# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DY2Sjk0AeHT
- **Gondola URL:** https://gondola.cc/posts/66053065-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/d6caac9713.jpg
- **Posted:** 2026-05-27T16:12:04.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

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 glassworker is racing against a viscosity curve with every gather, blow, and pull.

The most critical and least visible step is annealing — a controlled slow-cooling process through a specific temperature range called the annealing point (roughly 450–550°C). Rapid cooling creates steep thermal gradients between the surface and core, generating residual tensile stress that can cause spontaneous fracture hours, days, or even weeks later. Proper annealing allows stress relaxation to occur before the glass becomes too rigid to accommodate it.

Colored glass introduces an additional layer of chemistry. Transition metal oxides dissolved into the melt selectively absorb specific wavelengths: cobalt produces blue, copper produces green or red depending on oxidation state, manganese yields purple. The optical response is a direct product of d-orbital electron transitions — quantum mechanics made visible.

Every piece of handmade glass is a record of the thermal and mechanical history it endured.

#stemantics #materialsscience #glassmaking #appliedphysics #craftsmanship

## Stats

- **Views:** 8,039
- **Likes:** 133
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## Tags

glassmaking, appliedphysics, materialsscience, craftsmanship, stemantics

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