of plate tectonics)...One of the most useful properties of scientific theories is that they can be used to make predictions about natural events or phenomena that have not yet been observed.[URL="http://en.wikipedia.org/wiki/Theory#cite_note-16"][16][/URL]From the American Association for the Advancement of Science:
A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. The theory of biological evolution is more than "just a theory." It is as factual an explanation of the universe as the atomic theory of matter or the germ theory of disease. Our understanding of gravity is still a work in progress. But the phenomenon of gravity, like evolution, is an accepted fact.[URL="http://en.wikipedia.org/wiki/Theory#cite_note-AAAS_Evolution_Resources-15"][15][/URL]Note that the term theory would not be appropriate for describing untested but intricate hypotheses or even scientific models.
As alluded to above...the fun ones where it is both theory and fact such as gravity and evolution. The observable phenomena of gravity and evolution, and the associated theory of the same name to explain it.