To imagine an extraterrestrial civilization, we really need to think outside the box.

Understanding our environment can guide us in imagining extraterrestrial technologies, but we may need to rethink our assumptions about what intelligent extraterrestrial life might look like.

This is because this life would have evolved completely independently of ours. Many of the conditions that led to the evolution of life on Earth may not exist in a distant solar system.

With these endless possibilities in mind, Dr. Clément Vidal, a philosopher from Vrije University in Brussels, Belgium, recently proposed a very unconventional hypothesis.

Vidal believes an intelligent alien species could use its host star as a spaceship. Additionally, it could transport its entire solar system to other stars. The goal? To “eat” these stars and harvest their energy, Vidal explained in an interview with Interesting engineering.

Ask the big questions

Are we alone in the universe? For centuries, philosophers have been asking this question. More recently, the scientific community has taken up the torch. For example, NASA’s James Webb Space Telescope is probing distant worlds for signs of extraterrestrial life. During this time, the Research Institute for Extraterrestrial Intelligence (SETI) was founded to search for evidence of technological civilizations beyond Earth.

On his websiteVidal notes that he likes to think about “big questions.” This is clear in his new article “Spider Stellar Engine”. In it, he proposes that extraterrestrial civilizations could direct their host stars across the universe. He also suggests several signatures we could look for to prove his hypothesis.

In his article, Vidal suggests that these civilizations with moving stars would transform their planetary system into a “spaceship”. In theory, a civilization could continue to function. At the same time, its star system is propelled through space at immense speeds: we fly in the interstellar medium at hundreds of thousands of kilometers per second.

Vidal hypothesizes that an intelligent extraterrestrial civilization could have discovered how to eject matter from its host star. By ejecting this material in a specific direction, it would create thrust. This would propel the star and surrounding planets in a specific direction.

“The essence of generating thrust is to expel matter in the direction opposite to the desired motion,” Vidal explained to IE. It is a simple notion that can be demonstrated in class or in the street: “We can actually experiment with this fundamental law formalized by Newton by placing yourself on a skateboard with a large bottle of water, and throwing it backwards: the skateboard will move forward. »

Could binary star systems be the key?

Vidal is not alone in suggesting that extraterrestrial civilizations could move their stars. Astronomers estimate around 1,000 so-called “hypervelocity” stars fly over our galaxy. However, efforts to link them to a technological civilization have failed.

In his article, Vidal focuses on the potential of binary star systems. “As about half of the stars in our galaxy are in binary systems where life could also develop, we introduce a binary stellar engine model,” he wrote in his paper, published on the preserver -arXiv print.

“The idea of ​​a binary stellar engine was born in several stages over several years,” Vidal told IE. “First, when I started studying the behavior of accreting binary systems, I thought they looked like a metabolism: a compact object sucks up the plasma of a companion star, irregularly, and ejects the matter out of his system. »

“All living things metabolize: they extract energy from their environment, use it for survival and maintenance, and generate waste,” he continued. “I wondered: Could this be a living system on a stellar scale? I called this hypothesis “the stellivore hypothesis.”

“The next challenge is to test the hypothesis,” Vidal said. “Living systems are naturally expected to want to survive, and finding food is essential to achieving this goal. So I thought that if a stellivore had almost entirely eaten its star, it would naturally aim to go to another star to eat it. »

Spider pulsars

This line of thinking led Vidal to focus on spider pulsars. Pulsars are dense, rotating cores of dead stars. These are neutron stars that rotate so fast that they produce rotating beams of radiation. Spider pulsars are a class of millisecond pulsars that get their name because they damage their smaller companion stars.

According to the philosophy professor, these fit perfectly. These are binary systems with a very low mass companion star – between 0.01 and 0.7 solar masses. Could these companion stars have been deliberately eaten away by an extraterrestrial civilization?

In another paperVidal asked the question: are spider pulsars directed toward a goal? He asked them if they were looking for other stars to consume. In his most recent paper, he looked at the possible mechanisms that these spider pulsars – piloted by an advanced civilization – could use to accelerate, decelerate and steer.

How would binary stars navigate?

The idea behind a binary star stellar engine is that it would steer itself by ejecting energy from stars at specific times in their orbits. An alien civilization could achieve this in several ways, including using asymmetric magnetic fields and an advanced device causing uneven heating on the star’s surface.

“The main idea of ​​a binary stellar engine is to generate thrust by ejecting the mass of the small companion star in the opposite direction of motion,” Vidal told IE. “What is unusual due to the binary nature of the engine is that the mass must be ejected not continuously (as with most man-made rockets), but in a pulsed manner, only when the The companion star is behind the desired motion.

“The advantage of this timed propulsion method is that you can go in any direction in the orbital plane, simply by timing the evaporation of the companion star,” he continued.

All of this begs the question: how could an alien civilization survive navigating interstellar space? According to Vidal, there are several possibilities. It is essential that we are open to the idea that life in a distant star system might be very different from our own. This is especially true if life is advanced enough to exploit its host star for transportation.

“As for planets, their masses are negligible compared to a neutron star, so they would just follow,” Vidal explained. “However, as far as I know, spider pulsars do not have planets, and the stellivore hypothesis does not require life to remain planet-bound, it could be a technological life form or “postbiological.”

Can we prove that aliens rule entire star systems?

Vidal’s hypothesis will be incredibly interesting to anyone curious about the possibility of life far beyond Earth. However, extraterrestrial hypotheses are of little value without specific lines of inquiry. Fortunately, Vidal points to specific cases that deserve further investigation.

According to Vidal, maximizing thrust could be the key. “A designed spider star engine would want to maximize its thrust by aligning the thrust with the direction of motion,” he explained. “In astronomy terms, this translates to finding alignment between the orbital plane and the appropriate motion vector. There would be no natural reason for such an alignment by chance.”

Vidal also points out some observations of spider pulsars that deserve another look. The red pulsar J2043+1711, for example, has decelerated, which could be due to its approach to another star. The black widow J1641+8049, for its part, seems to have slowed down significantly. Vidal says this “requires follow-up to verify whether this is real or whether it could be a measurement error.”

And if we discover that an extraterrestrial civilization is capable of navigating its entire star system through interstellar space, what happens next? Communication at such distances is unthinkable with existing technologies. The greatest value would be how this discovery would ignite our imagination. Vidal explained that the star engine idea “could also be scaled down to propose new designs for planetary defense purposes or as an additional advanced propulsion method for deep space missions.”