Astronomers have discovered what is believed to be the largest structure in the universe, more than 1.4 billion light-years across and containing seventy galactic superclusters. Our solar system is a mere two light-years across, and the entire Milky Way galaxy measures only 100,000 light-years.
The structure was dubbed Quipu (pronounced KEE-poo) after an Incan system of recording information using knotted cords, by the team at the Max Planck Institute for Physics in Munich, Germany, which discovered it.
To find Quipu, [astronomer Hans] Böhringer and his team analysed data from the German ROSAT X-ray satellite, looking at galaxy clusters several hundred million light years from Earth. They worked out which might be part of a larger structure using an algorithm that defines a maximum distance each cluster can be away from another before we consider them not linked. "This was a very apparent structure," says Böhringer. "It immediately catches the eye."
The discovery of large, clumped structures such as Quipu is a source of consternation for cosmologists as they violate the cosmological principle, which states that the universe is uniform and homogenous at large scales. Böhringer argues that viewing the universe at an even larger scale is necessary, at which point it once again appears homogenous. Cosmologists have yet to agree on a definition of the cosmological principle, so the correct scale is up for debate.
Previously: If you could see spacetime, it would look like this (video)
