During the 1950s British scientists and engineers started to benefit from access to electronic computers. This enabled them to perform calculations and process data far faster than the teams of human computers, mainly women, who had previously done this work. Learning how to make the most effective use of this new technology, which was so much more than a superfast slide-rule, was a gradual process and it took time for them to appreciate how to exploit its potential to the full. With little commercial software available, most early adopters learned to program for themselves, however as systems became more sophisticated some worried that relying too heavily on computer models could undermine people's ability to think at a fundamental level about the processes being modelled. Incorporating computers into their work changedthe process of research and design for scientists and engineers across every discipline, transforming working practices and work places. Computers, from EDSAC onwards, have been used by Earth scientists to perform the calculations necessary in attempts to understand complex systems, whether sea waves, the Earth’s moving crust, volcanoes, or – as in climate models – the whole Earth system. They have also been used by scientists in more familiar ways: to word process documents (including scientific papers), to correspond with colleagues, to organise and display data and to produce presentation slides.