Lisa: It looks like a vortex. A gateway into another dimension.
Homer: Oooh, a vortex. [takes an orange and tosses it in] Catch!
[the orange disappears with a pop]
Heeeeey! Pretty slick!
[a crumpled-up piece of paper comes back]
Lisa: [reads the message] "Quit throwing your garbage into our
dimension."
-- "Bad Dream House" in "Treehouse of Horror"