Shares in the electronics giant Apple fell by almost 5% within minutes of the eagerly anticipated launch of the company's latest smartphone. Analysts say investors and Apple fans had expected the new iPhone 4S to be a more radical improvement over its

predecessor

. The launch in California was the first product presentation led by Apple's new chief operating officer Tim Cook, who took over from the firm's

ailing

co-founder Steve Jobs, who's credited with driving much of Apple's innovation.

Forces of the

transitional

government in Libya have used tanks to pound the centre of the city of Sirte, the hometown of the fugitive Libyan leader Colonel Muammar Gaddafi. His supporters have been putting up stiff resistance for weeks. Residents have continued to flee the city, and humanitarian agencies say a full-scale assault would put many lives at risk.

This year's Nobel prize for physics has been won by American and Australian scientists for discovering that the universe is expanding faster than previously thought. The Nobel Committee said the team's findings came as a complete surprise, as one of the winners, Professor Brian Schmidt explains.

"The fact that we were getting an answer that was exactly the opposite of speeding up and that the universe should not be speeding up was pretty perplexing, and so it was a very bit of

trepidation

that we ended up telling our group and then eventually telling the world that we have this crazy result: the universe seems to be speeding up."