The Search for Extraterrestrial Life

The search for extra-terrestrial life began in the 19 sixties. The first strategy was to use radio telescopes at a frequency of 21 centimeters. This is the frequency at which tral hydrogen emits a signal. To day, our systems are lowing ten giga herts, so ten billion hurts compared to a hundred hurts. Maybe we shouldn't be looking for light waves or radio waves, we should be looking for zata rays. We haven't discovered it yet.