South Africa’s leader says a pile of cash stashed in a sofa represents no wrongdoing. The outcome of an investigation could be the undoing of his presidency and his party. We examine Britain’s hydrogen-economy plans as representing the tradeoffs that many countries will face. And remembering Jay Pasachoff, the world’s foremost expert on and exponent of eclipses.Help us make the show better: take our listener survey at http://economist.com/intelligencesurveyFor full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer Hosted on Acast. See acast.com/privacy for more information.