Michael Jackson, pop music legend, dead at 50

. Michael Jackson, the show-stopping singer whose best-selling albums -- including "Off the Wall," "Thriller" and "Bad" -- and electrifying stage presence made him one of the most popular artists of all time, died Thursday, CNN has confirmed.

He was 50.

He collapsed at his residence in the Holmby Hills section of Los Angeles, California, about noon Pacific time, suffering cardiac arrest, according to brother Randy Jackson. He died at UCLA Medical Center.

Lt. Fred Corral of the Los Angeles County Coroner's Office said an autopsy would probably be done on the singer Friday, with results expected that afternoon.

"Michael Jackson made culture accept a person of color," the Rev. Al Sharpton said. "To say an 'icon' would only give these young people in Harlem a fraction of what he was. He was a historic figure that people will measure music and the industry by."

Jackson's blazing rise to stardom -- and later fall from grace -- is among the most startling of show business tales. The son of a steelworker, he rose to fame as the lead singer of the Jackson 5, a band he formed with his brothers in the late 1960s. By the late '70s, as a solo artist, he was topping the charts with cuts from "Off the Wall," including "Rock With You" and "Don't Stop 'Til You Get Enough."

In 1982, he released "Thriller," an album that eventually produced seven hit singles. An appearance the next year on a Motown Records 25th-anniversary special cemented his status as the biggest star in the country.

And then "Dangerous" was knocked out of its No. 1 spot on the album charts by Nirvana's "Nevermind," an occurrence noted for its symbolism by rock critics.

After that, more attention was paid to Jackson's private life than his music career, which faltered. A 1995 two-CD greatest hits, "HIStory," sold relatively poorly, given the huge expense of Jackson's recording contract: about 7 million copies, according to Recording Industry of America certifications.

A 2001 album of new material, "Invincible," did even worse.

In 2005, he went to trial on child-molestation charges. He was acquitted.

Legless frogs mystery solved

.Scientists think they have resolved one of the most controversial environmental issues of the past decade: the curious case of the missing frogs' legs.

Around the world, frogs are found with missing or misshaped limbs, a striking deformity that many researchers believe is caused by chemical pollution.

However, tests on frogs and toads have revealed a more natural, benign cause.

The deformed frogs are actually victims of the predatory habits of dragonfly nymphs, which eat the legs of tadpoles.

In the late 1980s and early 1990s, researchers started getting reports of numerous wild frogs or toads being found with extra legs or arms, or with limbs that were partly formed or missing completely.

The cause of these deformities soon became a hotly contested issue.

Some researchers believed they might be caused naturally, by predators or parasites.

Others thought that was highly unlikely, fearing that chemical pollution, or UV-B radiation caused by the thinning of the ozone layer, was triggering the deformations.

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"Deformed frogs became one of the most contentious environmental issues of all time, with the parasite researchers on one side, and the 'chemical company' as I call them, on the other," says Stanley Sessions, an amphibian specialist and professor of biology at Hartwick College, in Oneonta, New York.

"There was a veritable media firestorm, with millions of dollars of grant money at stake."

After a long period of research, Sessions and other researchers established that many amphibians with extra limbs were actually infected by small parasitic flatworms called Riberoria trematodes.

These creatures burrow into the hindquarters of tadpoles where they physically rearrange the limb bud cells and thereby interfere with limb development.

"But that was not end of the story," says Sessions.

"Frogs with extra limbs may have been the most dramatic-looking deformities, but they are by far the least common deformities found," he explains.

"The most commonly found deformities are frogs or toads found with missing or truncated limbs, and although parasites occasionally cause limblessness in a frog, these deformities are almost never associated with the trematode species known to cause extra limbs."

Ivory bird displays ancient skill

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A sculpted piece of mammoth ivory may be the earliest representation of a bird in the archaeological record.

The 30,000-year-old figurine, found at Hohle Fels Cave in Germany's Ach Valley, depicts what looks to be a diving cormorant with swept-back wings.

It was found with carvings of a similar style - one shaped like a horse's head; the other is half-animal, half-human.

Experts have told the journal Nature that the figurines are among the most exquisite examples of early human art.

It is not possible to say for sure which particular hominid species made the objects.

However, Professor Nicholas Conard, from the department of Early Prehistory and Quaternary Ecology, Tubingen University, who reports their discovery, says the sculptors were probably modern humans (Homo sapiens).

'Oldest musical instrument' found

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Scientists in Germany have published details of flutes dating back to the time that modern humans began colonising Europe, 35,000 years ago.

The flutes are the oldest musical instruments found to date.

The researchers say in the Journal Nature that music was widespread in pre-historic times.

Music, they suggest, may have been one of a suite of behaviours displayed by our own species which helped give them an edge over the Neanderthals.

