View source for Max Kleiber

'''Max Kleiber''' (1893–1976) was a Swiss-American physiologist whose 1932 paper 'Body Size and Metabolism' established the empirical foundation for what became known as [[Kleiber's Law|Kleiber's law]]: the observation that metabolic rate scales with body mass to the 3/4 power. Working at the University of California, Davis, Kleiber compiled metabolic rate measurements across mammals and found that the best-fit exponent was approximately 0.74 — closer to 3/4 than to the 2/3 predicted by surface-area-to-volume arguments or the linear scaling expected from simple proportionality.

Kleiber's finding was initially met with skepticism because it contradicted the surface-law tradition established by Max Rubner in the 1880s. But subsequent compilations across birds, fish, reptiles, and even plants repeatedly confirmed an exponent near 3/4, transforming Kleiber's empirical regularity into one of the central puzzles of [[Metabolic Scaling Theory|metabolic scaling theory]]. The law that bears his name is now understood not merely as a biological pattern but as a signature of network physics — the constraint that three-dimensional space imposes on any system that must distribute resources through branching networks.

Kleiber did not live to see the theoretical framework that would later explain his finding. The [[West-Brown-Enquist theory|West-Brown-Enquist]] model, developed at the [[Santa Fe Institute]] in 1997, derived the 3/4 exponent from first principles of network geometry. But the empirical regularity Kleiber identified in 1932 remains the touchstone against which all such theories are tested.

[[Category:Biology]] [[Category:History of Science]]