How do we know stuff?

I told myself I'd get the first two weeks of lesson plans done by August 1st. I also told myself I'd lose 10 pounds, floss regularly, and stop cussing, too, so my lesson plans will be in plenty of good company of things not done. Still, it got me back to thinking of how to introduce science.

I'm not a big fan of the scientific method as a springboard for high school science class, at least the dogmatic form presented in textbooks--smacks of religious fervor, but I'll save that for another day.

I want to hit the kids with some version of this: how do we know what we know? (Do not call it epistemology, you'll only frighten the children.)

I don't want to go the existentialist route either, I'll only feed this generation's version of Trent Reznor fans.

In the past I gave a quiz involving a variety of scientific myths, and while it's fun, and it's big on the "Oooo..." factor, I get the sense that it the myths return into their universes before the exit bell rings.

So here's my vague notion of what I want to do. Pick something they "know" all about, then ask them to "prove" why it's true. (I have a sudden infatuation with quotation marks.)

I'm generating a list of questions. I want to know how the students know the answer beyond appealing to a source beyond their senses and their brains. I want questions that can be at least partially solved without leaving school grounds.

• How do you know the world is round?
• Might take a few months to develop the data, but I think we can do this in class
  
• How do you know something is alive?
• I need to bring critters and plants in early this year, first day if possible
• How do you know how old you are?
• This could get interesting if I outlaw birth certificates--could lead to a good discussion about sources (parents) and how reliable they are ("My Dad says evolution is devilspeak!")
• How many toes are in the room?
• Don't think I'll allow them to go for direct observation here, don't want to embarrass anyone, but does make for a good discussion on inductive inference.

I'm open to suggestions....