segunda-feira, julho 12, 2010

Mais um projeto SETI desafiado pelo Paradoxo de Fermi

A Failure of Serendipity: the Square Kilometre Array will struggle to eavesdrop on Human-like ETI

The Square Kilometre Array (SKA) will operate in frequency ranges often used by military radar and other communications technology. It has been shown that if Extraterrestrial Intelligences (ETIs) communicate using similar technology, then the SKA should be able to detect such transmissions up to distances of ~100 pc (~300 light years) from Earth. However, Mankind has greatly improved its communications technology over the last century, dramatically reducing signal leakage and making the Earth "radio quiet". If ETIs follow the same pattern as the human race, will we be able to detect their signal leakage before they become radio quiet? We investigate this question using Monte Carlo Realisation techniques to simulate the growth and evolution of intelligent life in the Galaxy. We show that if civilisations are "human" in nature (i.e. they are only "radio loud" for ~100 years, and can only detect each other with an SKA-like instrument out to 100 pc, within a maximum communication time of 100 years), then the probability for such civilisations accidentally detecting each other is low (~10^{-7}), much lower than if other, dedicated communication techniques are permissible (e.g. optical SETI or neutrino communication).
Comments:8 pages, 2 figures, accepted for publication in the International Journal of Astrobiology
Subjects:Earth and Planetary Astrophysics (astro-ph.EP); Galaxy Astrophysics (astro-ph.GA)
Cite as:arXiv:1007.0850v1 [astro-ph.EP]

PS: Além do mais, se existissem civilizações tecnológicas (CTs) em um raio de 300 anos-luz, elas já teriam tido tempo de nos colonizar ou colonizar as CTs que estão nesta janela de 100 anos de radio loud (e que portanto, deixariam de ser radio loud). Parece desperdício de dinheiro, acho que outros projetos SETI seriam mais promissores... 
Ver a continuação do "Argumento de Fermi Local" aqui

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