Dyson and extraterrestrial civilizations

Who was Dyson? What contribution has it made to the search for extraterrestrial life forms?

On February 28th, the great theoretical and mathematical physicist Freeman John Dyson passed away. His works have ranged from quantum electrodynamics to nuclear engineering and astrophysics. During his life he has dealt with various topics, including that of the birth of life in the universe (in "Origins of Life", 1986) and that of the search for extraterrestrial civilizations in the space around us.

Freeman John Dyson

It was around 1937, reading the novel "Star Maker", that Dyson came up with a very fascinating idea: a sufficiently advanced civilization would most likely be able to exploit the energy of a star to its advantage, through a mechanism that it would later be referred to as the Dyson Sphere.

But before talking about the so-called Dyson Sphere, I would like to talk to you about the types of civilization that we can have in the Universe according to the Kardasev scale. According to this scale, in fact, civilizations would be classified into three categories on the basis of their technological development and their demand for energy, ever increasing with the progress of civilization itself: a level I civilization would be able to fully exploit the energy of its own planet, a level II would be able to fully exploit the energy of its solar system and therefore its star, while a level III would be able to exploit the energy of an entire galaxy.

Environment exploited according to the type of civilization.

And so a hypothetical level II civilization would already be able to create the complex device devised by Dyson, that is a gigantic spherical structure, which, by wrapping a star, would be able to capture much of its energy and make it usable.

According to Dyson, being able to find similar structures in the observable universe would be of great help in our ongoing search for extraterrestrial life forms.

In fact, a very interesting discovery dates back to 2018: the star Tabby (KIC 8462852), located in the constellation of Cygnus, emitted light in a very strange way. So strange as to make the scientific community hypothesize the existence of a Dyson sphere or a conceptually similar structure right around this star 1480 light years away from us.

Artistic realization of the hypothetical structure around the Tabby Star

However, scientists are still unable to determine with certainty whether the variability of Tabby's brightness is due to the presence of a Dyson sphere or to the presence of natural material orbiting the star.

We can therefore say that, if in the near future we manage to find an extraterrestrial civilization, it could also be due to the important contribution of the great scientist Freeman John Dyson.