4Pi (original) (raw)

The expression 4Pi may refer to: * IBM System/4 Pi, a family of avionics computers * 4Pi microscope, a microscope that uses interference and fluorescence computers * 4×π = 12.56637..., the solid angle of a complete sphere measured in steradians * 4Pi Reprap controller * Hermetic detector (also called a 4π detector)This disambiguation page lists articles associated with the same title formed as a letter-number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article.