Are we alone in the universe?
Despite the vastness of space, we have yet to receive any confirmed contact with extraterrestrial life. However, researchers from the Laboratory of Statistical Biophysics at the École Polytechnique Fédérale de Lausanne in Switzerland proposed a new explanation for the lack of communication. According to Grimaldi's statistical model, there may be too much space to scan for radio signals emitted by extraterrestrial life, resulting in Earth's "quiet bubble" devoid of such signals.
Grimaldi's model assumes that there is at least one electromagnetic signal of technological origin in the Milky Way at any given time, but Earth has been in a quiet bubble for at least 60 years. With these assumptions, there are statistically fewer than one to five electromagnetic emissions per century anywhere in our galaxy. This means that the chances of receiving a signal are about as common as supernovas in the Milky Way, which is not very common.
While there is debate over whether or not the search for extraterrestrial intelligence (SETI) is worth our while, Grimaldi suggests that the best way forward is to adopt the SETI community's past approach of using data from other astrophysical studies to see if they contain any tech signals. This approach is known as commensal investigations and involves looking for signals in data collected by telescopes focused on other missions rather than using telescopes specifically to look for alien communications.
Grimaldi's statistical model also suggests that we may have been unlucky in discovering radio telescopes just as we crossed a portion of space in which electromagnetic signals from other civilizations were absent. Nevertheless, as our instruments for observing space continue to improve, we are discovering more and more planets that might have the right conditions for life to exist on them. This means a greater chance that alien life is trying to get in touch, but we still have much space to cover in the search.