摘要
A formula is proposed to quantitatively estimate the signal euission rate of Commumicating Extra-Terrestrial Intelligent civilizations(CETIs)in the Galaxy.I suggest that one possible type of CETI signal would be brief radio bursts similar to fast radio bursts(FRBs).A dedicated search for FRB-like artificial signals in the Galaxy for decades may pose a meaningful upper limit on the emission rate of these signals by CETIs.The Fermi-Hart paradox is answered in terms of not having enough observing times for this and other types of signals.Whether humans should send FRB like signals in the far future is briefy discissed.
