ballooning theory

Ballooning theory explains how certain early universe repulsive forces, such as dark energy, caused space itself to expand rapidly—much like a balloon inflating. Just as a balloon's surface stretches as it enlarges, the universe expanded exponentially in its infancy, smoothing out irregularities and setting the stage for galaxy formation. This rapid expansion, called inflation, occurred in fractions of a second, shaping the large-scale structure we observe today. The theory helps explain why the universe appears vast, uniform, and flat, despite originating from extremely dense and hot conditions.