Each scenario swaps two things: the backbone element that links into chains (carbon or silicon) and the solvent the chemistry happens in (water or liquid ammonia). Small dots drift in the arena and bond into pairs, then break apart, at a rate set by the scenario's real bond-energy asymmetry and by whether the current temperature keeps the solvent liquid.
C–O bond energy ≈ 360 kJ/mol → CO₂ escapes as gas
Si–O bond energy ≈ 452 kJ/mol → SiO₂ stays a solid (silicate rock)
H₂O liquid range: 0 °C to 100 °C
NH₃ liquid range: −78 °C to −33 °C
- Carbon–Water — Earth's chemistry. Carbon forms four bonds like silicon does, but C–O bonds are weak enough that the oxidized waste product (CO₂) is a gas at body temperature, so it diffuses away easily. Assembly and breakdown stay balanced and fast.
- Silicon-based — silicon also forms four bonds, but Si–O bonds are far stronger, so oxidized silicon (SiO₂ — quartz, sand) is a solid, not a gas. "Waste" clogs the system instead of venting, so pair assembly runs fast but breakdown lags badly — the visualization shows dots piling up unbroken (red).
- Ammonia solvent — keeps carbon chemistry but swaps water for liquid ammonia, which is only liquid between −78 °C and −33 °C. That lets hypothetical "life" run at cryogenic temperatures (relevant to moons like Titan), but the reaction rate itself is slower — everything happens more sluggishly than the water case.
- Temperature slider — outside a scenario's liquid range the solvent is frozen solid or boiled off, so no new bonds can form at all — the arena shows this by halting assembly outside the green band.
This is a simplified pedagogical model, not a chemical simulator — it visualizes the qualitative trade-offs (bond strength, waste-product phase, solvent liquid range) that make silicon- and ammonia-based biochemistries plausible-but-harder alternatives to carbon-water life, rather than computing real reaction kinetics.