Worlds of David Darling > Children's
Encyclopedia of Science > Computers of the Future > 3. Chips, Changes,
COMPUTERS OF THE FUTURE:
Intelligent Machines and Virtual Reality
a book in the Beyond 2000 series by David Darling
3. Chips, Changes, and Challenges
According to one estimate,
if cars had progressed as much as computers over the past 40 years, then
a car today would cost less than 15 cents, go over 1 million miles on a
gallon of gas, and travel at five times the speed of sound. The astonishing
rate of development of computer machinery and programming seems likely to
continue in the years to come. As a rough guide, we can expect the processing
speed and storage capacity of computers to double about every 18 months.
Making Light Work
Just one thin CD-ROM can hold all the information in a 20-volume encyclopedia,
or about 600 million bytes. But personal computers have hard disk drives
that dwarf this capacity and future machines will be able to hold even more.
Researchers in the United States and other countries are investigating new
forms of computer storage that improve upon the flat, or two-dimensional,
disks used at present. The researchers are developing ways to write and
read data in three dimensions by building up and decoding layer upon layer
of information in a solid block of material.
One promising approach to 3-D storage utilizes a cube of special light-sensitive
chemical called spirobenzopyran (SP). The crystal structure of thus substance
changes when it is hit simultaneously by beams of green and infrared (IR)
light. The green and IR light encode data in the cube, just as information
in Morse Code is encoded by a series of dots and dashes. However, in the
case of the 3-D technology, the dots and dashes are instead points where
the crystal structure of SP has been changed and points where it has been
Here's how the process works. Points within a block of SP that have been
altered by a combination of green and infrared rays will glow afterward
when they are exposed to green light. The glowing points represent locations
of information that have been previously written in the cube. A special
scanner is then used to detect the glowing points and read the information
in the cube. A cube of SP about the size of five audio-cassette boxes stacked
together, could hold as much information as 250 CD-ROMs and could be read
1,000 times faster.
Scientists are also exploring the possibility of substituting beams of light
for pulses of electricity to operate computer processors. These so-called
OPTICAL COMPUTERS (see box below) would operate many times faster than machines
built with ordinary chips. Optical computers would also eliminate difficult
technical problems that arise when tiny electrical devices are crammed very
close together as is the case with conventional computers.
The most powerful computers in the world are called supercomputers. Among
other things, these computers are used to design new cars and planes, to
forecast the weather days in advance, to help geologists find out where
to drill for new deposits of oil and natural gas, and to rapidly produce
high-quality pictures that include shading and texture. Supercomputers can
do the trillions of calculations needed to show what happens when a giant
star explodes or when tiny particles of matter crash into one another at
|A Cray X-MP/48 supercomputer at CERN, the
European center for particle physics research near Geneva, Switzerland,
|A computer simulation carried out on a supercomputer
shows how air flows around the space shuttle
Supercomputers are also used as mathematical laboratories where, instead
of real experiments, scientists carry out SIMULATIONS. For instance, engineers
at an automobile company might use a supercomputer to calculate what would
happen if a new type of car smashed into a wall at 30 miles per hour. Would
the car be able to protect the passengers from serious injury? Smashing
up real cars is expensive, whereas performing a series of crash simulations
on a computer can be done quickly and at relatively low cost.
In 2009 the fastest computer in the world, called Sequoia, could do up to
20 quadrillion calculations a second. Incredibly quick as this is, researchers
in many different fields of science and technology are faced with tasks
that require even speedier machines. Such tasks may involve carrying out
extremely complex sequences of calculations of calculations creating highly
involved simulations, or making accurate predictions about natural phenomena.
One way to make computers that work faster is to use faster components.
Speedier chips and speedier ways of moving information from one part of
a computer to another are constantly being developed.
Another approach to making faster computers is to build them so that they
can carry out many calculations at once. This involves using not just one
central processor but a group of processors that work together on a task.
Such an approach to building computers is called PARALLEL PROCESSING. In
theory, a parallel processor made from hundreds or thousands of separate
processing elements ought to be very fast indeed. But how quick it proves
to be in practice depends on whether it is given software that can keep
its many processors busy all the time. Developing better programs for parallel
processing is an important challenge for those who make and use supercomputers.
|Inside Optical Computers
Today, bright flashes of laser light can be sent hundreds of miles
along fine strands of specially made glass or plastic called OPTICAL
FIBERS. In the future, these fibers will be used to replace ordinary
wires in a revolutionary type of computer – the optical computer.
Instead of transistors, such a computer will have TRANSPHASORS. These
are switches that are activated by beams of light rather than by pulses
of electricity. Experimental transphasors have already been made to
flip on and off 1,000 times faster than any present-day switch. And
unlike transistors, transphasors can be built to handle several incoming
signals at once. Beams of light can crisscross and overlap without
becoming mixed up, whereas crossed electric currents would get hopelessly
confused. Optical computers will have other advantages, too. Many
instructions or pieces of data could be sent through such a computer
along one optical fiber. Also, the arrangement of connections and
switches would not have to be flat, as in an electronic computer.
It could be placed in any direction in space, allowing totally new
designs in information processing.
|A technician at the University of Colorado
works on the first optical computer capable of storing and manipulating
data and instructions as pulses of light. The computer was first
demonstrated in January 1993.
When Computers Go Wrong
Machines can be very useful – until they break down. And in the case
of computers, this can lead to serious consequences. For as we come to depend
increasingly on computers, we could be left helpless when something goes
very wrong with them. Even a small defect in a widely used program or piece
of hardware could cause many computers around the world to start making
mistakes. For instance, if one such mistake were to occur in a computer
that helped fly airplanes, the result could be disastrous.
Faulty chips pose a particularly serious threat. Man new computers, which
may look different from the outside, contain the same type of processing
chips inside. If a tiny error is made in the design of such a chip and the
error goes undetected by the manufacturer, it can cause problems in a very
large number of computers.
In 1994, a powerful new chip, 5 million copies of which had been put inside
computers, was found to contain a design flaw. People discovered that it
made mistakes when carrying out certain kinds of long division. In most
everyday tasks that were performed by the computers, the problem did not
show up. But researchers who had used computers that contained the flawed
chip to do long, complex calculations realized that there work might have
been badly affected. Among those most concerned were scientists and engineers
at NASA's Lyndon B. Johnson Space Center, in Houston, Texas. They had relied
on ten computers with the defective chip to carry out important stress calculations
and flight simulations on the space shuttle. After finding out about the
chip problem, NASA scientists could no longer trust the results that had
taken months to obtain. They had to repeat many of the calculations on different
computers, thus wasting a great deal of time and money.
In the future, as everyone from surgeons to astronauts comes to depend more
and more on computers, the issue of faulty hardware and software will grow
in importance. More reliable ways of testing new chips and programs will
become essential if expensive projects and even people's lives are not to
be put at risk.