Science at Hogwarts: a little magic show Presentation for NSTA Minneapolis Regional Conference October 30, 2009 Jane Snell Copes Science Outside the Box Photo by Larry Copes A Handful of Flames “There was a soft, crackling noise, and a shivering light filled the compartment. Professor Lupin appeared to be holding a handful of flames.” Harry Potter and the Prisoner of Azkaban, page 83 Flash Paper • Flash paper is cellulose nitrate, also called guncotton. • It’s made by dissolving the lignin out of paper or cotton with nitric and sulfuric acids. • Buy flash paper at a magic shop. Let it dry before using. • Toss it high and LET GO OF IT! • Flash paper burns so completely because what remains of the paper contains enough oxygen to convert it to gaseous products. Photo: American Chemical Society Fire in a Jam Jar “The day before Harry’ s first Quidditch match t he three of them were out in the freezing courtyard during break, and Hermione had conjured them up a bright blue fire that could be c arried around in a jam jar.” Harry Potter and the Sorcerer’ s Stone, page 181 • a gel of saturated aqueous calcium acetate solution and 95% ethanol (a.k.a. Sterno) makes the portable fire • 1 part calcium acetate solution to 6 parts alcohol • alcohol flames are nearly colorless; add salts to change the fire’s color Photo by Jane Copes Colored Flames “He took a pinch of glittering powder out of the flowerpot, stepped up to the fire, and threw the powder into the flames. With a roar, the fire turned emerald green and rose higher than Fred, who stepped right into it, shouted ‘Diagon Alley!’ and vanished.” Harry Potter and the Chamber of Secrets, page 47 • boric acid H3BO3 makes fine green flames • alkali metal salts have distinctive flame colors • highway flares and fireworks rely on electronic transitions of their constituent elements • emission spectra of stars (including our Sun) tell us what elements are present there Photo: American Chemical Society Advanced Colored Flames ¥ A good choice for outdoor purple flames: iodine mixed with zinc dust and accelerators ¥ Just canΥt do the black flames . . . sorry! “They stepped over the threshold, and immediately a fire sprang up behind them in the doorway. It wasn’t an ordinary fire either; it was purple. At the same instant, black flames shot up in the doorway leading onward. They were trapped!” Harry Potter and the Sorcerer’s Stone, pages 284-285 Photo: American Chemical Society The Put-Outer or Deluminator Photo: American Chemical Society A Useful Little Device . . . “[Dumbledore] found what he was looking for in his inside pocket . . . . He flicked it open, held it up in the air, and clicked it. The nearest street lamp went out with a little pop.” Harry Potter and the Sorcerer’s Stone, p. 9 SOMEthing does NOthing • Carbon dioxide from subliming dry ice puts out flames nicely • CO2 doesn’t burn because it’s already oxidized as far as possible • Even without the water vapor fog, CO2 deluminates flames Photo by Jane Copes Thickening Potion “They had Potions that afternoon, which was an unqualified disaster. Try as Harry might, he couldn’t get his Confusing Concoction to thicken.” Harry Potter and the Prisoner of Azkaban, page 318 Photo: American Chemical Society Double Duty Powder! • sodium polyacrylate absorbs about 800 times its weight of water • also known as Water Lock, it’s used in potting soils and disposable diapers • table salt is the “antidote” to break the gel • same polymer, but “folded” makes InstaSnow • Find both at www.stevespanglerscience.com Photo: American Chemical Society Crystal Ball ”Together they climbed the ladder into the dim, stifling tower room. Glowing on every little table was a crystal ball full of pearly white mist.” Harry Potter and the Prisoner of Azkaban, page 296 Photo by David Roy Crystal Ball • You need bubble solution, a container with a smooth lip, and Bubble Fur (polar fleece) • dry ice sublimes rapidly in warm water, producing clouds of water vapor and carbon dioxide • a film of bubble solution expands quite nicely from the CO2 pressure • Try the “teacup” version for each student Photo by David Roy Bat Breath • Bromthymol Blue indicator is yellow in acid, blue in base • We all have CO2 in exhaled breath • Add NaHCO3 (baking soda) to keep the indicator blue. Photo by Larry Copes Hagrid’s Toothpaste • Elephant’s Toothpaste uses 30% hydrogen peroxide + KI or NaI and a little dish soap • “Teacup” version uses 3% drugstore peroxide and dry yeast Photo: American Chemical Society The Witch Eats the Pumpkin • Iodine Clock Reaction • IO3- + reducing agent (S2O52) + starch I• potassium iodate + sodium meta-bisulfite + food coloring iodide • I- + intermediate delays production of free I• When intermediate is used up, I- reacts with starch BLACK • vary volume of one solution to make different times Photo by Jane Copes Exploding Pillow -orAutomatic Alarm Clock • You need a freezer weight, quart size, single zipper bag • A little dry ice + water • Use goggles and hold the bag firmly by the sides • Re-seal for Snooze Alarm • For George and Fred (of blessed memory) Weasley’s Joke Shop Does it ruin the magic to unravel the science? “You are here to learn the subtle science and exact art of potion-making.” Harry Potter and the Sorcerer’s Stone, page 136. Photo by Larry Copes Contact Professor Sepoc Jane Snell Copes Science Outside the Box www.scienceoutsidethebox.com Find SOtB on Facebook profsepoc@scienceoutsidethebox.com Photo by Larry Copes