No material
system whether artificial or living can compute more than 2 x 10e47
bits per second and per gram of its mass. This limit refers to a self-contained system where the power supply is included in the total mass and where
computation " is defined as the transmission of
information over one or more
channels within the system. Recognizing that computation requires
energy for changing physical markers and for recognizing such changes in subsequent steps, the limit is obtained from Einstein's relation between energy and matter, E=mc2, and Heisenberg's
uncertainty principle, which specifies the inaccuracy or
noise in the
measurement of energy. Current
computers are far from approximating this limit because they are not yet designed to utilize atomic events for the storage and transmission of information and are subject to thermodynamic limitations instead. Bremermann's limit applies to material systems and concerns real events, sign vehicles or descriptions. It does not apply to events outside the system that can or are represented within it (
see symbol ). (
krippendorff )
