wormhole
The (hypothetical) wormhole proposed by Kuefettig, Salucci et al connecting the centre with a very far position of our Galaxy when one passes through its throatSISSA

The Milky Way could be a huge galactic transport system, with dark matter "another dimension", scientists have said.

Paolo Salucci, a dark matter expert and astrophysicist of the International School for Advanced Studies (SISSA) of Trieste, has suggested an alternative theory about dark matter and the universe.

Wormholes – also known as space time tunnels and Einstein-Penrose bridges – have been the subject of astrophysicists' research for many years. They are a hypothetical feature that would provide a shortcut through space time – each end would be separate points.

In their study, published in the Annals of Physics, Salucci and his co-authors combined the equations of general relativity with a detailed map of the distribution of dark matter in the Milky Way.

"If we combine the map of the dark matter in the Milky Way with the most recent Big Bang model to explain the universe and we hypothesise the existence of space-time tunnels, what we get is that our galaxy could really contain one of these tunnels, and that the tunnel could even be the size of the galaxy itself. But there's more," Salucci said.

"We could even travel through this tunnel, since, based on our calculations, it could be navigable. Just like the one we've all seen in the recent film Interstellar."

The authors tried to solve the equation that Murph from Interstellar was working on – "Clearly we did it long before the film came out," Salucci noted.

"Obviously we're not claiming that our galaxy is definitely a wormhole, but simply that, according to theoretical models, this hypothesis is a possibility. In principle, we could test it by comparing two galaxies - our galaxy and another, very close one like, for example, the Magellanic Cloud, but we are still very far from any actual possibility of making such a comparison."

He said scientists have been trying to explain dark matter – the mystery matter that makes up most of the universe – through the existence of the neutralino particle for years, so perhaps it is time for a different perspective.

"Dark matter may be 'another dimension', perhaps even a major galactic transport system. In any case, we really need to start asking ourselves what it is."