The ancients tell us that before the Big Dark, there was light. Sunlight during the day; human-made light during the night: but then the fighting happened and then the Big Dark. There were no shadows, only dark.
Later, our story goes, when curiosity returned to the world and before we lost our memory of light, the higher ones (those with a need to progress) started experimenting with capturing light. Rudimentary devices like this one were used by the higher ones to locate exploding stars which they hypothesized could create energy that might be turned into sunlight. Devices, like this, became tools for tracking the stars at the moment of explosion. This box used to be called a radio but when its tubes and wires were connected in a very different way, it was able to send radio waves through the uncluttered atmosphere out into deep space where the waves could detect explosions on suns and stars.
Subsequent experimenters learned how to build other instruments that not only could locate the exploding stars millions of miles away but could harness the energy. The energy was woven into a field that draped around half the earth and used the magnetic pull of the poles to rotate it north and south so our world could be returned to Night and Day.