Few scientific concepts are regularly abused as much as the scientific concept of a theory (I’m pretty sure the Heisenberg uncertainty principle is up there, but not quite reaching this level). What confuses most people is that the colloquial usage and the scientific usage are completely different.
The everyday usage typically hovers somewhere between “wild-ass guess” and “what kind of drugs are you on?” For example I have a theory that one of my neighbors is a serial killer and keeps the heads of his victims in his freezer and another one about how Courtney Love killed Kurt Cobain. Of course, I have no proof of this, but that’s not what the colloquial usage is all about. No proof is needed because it’s not something that is taken very seriously (or at least it shouldn’t be).
A scientific theory is about as far removed from the everyday usage as it could be. Essentially, it is an explanation based on a large amount of accumulated empirical evidence that is then used to future results. It is also the greatest honor that can be bestowed on a scientific idea. Atomic theory, the germ theory of disease, gravity, special relativity, and, of course, evolution are all well respected theories. While very few people will question the first four examples there are many who speak of evolution being “just/only a theory.” The reasons for this are legion and I don’t even want to begin to go into them since they mostly center around religious idiocy, but it just goes to show one thing: most people can’t tell a scientific theory from a pile of cat shit in the corner (my cat just pooped in the corner).
Part of this may be due to the way most people think about science. Lay people I have talked to give me the impression that they believe scientists to be dogmatic conservatives (not in a political sense) who are incapable of giving up their cherished theories. This definition is only partially correct. Science is extremely conservative in nature due to the relatively common false positives that plague all facets of scientific exploration. So, in order to supplant an accepted theory a scientist must have proven beyond a reasonable doubt that their new theory is better than the previous one. There are many theories out there, but not all of them are created equally and that’s why we don’t teach all of them in schools and this “teach the controversy” shit that’s going on right now is pure bullshit.
Fucking crazy creationists piss me off.