What are the characteristics of all scientific theory?

Answer 1

A scientific theory is either (1) an explanation of why or how something happens in nature (physical sciences), or (2) an accepted body of statements that is all we know at present about something (mathematics).

Most theories in the physical sciences involve technical knowledge, such as a mathematical description of things, and\or statements of laws. (But laws are not theories, they are patterns of occurrences in nature.) In the physical sciences, a scientist trying to explain something may make one or more hypotheses, as educated guesses; these hypotheses are then tested in some relevant way to try to refute them. The one that passes the most tests becomes the reigning theory.

Other features of theories are that they explain the largest amount of relevant data, and that they explain it parsimoniously or "prosaically." This means that they obey "Occam's Razor:" they explain the data without needlessly postulating new entities or processes in the world. (It's named after William of Occam, a British philosopher of the 14th century A.D. who thought it up.)

Most theories are tested by making "testable predictions;" the theory or scientist makes predictions of events and\or entities that no one has detected yet, and a relevant test is made to see if the event or entity really does happen or exist.

Examples of Theories And Other Related Information:

(1) Relativity theory: This is the theory of Albert Einstein; it involves a mathematical description of the four dimensional manifold called "space-time," and the theory says that a gravitational field "warps" the space-time around a massive body; this is an explanation of gravity and its effects. Relativity was tested by measuring the positions of certain stars that were close to the sun, before and during an eclipse. Einstein had predicted that light-rays passing close to a massive body like the Sun would be bent by the gravitational field of the Sun. It was seen that the positions differed by amounts that were close to the predictions of the theory. The theory also accounted for an anomaly in Mercury's orbit, and it did away with the "luminiferous ether." (This was a substance thought to permeate all space in the universe.) So the theory explained a little more than Newton's, and it was more "prosaic" than its predecessor (Newton's theory could not account for everything about Mercury's orbit).

(2) Theory of Natural Selection: This is the theory of Charles Darwin that says that the advent of all species in nature is the result of Natural Selection. Darwin said that Natural Selection was analogous to the selection that people do when they breed animals and plants. Certain inherited features of organisms make them better adapted to their environment, and so those species stay long enough to leave progeny, while other species are maladapted to the environment, so they become extinct. Changes in the inherited characteristics, if allowed long enough to accumulate, lead to new species. The theory was tested against its rivals, and also tested in genetics laboratories. One testable prediction it made was about the age of the Earth. Darwin held out against the verdict of the physicists of his day; they said that the Earth can only be hundreds of thousands of years old, while Darwin, given what he knew about the pace of evolution, said it must be in the hundreds of millions of years old. He proved to be right- it's in the billions, 4.5 billion years old to be exact. The theory proved also to be more parsimonious: it eliminated the older theory of Lamarck, who said that acquired characteristics are passed on to an animal's progeny (e.g., if a giraffe tries really hard to reach the highest buds on a tree and its neck stretches, it passes the longer neck on to its offspring.), it eliminated the "scale of nature," which was the idea that we human beings are the pinnacle of creation, and it eliminated the older idea that evolution or creation is "trying" to make us human beings.