Weak gravitational lensing: invisible dark matter revealed through coherent galaxy shapes. Based on Scognamiglio et al. (Nature Astronomy, Jan 2026), who used JWST's COSMOS-Web survey to create the most detailed dark matter map ever — 800,000 galaxies, 255 hours of observation, twice the resolution of Hubble. The galaxies aren't randomly oriented. They're all slightly stretched by the same invisible structure. That coherence is the signal.