Tardigrades survive near-total water loss by contracting into a compact "tun" and replacing lost water's structural role with trehalose sugar and intrinsically-disordered CAHS proteins, which solidify into a molecular glass — the vitrification hypothesis of anhydrobiosis (Crowe et al.).
The mixture's glass-transition temperature is estimated with the Gordon-Taylor equation, a real empirical model for the Tg of a two-component amorphous blend:
T_g,mix = (w_w·T_g,water + K·w_s·T_g,solute) / (w_w + K·w_s)
w_w = water mass fraction, w_s = solute mass fraction = 1 − w_w
T_g,water ≈ −137°C (pure water, extrapolated)
T_g,solute ≈ +115°C (dry trehalose)
K ≈ 4.7 (Gordon-Taylor constant, trehalose-water)
As water content w falls, w_s rises and T_g,mix climbs from far below body temperature toward the dry solute's high Tg. Once the ambient temperature drops below T_g,mix, the cytoplasm passes from a mobile, rubbery liquid into an arrested glass — molecular diffusion effectively stops, which is exactly what protects proteins and membranes from denaturation during desiccation.
- Desiccation rate — how fast body water evaporates once "Desiccate" is active.
- Ambient temperature — compared against T_g,mix each frame to decide liquid / rubbery / glass state.
- Trehalose / CAHS level — sets the dry-solute mass fraction available to vitrify; more solute → higher T_g,mix at a given water content → easier vitrification.
- The amber↔cyan spheres inside the body are biomolecules: amber and jittering = mobile (at risk if also dehydrated), cyan and still = vitrified and protected.
- The "vulnerable window" is low water content before vitrification catches up — real anhydrobiotes must dry fast enough, or synthesize enough trehalose/CAHS fast enough, to vitrify before that window causes lethal protein unfolding.