Sheldon, Leonard, Howard, and Raj create an oobleck using corn starch and water. Initially, it's a liquid, but when they turn the music on, it resembles a solid. Sheldon explains the phenomenon to Penny: it's a non-Newtonian fluid which is liquid but becomes solid due to the percussion from the speaker.
Professor Philip Brainard creates Flubber and tries to learn more about it. He performs quick tests on the physical properties of Flubber and finds that it is a highly viscous elastomer that can also phase shift between a liquid and a solid. Using observation skills, he also learns that Flubber is moldable, foldable, ductile, and elastic, among other properties.
Lester is challenged to use only a piece of string to pick up a piece of ice without touching it. USing salt, he sprinkles it on the ice and wets the string and sits it on the ice. After about 2 minutes, the string is now frozen to the ice and it can be picked up. This is because salt lowered the freezing point of water and now the water on the string can freeze to the ice cube.