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A spaceship that revealed the details of the hidden tapestry of the infantile cosmos had its last hurray.
Scientists unveiled the final result of Planck satellite from the European Space Agency, which observed the oldest light in the universe. microwave background – from 2009 to 2013. During his mission, the spacecraft provided new details of intricate patterns woven into this light, across the entire sky. Now, a collection of postmortem articles posted on July 17 on arXiv.org is the focus of the measurements, published in a series of studies beginning in 2010 ( SN Online: 7/5/10 ).
Since its inception, Planck has helped scientists to establish a detailed and coherent history of the youth of the universe, its life history and its current properties, taking into account the content of the universe. universe, its age and its speed. In addition, Planck has left physicists with few options other than accepting the harsh truth that we do not understand what constitutes the majority of the universe.
Before the spaceship. made its measurements, scientists had a theory of the composition of the universe: it is composed of an original cast of characters, including mysterious and unidentified dark energy and dark matter. Dark matter is considered a type of subatomic particle, until now only detectable by its gravitational effects on visible matter, while dark energy causes the accelerated expansion of the universe.
Now, this concept – as strange as it may sound – has Planck strongly confirmed, leaving no other theory that is close to explaining Planck's data. "There is no other player in town," says cosmologist Shaul Hanany of the University of Minnesota in Minneapolis. "And the fact that there is no other strong candidate is to a large extent a contribution from Planck." This means that dark matter and dark energy are likely to stay here. According to Planck's final tally, the matter and the energy of the universe are divided into about 68% dark energy, 27% dark matter and 5% normal matter, which includes everything what we know and love.
He knows that dark matter and dark energy are "should make everyone uncomfortable," says cosmologist Scott Dodelson of Carnegie Mellon University in Pittsburgh. But this image, for all its quirks, explains extremely well Planck's data, says. "We do not live on the backs of turtles," he says, referring to certain cosmic mythologies that suggested that the Earth rested on the shells of creatures.
Instead, scientists have staked their cosmology on Planck. Matching the cosmic microwave background across the sky to an unprecedented level of detail, Planck measured both the temperature of light and its polarization, the orientation of agitated electromagnetic waves. The observations have provided essential data mining, which allows scientists to catalog properties of & # 39; universe for better accuracy than ever before
" It remains the best overall determination of the large-scale features of the universe, "says Jan Tauber, astrophysicist and member of the Planck team of the European Center for Space research and space technology from ESA to Noordwijk.
Planck revealed that the universe was slightly older than expected ( SN: 20/04/13, p.5 ), helped to identify when the first stars appeared ( SN Online: 2/9/15 ) and how structures such as galaxies and galaxy clusters are formed Another claim to fame: Planck broke hopes that scientists had detected signs of inflation, a hypothetical period just after the birth of the universe.Planck showed that the vortices in the cosmic microwave background polarization, due to the originated at inflation, were caused by dust ( SN: 2/21/15, p.13 )
. ] The new result uses the same data as Pl The last result of anck, released in 2015 ( SN: 3/21/15, p.7 ). But this time, scientists have improved their badysis of these data. In previous studies, researchers were not fully convinced of their understanding of polarization data. Tauber says that both temperature and polarization are considered solid
. Scientists have used Planck's observations on the cosmic microwave background to estimate how quickly the universe is developing today. This number, however, does not agree with a measure of the rate of expansion made using distant exploding stars ( SN: 8/6/16, p.10 ]). The discrepancy could hint at the existence of a new subatomic particle or the possibility that dark energy varies with time. But measurement errors in one or two types of experiments might also be to blame.
"It's hard," says cosmologist Renee Hložek of the University of Toronto. "There is something interesting happening, and we must understand it." Before getting excited, scientists need to be sure that all aspects of the experiments are well understood, confirms Hložek, and confirm the results with other experiments.
By deactivating Planck in 2013, scientists are preparing for the next stage of cosmic microwave background space experiments. Plans are underway for possible future missions that, like Planck, would cover the entire sky. Hanany is studying the potential of a NASA mission called Probe of Inflation and Cosmic Origins, or PICO. Other proposed space missions, such as LiteBIRD and Cosmic Origins Explorer, are also being planned. And other terrestrial telescopes, which would map smaller slices of sky, are being prepared
Such efforts, scientists hope, could possibly provide evidence of an inflation that does not turn into dust .
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