Mpemba Effect Simulator (2D)

Starting Temperatures

Initial temp. difference 45 °C

Contributing Factors

Evaporation rate 60%

Convection strength 70%

Both beakers cooling toward the freezer temperature.

Live Readout

Hot beaker

65.0 °C

Cold beaker

20.0 °C

Hot froze at

—

Cold froze at

—

Race time

0.0 s

How it works

The Mpemba effect is the observation that, under certain conditions, initially hotter water can freeze before initially cooler water — a real, reproducible-in-some-setups phenomenon that still has no single agreed explanation. This simulator combines three of the most-cited contributing mechanisms so you can see each one's share of the effect.

Evaporative mass loss — the hot beaker loses water to evaporation while it is warm, so there is simply less mass left to cool down by the time it approaches freezing.
Convection currents — a large internal temperature gradient drives stronger convection, which keeps circulating warm water to the surface where it loses heat fastest; this effect fades as the beaker cools and the gradient shrinks.
Dissolved gas content — heating drives dissolved gas out of the water; degassed water can conduct and freeze slightly differently than gas-saturated water.

None of these factors alone reliably makes hot water win — real experiments are notoriously sensitive to container shape, sensor placement and what "frozen" means. Adjust the sliders to see how the balance shifts, including cases where the cold beaker wins as intuition expects.

Hot beaker Cold beaker Ice once frozen