Perhaps the most iconic instrument in modern rock is the guitar. It's really just a bunch of strings stretched across a board, which you can strum to make awesome tunes, thanks to the physics of waves ...

I'm reading Randall Munroe's book How To: Absurd Scientific Advice for Common Real-World Problems. I probably don't have to tell you this, but it's awesome (as is everything from Randall Munroe, the ...