A poor man, Mackey was unable to publish any of his ideas until 1822, when
The Mythological Astronomy of the Ancients Demonstrated by Restoring to their Fables & Symbols their Original Meanings was first printed. One of Mackey's key theories concerned Earth's
axial tilt (or
obliquity), and its change over significant periods of time. The axial tilt is responsible for the seasons, as when one hemisphere tilts more towards the Sun, it experiences summer, and when away from it, winter. Mackey believed that in earlier times, the inclination had been much greater, and that the Earth cycled between an "age of horror" and a "golden age", over thousands of years, based on its inclination.
Joscelyn Godwin explains Mackey's belief that:At the maximum angle, each hemisphere would be pointed directly at the sun day and night during the summer, and pointed away for weeks on end during the winter. These extremes of light and dark, of heat and cold, would be virtually insupportable for life as we know it. In Mackey’s words, it was an “age of horror” for the planet. Conversely, if the axial angle were to continue to diminish in the future, eventually it would be perpendicular to the ecliptic... and there would be no seasons on earth, but a perpetual spring and a “golden age.” Then the cycle would begin again.Godwin explains that as an avid reader, Mackey "could easily have come across the idea of the steady diminution of the angle of inclination", but his "originality lay in drawing conclusions without any fear of exceeding the canonical age of the earth". On the basis of cycles of 25,920 altering the axial tilt by four degrees, Mackey dated the "Age of Horror" to 425,000 years in the past, and the "Golden Age" to about a million years ago. He also believed that human beings had been around to experience and subsequently pass on stories about these periods, extending the existence of the human race to far longer than the then accepted 6000 years since the creation of the Earth. == Death and legacy ==