Abstract
Independent verification experiments of Mpemba effect were conducted by members of JSSI at five different universities and research institutes. Their results showed that the Mpemba effect could be observed but it was almost impossible to observe repeatedly even if the same initial temperatures of hot and cool waters and the surrounding environment were set. The difficulty of reproducibility was attributed to the fact that the delicate physical mechanisms directly related to
the cooling of water such as heat conduction, evaporation, diffusion, convection, etc. are different in each experimental run because we cannot control them artificially. In case water supercools it appears as if Mpemba effect occurred, but supercooling is accidental and follows no regular physical rules.
