In 1965 Gordon Moore, one of the founders of Intel Corporation, predicted that computer chip density (and thus computer processing power) would double every 18 months, and this prediction has proved remarkably accurate for the past 35 years. Chip designers can make chips smaller, or they can pack more electronic circuits onto the chips. Sometimes they do both. Both techniques are aimed at making chips faster and able to process more information in a shorter period of time.
Today, many of the most advanced chips are made with wires 0.18 micron wide. (A human hair is about 100 microns wide.) The next generation will be 0.15 micron wide. Most chips now contain millions of switches to process electronic impulses.
There have long been predictions that Moore’s Law, as Gordon Moore’s prediction is called, will end soon. That’s because the density of components and the extremely small width of the circuit wires on chips today are approaching the limit of what we can expect to get onto a silicon chip. Many experts feel that we’re likely to see the end of the silicon chip by the year 2012, perhaps earlier.
Because of this, there are many research projects going on now that are investigating different models of computer chips, including molecular chips, biological chips, and the processing of packets of light instead of electricity. It’s too early to tell which of these projects will be successful. But someday computers may become as small as molecules or bacteria.
Q: What are the two or three most common types of operating systems today?
A: The answer to this question depends on what kinds of computers you’re talking about. For personal computers, the leading operating system is some version of Microsoft Windows, such as Windows 95, Windows 98, Windows 2000, Windows Me, or Windows NT. Collectively, Microsoft’s family of operating systems reportedly runs about 95 percent of personal computers worldwide.
The second-place operating system for personal computers is Apple’s Macintosh OS, which runs between 3 and 4 percent of all personal computers.
In third place, according to StatMarket.com, is Microsoft’s WebTV service, which is not a PC operating system at all but can be considered a “personal” operating system in use by consumers at home. WebTV is a service and a set-top box that turns a television into a device for Web browsing and reading and sending e-mail. It is gradually being replaced by Microsoft’s new UltimateTV service, which adds new features to WebTV’s Internet access.
When you look at computers used as Internet servers—the computers that “serve” up Web pages, e-mail, graphics, and other files to Internet users—these statistics change. There are millions of server computers around the world, although far fewer than personal computers.
In the server market, about 60 percent of computers run on some version of the Unix operating system, including the free operating system known as Linux. A majority of Web servers, for example, use the free Web-hosting software program called Apache, which runs on Unix-based computers. In this market, Microsoft’s Windows NT or Windows 2000 are in second place.
Q: What are the most common computer-related health problems?
A: Computer-related health problems are almost never the sole product of the computer itself. Instead, they are usually caused by using a computer in a particular, unhealthy way, and most health problems can be avoided by altering computer-use habits.
For example, one health risk is repetitive stress injury (RSI), an array of different injuries usually to the hand, wrist, or forearm. These are often caused by accumulated stress related to the use of a keyboard and a mouse for long periods of time without a break. RSI injuries, if left untreated or allowed to worsen, can be very serious and debilitating. The worst version is called carpal tunnel syndrome, which can cause chronic pain in the wrist. In serious cases of carpal tunnel syndrome, the hand can become so weak that the person finds it difficult to hold a cup or a fork.
RSI injuries can be prevented by giving the hands and wrists a period of rest during the use of the computer and also by using special pads or supports that help reduce the strain. It’s also important that one’s posture in the chair is correct.
Other health risks related to computer use are problems such as blurry vision, headaches, or muscle aches in the neck and back. These can almost always be relieved by taking short breaks whenever you’re using the computer for a long period of time.
Q: How big was the biggest computer ever?
A: The answer to this question depends somewhat on how one defines a computer. Using the conventional definition of computer, meaning a single machine that processes the same computer program, the biggest computer was almost certainly the ENIAC, which was introduced to the public in 1946 at the University of Pennsylvania. (The name ENIAC is an acronym for electronic numerical integrator and computer.) ENIAC contained 18,000 vacuum tubes, 6,000 switches, 10,000 capacitors, 70,000 resistors, and 1,500 relays. It stood 3 m (10 ft) tall, occupied 200 sq m (1,800 sq ft), and weighed 30 tons. In other words, ENIAC covered the space of a modestly sized American house. A single computer chip in a modern personal computer has more than 60,000 times the computing power of ENIAC.
There’s another definition of a computer that would imply a different answer to the question. If we take into account the idea of distributed computing, which means that a single computer can be made up of many different and separate computers all linked together to accomplish some task, then we might view the entire global Internet as the largest computer ever. And it is getting bigger all the time. Some computer scientists are starting to think of the Internet in this way.