My posting has been erratic over the last few weeks, mostly due to a crazy schedule. School is winding down, however, so I hope to have more time to look at some interesting things. In addition, my last grad course started today, Evolutionary Biology, so I plan on posting on some of the more interesting topics we cover.
I'll start with something basic: scientific theories, hypothesis, and laws. Most scientific misunderstandings stem from the publics lack of knowledge regarding some simple terminology. A theory in science is much different than the lay term. Peter Wilson provides a good explanation of these terms:
If you can keep these definitions in mind, you'll already be better prepared to interpret scientific information.
Scientific Law: This is a statement of fact meant to explain, in concise terms, an action or set of actions. It is generally accepted to be true and univseral, and can sometimes be expressed in terms of a single mathematical equation. Scientific laws are similar to mathematical postulates. They don’t really need any complex external proofs; they are accepted at face value based upon the fact that they have always been observed to be true.
Some scientific laws, or laws of nature, include the law of gravity, the law of thermodynamics, and Hook’s law of elasticity.
Hypothesis: This is an educated guess based upon observation. It is a rational explanation of a single event or phenomenon based upon what is observed, but which has not been proved. Most hypotheses can be supported or refuted by experimentation or continued observation.
Theory: A theory is more like a scientific law than a hypothesis. A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers. One scientist cannot create a theory; he can only create a hypothesis.
In general, both a scientific theory and a scientific law are accepted to be true by the scientific community as a whole. Both are used to make predictions of events. Both are used to advance technology.
The biggest difference between a law and a theory is that a theory is much more complex and dynamic. A law governs a single action, whereas a theory explains a whole series of related phenomena.
Some scientific theories include the theory of evolution, the theory of relativity, and the quantum theory. All of these theories are well documented and proved beyond reasonable doubt. Yet scientists continue to tinker with the component hypotheses of each theory in an attempt to make them more elegant and concise, or to make them more all-encompassing. Theories can be tweaked, but they are seldom, if ever, entirely replaced.