C haptEr 9 design Environments and systems
336
Yet it is not only in the domain of light-emission technologies that
benefits can accrue from the use of nanotechnologies. In our living
and work environments, for example, the effect of a light source is
highly influenced by the nature of its surroundings, including the
optical properties, such as reflectance or refractive properties, of the
materials that define the environments. The way humans perceive
light—how it affects them or the information they receive from
it—are all affected by interactions between the nature of the light
source and that of the surrounding material environment. Hence
we look here at the more general qualities of what is termed the
luminous environment where humans live and work and perceive the
visual world. In designing a luminous environment, for example,
nanofilms or nanocoatings with specially designed optical properties can be expected to find wide use. Nano-based approaches
already form the basis for many now common smart technologies
for controlling lighting and the visual environment, including electrochromic glasses.
Fundamentals of light
As we discussed in Section 4.7, light is a form of electromagnetic
(interacting electric and magnetic fields) radiant energy that propagates through space in a way that can be characterized as waves. Electromagnetic radiation can be defined in terms of its wavelength or
frequency (reciprocals of one another). The electromagnetic spectrum
is very large ranging, from wavelengths at the kilometer scale to those
near the atomic scale. Many devices that could potentially benefit
from the use of nanotechnologies operate in different zones of this
spectrum. Radio waves, for example, are quite long. Devices relying
on infrared radiation involve much shorter wavelengths. Ultraviolet
rays and X-rays are considerably shorter. The portion of the spectrum
that is actually visible to humans is quite narrow and lies between
infrared and ultraviolet rays. Within the narrow “visible spectrum,”
each wavelength corresponds to a particular color that is perceived
by humans. The basic colors in the visible spectrum are red, orange,
yellow, green, blue, indigo, and violet. In this continuous spectrum,
red wavelengths of light are the longest and the violet wavelengths
of light are the shortest. When all these wavelengths are present at
the same time, “white light” is perceived. White is not a color but a
combination of all perceptible colors. Black is not a color either, but
rather the absence of any wavelengths within the visible spectrum.
Typical light waves oscillate in three dimensions. Under certain conditions, there can be preferred directions to the oscillations wherein
336
Yet it is not only in the domain of light-emission technologies that
benefits can accrue from the use of nanotechnologies. In our living
and work environments, for example, the effect of a light source is
highly influenced by the nature of its surroundings, including the
optical properties, such as reflectance or refractive properties, of the
materials that define the environments. The way humans perceive
light—how it affects them or the information they receive from
it—are all affected by interactions between the nature of the light
source and that of the surrounding material environment. Hence
we look here at the more general qualities of what is termed the
luminous environment where humans live and work and perceive the
visual world. In designing a luminous environment, for example,
nanofilms or nanocoatings with specially designed optical properties can be expected to find wide use. Nano-based approaches
already form the basis for many now common smart technologies
for controlling lighting and the visual environment, including electrochromic glasses.
Fundamentals of light
As we discussed in Section 4.7, light is a form of electromagnetic
(interacting electric and magnetic fields) radiant energy that propagates through space in a way that can be characterized as waves. Electromagnetic radiation can be defined in terms of its wavelength or
frequency (reciprocals of one another). The electromagnetic spectrum
is very large ranging, from wavelengths at the kilometer scale to those
near the atomic scale. Many devices that could potentially benefit
from the use of nanotechnologies operate in different zones of this
spectrum. Radio waves, for example, are quite long. Devices relying
on infrared radiation involve much shorter wavelengths. Ultraviolet
rays and X-rays are considerably shorter. The portion of the spectrum
that is actually visible to humans is quite narrow and lies between
infrared and ultraviolet rays. Within the narrow “visible spectrum,”
each wavelength corresponds to a particular color that is perceived
by humans. The basic colors in the visible spectrum are red, orange,
yellow, green, blue, indigo, and violet. In this continuous spectrum,
red wavelengths of light are the longest and the violet wavelengths
of light are the shortest. When all these wavelengths are present at
the same time, “white light” is perceived. White is not a color but a
combination of all perceptible colors. Black is not a color either, but
rather the absence of any wavelengths within the visible spectrum.
Typical light waves oscillate in three dimensions. Under certain conditions, there can be preferred directions to the oscillations wherein