Here are some more ideas about the differences between scientific fact, speculation, hypothesis, theory, and law using the example of the feather tubes (one tube in which feathers and coins fall at the same rate next to a similar-looking tube in which feathers float as they fall) and Newton's and Einstein's differing conceptions of gravity.
A scientific fact (e.g., coins in the two tubes fall at essentially the same rate, feathers do not) is an observation that is the same for all competent observers. Facts tell us what is, not why or how.
Scientific speculation (e.g., The reason the feathers in one tube fall faster than in the other is because the feathers are different.) is a preliminary explanation without significant experimental testing.
A scientific hypothesis (e.g., the reason the feathers in one tube fall faster is because the tubes are different or because the feathers are different.) is an explanation for which some experimentation is being or has been done to test it and for which alternate hypotheses or speculations that would disprove the hypothesis have been created, and possibly tested and rejected.
A scientific theory (Newton’s long-range force of attraction theory or Einstein’s space-time curvature theory) is an explanation for many different phenomena, with lots of experimental confirmation, and for which alternative hypotheses have been formed and possibly tested and rejected.
A scientific law (all massive objects fall with an acceleration of about 10 m/s^2 when dropped near the Earth's surface if air friction is negligible = the Law of Gravity applied to the Earth’s surface), is a principle that applies universally, that encompasses a wide number of facts, or individual observations, and for which there are no reasonable alternative descriptions. A law tells us what is universally, not why, how, or the meaning.
Scientific facts and laws are necessarily accepted as true. Although a particular scientific hypothesis or theory cannot be logically proven as true, they are considered valid or true when no competing hypotheses or theories survive after considerable testing.
Biological evolution should be considered a law, not a theory. Whether biological forms have changed in time and do change is not questioned by competent observers.
Darwin's Natural Selection with its assumption of slow gradualism should be considered a theory. Work is being done to determine how much evolution is due to gradual and how much to rapid changes in biological forms and other questions about the process of evolution. No religion-based speculation (such as the Genesis myth) has enough scientific backing for it to reasonably challenge modern scientific ideas about evolution.
Evolution is a law. All competent observers agree it happened. How evolution works is a theory, an explanation.
What do the rest of you think about these statements?