Benefits of a Computer Virus

In the wake of the Melissa virus, an increasing number of warnings are being made about the dark side of our technological revolution. Because of the widespread use of the Internet we are becoming uniquely vulnerable to these mysterious threats.

Nevertheless, computer viruses are pretty much as old as the computing networks that make them communicable and can teach us valuable lessons as well as threaten us with calamity.

Returning to the birthplace of the field -- Xerox's Palo Alto Research Center, the legendary Xerox PARC gave us not only the first personal computer, the first graphical user interface and the first laser printer, but the first virus. John Shoch, inventor of this new form of programming, created the dynamic, roaming program known as the "worm" that was designed not to destroy or damage computer systems but enhance them. Nevertheless, in 1978, Shoch's worm got loose in PARC's internal network, setting him and his colleagues on the first desperate virus chase.

Shoch was a PARC engineer working on his Stanford doctorate when he created the first worm. The program took its name from the "tapeworm," a program that appeared in John Brunner's "The Shockwave Rider," a popular science-fiction novel of the time, in which it is used by the hero to destroy a sinister computer network.

The PARC worm's purpose was at first to save Shoch hours of tedious scut work. Shoch's doctoral research was an analysis of the traffic patterns of PARC's Ethernet that linked 200 of its "Altos," personal computers invented in 1973. His idea was to arrange for about 100 of the machines to spew bits into the Ethernet simultaneously, then measure the ensuing electronic gridlock. Rather than loading the same program individually into every machine, he devised the worm to do the loading automatically by seeking out idle Altos computers and transmitting the test program by wire to those that signaled they were available.

The test proved successful and soon he turned his thoughts from communicating directly with each machine to instructing them to talk among themselves. What if, rather than loading the same program onto 100 machines from one central point, he gave each machine the ability to seek out others, and pass the program on from one to another? Shoch's brainstorm hinted at a method of compounding processor power that would one day find wide application in the field of supercomputers.

"In the middle of the night, such a program could mobilize hundreds of machines in one building," he wrote later. Before morning, as users arrived to reclaim their machines, the worm would retreat. After hibernating in a machine or two during the day, it would reemerge the next evening -- an image that led one of Shoch's colleagues to liken it less to a worm than to a vampire.

Shoch eventually was able to invest his worm with the ability to seek out idle Altos, boot up a host machine through the network and replicate by sending copies of itself from machine to machine, remaining in communication with its dispersed offspring.

Still, he was also well aware that a program capable of commandeering idle computers in their owners' absence would have to be stringently controlled. It was, for example, forbidden to access any Alto's disk drive -- a necessary precaution lest it inadvertently overwrite someone's work, which he knew would be viewed as "a profoundly antisocial act."

One night, however, something unexpectedly went wrong. Shoch and two colleagues had set a small worm loose in the PARC Ethernet to test a control function. Confident that their program was suitably innocuous, they left it running and went home.

At some point -- they never figured out exactly when and why -- the program became corrupted so badly it crashed its host computer. Sensing it had lost a segment, the control worm sent out a tendril to another idle Alto. That host crashed, and the next, and the next. For hours, the silent carnage spread through the building until scores of machines were disabled.

When morning came, dozens of PARC researchers arrived for work to discover their machines had crashed. At first this did not cause any alarm -- in those early years Altos frequently crashed for no reason. Soon, however, it became obvious that this was no random occurrence. For one thing, whenever anyone stepped away from an Alto for even a few minutes, it crashed again, seized by the still-insatiable worm.

Summoned to the lab, Shoch and his colleagues began pursuing the program through the network like exterminators chasing rats through a sewer. Eventually they had no choice but to eradicate it with a sort of software bomb -- a self-destruct command Shoch had preloaded as insurance against some unpredictable disaster.

To his relief, all worm activity ceased. That was the good news. The bad news was that the entire PARC Ethernet had been figuratively reduced to a smoking ruin. Scattered around the building were 100 dead Altos. The lesson to computer and network designers today is that rather than treating the worm as a menace, PARC learned from its experience and continued to develop the concept of a roving, self-executing program. The principle survives today -- "spiders," "bots" and all sorts of other programs designed to rove the Internet, collecting information on behalf of their users.

Author Unknown

The Computer Bug

In computer science, an error in software or hardware. In software, a bug is an error in coding or logic that causes a program to malfunction or to produce incorrect results. Minor bugs—for example, a cursor that does not behave as expected—can be inconvenient or frustrating, but not damaging to information. More severe bugs can cause a program to "hang" (stop responding to commands) and might leave the user with no alternative but to restart the program, losing whatever previous work had not been saved. In either case, the programmer must find and correct the error by the process known as debugging. Because of the potential risk to important data, commercial application programs are tested and debugged as completely as possible before release. Minor bugs found after the program becomes available are corrected in the next update; more severe bugs can sometimes be fixed with special software, called patches, that circumvents the problem or otherwise alleviates its effects. In hardware, a bug is a recurring physical problem that prevents a system or set of components from working together properly. The origin of the term reputedly goes back to the early days of computing, when a hardware problem in an electromechanical computer at Harvard University was traced to a moth caught between the contacts of a relay in the machine.

(Entomologists will undoubtedly be quick to note that a moth is not really a bug.)

