JOVANA
Library Glossary Getting Started Three Levels Fields How it works Mission
Join the mission
Back to the library
資訊理論 / 計算機科學 1989

資訊管理:一份提案

提姆·柏內茲-李

他把超文本接上網際網路,給每份文件一個位址——全球資訊網。

Choose your version
In depth · the introduction

1989 年,一座物理實驗室裡,一份不動聲色的提案,只求一件不大的事,卻無意間,描述出了今天大半個世界賴以棲居的媒介。

把核心想法拆開看

提姆·柏內茲-李,在日內瓦近郊那座巨大的粒子物理實驗室 CERN 工作。那裡頭緒太多、人太多、變得太快,以至於整個地方,老是對自己的知識失去掌控——誰懂什麼,某樣東西寫在了哪裡。當時的歸檔系統太僵硬了:一棵嚴格的樹,把每份文件塞進唯一一個抽屜;而關鍵字清單又會失敗,因為沒有兩個人,會給同一樣東西,貼同一個標籤。

他的答案,是給資訊換一種形狀。別用樹,用一張網:讓任意一份文件,都能帶著連結,指向任意另一份文件,落在任意一台電腦上,沒有哪個中心,來裁定什麼才可以相連。要閱讀,你便跟隨連結。這一張相互連結的文件之網,就是我們今天所說的全球資訊網。

它從哪裡來

早在 1980 年,柏內茲-李就在 CERN 寫過一個私用的小程式,叫 ENQUIRE,能把關於人和專案的筆記連結起來——那是這想法的一縷端倪。1989 年 3 月,他把它正經寫成了《資訊管理:一份提案》。他的主管麥克·森德爾,在頂上潦草地寫下「含糊,但令人興奮……」,而最要緊的是——給了他放手一試的餘地。

他和一位同事,羅伯特·卡約,在 1990 年重訂了提案,並動手去造:第一個瀏覽器、第一個網頁伺服器,都在一台烏黑俐落的 NeXT 電腦上。第一個網頁,1991 年上了線。接著,1993 年,CERN 做了那件決定性的事——它把全球資訊網送了出去,任何人都能免費使用、在其上建造。正是那份開放,讓它鋪滿了整個世界,而非困守為一座實驗室的工具。

它為何重要

全球資訊網勝出,不是因為它的設計最豐富——別人有過更宏大的構想——而是因為它簡單、開放。任何人都能掛一個頁面;任何人都能連向任何人;無需許可、不要執照、不付費用。那道極低的門檻,讓千百萬人都能往裡添東西;而一樣人人都能添的東西,長得比任何一家公司所能掌控的,都要快。不出十年,它便成了人類發布與閱讀的尋常方式。

一個類比

把網際網路想成道路與郵政的網絡:線纜,以及給每一棟樓(每一台電腦)的一個位址。光靠它自己,不過是在機器間運包裹。而全球資訊網,是跑在其上的郵政服務——一套共用的方式,去為一封「信」(一個頁面)編址,無論它棲身誰的樓裡,都能把它取來,還能在信裡,塞進指向別處任何信件的指標。柏內茲-李沒有去鋪路(那是網際網路,出自 1974 年的瑟夫與卡恩);他發明的,是信,和信裡的連結。在下方,親手跟著幾條連結走走看。

一幅可互動的節點—連結圖,取自柏內茲-李提案中的十份文件,由他親筆標註的連結相連。你從「這份提案」出發;只有當前頁面射出的連結可點。點一下,便走過去。目的地帶著圓環;抵達時,部件把你的點擊數與最短的可能路線相比。

它在知識長河中的位置

全球資訊網,立在本館中兩個更早的想法之上。范內瓦·布希(1945)最先構想出連結——把任意兩份文件繫在一起,沿著軌跡走下去——而泰德·尼爾森,給它取名「超文本」。它又跑在瑟夫與卡恩(1974)所造的網際網路之上:後者給了每台機器一個位址,與一套傳遞封包的辦法。柏內茲-李把這兩者——連結,與網絡——接成了一套簡單、開放的系統。他造出的那張連結之圖,後來餵養了為它排序的搜尋引擎,也餵養了在它所承載的文本上訓練出來的 AI 語言模型。他也曾警告:開放的全球資訊網,已漂向少數幾個巨頭平台;他在努力,要把它推回那非中心化的根上。

The original document
Original source text
Tim Berners-Lee · CERN (ref. DD/OC) · March 1989; reissued May 1990
Abstract
This proposal concerns the management of general information about accelerators and experiments at CERN. It discusses the problems of loss of information about complex evolving systems and derives a solution based on a distributed hypertext system.
Losing information at CERN
If a CERN experiment were a static once-only development, all the information could be written in a big book. As it is, CERN is constantly changing as new ideas are produced, as new technology becomes available, and in order to get around unforeseen technical problems.
Over the two-year scale of a typical project, Berners-Lee argues, people arrive and leave, and the informal mesh of who-knows-what decays with them; the details end up either lost or locked in a single person's head. A laboratory of thousands needs its records to outlive the people who made them.
Why hierarchies and keywords fail
He examines the two filing methods then in use — tree-like hierarchies (as in CERN's own CERNDOC, or a computer's filesystem) and keyword indexes (as in VAX/NOTES). A tree forces every item into a single branch, so a fact that belongs in two places can be filed in only one; keyword systems fail because, as he puts it, two people scarcely ever choose the same word for the same thing.
A solution: linked information
A 'web' of notes with links (like references) between them is far more useful than a fixed hierarchical system.
Information becomes a graph of nodes — documents — joined by typed links: 'describes', 'includes', 'refers to', 'wrote'. No node is the centre; a link need not respect any hierarchy; anyone may add a link from anything to anything. The proposal's hand-drawn diagram shows exactly this tangle of boxes and labelled arrows, with ENQUIRE — his own 1980 program — sitting among them.
What was proposed
Berners-Lee asks CERN to build a distributed hypertext system: documents held on many networked machines, a program (a browser) to display a document and follow its links to wherever the target lives, and a universal scheme to address any document on any computer. It must be non-centralised and able to wrap existing systems, so it can be adopted piece by piece. Reissued in May 1990 — co-written with Robert Cailliau as 'WorldWideWeb: Proposal for a HyperText Project' — it led to the first browser and server on a NeXT machine; his manager Mike Sendall famously pencilled 'Vague but exciting…' on the cover and let it proceed.
[ … ]
CERN · March 1989