New knowledge drives progress. For centuries Britain often led the way. Thomas Newcomen and James Watt created the steam engine. Edward Jenner pioneered the vaccine. Ada Lovelace wrote the first computer program. Today, claims of Britain being world-beating can sound desperate, as it struggles to convince even its own firms that prospects are anything but gloomy. Rumours of AstraZeneca, a pharma giant, moving its listing to New York don’t help.