The Science Is Unsettled

 From Science News: "A massive cosmic ring may challenge a key assumption about the universe." A ring of dense matter spanning more than 3.3 billion light-years is posing a problem for the cosmological principle, which holds that the universe looks the same in all directions on large scales.

    That principle is “the second most fundamental assumption in the field,” after Einstein’s theory of general relativity, says mathematical physicist Eoin ÓColgáin of Atlantic Technological University in Ireland, who studies challenges to the cosmological principle but was not involved in the new work. Every theoretical model of the universe assumes that matter is evenly distributed when you look at large enough volumes of space. Without that assumption, ÓColgáin says, “all hell would break loose.”

    The giant ring joins a growing list of huge structures that shouldn’t exist if that assumption holds. It is apparently an extension of a previously reported “giant arc,” and encircles a smaller — but still huge — “big ring” of material.

    “They appear to present more of a challenge to the cosmological principle together now,” says Lopez, of the University of Central Lancashire in Preston, England. “Can we explain something like a ring and an arc together?”