This is how the alien spaceships could be traveling throughout the galaxy

A new study considers the unusual possibility that the aliens are firing lasers against black holes to extract energy.

This is how the alien spaceships could be traveling throughout the galaxy

An astronomer at Columbia University has just published on arxiv.org a new assumption of how supposed extraterrestrial civilizations could be running around the galaxy without us noticing: firing lasers at binary black holes (two black holes that they orbit each other). And best of all, the idea, deep down, is nothing more than a futuristic adaptation of a technique that NASA has been using for decades in its missions through the Solar System.

At present, in fact, human ships move from one planet to another using “gravity wells” that drive them as if they were huge “gravitational slingshots”. The thing works like this: a ship enters the orbit of a planet, gets close to it as much as possible to gain speed and then uses all that extra energy to get to its destination faster. Physics also tells us that in doing so, the ship absorbs a small fraction of the planet’s impulse through space, although the effect is so minimal that it is impossible to detect.

But those same basic principles work also in gravity wells around black holes. Of course, those wells are much more intense than the planetariums. So much that they manage not only to bend the trajectories of solid objects, like ships, but also of the light itself. In fact, if a photon (a particle of light), is very close to a black hole (although not enough to fall inside), it will partially surround it and then be ejected backward, in exactly the same direction. Physicists call these regions “gravitational mirrors, and the photons that bounce “photons boomerang.”

Of course, the photons, which were already traveling at the speed of light when they reached the hole, do not increase their speed when they bounce off (nothing in the Universe can move faster than the speed of light), but in the process They do collect a certain extra amount of energy, which manifests itself in the form of a longer wavelength. In other words, “outgoing” photons carry more energy than they had when they approached the black hole.

Halo unit

In this way, David Kipping, author of this new research, proposes in his article that a hypothetical interstellar spacecraft could fire a laser directly against the gravity mirror of a black hole moving very fast around another black hole (or which is the same, a binary black hole). When the laser photons retraced their steps, with much more energy than when they were fired, the alien ship could absorb them again and transform all that extra energy into impulse.

The system, which Kipping has dubbed “halo unit” has a great advantage over conventional methods: it does not need a massive source of fuel to accelerate and travel through space. The current proposals of ships driven by “light candles”, on the contrary, need a lot of energy to reach relativistic speeds (important fractions of the speed of light). In fact, for this, they would need more energy than Humanity has produced in all its history.

But with a “halo unit” things would be very different. The necessary energy could simply be “extracted” from the black hole instead of being generated from a fuel source.

Of course, the halo units would also have their own limits since, at a certain point, the ships would move away so quickly from the black hole that they could no longer absorb enough light energy to keep accelerating.

Walk through the Milky Way

For the researcher, an eventual alien civilization could, at this very moment, be using a similar system to navigate freely throughout the Milky Way. Binary black holes, of course, do not lack. And if the physicist is right, and that supposed practice is used massively, the continuous extraction of energy could be having some effect on the orbits of the black holes. That is, we could detect signs of an intelligent civilization from the eccentric orbits of the binary black holes they were using for their purposes.

Of course, it is also possible that there is no civilization using this ingenious system to boost their ships. And in that case, Kipping reasons, Humanity could be the first to do so.

Updated: March 18, 2019 — 3:38 pm