Astronomers have discovered the largest structure yet seen in
the universe, a clump of quasars so large that it would take
light 4 billion years to traverse its widest dimension. Light
from these quasars started its journey when the universe was
only 5 billion years old, the researchers say. Far larger than
previously discovered groups of quasars, the structure (artist's
depiction of a single quasar) is so large that it challenges
Albert Einstein's cosmological principle—the notion that the
universe, at large scales, looks the same no matter the
direction and locale from which you look. According to that
theory, the researchers say, the universe's large-scale
structures—in this case, clumps of objects such as
quasars—shouldn't be larger than 1.2 billion light-years across.
The elongated, newly discovered large quasar group (LQG) is, on
average, about 1.63 billion light-years across but in its
largest dimension is more than 4 billion light-years across, the
researchers report today in Monthly Notices of the Ro