Fiber Optics- branch of physics based on the transmission of light through long strands of transparent material with a high refractive index. If light it              admitted at one end of the fiber, it can travel through the fiber extremely fast, with a very low loss, even if the fiber is curved.

                    -The principle on which this transmission of light depends is called total internal reflection. Light traveling inside the center of the fiber strikes the outside surface at an angle of incidence greater than the critical angle, so that all the light is reflected towards the inside of the fiber without loss

                    - Optical fibers are hair-thin strands of ultra pure glass , which is about 10 micrometers thick. A single pair of optical fibers can carry hundreds of thousands of two-way conversations at once. Many single glass fibers form the center of a fiber optic cable.

                    -Light travels along the fiber as the glass is transparent, but it has been designed so that any ray meeting the outer surface of the glass fiber is totally internally reflected back into the fiber, as the glass has a much higher refractive index than the surrounding air around the fiber. The critical angle traveling from glass to air is 42*, which is quite small. Therefore, any angle of incidence greater than this will produce total internal reflection, and as the fiber is very narrow, this angle is always achieved.

                    -The optical fiber communications network use lasers to generate a suitable and efficient light source as lasers can create very tightly focused pulses of light, which don't disperse or radiate away, as all the rays travel at the same frequency. If plain white light was used, the different frequencies of light would travel and reflect at slightly different speeds within the wire, and over a long distance, the signals would begin to overlap and lead to a distorted image or sound.

                    -Fiber Optics has a wide variety of uses, especially in telecommunication systems, and medical institutes. The simplest application of optical fibers is the transmission of light to and from locations otherwise hard to reach, for example, the bore of a dentist's drill. Image transmission by optical fibers is also widely used in medical instruments for viewing inside the human body, especially in childbirth; for laser surgery; in facsimile systems; and computer graphics.

1.The focal length of the eye is about 17 mm (2/3"). We see almost 180 degrees wide, 120 degrees high, in a goggle format.

2.If we can see 180 degrees wide with the whole retina and only 1.7 degrees in high definition (the fovea telescope - spot light), you might say that the eye has a 1.7 to 180 degree zoom ability. That's equivalent to a 8 mm to 800 mm lens on a still camera or a 100 to 1 zoom ratio. This all happens automatically without our thinking about it. What's missing are the frame lines that cameras, TVs, movie screens and pictures have.

3. A diaphragm to control the amount of light that gets through to the lens. This is the shutter in a camera, and the pupil, at the center of the iris, in the human eye.

1. Choose a scale to fit your paper.

2. Draw the first vector as an arrow with the correct direction and of the correct length.

3. Draw the second vector starting from the arrowhead of the first one.

4. The resultant is then the vector drawn from the tail of the first vector to the head of the last.

5. The magnitude can be determined from the length of its arrow using the scale.