New Scientist: THOMAS EDISON might have relished the irony. Just as his most famous legacy, the incandescent light bulb, heads for extinction, his other great passion, direct electric current, is set to boom. The bulb that has dominated lighting for more than a century is now a pariah in the era of climate change and banned in many countries. Meanwhile, direct current – defeated by alternating current in the race to capture the electricity market in the 1890s – could help us hold back global …