About 500 exhibits are being displayed in the permanent exhibition area. The most prominent exhibit is the 22-m high twin-tower Energy Machine which is the largest of its kind in the world. A total of 16 galleries cover a wide range of science and technology topics including light, sound, motion, electricity and magnetism, mathematics, life science, computer, transportation, communication, food science, energy, occupational safety and health and home technology. About 70% of the exhibits are participatory so that visitors may learn through direct involvement.