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-第 13 講
however, is no.
experience
"Red" is not a color contained in an object. It is an
30 involving reflected light, a human eye, and a human brain. We experience red only
when light of a certain wavelength (say, 600 nanometers) reflects from an object (in
②
the midst of other reflections at other wavelengths), and only while a receiver
translates this contrasting range of light into visual sensations. Our receiver is the
対をなす 15248
human *retina, (which uses its three types of photoreceptors, called *cones, to convert
35 the reflected light into electrical signals made meaningful by a brain. In a retina
that's missing a medium or long cone, light at 600 nanometers is experienced as
gray. And in the absence of a brain, there is no experience of color at all, only
reflected light in the world.
脳の欠
(2)
Even with the right equipment in place, the experience of a red apple is not a
ST
40 done deal. For the brain to convert a visual sensation into the experience of red, it
must possess the concept "Red." This concept can come from prior experience with
apples, roses, and other objects you perceive as red, or from learning about red from
other people. (Even people who are blind since birth have a concept of "Red" that
they learn from conversations and books.) (Without this concept, the apple would be
45 experienced differently. For instance, to the Berinmo people of Papua New Guinea,
apples reflecting light at 600 nanometers are experienced as brownish, because
Berinmo concepts for color divide up the continuous *spectrum differently.
These riddles about apples and trees invite us, as perceivers to
