Vitressa: Glass Transition
Thermodynamics & Statistical Physics arc, page 64 of 193. Back to The Pixelated Physics Universe
Who they are
Vitressa has one line, and says it often: “Not finished. just a glass.”
Vitressa is a character of the Thermodynamics & Statistical Physics arc: drawn in pixels, ruled by one piece of real physics, and never allowed to break it.
The physics
A glass is a liquid whose relaxation became too slow to follow on experimental timescales: kinetically arrested, not in equilibrium.
$$ \begin{gathered} \tau = \tau_0\, e^{B/(T - T_0)} \end{gathered} $$
| Symbol | Meaning | SI unit |
|---|---|---|
| $\tau$ | structural relaxation time | s |
| $\tau_0$ | high-temperature prefactor | s |
| $B$ | fragility parameter | K |
| $T$ | temperature | K |
| $T_0$ | Vogel temperature | K |
Sources
Crossovers
Vitressa meets Barrierwyn (Kramers Escape Rate). Vitressa's glass is a liquid whose particles must hop over barriers to rearrange. As it cools, Barrierwyn's escape rate drops so steeply that the rearranging stops on any lab timescale.
Vitressa meets Rimehold (Supercooled Water). Rimehold keeps water liquid below its freezing point until ice nucleates. Vitressa shows what happens if crystallisation never comes: the liquid slows until it is arrested as a glass.
Vitressa meets Foldara (Levinthal's Paradox). Foldara's funnel leads to one fold. Vitressa's rugged landscape traps a glass in many states. A smooth funnel is how a protein avoids getting stuck.
Wear the lore
Concept keywords: Glass Transition, Vitressa, Thermodynamics & Statistical Physics, physics lore, Pixelated Physics