'''Editor's note:''' Technologies like
trip hammers exist that can do physical labor better and faster. Soon, technologies will exist that can help people do intellectual labor better and faster.
Introduction: Many scientists, especially physicists, obtained new duties during
World War II. Now, after the war, they need new peaceful duties.
Section 1: Scientific knowledge has grown considerably, but the way we manage knowledge has remained the same for centuries. We are no longer able to keep up and find relevant information in the flood of information.
Leibniz's
computer and
Charles Babbage's
computer were both failures because technologies of their times could not produce them cheaply and precisely, but now we have enough technology.
Section 2: Science should not only be a vast store of knowledge, but also be frequently consulted and enhanced. Two kinds of technologies can help: analog information on microfilms, and digital information encoded by electric signals. While they are different, both kinds would be vastly cheaper than traditional printed media. With
instant photography and
microfilm, it will be cheap to copy and transmit analog information. Microfilm could shrink books and other paper-publications by a linear factor of 100x, or an area factor of 10000x. A library of 1 million books would occupy the volume of 100 books, which can fit on a bookshelf. All the world's books can fit inside a
moving van. Production and transmission would cost pennies. A possible future device would be a walnut-sized camera strapped to the head of the wearer that can take a photo at the squeeze of a hand, and develop it. The photos can be taken out at the end of a day for further processing. (Illustrated in the header image.) Bush goes into some technical details about instant photography and electric fax machines. In his days,
wet photography was the most common, yet it takes a long time and is hard to shrink into a small camera. However,
whiteprint technology might be miniaturized, leading to miniature dry photography. Printed material could be transmitted cheaply by digital signals, as demonstrated by
electric fax machines. The sending side uses
photocells to convert images to electric signals, and on the receiving side,
electric printers convert the electric signal into electric sparks hitting iodine-impregnated paper, turning it black.
Section 3: Not only will it be cheap to transmit and copy digital material, it will also be cheap to convert printed material into digital form. Language is interconvertible with digital signals, as shown by three technologies: • The
Voder can turn digital signals to speech. • The
Vocoder can turn speech to digital signals. • The
stenotype can turn speech or text to digital signals. While currently Vocoders need human operators, a future Vocoder could
transcribe speech automatically. A future researcher could walk around, take photos with the head-mounted camera, and record sound and speech. The photos and the sounds would have timing information. At the end of the day, this timed record of the day can be processed and reviewed. To study
cosmic rays, physicists built
vacuum tubes that could count at 0.1 MHz. Future electronic computers could operate at least 100 times faster, at 10 MHz.
Herman Hollerith's
tabulating machine showed that simple machines programmed by
punched cards could be commercially valuable. Future computers could perform complex programs according to punched cards or microfilms.
Section 4: Most of the existing computing machines are
tabulating machines,
arithmetic machines. Some are more advanced, like
tide-predicting machines, and
machines for solving differential and integration equations. Future scientists will delegate even more advanced routine mathematics to machines, just as one would delegate the operation of a car to its engine. By delegating away more routines, scientists can perform creative, intuitive work.
Section 5: Scientists and other knowledge workers manipulate data and perform logical inferences. Any routine logical process that a worker performs repeatedly could be programmed into a machine. Normal or even mathematical language is too vague for programming. A "positional" logical language would be needed for entering information the machines. Not only will they be for entering information, machines will also help people find information. For example,
punched card sorters and
telephone exchanges are both search machines: the sorter can quickly produce a stack of cards listing, for example, all employees who live in
Trenton, New Jersey and know the
Spanish language, and a telephone exchange can quickly connect to the line specified by a number sequence. Bush proceeds to describe in detail a management system for a
department store, where a salesperson enters customer and product information, which a central machine uses to update inventory, credit sales, adjust accounts, and charge customers, using analog devices such as punched cards, dry photography, microfilms,
Valdemar Poulsen's
magnetic wire recorder, and so on.
Section 6: Traditional information systems, such as the
library classification system, are tree-like. At the top are the biggest classes, and each class can have subclasses, and so on. Each item belongs uniquely to a leaf on the tree of information. This is cumbersome, and the human mind does not operate that way, but operates by
association. In human thinking, one traces out a "trail" of information. This process can be augmented by the
memex. Like human memory, it retrieves information by association, not by going down a tree of classification. The memex is a machine for individual use, where they could store all their books, records, and communications. The memex looks like a desk. It contains a storage unit for microfilms, sufficient for an individual's lifetime. Microfilms can be bought like books and magazines. Letters, documents, and hand-drawn manuscripts can be
placed on a transparent plate that is then photographed and converted to microfilm. One can also manually type onto them with a keyboard. Typing on the keyboard, the user can find any microfilm by associative search. Pushing on levers allows users to flip through a microfilmed book, moving forward or backward at variable speeds. The user can open up several microfilms at once, then draw lines and commentaries between them using dry photography or by a
telautograph-like pen.
Section 7: The essence of memex is
associative indexing: the user can make any item associate with any other, so that pulling up the first item automatically pulls up the second. Associations can be chained, building a "trail". A trail can be named and later retrieved by typing on the keyboard. Any item can be a part of many trails. Associative indexing can be implemented by coded dots printed on the bottoms of microfilms, and an optical reader can read the printed code and electrically signal the memex to pull up the next item. Bush describes a
use scenario, where the user is studying why the
short Turkish bow was apparently superior to the
English longbow in
the Crusades. He searches through encyclopedias and textbooks, building a trail of connections. He also branches off another trail through textbooks and handbooks on elasticity. Later, in conversation with a friend about how people resist innovation, he brings up the trail again, and then copies the whole trail out to be installed into his friend's memex. There, the trail is joined into a more general trail about how people resist innovation.
Section 8: Bush envisions a future where memex machines are everywhere. There will be microfilmed encyclopedias with trails already installed. Lawyers, patent attorneys, and other knowledge workers will use the memex to store their associative trails accumulated over their professional life. There will be a new kind of job: "trail blazers", who find new and useful trails. Bush expect future technology to be superior than those described in the essay, but he keeps to only known technologies, instead of the possible unknown, to keep the idea of memex practical. More speculatively, since the human nervous system is electrical, future
human-machine interfaces could be purely electrical. ==Critical opinion==