City of Light: The Story of Fiber Optics

THE QUEST FOR REMOTE VIEWING 35
In practice, you need some refinements. If a bundle of fibers is to reproduce
an image, the fibers must be arranged in the same pattern on both ends. If
the fibers are not aligned, light collected from one spot on the picture ends
up somewhere else on the display end, scrambling the image.
The fibers also must be small, because the light passing through them is
homogenized. Look through a single long thin, bent rod or fiber that covers
a printed letter and you see not the black-and-white pattern of the letter, but
a gray spot that mixes the black and white. If you want to read the letter,
you have to cover it with many fibers, with each showing a dot representing
part of the letter. The thinner the fibers, the smaller the dots and the clearer
the image. Specialists in printing and imaging call this resolution and measure
it in dots per inch. Pack small dots tightly and you don’t notice that the
letters or pictures are made of dots.
The Problem of Remote Viewing
From the Victorian era into the early twentieth century, inventors took many
approaches to achieving what they called remote viewing. They began with
a naive optimism. Telegraphs had been sending messages for decades; Alexander
Graham Bell had launched the telephone era in 1876. Sending pictures
from one point to another seemed just another logical step.
Still pictures are much simpler to send than moving ones, particularly if
you write on treated paper or photographic film. The first facsimile machine
was tested in the 1840s, 2 although the image quality was awful. True remote
viewing of a constantly changing scene is a much bigger challenge. You need
a sensitive camera that responds quickly, a transmission medium to carry the
picture, and a screen that can display a changing image.
Ingenious inventors devised a host of schemes, quickly adapting the latest
scientific discoveries. They waxed enthusiastic over the 1870s discovery that
light made selenium conduct electricity better; the more light, the more readily
the material carried current. A single selenium cell could monitor changes
in a beam of light. A Boston inventor proposed building an array of selenium
cells to sense light intensity at different points on its surface. 3 He thought
electrical signals from the selenium cells could reproduce an image by controlling
brightness of an array of incandescent bulbs.
Such a system would be simple to build today, but it was beyond 1880
technology. Selenium cells and incandescent bulbs were new; assembling
them in arrays would have been difficult. Connecting them would have
required a complex tangle of wires—at least 10,000 to feed a display 100
bulbs wide and 100 high. Modern solid-state electronics can handle the problem
by combining many signals into one, but even the vacuum tube was
decades away in 1880. William Wheeler’s light pipes were practical in comparison.