Chapters
One piece of glass, a stage at a time
These are the stages of the walk, one card each, in studio order. Each card states the stage's claim and the physics it belongs to. The atlas lays the same lessons out by physics. Two stages have their own chapter page so far; the rest open at their place on the walk.
- 00 · the material Glass is a liquid that stopped A silicate melt stiffens smoothly instead of crystallizing. The network keeps the liquid's disorder, and one viscosity curve runs the studio.
- 01 · the batch Clear glass is not clear A trace of iron turns a pane's edge green, because absorption compounds with path length. The oxide bench shows how the recipe sets every property.
- 02 · the melt The furnace air picks the color Oxidizing or reducing air sets how much iron sits as Fe³⁺ or Fe²⁺, and the two ions absorb differently.
- 02′ · the melt, long and short Some glasses are long, some short Fragility measures how steeply viscosity rises near Tg, and it sets how long a glass stays workable.
- 03 · the color rod Each ion absorbs its own bands Each transition-metal or rare-earth ion takes its own bands out of the spectrum, and a blown piece is colored by its own wall thickness.
- 04 · the glory hole At heat, glass gives back what it takes Hot glass glows with emissivity equal to its absorptance (Kirchhoff), so a colorant that absorbs a band also glows in it.
- 05 · the reheat Some colors must be struck Gold ruby and cadmium reds appear only after a reheat grows particles or crystals: plasmon absorption and band-gap edges.
- 06 · the lehr Glass remembers how it cooled Uneven cooling freezes in stress, which makes glass birefringent; crossed polarizers turn that into interference colors.
- 07 · the cold shop Color with no colorant Dichroic coatings reflect one band by thin-film interference and pass its complement; nothing is absorbed.
- 07′ · the cold shop, cut Clear glass holds every color Refractive index climbs toward the ultraviolet, so a cut glass splits white light; lead raises the dispersion, and crown and flint can cancel it.
- 08 · the rack Every color on the shelf Working backwards from a swatch to a melt has many answers, because three numbers cannot fix a spectrum.
- 09 · the showroom One glass gives light back Uranium glass fluoresces green under ultraviolet, and neodymium glass changes color from lamp to lamp.
- 09′ · the showroom, other eyes Color is a fact about an eye Every color on the site is a spectrum through a lamp and an observer; change the observer and matches break.