Cement's Boson Hum: Terahertz Waves Eavesdrop on Nano-Inhomogeneities
The most abundant construction material on Earth, concrete, hides its deepest secrets at nanometer scales. Its strength and tendency to creep slowly under load are governed by a microscopic gel of calcium silicate hydrate (C-S-H), whose structure is as chaotic as a frozen vortex of atoms.