The acronym SEWTHA stands for the title of the book ‘Sustainable Energy: Without the Hot Air’, written by the late Sir David MacKay (above, on his bike), who was a physicist profoundly interested in the energy future of the world. In SEWTHA, he uses the physicist’s toolkit to analyze how much energy we use, how we obtain it, and, most importantly, how we can replace our current use of fossil fuels with sustainable energy sources.… Read the rest “The Great Common Sense of SEWTHA”