The Benzene Ring

The chemist, Friedrich August Kekule (b. Sept. 7, 1829, Darmstadt, Hesse -- d. July 13, 1896, Bonn) laid the groundwork for the modern structural theory in organic chemistry. Intending to be an architect, he entered the University of Giessen but came under the influence of Justus von Liebig and switched to chemistry.

After receiving his doctorate (1852) he studied at Paris, where he met Charles-Frédéric Gerhardt, from whose type theory of organic structure Kekule developed his own ideas. He became a lecturer at the University of Heidelberg (1856) and professor of chemistry at Ghent, Belg. (1858). He moved to Bonn in 1865.

His early training in architecture may have helped him conceive his structural theories. In 1858 he showed that carbon is tetravalent and that its atoms can link together to form long chains. This idea, which opened the way to an understanding of aliphatic compounds, was announced almost simultaneously, but independently, by Archibald Scott Couper.

One night in 1865 Kekule dreamed of the benzene molecule as a snake biting its tail while in whirling motion. From that vision his concept of the six-carbon benzene ring was born, and the facts of organic chemistry known up to that time fell into place.

He also carried out valuable work on mercury fulminate, unsaturated acids, and thio acids and wrote a four-volume textbook of organic chemistry. When he was ennobled he added "von Stradonitz" to his name.

-- Encyclopedia Britannica On-Line, April, 1997

The Clock that Wakes You when You are Ready

ARE you a real grump in the mornings? Do you wake up every day feeling tired, embittered, aggrieved, and all too ready to hit the snooze button? If so, then a new alarm clock could be just for you.

The clock, called SleepSmart, measures your sleep cycle, and waits for you to be in your lightest phase of sleep before rousing you. Its makers say that it should ensure you wake up feeling refreshed every morning.

As you sleep you pass through a sequence of sleep states - light sleep, deep sleep and REM sleep - that repeats approximately every 90 minutes. The point in that cycle at which you wake can affect how you feel later, and may even have a greater impact than how long or little you have slept. Being roused during a light phase means you are more likely to wake up perky.

SleepSmart records the distinct pattern of brain waves produced during each phase of sleep, via a headband equipped with electrodes and a microprocessor. This measures electrical activity of the wearer's brain, in much the same way as EEG machines used for medical and research purposes, and communicates wirelessly with a clock unit near the bed. You program the clock with the latest time at which you want to be wakened, and it then duly wakes you during the last light sleep phase before that.

The concept was invented by a group of students at Brown University in Rhode Island after a friend complained of waking up groggy and performing poorly on a test. "As sleep-deprived people ourselves, we started thinking of what to do about it," says Eric Shashoua, a recent college graduate and now chief executive officer of Axon Sleep Research Laboratories, a company created by the students to develop their idea. With help from entrepreneurial grants and alumni investors, they have almost finished a prototype and plan to market the product by next year.

14 April 2005
New Scientist
Emily Singer

SleepSmart, Axon Sleep Research Laboratories

The History of Search Engines (before Google)

Although we credit Google, Yahoo, and other major search engines for giving us the system we use today to find information, the concept of hypertext came to life in 1945 when Vannaver Bush urged scientists to work together to build a body of knowledge for all mankind. He proposed the idea of a virtually limitless, fast, reliable, extensible, associative memory storage and retrieval system. In fact, a long list of great minds contributed to the development of the information system we use today:

Ted Nelson created Project Xanadu in 1960 and coined the term hypertext in 1963. His goal with Project Xanadu was to create a computer network with a simple user interface that solved many social problems like attribution. While Ted's project Xanadu, for reasons unknown, never really took off, much of the inspiration to create the WWW came from his work.

Theories of Indexing
George Salton was the father of modern search technology. He died in August of 1995. His teams at Harvard and Cornell developed the Saltons Magic Automatic Retriever of Text, otherwise known as the SMART informational retrieval system. It included important concepts like the vector space model, Inverse Document Frequency (IDF), Term Frequency (TF), term discrimination values, and relevancy feedback mechanisms. Search today is still based on his theories.

In 1990, Alan Emtage, a student at McGill University in Montreal, created Archie; the first search engine. It was invented to index FTP archives, allowing people to quickly access specific files. Archie users could use a variety of methods including e-mail queries, telneting directly to a server, and eventually through World Wide Web interfaces. Originally, it was to be named “archives” but was changed to “Archie” for short.

Archie gained such popularity that in 1991 Paul Linder and Mark P. McCahill created a text-based information browsing system that used a menu-driven interface to pull information from across the globe to the user's computer. Named for the Golden Gophers mascot at the University of Minnesota, Gopher tunnels through other Gophers located in computers around the world, arranging data in a series of menus, so that users can search for specific topics.

World Wide Web
Until 1991, the World Wide Web had not yet come into existence. The main method of sharing information was via FTP. Tim Berners-Lee wanted to join hypertext with the Internet and created the World Wide Web, for which he designed and built the first web browser and editor, called WorldWideWeb. He then created the first Web server called httpd, short for HyperText Transfer Protocol daemon.

The first Web site was built at: and put online on August 6, 1991. Tim Berners-Lee created the World Wide Web Consortium in 1994, and the Virtual Web library, which is the oldest catalogue of the web.

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