The Bad Astronomy post talks about dark matter: [Note: before you ask, this has nothing to do with dark matter. See below!] I’ll note: this has nothing to do with dark matter. As it happens, 90% of the matter in the Universe is in a form that emits no light, but affects other matter through gravity. We know it exists, and you can find out why here. We know it exists locally, in nearby galaxies and clusters of galaxies, too. This new result doesn’t affect that, since the now un-hidden galaxies are very far away, like many billions of light years away. They can’t possibly affect nearby galaxies, so they don’t account for dark matter.
Teach the kids Scheme! Seriously, it's a better transition from pure math to programming. (http://www.teach-scheme.org/)
Reminds me of my Human Factors class, we read the book Set Phasers on Stun, which included horror stories about human design disasters.