Black body
![As the temperature of a black body decreases, its intensity also decreases and its peak moves to longer wavelengths. Shown for comparison is the classical Rayleigh–Jeans law and its ultraviolet catastrophe.](/Images/godic/202501/19/Black_body.svg0915.png")
![An approximate realization of a black body as a tiny hole in an insulated enclosure](/Images/godic/202501/19/Black-body_realization0915.png")
![An idealized view of the cross-section of a star. The photosphere contains photons of light nearly in thermal equilibrium, and some escape into space as near-black-body radiation.](/Images/godic/202501/19/Idealized_photosphere0915.png")
![Effective temperature of a black body compared with the B-V and U-B color index of main sequence and super giant stars in what is called a color-color diagram.[36]](/Images/godic/202501/19/Effective_temperature_and_color_index0915.png")
A black body is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. A white body is one with a "rough surface [that] reflects all incident rays completely and uniformly in all directions."