Currently, the search for extraterrestrial intelligence continues. But scientists have not yet found convincing evidence for the existence of a signal from an alien civilization.
Signals from aliens can come from any part of our galaxy and on any frequency. But limiting the search space for this signal will help detect the signal itself, report scientists from Kyoto University, Japan Universe today.
One of the most famous examples of attempts to communicate with potential aliens is the Arecibo message, in which humanity attempted to announce its existence using scientific and mathematical standards.
This signal was sent in the form of a binary code in 1975 towards the globular star cluster Messier 13, located in our Milky Way. The likelihood that an alien civilization could both receive and interpret such signals is very low.
It would be great if potential aliens had some idea of how to interpret the signal. But how can you pass a key to unlock a message without the key itself being interpreted only by the same key? Japanese scientists have spent a lot of time thinking about this question.
In previous research, scientists have proposed using the timing of a future binary star merger or a past supernova explosion to narrow the area of space for potential contact. But a new study suggests that the orbital period of a very bright star around the supermassive black hole in the Milky Way is being used.
The supermassive black hole at the center of our Milky Way, known as Sagittarius A*, will be well known to any alien civilization that, like us, sends signals into space.
It is very convenient that several very bright stars orbit this black hole at regular intervals. The study authors chose a star called S2, which has 15 times the mass of the Sun and an orbital period of almost exactly 16 Earth years.
These features are important because of their prominence and also because of the ease with which the so-called Schelling point can be calculated. Schelling’s point comes from game theory, namely how two people can talk about something without communicating it at all.
For example, someone wants to meet his friend, but doesn’t want to tell him when and where he wants to meet. The other person is also interested in meeting, but is equally interested in not sharing when and where.
The Schelling point is thinking about common ground to try to determine a meeting place without saying it directly. For example, two people roughly know that they are choosing one of the most famous days of the year, and that could be New Year’s Eve, December 31st.
As for the meeting place, most likely, two people will choose the most famous city and the most famous place in it. This would be Schelling’s point for two Earthlings, but the same judgments can be applied to communication with alien life forms.
We have the star S2 and the period of its orbital motion in common with all alien life in the Milky Way, because the aliens most likely also have an idea about the object and its properties.
Scientists believe that using the characteristics of this particular star, astronomers can begin to search for signals in a specific region of space, using the period of the star’s movement as a basis for communication.
The idea, scientists say, is to find a common experience that can be used as a basis for trying to communicate with aliens without communicating first.
