From what little I know, there does seem to be a hierarchy from hypothesis to theory with law and theory being almost the same (these days). A hypothesis is defined as this:
Hypothesis
A hypothesis is an educated guess, based on observation. Usually, a hypothesis can be supported or refuted through experimentation or more observation. A hypothesis can be disproven, but not proven to be true.
A theory as this:
Theory
A scientific theory summarizes a hypothesis or group of hypotheses that have been supported with repeated testing. A theory is valid as long as there is no evidence to dispute it. Therefore, theories can be disproven. Basically, if evidence accumulates to support a hypothesis, then the hypothesis can become accepted as a good explanation of a phenomenon. One definition of a theory is to say it's an accepted hypothesis.
And a law thus:
Law
A law generalizes a body of observations. At the time it is made, no exceptions have been found to a law. Scientific laws explain things, but they do not describe them. One way to tell a law and a theory apart is to ask if the description gives you a means to explain 'why'.
Laws are considered "fact" ... non-changeable ... absolute. Hypothesis are considered guesses. Theories are considered "proven" hypothesis, but they are left open for the possibility of error ... that not everything was taken into account. However, Law and theory are so closely related that they are often understood the mean the same thing.
Here are some links:
http://chemistry.about.com/od/chemistry101/a/lawtheory.htmhttp://evidence-based-science.blogspot.com/2008/02/what-is-scientific-law-theory.htmlhttp://physics.suite101.com/article.cfm/theory_vs__hypothesis_vs__lawhttp://sci.waikato.ac.nz/evolution/Theories.shtmlHowever, it seems historically that the word "law" and "theory" were used a bit differently and that today the word "theory" takes an equal footing with "law". From some things I have read, it seems that people drew back from using the term "law" a bit because it indicates that what is being referenced is absolutely true in every single instance without exception. To know this for a fact (a "law") would require the ability to test under ever single circumstance and that is not practical or possible. So the word theory seems to have moved to the dominant position and has taken an equal place along side "law".
