Scientists have figured out how the radio noise produced by billions of cell phones might appear to hypothetical aliens. Reported by the SETI Institute.
In the second half of the 20th century, the idea of searching for extraterrestrial intelligent life using radio telescopes was popular with a number of astronomers and activists. They proceeded from the fact that human civilization actively uses radio communication, on the basis that it can be assumed that another civilization with a similar or higher level of development also uses it. In turn, hypothetically, the work of the earth’s radio transmitter can be “heard” even from stars tens and hundreds of light-years away.
Radio physicist Ramiro Saide and colleagues modeled how a “leak” signal from cell towers would be detected from nearby stars, including Barnard’s Star, six light-years from Earth. The model takes into account the total signal energy that changes at different times of the day as the cell towers descend below the horizon and rise behind them. The calculation showed that if a hypothetical alien civilization were at the world’s level of development or slightly higher, it would not be easy for it to isolate this signal.
At the same time, it should basically be possible. “I’ve heard many colleagues argue that the Earth is getting quieter on the radio band in recent years, which I’ve always disputed. While it’s true that we have less powerful TV and radio transmitters today, mobile communication systems around the world are becoming more common. While each system individually represents a relatively low-power radio source, the sum of the energy of its signals is high,” said Mike Garrett, one of the study’s authors.
In the future, the authors plan to simulate “eavesdropping” by aliens by radar signals, Wi-Fi, cell phones, and satellites.