Orrery on display in Kassel at the Astronomisch-Physikalisches Kabinett and in Dresden at the Mathematisch-Physikalischer Salon. In "De revolutionibus orbium coelestium", published in Nuremberg in 1543, Nicolaus Copernicus challenged the Western teaching of a geocentric universe in which the Sun revolved daily around the Earth. He observed that some Greek philosophers had proposed a heliocentric universe. This simplified the apparent epicyclic motions of the planets, making it feasible to represent the planets' paths as simple circles. This could be modelled by the use of gears. Tycho Brahe's improved instruments made precise observations of the skies (1576–1601), and from these Johannes Kepler
Return to the Centre of the Earth idea soon after, partly due to Richard Branson's world record attempts to circumnavigate the Earth by hot air balloon and thinking people will relate his music to the event. Soon after, Wakeman came across a newspaper article by Steven Spielberg, "who was talking about have sequels for making films, how you have a story and you spin up from the story for a whole new story, but you have a relationship, which is very comfortable for the people who listen a whole new story, new characters, but there's still a relationship." This prompted the thought in Wakeman's mind, after revisiting