The Ancient Greeks first argued the earth was round more than 2,000 years ago while Ferdinand Magellan proved it with the first successful circumnavigation in the 16th century.

Yet 500 years on, a growing number of conspiracy theorists are convinced that every single mainstream scientist since then has got it wrong. The planet, they insist, isn’t spherical at all. The earth, they maintain, is flat.

This weekend, more than 200 believers - among them an NHS manager and a special needs educational worker - attended Britain’s first ever Flat Earth Convention, held in a nondescript, three-star hotel in Birmingham.