Welcome to Recharge, a weekly newsletter full of stories that will energize your inner hellraiser. See more editions and sign up here. Pink Floyd guitarist David Gilmour, stirred by the message of 16-year-old climate activist Greta Thunberg, wanted to do something to improve the world. But what could he do? Last week, Gilmour auctioned off his guitars, including the black Fender Stratocaster that helped create Dark Side of the Moon and Shine On You Crazy Diamond.