Will humanity survive the expansion of the universe?

As you know, our universe expands with ever-increasing speed due to the influence of the mysterious dark energy. In the future, when people colonize the entire galaxy and will extract energy from the stars, they will face the inevitable energy crisis of a galactic scale. However, scientists are already developing strategies for how to avoid extinction in the starless emptiness of the cosmic abyss.

If you think that humanity living on Earth has problems, then wait for just a couple of billion years. Approximately at this time, the accelerating expansion of the universe will cause an energy crisis of cosmic proportions. Such forecasts always sound very gloomy and give up hopelessness, but a new study assures that a developed civilization, faced with the inevitable, does not have to obediently meet its end – it has quite real chances of survival.

In the gloom of the distant future

Because of the inexorable influence of dark energy, space in our universe expands with ever-increasing speed. Now we should not worry about it, but if humanity survives for several tens of billions of years, then for our descendants this problem will turn into a serious headache. At this stage of the galaxy outside of our Local Group (this conglomerate of 54 galaxies located in a relatively close neighborhood) will move away from us faster than their light will reach the Milky Way. As a result, galaxies will become unobservable and, as a consequence, inaccessible.

The theoretical physicist Freeman Dyson once suggested that a technologically advanced civilization is likely to extract energy in industrial space scales in the simplest possible way – to build around the star a sphere of solar cells that will absorb 99.9% of the radiation. This structure is now known as Dyson’s sphere and its construction looks like a very rational step. However, if humanity is cut off by cosmic darkness from new stars, sooner or later the technology will reach its natural limit and stop. For a civilization whose population can at that time be calculated by the quintillion of people scattered throughout the galaxy, this could mean a crisis of unprecedented proportions – it will just run out of stars.

The future of mankind

However, this is no reason to lose heart. Astronomer Dan Hooper (Dan Hooper) in his new article, published on the portal arXiv, found a solution to the problem. In his opinion, a highly developed human civilization or any extraterrestrial intelligence (ETI, from English extraterrestrial intelligences). To do this, it will have to reach at least a third type on the Kardashov scale – a special method for measuring the technological development of civilization, proposed in the 1960s by the Soviet radio astronomer Nikolai Kardashov. The third type of civilization consumes energy equivalent to the power of an entire galaxy. According to Hooper, with the help of Dyson spheres it is possible to collect energy not only for general consumption: the scientist believes that the same energy can be used to pre-draw to the galaxy as many stars as possible and thereby ensure a huge energy reserve:

Given the inevitability of the crisis, any sufficiently developed civilization that seeks to maximize its ability to use energy will try to provide for its needs as many stars as possible, while they are still available. To do this, you can use Dyson spheres, which will help draw stars from the periphery to the center of the galaxy, which will make them gravitationally connected with it and prevent energy starvation due to the expansion of the universe.

However, not all stars are suitable for this large-scale project. Hooper believes that the most appropriate will be only the stars, whose mass is from 20% to 100% of the mass of our Sun. All because the stars of a larger mass are very short-lived, and therefore most likely will be extinguished before they reach their destination; on the other hand, stars of a very small mass can not produce enough energy for traction, which also makes them almost useless. If the project started today and the Dyson spheres could move at a speed of about 10% of the speed of light, then it would be possible to create a gravitationally connected star conglomerate 65 million light-years (for comparison, the Milky Way’s length is only about 100 light-years) . Thus, the successful completion of the project will expand the energy base for humanity in the future by several thousand times!

Brothers in mind

There is a possibility that other space civilizations (if they exist, of course, exist) have already started creating such a “star reserve”. Hooper notes that signatures created by Dyson’s mobile spheres can indicate this. “If you find that there are not enough intermediate mass stars in the Universes, then this will be one of the brightest signs that someone has already begun to collect them,” he explains.

Needless to say, this solid work is based on a number of very significant assumptions. We do not even know with 100% accuracy what the dark energy is and how it affects the expansion of the universe. However, one should not think that such works are completely useless and have only a hypothetical character: the more spare strategies for the survival of mankind will be created by scientists, the higher the probability of a favorable outcome when we face a real crisis.