Professor Dame Julia King, Baroness Brown of Cambridge, is an engineer whose fascination with metals, and skill for handling both research projects and people, has taken her from academia to industry to the House of Lords. She tells Jim Al-Khalili how the dressmaking skills she learnt from her mother as a child helped her to understand the composite structures used in wind turbines later in life. And how she designed metal alloys that are resistant to both large and small cracks. As the author of the UK government's Review of Low Carbon Cars in 2007, Julia set out a route to decarbonising a major segment of the transport sector within 25 years, making an important contribution to the UK's plans to try and achieve Net Zero. But achieving Net Zero is not enough. With demand for electricity set to double or treble by 2050, there’s an urgent need to radically reform our national infrastructure and guarantee supply. Julia became a cross-bench member of the House of Lords in 2015. She’s now chair of its Science and Technology Committee, holding the government to account on its promise to make the UK a science superpower.