Zoology Question: How do we distinguish the terms hypothesis, theory, paradigm and scientific fact?Discuss the differences.

A scientific fact is an observation that can be made by anyone and can be reproduced under similar conditions.  If I say water extinguishes certain kinds of fires this can be done over and over again both here and anywhere else on Earth.  If it is based on a single event, such as the sinking of the Titannic, we have documents in the form of diaries and ship'slogs, plus physical evidence that serve as the facts.

A theory is a tentative explanation that explains all the facts using logic.  A scientific theory must be based upon scientific facts and be composed of measurable variables.  It must be testable by allowing experiements to verify it or disprove it.  (It seems ironic that a valid scietific theory must be able to be disproved!)  It must make predicitions as to future observations.

A hypothesis is a testable predicition based on the theory.  It is generally in the form of an IF...THEN... proposition.  IF we do X THEN Y will happen, be observed.  An experiment is then carried out to test the hypothesis.  Again, for this to done all the variables must be definable and observable.

A paradign is an overall guiding philosophy or point of view of groups of theories and the way experiments are done.  For three hundred years from the time of Newton until the time of Einstein physics was dominated by classicalphysics which worked well on a macroscopic scales and at everyday speeds.  At the turn of the century science advanced to the atomic scale and experiments were done test phenomena at the speed of light.  Classical physics made incorrect predictions and so a new way of thinking about physics was needed.  This gave birth to quantum mechanics and relativity which has dominated this century.  It isn't that classical physics is wrong.  It works fine for the big and slow everyday world.  One test of these modern theories is that when things are big and/or slow you get the classical result. However, our everyday world is incorporating more and more the fruits of modern physics.  Take the laser which was developed in 1960. Today lasers are cheap and found in all sorts of things such as  computers, CD and DVD players.  Much of the development of the ideas of a paradigm are the work of Thomas Kuhn.