Scientists, especially astrophysicists, like to know what’s possible in our universe. Their theories and complex computer simulations are aimed at showing what might exist. This week (January 20, 2015), an international group of researchers reiterated that it’s possible our Milky Way galaxy is a huge wormhole – a space-time tunnel – a galactic transport system to other parts of space. They made that determination by including dark matter – that mysterious something that makes up the bulk of our universe. According to these researchers, when you consider dark matter along with the regular matter in the Milky Way, our galaxy’s density appears great enough to allow for a wormhole at the galaxy’s heart. If so, these researchers say, this wormhole is:

… stable and navigable.

This is the hypothesis put forward in a study published in the Annals of Physics via a collaboration between Indian, Italian and North American researchers, who say their results:

… prompt scientists to re-think dark matter more accurately.

Paolo Salucci, astrophysicist of the International School for Advanced Studies (SISSA) of Trieste and a dark matter expert, explained:

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 hypothesize 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. 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.’ Although space-time tunnels (or wormholes or Einstein-Rosen bridges) have only recently gained great popularity among the public thanks to Christopher Nolan’s sci-fi film, they have been the focus of astrophysicists’ attention for many years. Salucci joked: What we tried to do in our study was to solve the very equation that the astrophysicist ‘Murph’ was working on. Clearly we did it long before the film came out. It is, in fact, an extremely interesting problem for dark matter studies. Obviously we’re not claiming that our galaxy is definitely a wormhole, but simply that, according to theoretical models, this hypothesis is a possibility.

Can this ever be tested experimentally? Salucci said:

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.

To reach their conclusions the astrophysicists combined the equations of general relativity with an extremely detailed map of the distribution of dark matter in the Milky Way. Salucci explained:

The map was one we obtained in a study we carried out in 2013. Beyond the sci-fi hypothesis, our research is interesting because it proposes a more complex reflection on dark matter.

Scientists have long tried to explain dark matter by hypothesizing the existence of a particular particle, the neutralino, which, however, has never been identified at CERN or observed in the universe.

But alternative theories also exist that don’t rely on the particle, and, Salucci concluded:

… perhaps it’s time for scientists to take this issue seriously. 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.

Bottom line: In theory, our home galaxy – the Milky Way – could be a galactic transport system, says a team of Indian, Italian and North American astrophysicists.

Via SISSA