The Modern Mythos of the Eridanus Supervoid

Deep space astrophotograph of galactic star clusters and nebulae

Could the Eridanus supervoid suggest evidence for the multiverse theory?
(Image credit: Bigstock/maximusnd)

What is the Eridanus Supervoid?

It’s the largest known structure in the universe. It baffles cosmologists and catches the imagination of quantum physicists. It defies known patterns and statistical probability. It may be the point at which another universe in the multiverse bumped into our own.

And it’s a giant stretch of nothing.

The Eridanus supervoid was discovered back in 2004, as scientists scanned the patterns of the cosmic microwave background (CMB) left over from the Big Bang. As they looked at the Eridanus constellation, they found a spot that was both colder than it should have been - and larger than any model could predict.

Constellation Eridanus in Ancient Mythologies

The Eridanus constellation has held a special spot in the consciousness of humanity since ancient times. As a constellation in the southern hemisphere, it was often considered to be a representation of some important rivers like the Tigris, Euphrates, Rhine, and Nile, both because of its trail-like shape and because it was the constellation that stayed longest in the sky.

The Greek myth surrounding it tells of Phaeton, the son of the sun god Helios, who begged his father to let him drive the chariot which pulled the sun across the sky. He got his wish, but the horses were so strong that they overpowered him, driving the sun too close to the earth and the heavens in turns. According to Greek myth, the Eridanus constellation is therefore the trail of Phaeton as he fell from the sky, struck down by Zeus in order to prevent Phaeton from destroying everything.

The Eridanus constellation is starting to hold a similarly precious place in the modern imagination. Voids are everywhere in our universe, but the term is a bit misleading, as there’s very little truly “empty space” out there--just less dense patches of matter. While the Eridanus supervoid has about 10% of the matter found in the rest of the universe, this lack of matter doesn’t account for the striking temperature difference, nor does it explain why the empty space is so large.

Why is the Supervoid so Massive?

Scientists are partially puzzled because of just how cold it is. Cosmology’s standard model of heat distribution predicts relatively even heat everywhere, but a belt of warmer temperatures runs along the line of the southern hemisphere, and just beyond it lays the abnormally-cold Eridanus supervoid. No standard models explain how or why that area of the universe is the coldest we’ve found. It just is.

Even more scientists are flummoxed as to why the supervoid is so big. Most voids were formed during the Big Bang and its immediate aftermath because of quantum fluctuations, but the sheer size of the Eridanus supervoid (1.8 billion light years across, in fact) makes such an explanation insensible in this case.

Instead, we are left to wonder.

Outer space stars and blue nebulae

Some scientists think that the supervoid could possibly be a point at which another universe came into contact with our own.
(Image credit: Bigstock/clearviewstock)

Fingerprint of a Parallel Universe?

Quantum physicists, string theorists, and supporters of the multiverse theory have proposed that the Eridanus supervoid is so cold and so empty because it could possibly be a point at which another universe in the multiverse touched ours. String theory suggests that there are more than 10,500 other universes along with ours, connected by vibrating cosmic strings.

The Big Bang, in such a theory, might have been caused by a wormhole which connected another universe to ours for a time and funneled matter from that universe to ours. The Eridanus supervoid might have been another such wormhole site, though one that went the other way around, a brief channeling of matter from our universe to another. That quantum entanglement lasted until our universe was separated by cosmic expansion.

Does the Eridanus supervoid actually suggest evidence of a multiverse? Maybe someday we'll find out. Until then, it's interesting to think that a constellation that held such importance in ancient mythology might actually represent incredible future importance among the scientific community in our quest for understanding reality.