There’s no denying that the universe is one of the most complex things we can possibly try to get our heads around.

Not only is it difficult to understand what goes on beyond the limits of the solar system that our planet calls home, the theoretical expansiveness of the universe, its power, and what came before and after the big bang can overwhelm even the biggest of brains.

And what we consider an ‘understanding’ of the universe – most commonly based on concepts including string theory and cosmic inflation – are entirely theoretical, the work of the planet’s smartest physicists.

But that’s not to say that new ideas can’t be simpler, or cannot add to the fundamental picture we think we’ve drawn regarding how our universe operates.

And thanks to Neil Turok, Higgs Chair of Theoretical Physics at the University of Edinburgh, and colleagues, we have a whole new – and somewhat more digestible – theory to throw into the mix.

As Turok explains in a paper for the journal Annals of Physics, he and his colleagues have developed a new theory that revolves around the idea of a ‘mirror universe’ on the other side of the Big Bang.

This means that the big bang was a fundamental and dividing moment in cosmology, splitting past from present. On one side of the big bang (our side), things more forward in space and time; on the other side, the cosmos is acting as a reflection, moving backwards.

This ‘anti-verse’, as the researchers call it, holds explanations for a vast number of things, including dark matter, and moves away from more complex theoretical ideas like string theory, as Turok notes in an essay for The Conversation:

“Picturing the big bang as a mirror neatly explains many features of the universe which might otherwise appear to conflict with the most basic laws of physics. The progress we have already made convinces me that, in all likelihood, there are alternatives to the standard orthodoxy — which has become a straitjacket we need to break out of.”

And once you’ve got your head around the idea of the symmetry of the universe and the anti-verse, Turok suggests that many other concepts start to fall into place.

Take for example, dark matter.

This curious substance – invisible to telescopes or the naked eye – is thought to constitute significant amounts of our universe’s matter. Even though it can’t be seen, scientists suggest that it comprises two kinds: hot dark matter and cold dark matter. The former are high-energy particles, whilst the latter move slowly or with less strength.

Cold dark matter (CDM) is thought to have helped to grow the first stars and galaxies, whilst hot dark matter (HDM) moves at the speed of light after being created by the big bang. While physicists don’t always agree on CDM and HDM – it is invisible, after all – the most widely-accepted consensus is that our universe is made up of a mix of both types of particles, with CDM greatly outnumbering its more energetic counterpart.

And as Turok and colleagues note in their paper, this mirror theory could give us a deeper understanding of what dark matter really is:

“This model gives an elegant and testable new explanation for dark matter: it a sterile neutrino, radiated from the Bang like Hawking radiation from a black hole.”

Furthermore, the researchers suggest that under current theoretical knowledge, theories around the physical laws of the universe don’t fully make sense.

While physics suggests that CPT symmetry (charge, parity, and time reversal) should exist, we know that – as far as we understand at least – there is not an opposite and equal reaction when it comes to time and space. We cannot go back in time, and the particles that make up our universe don’t seem to have an anti-particle holding the opposite charge.

But the mirror theory accounts for this in full, with the authors explaining such in their paper:

“We suggest the universe before the Big Bang is the “anti-verse” of the universe after the Big Bang. Thus the universe as a whole is CPT symmetric.”

And, as Turok continued in his essay for The Conversation, this simple concept can be universally understood, since it is not unlike looking at yourself in a mirror:

“Our mirror hypothesis restores the symmetry of the universe. The combination of you and your mirror image are more symmetrical than you are alone.”

So if we truly begin to think of the Big Bang as a kind of mirror, content in the knowledge that every part of our universe does indeed follow Newton’s third law of motion, we have to wonder if we ever are truly alone.

If you thought that was interesting, you might like to read about the mysterious “pyramids” discovered in Antarctica. What are they?