How to find evidence of the existence of technologically advanced civilizations in the universe? It all depends on what exactly you are looking for.
After all, it is absolutely incomprehensible what opportunities an extraterrestrial civilization can achieve in the process of its development.
This question is directly related to the so-called “Kardashev scale”. A Type I civilization in Kardashev’s scheme can capture all the energy falling on its home planet. A Type II civilization can capture all the energy generated by the parent star. And a Type III civilization can do the same to an entire galaxy.
Harvesting the energy of an entire galaxy seems like a pretty advanced skill. But in fact, this idea can be developed even further. Can a Type IV or Type V civilization exist? Are there any restrictions at all for the development of alien species? And if so, where are those limits?
Intervention in dark matter
Kardashev in his classification spoke of civilizations that still obey the laws of physics. The universe gives them these laws just as it gives us. We cannot change these laws. We can only use them more or less effectively.
But what if an alien civilization becomes so advanced that it can change these laws? Such a civilization would certainly go far beyond mere energy harvesting.
The very nature of energy, with established rules such as energy conservation, would necessarily be subject to revision in this case.
Astrophysicist Caleb Scharf explored this question in a paper entitled “Is Physical Law an Alien Intelligence?”. This work is simply a masterpiece of creative fiction. Scharf researched the laws of physics and asked himself – which of them could be rewritten by a sufficiently advanced form of life?
One possibility described concerned the nature of dark matter. When astronomers track the movement of galaxies and clusters of galaxies, they discover a problem.
It turns out that there is not enough mass to generate the forces necessary to control the observed movement. Astronomers suggest that to solve this problem, there must be a lot of matter that cannot be seen.
This means that it does not emit light and does not interact with ordinary matter that we see, except through gravity. From here the legs of the assertion grow that the Universe is mainly filled with “dark matter”. The nature of which no one can explain.
Therefore, Scharf asked himself the question – could the absence of interactions of dark matter not be a consequence of the laws of nature, but rather the result of interference in the laws of physics of some advanced civilization?
Perhaps, Scharf muses, the best way for life to avoid catastrophes, such as radiation fluxes or blast waves from exploding stars, is to almost completely separate from the rest of the universe.
Using a sort of “dark matter” 3D printer, you can, as Scharf puts it, “upload your world into a massive amount of real estate on the dark side and be done with it.”
Scharf had other ideas too. For example, an overdeveloped civilization accelerating the expansion of the universe. This effect is attributed to the so-called “dark energy”.
Scharf speculated that a sufficiently advanced civilization could also be responsible for this acceleration. Perhaps they are using it to prevent the heat death of the universe and ensure that chaos does not arise in space.
But is any of the above possible in reality? Hard to say.
Most likely, the laws of physics impose severe limits on life and its possibilities. These limitations may hold back technological development enough to stop it far beyond what our science fiction can imagine.
Most likely, it is simply impossible to circumvent the limitations imposed by the speed of light. And crossing the vast distances between stars will always be extremely difficult and costly.