Profiles of the Future: Small Smarties
pp. 181 - 182
"If, on planets with powerful gravitational fields, living creatures are reduced to a height of a few inches, they cannot be intelligent - unless they make up for their lost height by increasing their area, to give an adequate volume of brain."

Here, Mr. Clarke appears to assume that a cellular makeup like those we humans have is the only option, and, therefore, the limiting factor on intelligence. I presume he'd probably agree that other configurations of matter might also create intelligent life so that such a volume as consumed within our heads was not required to do the thinking we do.

No doubt there are limiting factors on the current pace of processor speeds and harddrive size reductions, but surely they may help to illustrate the point that atoms can be arranged in ways entirely novel to our conception of biology, yet far superior to it in size efficiency.

This analogy ignores that a brain in a living organism requires oxygen and nutrients to function, but perhaps the aliens that Clarke envisions visiting us in the none-too-distant future will differ dramatically from us beginning at the molecular level. I'm no xeno-biologist, but it seems not entirely dismissable that humans are not the prototype for all living, intelligent beings in the galaxy (but, then, for all I know, we are). Consider further that a brain based on a different body, and a different evolution, may not have much of our baggage to carry along with it, and could thus be more compact in size even if it is still based on cells akin to ours.

Finally, I might mention that the aliens that we encounter could be distributed collectives of small organisms that can process and pass along information in such a way as to approximate a higher intelligence even if no individual amongst them were "intelligent" on its own (this is not all that different from the way our brain works when you consider that individual cells in our bodies are living things in their own right).
- posted @ 7:48 PM