METI / Active SETI debate.
hypothesisframeworkSETI & Technosignatures
The contested practice of deliberately transmitting to ETI. Critics (Hawking, Brin) warn of existential/consent risk; Vakoch's METI International transmits anyway.
Active SETI/METI sends intentional signals rather than only listening. Hawking (2010) likened contact to Columbus's arrival; David Brin argues for passive SETI only and against unilateral broadcasting without global consent ('who speaks for Earth?'). Douglas Vakoch, founder of METI International (rebranded 2016), counters that advanced aliens already detect Earth and that listening implies eventual replying; METI transmitted to Luyten's Star (GJ 273) in 2017. The risk is unquantifiable and the debate genuinely unresolved.