Dark matter mystery solved? Oxford University scientists may have answered one of universe's biggest questions

'We had forgotten to include a simple minus sign'

Scientists might have solved the mystery of dark matter and dark energy, one of the most mysterious and troubling parts of the entire universe.

And the solution might have been entirely simple all along: astrophysicists had just forgotten to add a simple minus sign.

Dark matter is perhaps the biggest question in astrophysics. Our current model suggests that there is vast amounts of energy and matter – 95 per cent of the universe – which must exist but is simply missing and which we cannot see.

We know about the two phenomena because of the effects they have on other matter that we can see. But we know nothing about them directly, including what they might be physically made up of.

An Oxford University scientist has suggested a new theory that would bring them together, solving a question that has haunted astronomers and astrophysicists for decades.

Dr Farnes suggests that both dark energy and dark matter are a fluid that possess "negative mass". That means in effect that it would be the inversion of normal mass: if you pushed it, it would be propelled towards you.

The implications of such a breakthrough suggestion are huge, offering a solution to what that vast amount of missing stuff might be.

"We now think that both dark matter and dark energy can be unified into a fluid which possesses a type of 'negative gravity', repelling all other material around them," said Dr Farnes. "Although this matter is peculiar to us, it suggests that our cosmos is symmetrical in both positive and negative qualities."

Negative matter has been proposed before, since it would mean that the material would become less dense as the universe expands. That would contradict real observations, which shows that dark energy does not thin out over time.

However, Dr Farnes theory suggests that new dark energy is being created all the time. Since more and more negative energy is constantly bursting into existence, such a fluid would not dilute even as the universe expanded.

That proposed fluid appears to work exactly as dark energy does.

"The outcome seems rather beautiful: dark energy and dark matter can be unified into a single substance, with both effects being simply explainable as positive mass matter surfing on a sea of negative masses," he said.

Researchers now hope the theory can be tested using the huge Square Kilometre Array, which is being built now and when finished will be the biggest telescope in the world. But if true it could fix LambdaCDM, our current picture of the universe, explaining what exactly the dark matter and energy that has been so problematic for our physics is made up of.

"There are still many theoretical issues and computational simulations to work through, and LambdaCDM has a nearly 30 year head start, but I'm looking forward to seeing whether this new extended version of LambdaCDM can accurately match other observational evidence of our cosmology," he said. "If real, it would suggest that the missing 95% of the cosmos had an aesthetic solution: we had forgotten to include a simple minus sign."