Science is Fun Fridays!
Finishing off the week with Halloween spirit, I watch this movie every year, and while his experiments are to understand Christmas, it is indeed a nightmare. In this scene (start at 2:12), Jack creates an oscillating chemiluminescence reaction. Two components react to create an excited, high-energy intermediate state in which an electron is bumped from a lower energy level to a higher one. In order to reach its ground state, the electron drops back down to its original energy level, which causes a release in energy in the form of a photon, or light. In an oscillating reaction, the concentrations of the reactants or products fluctuate, causing "observable fluctuations of time," which is why this is also called a clock reaction. Now, there is nothing in a Christmas ornament that would cause this kind of reaction, but it's fun in the movie, and there is a scientific basis for what is shown. Science Blog