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Satellite maps oldest light in the Universe

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(Globalpost/GlobalPost)

A new, detailed map of the most ancient light in the cosmos has revealed our Universe to be about 80 million years older than thought, the European Space Agency (ESA) said Thursday.

The 50-million pixel, all-sky image of radiation left over from the Big Bang was compiled from data gathered by ESA's Planck satellite, launched four years ago.

"This is a giant leap in our understanding of the origins of the Universe," the agency's director general Jean-Jacques Dordain told a press conference unveiling the data in Paris.

"This image is the closest one yet of the Big Bang. You are looking 13.8 billion years ago."

The data boosted our knowledge of the creation and subsequent expansion of the Universe by twentyfold, added Dordain.

The oval-shaped map dotted with pixels in blue and brown representing temperature fluctuations, adds an edge of precision to many existing cosmological theories -- but may shed doubt on others.

It depicts Cosmic Microwave Background -- relic radiation released about 380,000 years after the Big Bang, as the early Universe started cooling down.

The data shows the Universe to be expanding at a slower rate than previously thought, which required adjusting its age to 13.82 billion years.

It also revealed that "normal matter" which makes up human beings, planets, stars and galaxies, comprised 4.9 percent of the Universe -- up from 4.5 percent previously measured.

Dark matter, a mysterious substance thus far only perceived through its gravitational pull, makes up a fifth more than thought -- 26.8 percent in total.

And dark energy, an unexplained force thought responsible for accelerating the expansion of the Universe, accounts for the rest -- 68.3 percent, down from 72.8 percent.

"We've discovered a fundamental truth about the universe,"said George Efstathiou, director of the Kavli Institute for Cosmology at the University of Cambridge.

"One of our achievements is that there's less stuff that we don't understand, by a tiny amount," -- referring to dark energy and dark matter.

"But we still have a major problem in cosmology, because we don't understand the major constituents of the Universe."

The Planck data threw up a few questions which the cosmologist said may require "new physics" to explain.

Among them, it seems to challenge several theories on "inflation" -- a brief period directly after the Big Bang in which the Universe was thought to have expanded at a faster rate than the speed of light.

Direcly after the Big Bang, scientists say the Universe was a "hot, dense soup" of protons, electrons and photons at about 2,700 degrees Celsius (4,892 degrees Fahrenheit).

As cooling started, the protons and electrons fused to form hydrogen, and photons or light particles were set free.

As the Universe expanded, these light waves stretched out into shorter microwave wavelengths, reaching a temperature today of just 2.7 degrees above absolute zero -- minus 273.15 C (minus 459.67 F).

"The conclusion is that our Universe is odd," said Efstathiou, who likened the Planck map to a "dirty rugby ball".

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http://www.globalpost.com/dispatch/news/afp/130321/satellite-maps-oldest-light-the-universe