If there is one simple distinction between science and foolishness, I think it is this: Science takes the mundane and makes it wonderful; foolishness takes the wonderful and makes it merely mysterious.
Penn and Teller have a perfect example of how this works. In most of their road shows, they have one illusion that they do the usual way and then repeat with the mechanism explained. One that they have done several times is a kind of expansion of the "woman sawed in half." As an illusion, you see a set of painted boxes with little doors here and there. Teller gets inside, Penn rearranges the boxes and, on a musical cue, a door flips open to show a foot or a hand or Teller's face. As the music goes on the rearrangements get more impossible but there is never a missed cue. There you are, faced with a mystery; how'd they DO that?
They repeat the trick with transparent boxes. This time, you can see exactly how it's done, with Teller slithering here and scooting there inside the boxes; it turns out that the hand you see is occasionally Penn's. It's utterly mundane and completely obvious and totally wonderful. All the mystery is gone. It doesn't spoil anything. The feeling that replaces it, that combination of "Oh, wow!" and "Ah ha!," that rush, is the special sense of wonder that comes with seeing an entire mechanism laid bare for the very first time.
I think that the rush is really why people do science. The next best thing is explaining something so well that you see "Ah ha!" in another's eyes. That rush is why people teach science.
True, few of us have the opportunity either to do original science or to teach in a traditional setting. Any of us, however, can get the same rush of discovery from study and any of us can get the rush of teaching from explaining one thing well to one other person. "Good Science Simply Explained" is a nice little sound-bite of a goal and it offers an opportunity to learn something, teach something and get a rush all at the same time. Not bad, but explain just what to whom?
Perhaps the best audience is the honestly curious, non-credulous but uninformed person, one of the proverbially "open-minded," for that person is the most likely future victim of mystery.
There's nothing wrong with mystery as such. It gets the juices going, gets us thinking, gets us trying to solve a problem. However, when some guru of foolishness tells a person that some things are meant to remain mysteries, that some things cannot or ought not to be investigated -- when someone hears that and believes it -- that person is diminished. That's a battle worth fighting.
Given a worthy audience, what is a good topic? Some kinds of foolishness, things like astrology, UFOs and creationism, are simply laughable. It's unlikely that anyone will change the minds of the people who believe in these things since, deny it though they will, they are acting out of faith. However, because they argue faith as a matter of fact, other facts are potent weapons. The battle is worth fighting not so much to convince the believer as to supply the rational alternative to the honestly curious. That's why the detailed critical work, what's often called debunking, is so very valuable and necessary.
Many of us feel that we don't have a big problem in dealing with laughable foolishness because most of this stuff doesn't even make the grade as pseudoscience. It doesn't take too long to decide if the person we're dealing with is honestly curious or a true believer; but either way, there is something particularly aggravating in dealing with this kind of foolishness. I think this is because virtually all of the arguments are inductive: identify a thousand UFOs and a believer points to the thousand and first sighting; analyze the tears of a hundred weeping statues as olive oil and a believer can both acknowledge that and still claim that the one you didn't analyze is the real thing. The lack of closure fundamental to induction is the wedge that the believer hammers on to keep the argument forever open. It takes a strong stomach and an even temper to deal with this mindset.
A topic that might be a little more in line with the goal here is a small but disturbing category of pseudoscience. Its argument sounds plausible, it looks like it's based in fact, it doesn't seem to deal with unconventional science most of the time and yet we're sure it's wrong from the first hearing. These things are often alternative physical theories or gadgets: stuff like perpetual motion machines, home-built anti-gravity devices, and faster-than-light drives. These can be a most embarrassing problem when they catch us unaware because here we seem to be confronted with fact and our initial response sounds like faith.
That is a most uncomfortable place in which to be. "Why won't this particular over-unity machine work?" asks an honestly curious person. "Violates the second law of thermodynamics," we respond. "Why can't we travel faster than light," asks another. "Violates special relativity," we say. Hmm ... and just what bible are WE quoting?
It takes a little work to counter one of these things but the reward is that it can be done definitively because it can be done deductively. These pretty little bits of pseudotheory carry the seeds of their own destruction because they are based on the facts of accepted (believers call it Establishment) science. It's possible to start with that fact, add the facts that have been ignored, correct the errors in methodology and establish a deductive train of logic that follows from the same source and handily refutes the pseudotheory. It's very satisfying and a lot of fun.
The errors in these things fall into two categories: matters of fact and matters of methodology. Matters of fact are seldom disputed in pseudotheories; they are just used selectively. Things like the mass of the Sun, the speed of light or the charge of the electron are easy enough to look up. In matters of methodology it's a little more difficult to point at a specific reference.
Scientific method is a lot more complex than the six-paragraph five-step distillation of Bacon we've all seen at the beginning of some textbook. There are works specific to the subject (Popper and Kuhn leap to mind) but, as with so many other things, the best way to learn it is to do it. A good way to learn how to do it is to watch it being done and scientific biographies and primary sources are a great way to get a bird's eye view of scientific method as it happens.
Scientific biographies -- works like Pais on Einstein, Westfall on Newton or Sime on Meitner -- combine the story of a life with the story of the life's work. Unlike the more common historical biography, the emphasis is on the work: where did the ideas come from and how did they grow? The stories can be centuries apart, but they all have one thing in common: good scientists have a childlike sense of wonder. They know how to ask an innocent and truly open-minded "Why?" Great scientists (in the vernacular of the trade those that "have a knack for picking the right problems") ask the most profound whys. These are questions like Bethe's "Why does the Sun shine?," Rayleigh's "Why is the sky blue?," and Olber's "Why is the night dark?"
Primary sources are the works these scientists wrote themselves in which they answer these questions for the very first time.
The very best scientists can not only ask childlike questions but also answer them in the same spirit. They are the very best explainers of their ideas. Galileo did not rant at the church in writings like "A Dialogue Concerning Two New Sciences"; he explained things to Simplicio, Everyman, in a dialogue. Einstein's fundamental work never was "understandable to only four people on the planet." That's mystery talking. His popular explanation of relativity is still in print -- in paperback, no less -- and eminently accessible to anyone with a high school education (perhaps even a modern one) and a willingness to turn off the TV for a few nights. A lot of his scientific work is equally simple and accessible. (The mass- energy proof, for example, is barely three pages long and, again, it requires no more than a high school education to follow it.)
All the greats, every one of them, had to explain fundamentally new ideas to people who had never heard them before. They are remembered not only because they thought the thoughts but also because they succeeded in explaining them.
It may be an exaggeration, but it seems to me that the pseudotheories are born of people who learned all of their science only from textbooks. There is the same mile-wide inch- deep cover-the-material-quickly feel to them that you get from the typical textbook. That's something to remember the next time you crack open Thus and Such's "Introductory Physics" or This and That's "Elementary Biology" and find yourself overwhelmed with sidebars and problem sets. The primary sources are more leisurely, more thorough and still the best place to start.