Human exploration of the nature of time has never ceased. What is time? Einstein revealed the relationship between time and speed in Special Relativity, that is, the faster the speed, the slower the time, and the relationship between time and gravitational field in General Relativity, that is, the stronger the gravitational field, the slower the time. This paper advances our understanding of the nature of time further through the study of Mpemba phenomenon and the inverse Mpemba phenomenon.
This paper concludes that " time is one of the properties of energy, which is the flow rate of energy from object to space or from space to object. When energy flows from object to space, the time on an object is proportional to the energy density inside the object and inversely proportional to the energy density of the space in which the object is located. When energy flows from space to object, the time on an object is inversely proportional to the energy density inside the object and is proportional to the energy density of the space in which the object is located” Using this time characteristic, the Mpemba effect and "inverse" Mpamba effect are analyzed and a reasonable explanation is given.