In October 2009, at a technology symposium at the Embassy of Finland in Washington, New York Times reporter Steve Lohr asked Sir Tim Berners-Lee what he would have done differently when he created the World Wide Web, as Beet.TV recorded. You might expect the answer to be something about privacy, security or advertising. Instead, he picked two tiny characters: the double slash, //, that sits after “http:” in web addresses. Working in IT, I see those two slashes hundreds of times a day, and it had never occurred to me that they did not need to be there.
What Berners-Lee actually said
According to the New York Times report, quoted by Australian tech site iTnews, Berners-Lee explained that the double slash was a programming convention at the time he designed the system, but that it turned out not to be really necessary. He joked about all the paper and trees that could have been saved if people had not had to write or type those slashes over the years, not to mention the time spent typing them millions of times into browser address bars. He had even noticed radio presenters reading out web addresses and calling the slashes “backslash backslash”, which, as Fox News pointed out, is not even the right character.
Why the slashes are there at all
It helps to break a web address into its parts. Take https://theprodigious.com/what-is-a-rainbow/ as an example.
| Part | Example | What it does |
|---|---|---|
| Scheme | https | Tells the browser which method to use to fetch the page |
| Colon | : | Separates the scheme from the rest of the address |
| Double slash | // | The part Berners-Lee regrets |
| Domain | theprodigious.com | Identifies the website |
| Path | /what-is-a-rainbow/ | Identifies the page on that website |
Berners-Lee’s intention was to separate the protocol name, such as HTTP or FTP, from the rest of the address. But as he explained, only the colon was actually needed for that, according to Computing. The double slash was there because it was a common programming convention at the time, and once the web took off, it simply stuck. Had he left it out, every web address would have looked like https:theprodigious.com instead.
Web, not internet
One thing worth clearing up, because the original version of this post got it wrong: Tim Berners-Lee invented the World Wide Web, not the internet. The internet is the global network of connected computers, and it existed long before the web. Its roots go back to ARPANET in October 1969, and the TCP/IP protocols developed by Vint Cerf and Bob Kahn in the 1970s, which were adopted on 1 January 1983, as The Star’s timeline explains. The web is a system that runs on top of the internet: web pages, linked together, that you can open in a browser.
Berners-Lee came up with it while working at CERN, the European physics laboratory near Geneva. On 12 March 1989, he proposed a system for sharing information there. By December 1990, the first web server and the first web pages were up and running at CERN, and in 1991 the world’s first website, info.cern.ch, was made available more widely. As the British Council puts it, the internet already existed in 1989, and Berners-Lee’s idea was to combine it with domain names and hypertext into one system. That is the system that gave us the URL, and those two slashes.
A regret most of us no longer notice
In practice, the problem has largely solved itself. Most browsers now fill in the start of a web address for you, as iTnews noted back in 2009, and many hide it from view entirely, so most people type little more than the website’s name. The slashes are still there in the background, though, in every link we click, copy and share.
I like this story because it is such a human one. The man who designed one of the most important inventions of the past century, when asked about regrets, picked two keystrokes, and then calmly worked out the cost in paper and trees. It is also a reminder that small design decisions can last far longer than anyone expects; there is a similar story behind the name of another everyday technology in why Bluetooth is called Bluetooth. And if you are curious how a technology built without a central authority can work at all, my post on Bitcoin explained is another good example.
Sources
- Beet.TV: Web’s inventor Sir Tim Berners-Lee says the double slashes were unnecessary (2009)
- iTnews: Sorry about the “//”, says Tim Berners-Lee
- Computing: Berners-Lee laments lengthy URL decision
- Fox News: Internet’s inventor regrets the whole backslash thing
- The Star: A timeline of the internet
- British Council: The web at 30