Saturday, April 24, 2010

Electric Hot Dog (or find the weenie in this story)

Note: This certainly falls into the "Don't try this at home" category so . . .DON"T!

One of my favorite physics demonstrations is electrocuting a hot dog. You take a standard hot dog and shove a big nail into each end. This part is actually kind of hard to watch. Next you attach the dog to a death cord. This was our name for a simple lamp cord with a plug on one end and two alligator clips on the other. Not a really very safe thing to have lying about but we kept it stored away. . . usually. The idea now is to attach the alligator clips to the nails and plug 'er in and thus cook the hot dog. The dog will have several amps running through it and usually cooks in 20-30 seconds. I would bring buns and mustard (NO KETCHUP!) and allow some volunteers to eat the electrically cooked hot dog.

I had built a little stand for supporting the dog while it cooked but on this day I didn't have that stand. I didn't want to just lay the dog on the nasty table. What to do. . .? It's at this moment where I get a great idea and once I get a great idea I tend to run with it and not to consider any possible down sides. My great idea is to cook the hot dog in the bun which I could hold in my hand as surely the bun is an insulator and I can make the bonus point about insulators versus conductors. Brilliant!

So, in front of about 20 sophomore physics students I arrange the hot dog with nails and wires on to the bun. I hold the assembly in my left hand and plug 'er in with my right.

"SHIT!",

says the strangely vibrating teacher while dropping his dog to the floor.

Hot dog buns are NOT insulators. Who knew?

"What happened at school today dear?"
"Not much. Oh, Mr. Welty electrocuted himself and said poop."
"What? "
"Never mind."

Saturday, April 17, 2010

The Drip

Most of the good stories come from my first year of teaching. I was teaching physics and earth science at Joliet Catholic. This was 1975 and Joliet Catholic was all boys. Of course to get full use out of me for the $8300 they were paying me I was also farmed out to their sister school, the all girls St. Francis Academy to which I drove once a day in my own car. Come to think of it here was my schedule. . .

Period 1 - Remedial (or as we called it - Weenie) Earth Science. This was a required freshman course. I had 30 freshman boys (5 rows - 6 seats per row) and 3 sets of identical twins. I also have absolutely zero training in earth science. Needless to say this course turned into Weenie Physics rather quickly.

Period 2 - Regular Physics or Physics for future Convicts. These were ‘regular’ seniors and that means mouth breathing seniors that if they should somehow stay out of prison will be working in their dad’s body shop starting in June.

Now off to St. Francis. . .

Teach physics there. They only have one class. Good kids.

Back to Joliet Catholic - if I didn’t get held up or schedules weren’t screwy I sometimes had time for a brief lunch here.

Now two sections of honors physics which took up the remaining three periods of the day as each class met for a double period 2 days a week while the other class would have a single period that day. But, on Friday I got a special treat. Each class met for a single period so I got my ONE free period of the week. . . Unless I was needed to sub since we all subbed for each other.

Oh, I coached varsity tennis too about which I knew about as much as I knew about earth science but that’s another story.

So, I’m lecturing away at St. Francis one day. I’m sure it was quite fascinating. I see 20 faces locked on me with a concentration (and smiles!) that only the truly inspired learner in the throes of a well crafted lecture can muster. No wandering minds today. I’ve captured them all. This must truly be one of my best lectures ever! I was standing by the windows and not behind a lectern or demo table and I happened to notice a drip of some sort on my shoe. I noticed it because it was clearly fresh and not a dried up little stain. It’s funny about teaching in that your mind is intent on playing teacher and thinking of your subject but there’s other mind that’s thinking “I’m hungry”, or “God I’m still a little hung over”, or “When the hell is this period over”? So other mind thinks, “What’s with that drip”? Moments pass and I see a second drip on my shoe. For sure it was not there before. I keep teaching but also naturally look up for other mind is curious about the source of these drips.

Are my inspired learners giggling? No. Couldn’t be. My eyes return to lock on my students and I actually see a drip fall to the floor out of the corner of my eye! I look up again. Where is this coming from?

Who’s laughing? Actually, who’s nearly peeing their catholic panties? Keep in mind that through all of this I have not missed a beat about Sir Isaac or some other dead scientist. I scratch my head in mild consternation. What’s that? My hand comes back all black. The side of my bearded face is all black!

And drippy!

HOLY Ghost! I’ve a pen behind my ear and the ball has come out. It has been steadily leaking into my beard and then out to my shoe and EVERYONE has known this but me! Now try to get the class back in order. Try acting like this is a normal event that surely all humans have experienced once or twice. Oh sure you young-uns haven’t had the pleasure yet but trust me, you will.

Teaching can be a very lonely affair. I mean you can’t even go to a colleague and say, “Boy I had that leaky pen behind my ear deal today. . . Oh you know!” Nope. You’re all alone out there with a two tone beard and 20 young girls crossing their legs and asking for hall passes to the bathroom.