1011 Orders of magnitude (numbers)
^ there was, our knowledge, no actual, direct estimate of numbers of cells or of neurons in entire human brain cited until 2009. reasonable approximation provided williams , herrup (1988), compilation of partial numbers in literature. these authors estimated number of neurons in human brain @ 85 billion [...] more recent estimates of 21–26 billion neurons in cerebral cortex (pelvig et al., 2008 ) , 101 billion neurons in cerebellum (andersen et al., 1992 ), however, total number of neurons in human brain increase on 120 billion neurons. herculano-houzel, suzana. human brain in numbers: linearly scaled-up primate brain . front. hum. neurosci. 3. doi:10.3389/neuro.09.031.2009. pmc 2776484 . pmid 19915731. ^ kapitsa, sergei p (1996). phenomenological theory of world population growth . physics-uspekhi. 39 (1): 57–71. (citing range of 80 150 billion); see world population. ^ elizabeth howell, how many stars in milky way? archived 2016-05-28 @ wayback machine., spac...