Now and then, the universe presents us with enigmas that seem more like science fiction than science. And that’s exactly what happened with the discovery of a gigantic structure of galaxies, dubbed the Big Ring. We’re talking about billions of galaxies aligned, forming a near-perfect ring-shaped pattern, billions of light-years away from Earth.
The universe must answer: are cosmic giants breaking its own rules?
The Big Ring is a colossal cosmic superstructure. It stretches 1.3 billion light-years in diameter and about 4 billion light-years in circumference. To give you a better perspective, our galaxy, the Milky Way, measures about 100,000 light-years. In other words, the Big Ring is tens of thousands of times larger than our cosmic home.
This discovery was made by Alexia Lopez, a PhD student at the University of Central Lancashire (UCLan), who identified the structure by analyzing data from the Sloan Digital Sky Survey (SDSS). Instead of directly observing the light from these galaxies, she used an ingenious trick: measuring how these galaxies absorb the light from even more distant quasars, indirectly revealing their presence.
And here’s the point that bothers cosmologists: structures like this shouldn’t exist. This is because, according to accepted models, the upper limit for such formations would be about 1.2 billion light-years. In other words, the Big Ring not only exceeds this value, but also has an unexpected shape. After all, it’s not spherical, as one would expect from oscillations in the early universe, but rather a kind of spiral, almost like a slinky seen from the side.
“Neither of these two ultra-large structures is easy to explain in our current understanding of the universe. And their ultra-large sizes, distinctive shapes, and cosmological proximity must surely be telling us something important – but what exactly?”, said Alexia Lopez.
Cosmology faces a dilemma: ordered universe or impossible giants?
Since the Big Bang, we believe that the distribution of galaxies follows patterns left by Baryon Acoustic Oscillations (BAOs), waves that propagated through primordial plasma in the first 300,000 years of the universe. These waves left marks on the cosmic fabric, creating denser regions where galaxies and clusters formed. The problem is that the Big Ring doesn’t fit this narrative. This is because it is too large and its symmetry doesn’t match the spherical pattern that BAOs should generate.
And he’s not alone. The Big Ring is a “neighbor” to the Giant Arc, another superstructure discovered by Lopez in 2021, measuring 3.3 billion light-years across (which leads many to say it’s too large to exist). Both are just 12 degrees apart in the sky and existed at the same cosmic epoch, about 9.2 billion years ago. This raises the suspicion that they may be part of an even larger system, which would be even more difficult to explain. Other giant structures have been identified, such as the Sloan Great Wall (1.37 billion light-years), the South Pole Wall (1.4 billion), and even the Laniakea supercluster, home to the Milky Way, at a modest 520 million light-years. But none of them come close to the size and almost artistic symmetry of the Big Ring.
Science must choose: bold new physics or a broken cosmos?
If the Big Ring can’t be explained by accepted theories, what’s left? Some bold hypotheses are being considered:
Conformal Cyclic Cosmology.
Cosmic Strings.
Not stopping there, there’s also the possibility that the Big Ring and the Giant Arc are not two independent structures, but rather parts of a single colossal formation. If this is confirmed, the challenge to cosmology would be even more radical, requiring nothing less than new physics to be understood. This debate will continue for a long time, just as when NASA’s Hubble discovered we’d been wrong about Saturn since 1986.