While setting up our work for the Sur Polar exhibition in Buenos Aires last March, artist Phil Dadson described Len Lye’s notion of the Old Brain.
Today I finished an animation that I had begun yesterday. Listening to his words, I drew, and animated in a time line punctuated by the Milankovitch cycles.
The vertical line moving across the screen marks the ‘eccentric’ cycle of Earth’s orbit round the sun. This is the longest of three cycles that set the natural patterns of climate change. Within a time frame of 100,000 years, the elliptical shape of Earth’s orbit round the sun changes.
Within this cyclic pattern, two other Earth movement are cycling – the tilting of the Earth up its axis, and a wobbling on that axis, like a top. Together these three motions set our distance from the sun at different times. In this way, Earth experiences glacial and interglacial periods. Life forms grow and change and die. Human actions, we believe, are upsetting the natural pattern, tipping the balance.