We’ve come to expect to be connected instantly to anywhere in the world and to have unlimited information at our fingertips. We shop online, stream music, download books and boxsets onto our electronic devices. We share videos of our pets just because we can. But how much time have you spent recently thinking about the remarkable feats of engineering that make all this possible? Polina Bayvel has been at the forefront of creating the optical fibre networks that are capable of transporting vast quantities of data from one place to another: linking continents via cables laid under oceans or enabling computer systems in data centres to share information. Without these high speed networks, ultra-fast high-capacity broadband will remain a dream. Polina tells Jim Al Khalili how she moved to the UK from the Soviet Union when she was 12 and worked in industry for many years, before deciding that she wanted to set up a lab to find out what optical fibres were capable of: just how much data could they transport, and how fast? Producer: Anna Buckley