Adventures in Academia - the lengths to which students will go...
So here I am, droning along in class: blah, blah swing amplification blah blah m=2 instability blah blah Lindblad blah blah corotation resonance blah blah
when, suddenly, subliminal parental instincts kick in, out of the corner of my eye I see the dreaded upwardly pointing sharp pencil moving Argh! No!
Too late, one of my grad students has very elegantly done a cheek piercing, in class... much hilarity and several cc of venal blood follow.
Fortunately, residual parental instincts continue flowing, and I get out a (clean) kleenex (snot from one year olds, dried over 12 hours doesn't count, does it?). Blood is mopped up and measures taken.
Back to the existence of the inner Lindblad resonance in barred spiral galaxies.
Good news is: all the students are now awake, and, The Wife is Right - those pointy pencils are a Real Hazard. Big Kid take note please.