Basic Concepts

In a back-channel discussion among ScienceBloggers, John Wilkins suggested that it might be interesting to do occasional posts on really basic concepts in our fields– the sort of jargon terms that become so ingrained that we toss them around without realizing it, and end up confusing people. A lot of these terms often have a technical meaning that is subtly (or not-so-subtly) different from the use of the word in everyday language, which provides a further complication.

The original example given was “vector,” which turns up a lot in mathematical discussions, and loses a lot of people (it’s also a term whose technical meaning is different in different fields), but the canonical pan-science example would probably be “theory” as in “It’s just a theory.” “Model” was thrown out as another term that can mean different things in different contexts.

I like the idea a lot, so I’m going to adopt it, whether anybody else does or not. I’ve got a couple of ideas for really basic physics-type terms (I’ll probably start with “Force” next week), but I’m probably not thinking of a bunch of really obvious words. And, really, I’m exactly the wrong person to be trying to think of these– the point is to define basic concepts that confuse non-physicists, not to define basic concepts that I think it might be fun to define.

So, what are some really basic science concepts that I ought to define here? Obviously, I’m best equipped to deal with terms specific to physics, but I’m willing to take a crack at general science terms as well, or pass bits of jargon from other sciences on to colleagues who can do a better job with them. So what are some terms that we use around here that might be confusing?

(I should also note that this is an excellent opportunity for lurkers to de-lurk– if you’ve been holding off on commenting because you’re not sure what “phase” means in a physics context, this would be a great time to leave a comment saying that. Don’t worry about sounding stupid– if you’re confused by it, odds are somebody else is, too, and that means I’m not doing my job right…)