A Thermodynamic Limit on Brain Size

If our brains have to be cooled like computer chips, is there a limit on how big they can be?

In recent years, chip makers have conlcuded that the race to produce ever faster circuits is a fool’s game. As the clock speed increases, the amount of energy lost as heat becomes too large to dissipate efficiently and in any case, the waste is unjustifiable.

That raises some interesting questions about the human brain, says Jan Karbowski at the Sloan-Swartz Center for Theoretical Neurobiology at the California Institute of Technology. Karbowski points out that the problem of heat transfer could be a serious factor shaping brain evolution and so has embarked on a program to determine the relationship between brain temperature, its size, cerebral power generated and neural activity.

The question on Karbowski’s mind is whether there is any thermodynamic limit on brain size. And if so, does 5 kg, which Karbowski says is the mass of the largest mammalian brain, approach that limit?

Source: Arxiv blog.

Also see “Why Worry About This Sci-Fi Stuff Now? Mindfiles, Mindware and Mindclones” on IEET.