Scientists found a way to predict a quantum sensor's precision from a couple of simple measurements, without reconstructing the whole state. The key lies in spectral subtleties and internal correlations. Like guessing a kettle is boiling from its vibration, without opening it.
🎯 The term 'Fisher information' originated in 1920s statistics: Ronald Fisher introduced it long before the advent of quantum mechanics.
🎬 Extracting the essence from little data is a science fiction staple: think of scanners that determine a distant planet's composition with a single beam.