Captured light from the dawn of time shows the universe is older than was thought – but only by 48 million years.
Scientists are scratching their heads over an imprint of radiation left behind by the Big Bang that gave birth to the cosmos.
As well as providing a more accurate age for the universe, at 13.82 billion years, it has revealed new mysteries and questions.
The image, looking surprisingly like a colourfully wrapped Easter egg, was produced by the European Space Agency’s Planck telescope which has been studying the Cosmic Microwave Background (CMB) for more than 15 months.
British scientists are playing a major role in the Planck mission.
The super-sensitive €600 million space telescope can detect tiny ripples in the CMB that represent the earliest seeds of stars and galaxies.
They date back to when the universe was just 380,000 years old, making the glow of the CMB the oldest light ever seen. At that time the cosmos consisted of a formless hot primordial soup of energetic particles.
The incredibly small temperature fluctuations uncovered by Planck correspond to regions that later gave rise to the structured universe we see today.
They appear to match variations predicted by ‘inflation’, a theory that says the universe briefly expanded faster than the speed of light an instant after the Big Bang. Inflation is vital to our current understanding of the universe.
“The sizes of these tiny ripples hold the key to what happened in that first trillionth of a trillionth of a second,” said Planck scientist Joanna Dunkley, from Oxford University.
“Planck has given us striking new evidence that indicates they were created during this incredibly fast expansion, just after the Big Bang.”
Evidence from Planck also provides a better idea of how the mass-energy of the universe is divided up into parts that are visible and hidden.
Normal matter that forms stars and galaxies contributes just 4.9 per cent, according to the findings.
Dark matter, whose nature is still unknown and can only be detected by its gravitational influence, makes up 26.8 per cent, a fifth more than was previously thought.
Mysterious dark energy, believed to be the driving force behind the expansion of the universe, accounts for around 69 per cent.
The new age of the universe was calculated from the rate at which it is expanding outwards, which turns out to be a little slower than previous estimates. Because of its high precision, the Planck telescope has also highlighted peculiar unexplained features that may have physicists scrawling on their blackboards.
One is that over large scales, the CMB fluctuations do not match those predicted by the Standard Model theory that describes the workings of the universe.
Another oddity is that opposite sides of the sky look slightly different in terms of average temperature, and a cold spot covering a patch of the CMB is much larger than expected. One possible explanation is that, on a larger scale than we can observe, the universe is not the same in all directions.
“Our ultimate goal would be to construct a new model that predicts the anomalies and links them together,” said George Efstathiou, another member of the team from Cambridge University. “But these are early days. So far, we don’t know whether this is possible and what type of new physics might be needed – and that’s exciting.”
John Womersley, chief executive of the Science and Technology Facilities Council, said: “Planck has given us an amazing picture of the very earliest moments of the universe. These results are the culmination of many years of work by UK scientists and engineers supported by STFC. This kind of project can sometimes seem expensive but the pay-off in science and technology more than justifies the investment we’ve made.”
Launched in 2009, Planck is over three times more sensitive than its predecessor, the WMAP satellite. Its high frequency microwave detector is cooled to just 0.1˚C above absolute zero, the coldest temperature possible.
That enables it to detect variations in the temperature of the CMB as small as a millionth of a degree.
Richard Davis, who led the University of Manchester’s Planck team, said: “The information extracted from Planck’s new map provides excellent confirmation of the standard model of cosmology with unprecedented accuracy and sets a new benchmark for our knowledge of the ingredients of the universe.
“But because the precision of Planck’s map is so high, it has also revealed some unexplained anomalies in the data that require further study. Among these interesting findings are fluctuations in the cosmic microwave background over large scales that do not match what the standard model of physics predicts, including an asymmetry in the average temperatures on opposite hemispheres of the skies.” (PA)
The oldest light in the universe: a handout image of the anisotropies of the Cosmic Microwave Background as observed by Planck, released by the European Space Agency.