When we catch the waves of aliens, they disappear?

If the signals from an alien civilization reach us, the risk is great that they have disappeared, according to new research.

According to ScienceNews, physicist Claudio Grimaldi and colleagues at Lausanne Polytechnic University (Switzerland) have calculated the scope in the universe to exist the signal of another civilization.

This finding comes from a team effort to update the Drake equation in 1961. This is a method of estimating the number of civilizations that exist in the galaxy.

When aliens' signals reach Earth, their civilization may disappear - (Photo: SCIENCE NEWS).

The research team concluded that civilizations with developed technology were born and lost in a certain period of time.

When we throw rocks at the surface of the lake, the waves continue to spread while the epicenter is quiet. Similarly, a civilization disappears and stops transmitting, old signals continue to travel in space.

Part of the galaxy is filled with such "ghost" signals.

In the February 27 report, scientists argue that the time it takes for light to travel across the universe is 100,000 years. If that civilization exists less than that, the opportunity for their signals to reach Earth when they are still extremely small.

Humanity has only broadcast radio into space for 80 years, which means our signal even spreads to 0.001% of the galaxy.

Mr. Grimaldi took for example that if a civilization transmits the signal from the other end of the galaxy, when it reaches Earth, "that civilization has disappeared."

The team calculated that the average number of extraterrestrial signals coming to Earth at a given time would be equal to the number of civilizations that have the signal being transmitted. This calculation is proven true, even if those civilizations are not signaling.

Claudio Grimaldi is writing a report to explain why we have not found anything yet.