3.3.2 Enhancing the perceptual system

Magnificently evolved though it is, our sensory system is nothing special. We do not see as well as birds; our hearing is feeble compared to that of bats and some forest-dwelling mammals. Our sense of smell can't compare with that of dogs or pigs. There are many things we don't detect at all – radio waves, for instance.

In one capacity, though, humans are supreme: we have learned to enhance our perceptual systems with instruments. For example, the human eye has only a limited power to resolve very small objects, but we can now create images of atoms themselves with electron microscopes. Our retinas do not respond well to very dim light, but we can now detect the faintest light sources with telescopes or light-intensifying apparatus. Our capacity to build tools to strengthen our perceptual abilities is unique in the living world. And in the twenty-first century digital computer technology is an essential component of modern instruments. Neither of the microscopic and telescopic images in Figure 5 could have been made without advanced computer technology. Indeed, the galaxies shown in Figure 5 (b) are among the most distant objects ever seen, and are about four billion times fainter than the limits of human vision.

Figure 5 Computer-assisted images (a) red iron atoms on a mostly blue copper surface form the kanji character for the word ‘atom’ (b) galaxies

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Computer assisted images. The first shows red iron atoms on a blue copper background forming the kanji character for ‘atom’ and the second shows galaxies.

Figure 5 Computer-assisted images (a) red iron atoms on a mostly blue copper surface form the kanji character for the word ‘atom’ (b) ...