ted bradstraw, our ta. okay. waves are all part of the game and--we're not loud enough. here we go. do we see waves or do we see waves? yes. okay. we can also have voice waves and they look much more interesting. they go-- [makes sounds] [laughter] and you can get complicated wave forms and nice easy wave forms. you can make whistles. [whistling] that's good. let's go. you know that everyone has their own pattern like your own fingerprints. hold on. where are you going? go way on me. hello. testing, hello, hello. i think that's good. hello, hello. ha, ho. lots of fun. i admit-- i'm a great singer. maybe we could show the idea of interference. okay. i wanna do here is-- first of all, i have to show the students this happens with-- do you know--do you guys know that one wave can interfere with another in an interesting way sometimes? let me show you-- for water waves. right, the water waves. let's suppose i take another water wave and add it right on top and the other wave is exactly the same frequency, same wavelength, save everything, okay? but watch this. when those combine togethe