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.
The influenza virus is an recurring nightmare, killing thousands of people each year. Learn how the virus attacks its host, why it's nearly impossible to eradicate, and what scientists are doing to combat it.