Lecturas De Ingles

Computers
As the turn of the century fast approaches, we find that computers are playing a larger and larger role in our everyday lives. Computers operate telephone switching systems, bank machines, and instruments in our cars. Computers also provide us with entertainment and we use them for both business and personal reasons.
One of the reasons personal computers (PCs) are so versatile isbecause they can accept new programs (sets of instructions). Each new program allows a PC to perform a different task or operation. For example, one program lets the computer act like a word processor, another lets the same PC manage inventories, and still another transforms it into a virtual-reality video game.
The computers in use today are miniature models of the machines that once weighed 30 tonsand filled a warehouse back in the 1960s. Tiny silicon-wafer-sized integrated circuits, called chips, are the reason why a suit- pocket-size computer, that weighs only 3 pounds, can do as much as its older and obsolete distant cousin.

The average desktop PC can perform between 16 to 66 million operations per second, with some faster machines going to over 100 million. Along with this kind ofspeed and performance has come an entire new field of employment. Computer-related jobs are among the most rapidly growing employment fields in North America and the world. Computer specialists like systems analysts, programmers, and operators will be among the most sought-after employees.
While specialists will most likely work in an office environment, other computer jobs will be done from thecomfort of an employee's own home thanks to the computer's unique ability to link up and talk with other computers. Since the early 1980s governments, universities, businesses and research organizations have been forming large computer networks to exchange information. This network is called the Internet. People in "home offices" use the Internet to do their jobs from home.
Computer development isprogressing at a mind-boggling speed. Sophisticated supercomputers are now able to perform nearly 32 billion calculations per second and can store a billion characters in memory at one time. They can do in one hour what a PC would take 40 years to do! Supercomputers can do this because they use special circuitry that allows electrons to move at the speed of light.

The future of computerslooks as wide open as ever. Companies like Apple and Compaq are developing small, handheld personal digital assistants (PDAs) that let people handwrite information on a touch- sensitive screen that the PDA interprets and processes. Some researchers are working on the development of biochips: protein molecules squeezed between glass and metal. This type of computer would have a much greater storagecapacity than current computers.

Future models will also boast the ability to recognize the user's voice. Other models promise to adapt themselves to their user's personality and work habits to the point where the term personal computing will take on an entirely new meaning. These advances and others point to a global revolution in the way humans communicate and transfer information.

LasersLaser is short for "light amplification by stimulated emission of radiation." Gordon Gould, a physicist, invented the laser in 1957 and the first working model was built by Theodore Maiman in 1960. It is safe to say that the laser's inventors had no idea how many uses there would be for their invention.

The first laser worked like this: the opposite ends of a ruby rod were polished shiny like amirror. At one end of the rod there was a lens. The rod was full of atoms of gas. Then light from a flashing lamp entered the ruby and caused the atoms to move more rapidly. The atoms interacted with the light by bouncing light waves back and forth between the polished ends. The light bounced back and forth faster and faster until it burst through the lens as laser light. Unlike the light waves...