Lewis Andrews

Although the cosmos has endless wonders that light up the night sky, there are sections where it seems to be empty. Most of the cosmos is populated by them. These are the ‘Voids’. Immense patches of near nothingness. Let’s zoom out a little from our galaxy; we zoom out to see our local group of galaxies; zoom out a little further, and we can see the Virgo Supercluster 100 million light years across in a sort of wall-like shape. Here we come to the edge of a true monster, the Local Void. 200 Million Light-years across, it’s a giant empty bubble of darkness. So large that if you filled it with light, it would cover 40% of the night sky seen on Earth.

 

These ‘Voids’ are everywhere amongst galaxy clusters around their edges. One of the most well-known, the ‘Boötes Supervoid’, is a 300-million-light-year-wide giant of absolute blackness. If you put yourself in the centre, you would not be able to orient yourself. No up, down, left or right. No motion. No sign of the universe existing. An inescapable prison of complete darkness. Or are they? A very rare kind of galaxy resides here at the tips of very thin filaments of dark matter: ‘Void Galaxies’. Much smaller than the galaxies we are used to seeing, they appear blue and are full of gas, birthing new stars at a much calmer rate than in other galaxies. They are, as a result, possibly the last place of refuge for an advanced civilisation in a dying universe as age like they are in slow motion.

 

Over the decades, we found that our universe is structured like a giant cosmic web. A pattern has emerged with vast structures of clusters and superclusters forming in filaments, leaving gaps in between them. Almost as if we were looking at light reflecting off the edges of soap bubbles. Gravity also plays a big part in their formation; mass attracts mass. As a result, voids are actually getting emptier as the gravity from the clusters at their edges pulls on anything out of the void. The clusters around the voids, in turn, are also becoming denser and brighter. 

 

‘Supervoids’ also allow us to see the cosmic expansion caused by Dark Energy. Although not observable directly, the effect that Dark Energy has on ‘Supervoids’ can be. Over time, dark energy increases cosmic expansion, with the ‘Supervoids’ becoming larger, pulling at threads of galaxy clusters on their edges, drawing them out longer and thinner. Until inevitably, they break, and two voids can become one. This will continue until a point where the entire observable universe becomes a titanic-sized void of nothingness.