Ask Dr. SETI ®
Why has no radio astronomer ever managed to pick up any artificial extra terrestrial radio signal? Our solar system is equipped on its side - at the utmost border - with a huge sphere which nothing else but a gigantic spherical field, commonly called Oort Cloud, within which hundreds of thousands comets, asteroids, meteorites, and stellar fragments of all sorts and shapes orbit.
This Oort Cloud is actually a natural barrier and but for it life wouldn't have been on Earth. Why? Simply because this cloud takes on the role of - what we call in French Cage de Faraday. (Faraday cage), that protects us from noxious Supernovas' rays. However, this natural Cage de Faraday could very easily stop extra-terrestrial radio signals from entering our solar system, and prevent our own signals from going beyond it.
I hope that this very rational explanation will be the beginning of an answer from you.
The Doctor Responds:
Yet, optical astronomy and radio astronomy do indeed work from Earth! Thus, we must conclude that the Oort cloud is not an effective Faraday cage. Since it is not blocking starlight or natural emissions, it stands to reason that neither is it blocking ETI transmissions, if in fact they exist -- and we must therefore consider alternative explanations for the lack of confirmed SETI signals to date.
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this page last updated 8 August 2009
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