Glass is one of the oldest engineered materials on Earth — and one of the most misunderstood. At its core, glass is an amorphous solid: a material that lacks the long-range crystalline order found in metals or ceramics. When silica (SiO₂) is heated above roughly 1,700°C and then cooled rapidly, silicon and oxygen atoms form a disordered, three-dimensional network that never has the opportunity to organize into a crystal lattice. The result is a frozen liquid in thermodynamic terms — a supercooled state that behaves as a rigid solid at room temperature. What makes glass so demanding to craft is how viscosity governs the entire process: • At working temperature (~1,000–1,200°C), molten glass flows like thick honey — workable, but only briefly • As temperature drops, viscosity increases exponentially — not linearly • Below the glass transition temperature (Tg), typically around 500–600°C for soda-lime glass, atomic rearrangement becomes essentially impossible This means the glasswo...