Flatness Problem

The flatness problem refers to the surprising fact that the universe appears to be geometrically very close to flat, meaning its overall shape is neither curved into a sphere nor saddle-shaped. According to physics, any tiny initial curvature should have grown over time, making the universe more curved or less flat. Yet, observations show it remains nearly perfectly flat, implying a very precise initial condition. This fine-tuning challenge suggests an underlying mechanism, like cosmic inflation, which expanded the universe rapidly to smooth out any initial irregularities and explain its near-flatness today.