Toy figure our blue planet Earth

• Resin
• Length: ca. 5 cm
• With cord for hanging

Caution, choking hazard. Not suitable for children under 3 years of age. Swallowable small parts

Hollow Earth Theory

The first theory based on science was proposed by Edmond Halley in 1692. Isaac Newton had calculated that the moon was denser than the earth in a ratio of 1.76 : 1. Based on the general view that all matter of the planets and moons had the same density, Halley concluded that part of the Earth must be hollow. Furthermore, he had observed that the Earth's magnetic field changed over time. He assumed that the Earth consisted of a central sphere and three hollow spheres concentrically surrounding it, about the size of the Moon and the planets Mercury and Venus. Each of these bodies would have its own magnetic field, and since they rotate at different speeds, this would result in a changing overall magnetic field on the surface of the Earth. Since it was previously assumed that all celestial bodies were inhabited, he also colonised the inner planets. This hollow earth theory was the first conclusion drawn from Newton's new theory of gravitation in the Principia, even before Halley's prediction of a comet in 1695. On 6 March 1716, for the first time since the May Minimum, very bright auroras were observed in England and in large parts of Europe, which were even visible during the day. The Royal Society commissioned Halley to explain these phenomena. He attributed them to the fact that the earth's crust was thinner in northern latitudes and thus the light shone through from the cavities. When the 80-year-old Halley was portrayed as the Astronomer Royal, he had himself depicted with a diagram of the Hollow Earth. The Swiss mathematician Leonhard Euler discussed in a thought experiment in his Lettres à une princesse d'Allemagne whether the Earth (as well as the other planets) was hollow and illuminated by an inner "sun", "which gives warmth and light to an elevated inner terrestrial humanity".