Cosmic glow is map of early universe

 

Astronomers have peered billions of years back in time to make detailed maps of the early cosmos. They used a giant telescope near the South Pole to observe a faintly glowing echo of the young universe.

An international team jointly led by Professor Walter Gear of Cardiff University and Professor Sarah Church of America’s Stanford University has drawn up a picture of structure emerging in this so-called cosmic microwave background.

Their findings confirm that normal matter in the universe accounts for only a twentieth (five per cent) of what is there.

It means that an amazing 95 per cent of the universe must be formed of invisible dark matter and dark energy, as predicted in the standard cosmological model.

The team’s results are revealed in the November 1 issue of The Astrophysical Journal. They were achieved by measuring variations in the temperature of the background glow and how the light is polarized using the 2.6-meter QUaD telescope.

That told the astronomers where matter existed and how it was moving about when the universe was less than half a billion years old. Its age is now around 13.8 billion years. It follows other recent discoveries about the cosmos in its early days.

Professor Gear said: “Studying the CMB radiation has given us extremely precise pictures of the universe at just 400,000 years old. When we first started working on this project the polarization of the CMB hadn’t even been detected and we thought we might be able to find something wrong with the theory.

“The fact that these superb data fit the theory so beautifully is in many ways even more amazing. This reinforces the view that researchers are on the right track and need to learn more about the strange nature of dark energy and dark matter if we are to fully understand the workings of the universe.”

Picture: A representational “map” of the temperature and polarization of the cosmic microwave background and the 2.6-meter telescope that observed it. Credit: Cardiff University School of Physics and Astronomy.

• Discover space for yourself and do fun science with a telescope. Here is Skymania’s advice on how to choose a telescope. We also have a guide to the different types of telescope available.

 

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