Rock is a poor conductor of heat, so this wayward energy travels through it very slowly.

ECONOMIST: The hole story of global warming

Labour have criticised the government's sale of Northern Rock as a poor deal for taxpayers, saying it was sold off at a "fire sale" price.

BBC: Northern Rock: Labour hits out at 'fire sale' price

It also emerged that Sir John Gieve, the deputy governor in charge of financial stability, who came in for criticism for the central bank's poor response to the crisis at Northern Rock, will leave his job early, in 2009.

ECONOMIST: British banks

Gas does now contribute 35% to power generation, but rock-bottom prices and a sniffiness about gas as oil's poor relation mean that exploiting its bounty (Saudi Arabia apparently has the world's fifth-largest gas reserves) has proven hard.

ECONOMIST: Gulf states not only pump oil; they burn it, too

The debt-relief measure, championed by the White House, charity groups and religious and cultural figures from Pope John Paul II to singer Bono of the rock band U2, allows the United States to pay its share under the global Heavily Indebted Poor Countries (HIPC) initiative to forgive the debts of some 30 Third World countries.

CNN: Clinton to sign bill reducing Third World debt