I'll take "Crucial Science Knowledge" for 200, Alex

Several people have blogged this article on "science questions every high school graduate should be able to answer." The Fundamental Ten, as proposed by ten different scientists, are as follows:

• What percentage of the earth is covered by water?
• What sorts of signals does the brain use to communicate sensations, thoughts and actions?
• Did dinosaurs and humans ever exist at the same time?
• What is Darwin's theory of the origin of species?
• Why does a year consist of 365 days, and a day of 24 hours?
• Why is the sky blue?
• What causes a rainbow?
• What is it that makes diseases caused by viruses and bacteria hard to treat?
• How old are the oldest fossils on earth?
• Why do we put salt on sidewalks when it snows?
• Extra credit: What makes the seasons change?

I first saw this on the charming Adventures in Ethics and Science, where Dr. Free-Ride suggested a few crucial questions of her own:

• Why is leaving the refrigerator door open a really bad strategy for cooling off the kitchen on a hot day?
• Why does taking your tea with lemon and milk result in chunky tea?
• Licking the spoon while you're making the pudding makes it so the pudding doesn't set properly. What's up with that?
• When you're prescribed antibiotics, why should you take the whole course of them even if you feel better sooner (and why won't antibiotics do jack for the common cold)?
• Why are the days longer in the summer than in the winter?
• Why does ice float (and why is this probably a good thing for people living near big lakes)?
• Why shouldn't you use a blow-dryer/curling iron/paper shredder/electric carving knife while soaking in the bath tub?

Meanwhile, Evolgen added a few more:

• What is a hypothesis?
• What is a theory?
• What is probability?
• What is an atom? What is a neutron? What is a proton? What is an electron?
• What is a molecule?
• What is a cell?
• What is a gene? What is a genome? What is the central dogma of molecular biology?

What I'm finding really interesting is how everyone who suggests a set of questions has a very different idea of what it means to be informed about science. The original set of questions, as several people have pointed out, leans heavily towards trivia. These are "things every high school graduate should know" in the sense of "things where it's really embarassing to us as a country if our high school graduates don't know them." You really should know them, you're ripe for some faux pas with the educated if you don't know them, and depending on your answers to a few of them (e.g. the one about dinosaurs) people would be justified in declining your company, but they don't reflect a high level of understanding. Dr. Free-Ride's questions show the practical applications of science, and probably offer an excellent way of getting kids and humanities majors interested. They highlight everyday mysteries that can be rendered explicable with a smattering of science knowledge. These are questions whose answers will do you some good, not only because you'll be able to understand the phenomenon in question, but because in doing so you'll learn useful, applicable tenets. It's Discovery Channel knowledge -- not just "I never knew that," but "I always wondered." Then there are Evolgen's suggestions, which are much more basic; you can't consider yourself science-literate without being able to answer them, but what they allow is not immediate explanation of the real world (like Dr. Free-Ride's set), but the ability to participate in scientific discourse. If you can answer these questions, you're set to study, discuss, and maybe learn to contribute to science. If you can't, you can't.

And then there's Dave S.'s comment on the Adventures in Ethics and Science post. Dave doesn't state his questions in the form of a question, but lists several truths about science that he would like people to know, such as:

... that science is a method invented by humans to understand the natural world using natural methodology. It is not meant to reveal all knowledge about every aspect of existance.
... that due to the above, science is limited. But in this limitation lies its strength. The proof of this is the great success science has had.
... that science is not about truth, it's about evidence.
... that evidence is empirical, which means we need to be to observe it with our senses.
... that just because we don't know everything about a process doesn't mean we don't know anything.
... that science is tentative doesn't mean we can't ever be confident in it. Science is stable, but it never stands still.

These emphasize the philosophical side of science -- the significance of evidence, empiricism, reproducibility -- and they're probably my favorite, in terms of what I wish every student would graduate knowing. You can hook them with the ain't-it-cool factor of mundane mysteries ("why doesn't pudding set when you lick the bowl?"), and it's important to show them how science is relevant to their daily lives. You can teach them terminology, and in fact you shouldn't let them leave school without a working scientific vocabulary. But at the end of the day, I wouldn't mind if nobody in the country could explain why the sky was blue, diagnose the cause of chunky tea, or accurately define an atom, as long as we could have everyone understand what a theory is and how it comes about.