A wormhole to the other side of the galaxy in a second. One theory is that it is possible

Wormholes are one of those sci-fi pieces that beats black holes on your head. Thanks to such a tunnel, the theoretical interstellar or even intergalactic traveler could cover enormous distances between various points in the universe without exceeding the speed of light.

Too good to be true

Albert Einstein's theory of general relativity indicates that there cannot be black holes that can be passed through. And yet, the latest research shows that such tunnels described by quantum physics may already exist. The only problem is that they would take longer than normal to travel, and the tunnels themselves would be microscopic.

On August 15, a scientific article entitled Humanly traversable wormholes by Juan Macdacena and Alexei Milekin of Princeton University. In their paper, the authors point out that theoretically, there may be physical processes beyond the Standard Model that allow for the existence of wormholes large enough for humans to safely travel through them to other places in space.

Where did this idea come from?

For the first time, the existence of wormholes was proposed by the German physicist and astronomer Karl Schwarzschild, whose solutions to the Einstein field equations were the first to suggest the possibility of black holes. Schwarzschild's metric also indicated the existence of "infinite black holes", which were connections between different points in space. The problem, however, is that these Einstein-Rosen bridges (Schwarzschild wormholes) are not stable enough for anything to pass through.

So what about those journeys through wormholes ?

Maldacena and Milekhin write in their article that wormholes through which you can travel require special conditions. Among them is, for example, the existence of negative energy. Granted, the existence of negative energy is not possible in classical physics, but it is possible in quantum physics. They give an example of the Casimir phenomenon, where quantum fields generate negative energy as they travel through circles.

This effect is usually small, because it is quantum. However, we realized that it could become larger for black holes with high magnetic charge. This can be done using particularly the properties of electrically charged, massless fermions (particles like an electron but with zero mass). In the case of a magnetically charged black hole, they travel along the magnetic field lines, just as charged particles from the solar wind travel along the Earth's magnetic field lines

- the authors argue.

The way these massless particles move indicates that the vacuum energy is constantly changing, which means that it can become negative. The presence of negative energy, in turn, can allow for stable wormholes, bridges of some sort between different places in space-time.

The existence of such tunnels is possible on the basis of matter belonging to the Standard Model. The only problem is that these tunnels will be microscopic in size and will allow you to travel very short distances. However, if we use the Randall-Sundrum II model, a 5-dimensional curved geometry model, instead of the Standard Model, electrically charged black holes of medium size can generate extremely strong tidal interactions that would allow the formation of wormholes.

According to Maldacena and Milekin, theoretical travelers could immediately pass through wormholes, at least from their perspective. An observer farther away much longer would see a ship as it entered the tunnel. Just such a dissonance fits perfectly with the general theory of relativity.

For an astronaut flying through a wormhole, it would take 1 second to travel 10,000 light years. For an observer outside the tunnel, a passing vessel would take around 10,000 years. It is also worth noting that you do not need any fuel to fly, as it is gravity that accelerates and brakes the spacecraft in this scenario.

Back to reality

While this all sounds very encouraging, there are a few big catch here. First, such wormholes would have to be created by oneself, using a negative mass for this, because there is no known mechanism for its natural formation. In theory, it is possible, but for this you need an appropriate spacetime configuration. If space-time were also favorable to us, we would have to operate with such sizes and masses that so far it remains far beyond the capabilities of humanity.

Oh, one more element. Traveling through wormholes will only be safe when space is cold and flat… and this is nowhere to be found except for the Randall-Sundrum II model.

Considering the fact that ships entering the tunnel will be accelerated by gravity, even the presence of cosmic microwave background radiation will pose a serious risk.

Nevertheless, Maldacena and Miekin emphasize that the purpose of their study was to show that, at least in theory, wormholes that can be traversed are possible as a result of the interaction between general relativity and quantum physics.

In short, no, wormholes are not the future of space tourism, at least not in the near future. Perhaps Type II or Type III civilizations on the Kardaszewo Scale could think about it. Our civilization has so far developed to the level of 0.75, so there is still a lot to do.

Nevertheless, just showing that wormholes aren't impossible is an exciting discovery.

A wormhole to the other side of the galaxy in a second. One theory is that it is possible