After a 300-year absence, the Longitude Prize is back. The contest, which will reward a winning scientific idea with $10 million, is being organized by the charity Nesta, in partnership with the BBC.

The prize will be awarded to a revolutionary idea in one of six shortlisted categories. The British public is set to choose the favorite category on Thursday, May 22. The six potential categories are all significant problems besetting human civilization, and they are: antibiotic resistance, carbon-neutral flight, dementia care, food security, paralysis, and water security.

The first and only other Longitude Prize was offered by the British government in 1714, offering 20,000 pounds to anyone who could develop a technique for locating, or positioning, a ship. Latitude positioning wasn't so difficult; if you knew the location of the sun in relation to the horizon, as well as what day of the year it was, a good could navigator could figure out how far north or south of the equator a ship was. Longitude, or east-west positioning, was much more difficult. At least until John Harrison came along.

In 1756, nearly 50 years after the prize was announced, Harrison, a carpenter and self-taught clock-smith, was awarded the reward money for his maritime chronometer.

"What's really exciting about the Longitude Prize 300 years on in 2014 is that there might be another modern-day John Harrison somewhere out there," BBC director-general Tony Hall announced today, "someone who will be inspired to change our world fundamentally, and they may not even know that they're a scientist."

The new Longitude Prize won't give would-be scientists half a lifetime to develop their idea. After the category is announced in June, would-be scientists will have five years to develop their idea.

"This will be no easy ride," Athene Donald wrote in the Guardian. Donald, a physicist at Cambridge, is one several scientists who will serve on the Longitude Committee and decide the eventual winner. "If any of these problems could be solved straightforwardly, they already would have been."