Yes, in terms of electromagnetic radiation, a black tank tends to cool off faster than a white tank at night. This phenomenon is primarily due to the differences in how black and white surfaces interact with and emit thermal radiation.
When an object is exposed to radiation, it both absorbs and emits radiation. The rate at which an object cools down or loses heat depends on its ability to emit thermal radiation. Here's how the color of a surface affects this process:
Absorption of Radiation: A black surface absorbs more radiation across a wider range of wavelengths than a white surface. Black surfaces are good absorbers of radiation, while white surfaces reflect a significant portion of incident radiation. Therefore, a black tank absorbs more thermal radiation from its surroundings, including the cooler night sky, compared to a white tank.
Emission of Radiation: According to Stefan-Boltzmann's law, the rate at which an object radiates thermal energy is proportional to the fourth power of its temperature. Black surfaces also tend to emit radiation more efficiently than white surfaces. As a result, a black tank will radiate heat more quickly than a white tank, leading to faster cooling.
Combining these factors, a black tank absorbs more heat from its surroundings due to its higher absorption of radiation, and it also emits heat more rapidly due to its more efficient emission of radiation. Consequently, a black tank will cool down faster at night compared to a white tank.
It's worth noting that factors like ambient temperature, humidity, and the specific thermal properties of the tank material can also influence the cooling rate. However, in the context of the color of the tank, black surfaces generally cool off faster due to their enhanced absorption and emission of thermal radiation.