[ExI] Unsolved problems

[John K Clark]

The fastest signals in the human brain move at a couple of hundred
meters a second, many are far slower, light moves at 300 million 
meters per second. So if you insist that the 2 most distant parts of a
brain communicate as fast as they do in a human brain (and it is not
immediately obvious why you should insist on such a thing) then 
parts could be one million times as distant. The volume of such a 
brain would be a million trillion times larger than a human brain, 
and the components would be considerably smaller too.

  John K Clark