Microgravity Hydroponics: Root Growth & Nutrient Diffusion

Hydroponic roots in orbit face two compounding problems: without a gravity vector, gravitropism can no longer tell a root which way is "down," and without buoyancy-driven convection, dissolved nutrients can no longer restock themselves at the root surface — transport falls back to slow molecular diffusion alone. This simulator grows a small root system in a numerically solved 2-D nutrient field (a real diffusion equation with a root sink and a convective mixing term) so you can drag gravity from 1g down to true microgravity and watch both effects appear together: roots begin to wave and skew instead of growing straight down, and a visible depletion halo spreads through the medium around every root tip. A forced-flow toggle reproduces the countermeasure real ISS plant-growth chambers (Veggie, the Advanced Plant Habitat) use to keep roots fed when gravity can't do it for them.