Bored during a seminar?

Resonant surface waves in my coffee cup from seminar. I discovered that if I drag the cup slowly across the table (holding it near the middle of the cup) really interesting resonant wave patterns appear. Instead of paying attention to the seminar, I ended up playing with my coffee cup the whole time. http://youtu.be/OmS98AwR15o

Here's another video I made demonstrating even more interesting phenomena. http://youtu.be/Wp5BKhw4vQY

This video was uploaded from an Android phone.

Видео Bored during a seminar? канала Daniel Miller