Net gains
An international, cross-disciplinary survey by Nature on page 314 reveals just how powerfully the Apollo programme motivated young people to become scientists 40 years ago — a fact today’s space scientists ignore at their peril (see pages 325 and 327). Yet other events in the summer of 1969 would lead to a far deeper empowerment of scientists — and, indeed, many others. Even as Apollo 11 was putting the first humans on the Moon, Ken Thompson at AT&T’s Bell Labs was working to get Space Travel, a computer game he’d written for a mainframe computer, to run on a new, smaller machine. That effort led him to join with Dennis Ritchie and others to write a new computer operating system, which they named Unix. The rest is history: Unix triggered a still-ongoing boom in scientific computing, set the pattern for the open-source software movement and, along with its descendants, laid the foundations for the Internet. Thompson wrote the first version of Unix in four weeks. It was initially for internal use only. But when the code was licensed for use outside of Bell Labs in the 1970s, it was quickly adopted by scientists worldwide. They embraced Unix for its power, simplicity and its ability to let machines interact with multiple users at once. No longer did they have to run stacks of punch cards through huge mainframes and wait hours or days to get their results on reams of fan-fold paper. Now they could just type and the machine would respond. Timing was also key to the success of Unix. It appeared just as the mainframes were being challenged by a new generation of smaller, cheaper, interactive ‘minicomputers’ suited to individual departments and research groups. The new operating system could easily be adapted to run on any of these machines. Perhaps most importantly, researchers loved the fact that Unix was written in C, a new programming language that made it easy for them to write and share applications — and even to refine the operating system itself. They lost no time in doing so, in a flurry of innovation that presaged the open-source movement. In the 1980s and 1990s, that openness fell victim to shortsighted commercial interests, when infighting among vendors of proprietary Unix machines produced incompatible versions of the operating system. This allowed Unix to be blindsided by an upstart called Microsoft, which quickly acquired a dominant position in the burgeoning microcomputer market with its own operating systems. Nonetheless, Unix’s future had been guaranteed in the late 1970s by the US Defense Advanced Research Projects Agency, which chose a version of the operating system developed at the University of California, Berkeley, as the basis for a number of its projects. And by funding Berkeley to include an implementation of the then-new TCP/IP protocols that underlay the Internet, the agency essentially made Unix Internet-ready. At the same time, the open-source movement became central to the Internet’s development, with the Unix clone Linux, written in 1991 by Finnish student Linus Torvalds, coming to dominate. Today, Linux or some other flavour of Unix runs most of the servers, routers and other elements of Internet infrastructure, as well as most mobile phones and GPS devices. And last week Google announced that it will use Linux as the base for its planned opensource ‘Chrome’ operating system. The difference between the development of Unix and the topdown, colossal science and engineering project that was Apollo could hardly have been greater. Yet both are examples of the power of joint efforts. Unix, like Apollo, has earned its place in history. ■