News, Physics, Science Posted on Feb 19, 2019 in Astronomy

“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,” explained Paolo Salucci, astrophysicist with SISSA and a dark matter expert. “We could even travel through this tunnel, since, based on our calculations, it could be navigable. Salucci is among the authors of the paper published in Annals of Physics.

Spacetime as Einstein revealed is a field; the universe and our galaxy is made only of fields and particles; space and time are not something else, something different from the rest of nature: they are just a field among the others. The idea of a wormhole was first proposed by none other than Einstein himself.

In 1935 he wrote a paper with Nathan Rosen about how his theory of gravity might allow you to connect two distant points in space, connecting gravity to particle physics. It’s a problem that vexes us to this day. One end of this “Einstein-Rosen bridge” looks like a black hole, where things enter and don’t return, while the other end looks like the opposite. The result is kind of white hole where things seem to appear from nowhere. This led to the idea that perhaps black holes could be wormholes to distant galaxies, or even other universes.

But physicists eventually debunked the idea: a wormhole between distant stars, and the tunnel will collapse and pinch off before you have a chance to traverse it. In the 1970s Noble-Prize physicist Kip Thorne and others showed you could line a wormhole with “exotic matter” to keep it open, but, unfortunately, that exotic matter couldn’t be any kind of matter that existed.

Undauted, astrophysicists from the International School for Advanced Studies (SISSA) in Trieste, Italy, speculated in a 2015 study that wormholes, as predicted by Einstein in his theory of General Relativity as areas where space and time are bent to manipulate the distance, are possible, and could be hiding within dark matter inside the Milky Way. But, It would take a huge mass to produce the manipulation of spacetime, and no evidence of their existence has ever been found. Based on their theory, our galaxy could be a huge wormhole (or space-time tunnel) and, if that were true, it would be “stable and navigable.”

“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 it ever be tested experimentally? “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: “the map was one we obtained in a study we carried out in 2013,” explains Salucci. “Beyond the sci-fi hypothesis, our research is interesting because it proposes a more complex reflection on dark matter.”

As Salucci points out, 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 perhaps it’s time for scientists to take this issue ‘seriously’,” concludes Salucci. “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.”

“Our result is very important because it confirms the possible existence of wormholes. 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 film ‘Interstellar’.”

Scientists had believed any wormholes which exist in the universe could simply be the size of a pin prick. However, the team of astrophysicists say the one in our galaxy could be big enough to fit a spaceship which could traverse the cosmos, as they would likely exist in other spiral galaxies.

“Obviously we’re not claiming that our galaxy is definitely a wormhole, but simply that, according to theoretical models, this hypothesis is a possibility,” Salucci observed.

The Daily Galaxy via the International School for Advanced Studies (SISSA)