Einstein’s theory of relativity is 100 years old this year. It has been placed under scrutiny like no theory before it and passed with flying colours. In the most impressive of these tests, two ultra-high accuracy aluminium ion clocks were installed one foot vertically above the other.

Relativity predicts that the higher clock, experiencing less gravity, will run slightly faster. This tiny difference was experimentally observed and amounted to one part in 1,016, or for every 10,000,000,000,000,000 ticks of one clock the other lost a tock. However, researchers at Cambridge’s Department of Applied Mathematics and Theoretical Physics (DAMTP) have shown that if you allow our four-dimensional world (three spatial dimensions plus time) to extend to five, then black holes can be imagined that ‘break’ Einstein theory.

Einstein’s theory in part predicts that mass deforms space-time (the four-dimensional space we live in) and that this deformation is what causes gravity. If the ditch in space-time from the massive object descends to infinity, then even light cannot escape and a black hole is formed. This point at which space-time is deformed to infinity is called a singularity, and the Cosmic Censorship Conjecture claims that since nothing can escape the black hole’s gravity, observing them is impossible. Black holes are hidden behind their ‘event horizon’ – the boundary beyond which light cannot escape.

However, a theoretically possible five-dimensional black hole shaped in a very thin ring breaks this, leaving an observable singularity which would shatter relativity. The black hole in question is a spinning ring that warps and bulges, much like water droplets separating in a stream of water, until the connection between the bulges on the ring gets thinner and thinner. Most black holes collapse into a sphere which would enclose the singularity, but when the ring is sufficiently thin, the singularity is naked to our observation.

“The better we get at simulating Einstein’s theory of gravity in higher dimensions, the easier it will be for us to help with advancing new computational techniques – we’re pushing the limits of what you can do on a computer when it comes to Einstein’s theory,” said Saran Tunyasuvunakool, co-author of the paper and a PhD student at DAMTP. “But if cosmic censorship doesn’t hold in higher dimensions, then maybe we need to look at what’s so special about a four-dimensional universe that means it does hold.”

The concept of extra dimensions has long been a possibility. If you imagine a world of flatlanders who effectively live on a piece of paper, they could go happily about their two-dimensional lives without any concept of what the third dimension means. Similarly, the world could be a much higher multidimensional place of which we would have no understanding beyond the three spatial dimensions we experience.

However, where our imagination breaks off, the limit of physical intuition at the third dimension, the maths keep running and predicting phenomena such as this five-dimensional black hole. Whether this represents a closer image of ‘reality’ is another question altogether: one that research like this makes all the more pertinent.