How could a photograph like this have been taken?
The photograph was taken using flexible, transparent threads, or fibers, of glass. These are so thin that they can bend without breaking, like human hairs. Threads of glass like these are called optical fibers. If a strong light shines in at one end of an optical fiber, it will shine out at the other end, even if the fiber is several miles long and twisted up like wire! Light travels along the length of the thread by bouncing from side to side.
An instrument that uses optical fibers to look inside someone’s body is called an endoscope. It has two sets of optical fibers—one set carries light to the part of the body being examined, and the other set carries a picture of the area back to the doctor. The photograph of this baby was probably taken to make sure that the baby was developing properly.
Optical fibers are used to carry radio, telephone, television, and computer data.
The method of using optical fibers to carry images and messages is called fiber optics. The fibers are not only used in medicine, but also in communications. Some cable television companies use optical fibers instead of wires to carry sound and picture signals. These signals are changed into bursts, or pulses, of light. Optical fibers are also used by some telephone companies. They are lighter, cheaper, and easier to install than the normal copper cables.
When you speak into a telephone, the sound made by your voice is turned into electric signals which travel down the line. In a fiber optic system, these electric signals are changed again into pulses of laser light. These pulses travel at the speed of light along the fibers. They travel down the fiber until they reach the other end, where they are changed back into electric signals. The signals are then changed again into the sounds that you hear in your telephone earpiece.
