Leslie’s cube is a laboratory apparatus used to study thermal radiation and the properties of different surfaces in terms of their ability to absorb and emit heat. The cube is made up of four identical, hollow metal plates that are painted black on one side and white on the other. These plates can be filled with hot or cold water, allowing researchers to measure the rate at which heat is absorbed or emitted by the different surfaces.

By comparing the temperatures of the plates and the amount of heat exchanged between them, scientists can gain insights into the principles of thermal radiation and the behavior of different materials under various conditions. Leslie’s cube is named after Sir John Leslie, a Scottish physicist who invented the apparatus in the early 19th century.