Scientific theory
A scientific theory is a plausible and consistent explanation for observable phenomena. It is more substantial than a conjecture or hypothesis, but may not be verified as consistent with empirical data. [1] Controversially, some scientists have declared that causes other than natural, observable ones should not be examined - and that theories involving such causes are "not scientific", e.g., behavioral psychology. This limitation and its implications for the philosophy of science plays a large role in the origins debate.
For many philosophers of science, a theory must be falsifiable to be considered scientific. This means that there must be some way to do experiments that could counter the theory's predictions, thus disproving the current theory. [2]
Generally accepted scientific theories have survived over time, have evolved when appropriate, and modified toward consistency with newly discovered data, have not been shown to be false and can make predictions about natural phenomena. [3] Scientific theories can sometimes be used as the basis for industrial and technical developments.
A scientific theory does not necessarily have to have strong experimental support or accepted by the scientific community. Scientists often refer to untested theories and competing theories. Theories can be extremely well-confirmed, such as conservation of energy, or speculative, such as String Theory.
A successful theory is most consistent with the actual behavior of the universe. When a phenomenon is discovered that is inconsistent with the prevailing theory, the theory is either revised or thrown out entirely. An example of this is Newtonian mechanics--while Newton's 3 laws of motion provide extremely accurate descriptions/predictions of the behavior of medium-sized objects at low speeds, they are inconsistent with the behavior of very large, very fast, or very small objects. Newtonian mechanics has been shown to be a limiting case of the theory of relativity (in the limit where velocity goes to 0) and quantum mechanics (in the limit where Planck's constant goes to 0, essentially the limit of large objects). Usually a theory which is inconsistent with some experimental evidence is not completely falsified; it is instead shown to be a simplified version of a more complete theory.
In contrast to scientific consensus, science philosopher Karl Popper asserted that the theory of evolution could be considered a metaphysical research program depending on the definition being used. [4] depends on the definitions of evolution in use.
Common usage
Evolutionists frequently argue that the word "theory" means very different things to scientists and non-scientists. For example, a PBS TV show says: [5]
- When we use the word "theory" in everyday life, we usually mean an idea or a guess, but the word has a much different meaning in science. This video examines the vocabulary essential for understanding the nature of science and evolution and illustrates how evolution is a powerful, well-supported scientific explanation for the relatedness of all life.
The American Museum of Natural History exhibit on Darwin says: [6]
- In everyday use, the word "theory" often means an untested hunch, or a guess without supporting evidence. But for scientists, a theory has nearly the opposite meaning. A theory is a well-substantiated explanation of an aspect of the natural world that can incorporate laws, hypotheses and facts.
In fact, it is hard to find anyone who makes this distinction, outside those who are promoting the theory of evolution to the general public. [7]
Notes and references
- ↑ For example, scientists may refer to phlogiston theory or ether theory, even though empirical verification was lacking.
- ↑ "A theory not only explains known facts; it also allows scientists to make predictions of what they should observe if a theory is true. Scientific theories are testable. New evidence should be compatible with a theory. If it isn't, the theory is refined or rejected." [1]
- ↑ http://www.thefreedictionary.com/theory
- ↑ The science philosopher Karl Popper famously called Darwinian evolution a "metaphysical research program".
- ↑ http://www.pbs.org/wgbh/evolution/library/11/2/e_s_1.html
- ↑ http://www.amnh.org/exhibitions/darwin/evolution/theory.php
- ↑ For example, this 2004 NY Times article on the pros and cons of string theory [2] used the word "theory" 70 times without any suggestion that ideas must be well-substantiated before they qualify as a theory. Physicist Lawrence Krauss used the term "string theory" even though the theory has "yet to have any real successes in explaining or predicting anything measurable". [3] A month later, he argued that it should really be called the "string enterprise" because using the word "theory" causes problems with intelligent design advocates and those who say that evolution is "just a theory". [4]
