 The special and visual effects producers frequently used everyday  objects to create futuristic effects. The hovering killer probe in  "The Arsenal of Freedom" was made of a shampoo bottle and a  pantyhose container. The edge of the universe was created in "Where  No One Has Gone Before" by bouncing a laser beam off a beer can. One  element of the sliding door sound is sound editor  James Wolvington (qv)s shoe squeaking against the floor.