Albedo: [updated]

is a simple yet powerful measure of reflectivity . Derived from the Latin word for "whiteness," it describes the fraction of sunlight reflected by a surface back into space. While it might sound like a niche technical term, it is actually a cornerstone of climate science, planetary physics, and even urban design. The Scale of Brightness Albedo is measured on a scale from

: The brightness of a surface when viewed from the same direction as the light source, compared to an idealised reflecting disk. Blue-sky vs. White-sky vs. Black-sky : Black-sky : Reflectance under perfectly direct sunlight. Albedo