Magyar Posta is issuing a sheet of postage stamps and a book of special stamps to mark the Shanghai World Expo.
The "main character" in the Hungarian pavilion is the Gomboc, the first known homogeneous, convex object to have just one stable and one unstable point of equilibrium.
The Gomboc is shown on the stamps. This unique invention is being released in special sheets containing 30 ordinary postage stamps. The designs of the stamps illustrate the most characteristic phases of the movement of the Gomboc.
The stamps are also being released as a special issue in the form of an unusual book of stamps. By flicking the pages of the book, the designs showing the movement phases of the Gomboc are brought to life and its movement appears like a film.
On the first day cover the Gomboc and the equations describing its construction and operation can be seen. The special postmark uses the logo of the Gomboc.