The team from Tubingen University have published details of three flutes found in the Hohle Fels cavern in southwest Germany.

The cavern is already well known as a site for signs of early human efforts; in May, members of the same team unveiled a Hohle Fels find that could be the world's oldest Venus figure.

The most well-preserved of the flutes is made from a vulture's wing bone, measuring 20cm long with five finger holes and two "V"-shaped notches on one end of the instrument into which the researchers assume the player blew.

The archaeologists also found fragments of two other flutes carved from ivory that they believe was taken from the tusks of mammoths.

Creative origins

The find brings the total number of flutes discovered from this era to eight, four made from mammoth ivory and four made from bird bones.

According to Professor Nicholas Conard of Tubingen University, this suggests that the playing of music was common as far back as 40,000 years ago when modern humans spread across Europe.

"It's becoming increasingly clear that music was part of day-to-day life," he said.

"Music was used in many kinds of social contexts: possibly religious, possibly recreational - much like we use music today in many kinds of settings."

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The researchers also suggest that not only was music widespread much earlier than previously thought, but so was humanity's creative spirit.

Solar plane to make public debut

.Swiss adventurer Bertrand Picard is set to unveil a prototype of the solar-powered plane he hopes eventually to fly around the world.

The initial version, spanning 61m but weighing just 1,500kg, will undergo trials to prove it can fly at night.

Mr Picard, who made history by circling the globe non-stop in a balloon in 1999, says he wants to demonstrate the potential of renewable energies.

He expects to make a crossing of the Atlantic in 2012.

The flight would be a risky endeavour. Only now is solar and battery technology becoming mature enough to sustain flight through the night - and then only in unmanned planes.

But Picard's Solar Impulse team has invested tremendous energy - and no little money - in trying to find what they believe is a breakthrough design.

"I love this type of vision where you set the goal and then you try to find a way to reach it, because this is challenging," he told BBC News.

Testing programme

The HB-SIA has the look of a glider but is on the scale - in terms of its width - of a modern airliner.

The aeroplane incorporates composite materials to keep it extremely light and uses super-efficient solar cells, batteries, motors and propellers to get it through the dark hours.

Picard will begin testing with short runway flights in which the plane lifts just a few metres into the air.

As confidence in the machine develops, the team will move to a day-night circle. This has never been done before in a piloted solar-powered plane.

HB-SIA should be succeeded by HB-SIB. It is likely to be bigger, and will incorporate a pressurised capsule and better avionics.

It is probable that Picard will follow a route around the world in this aeroplane close to the path he took in the record-breaking Breitling Orbiter 3 balloon - going from the United Arab Emirates, to China, to Hawaii, across the southern US, southern Europe, and back to the UAE.

Measuring success

Although the vehicle is expected to be capable of flying non-stop around the globe, Picard will in fact make five long hops, sharing flying duties with project partner Andre Borschberg.

The aeroplane could do it theoretically non-stop - but not the pilot," said Picard.

"We should fly at roughly 25 knots and that would make it between 20 and 25 days to go around the world, which is too much for a pilot who has to steer the plane.

"In a balloon you can sleep, because it stays in the air even if you sleep. We believe the maximum for one pilot is five days."

The public unveiling on Friday of the HB-SIA is taking place at Dubendorf airfield near Zürich.

The real success for Solar Impulse would be to have enough millions of people following the project, being enthusiastic about it, and saying 'if they managed to do it around the world with renewable energies and energy savings, then we should be able to do it in our daily life'."

Windows 7 pricing gets unveiled

Microsoft will not be offering an upgrade version of Windows 7 in Europe.

In the past Microsoft has given people already using Windows a chance to upgrade to a new version when it becomes available.

While that option will be offered in the US, Microsoft said its efforts to comply with competition regulations meant it could not do so in Europe.

European regulators dismissed the claim, saying the move limited choices rather than opening them up.

No choice

Windows 7 is due to go on sale on 22 October around the world.

Anyone outside Europe buying a new PC between now and then - running Windows Vista Home Premium, Business or Ultimate - will get the chance to upgrade the operating system on it, at no cost, to Windows 7.

While Microsoft will not charge for the upgrade, some PC makers may impose a fee to ship disks with Windows 7 on them to customers.

The worldwide upgrade option programme is due to begin on 26 June.

Those who want to upgrade to Windows 7 on a older PC will pay a reduced price for the software. Stand alone versions of Windows 7, that can run on more than one PC, will also be available.

Microsoft said these upgrade options will not be available to Europeans.

"We will not be able to offer an upgrade product within Europe," said John Curran, Windows business lead at Microsoft UK, adding that only the full version of the software will be available to Europeans.

Microsoft will make an upgrade offer to buyers of new PCs but will send them a full version of the software rather than an upgrade version.

In Europe, the full version will be priced as if it were an upgrade version.