The Universe has a temperature. The edge of the visible world, like the wall of a furnace, radiates faint heat. This thermal energy possibly drives the expansion, solving the main cosmological puzzle.
🎯 The temperature of the cosmic horizon is about 10⁻²⁹ Kelvin — billions of times colder than the coldest point ever created by humans.
🎬 Science fiction writers sometimes talk about a 'warm Universe' with an inner fire — here it gets a scientific basis.