After the Big Bang, the universe began expanding — Edwin Hubble noticed this by the receding of galaxies, but in the first fractions of a second the pace was unimaginable. This rapid growth, or inflation (predicted by Alan Guth), was driven by immense spacetime curvature. Tiny quantum jitters stretched into waves, frozen as temperature variations in the cosmic microwave background — the cooled light of the Big Bang.

Physicists have discovered that different inflation scenarios (faster or slower) yield the same 'quantum pattern' in the sky. Quantum entanglement — invisible connections between distant regions, like threads in a tapestry — as well as entropy (a measure of chaos) and other quantum information parameters coincide. It’s like baking: changing the recipe, you get a cake with the same texture and taste.

Yet behind this lies a surprise: the perturbations themselves evolved differently, but the difference escapes ordinary measurements. Future quantum measurements, inspired by the work of John Stewart Bell, may be subtle enough to catch it — like a microscope finding bubbles in the dough invisible to the naked eye.