Royalties on production discriminate against ageing mines, with high extraction costs.

ECONOMIST: The political dangers of taxing carbon and mining

She talks to Olympians and to open-water champions like Lynne Cox to find out why they live to swim, why swimming is man's most sensuous sport (because skin is his largest sensory organ) and why it keeps your arteries elastic, your joints supple, is good for your heart as well as your brain, and offers more than a cursory help in the fight against ageing.

ECONOMIST: Lynn Sherr��s new book offers all the skinny on dipping

As you know, migration is driven by demography, as dramatically rising numbers of young people in the developing world bump up against an ageing and shrinking developed world.

UN: Secretary-General

In March this year, he joined 94 other Labour rebels to vote against renewing the ageing Trident nuclear missile system.

BBC: RELATED BBC SITES

Regardless of the biochemical details, the most intriguing thing Dr Baker's result provides is a new way of thinking about how to slow the process of ageing and one that works with the grain of nature, rather than against it.

ECONOMIST: A way to counteract part of the process of growing old