OrbisHorae

Orbis Horae is a workshop for people who seal a terrarium and then have to live with the weather they built. It does not run a timer you typed in. You describe the jar — soil volume, headspace, glass or acrylic, lid seal, temperature, and light — then add the plants, animals, and microbes inside. The app walks a small water, carbon, and oxygen model forward for 30 days and shows whether that mix stays inside bounds. The Sandbox is a living section of the active jar. Wetter soil darkens toward the bottom, fog thickens with humidity, and the air picks up a warning tint if oxygen is falling. A countdown shows the first day a collapse would latch, or Clear when the jar stays stable through day 30. Biota Bench is where leaf area, body mass, and microbial activity put a daily load on water and gas. Climate Cabin sets heat, photoperiod, lamp strength, volumes, wall material, starting moisture, and how tightly the lid sits. Balance Trace draws soil water, humidity, and oxygen on one chart, with carbon dioxide as a fourth reading, and marks the day a limit is crossed. Pulse Log is for what you actually do to the jar. Opening the lid to add water mixes the headspace with room air and leaves the seal venting for a while. A hard lamp warms the glass so it stops sweating, then a condensate rebound follows. Pruning rewrites the standing leaves for every later day. Each act is stored on a day index and the rest of the curve is recast. The Cabinet keeps more than one jar, with the latest forecast snapshot beside each name. What the model watches • Soil moisture, wall condensation, and standing water • Humidity and headspace oxygen • Carbon dioxide, including a sour, overly wet headspace • Drought, waterlogging, and hypoxia as separate end points This is a teaching instrument for terrarium keepers. It is not a laboratory measurement, and it will not tell you that a living animal is safe. The countdown is a model warning, not a promise.