Abstract: The dynamics of lantern＇ s rising is analyzed. The factors which influence the rising time in the experiments are identified and the corresponding influence are investigated. It is found necessary to choose the correct materials and candles. We explore the influence of multiple factors and propose the equivalent-force method for the candle choosing. Finally, we give the shape-optimizing program and demonstrate the experimental results in which the time of the lantern from floor to 2.5m vertical height after being lighted up is shortened.

Key words: shorten time, equations of motion, equivalent force method, optimization