@parados,
parados wrote:You are just going to repeat your attempt to shift the burden of proof? You made the claim. You get to provide supporting evidence.
We have the Drake Equation and its range of solutions: from 8x10^-12 to 36.4 MN (of possible civilization in our Galaxy). If we place a normal probability distribution function (Gaussean Distribution) on that range we have the bell of probability frequency, where the central value is around 10^-3 (if the scale is logarithmic). What is the physical interpretation of that - probability of 0.001 over the Galaxy for its lifetime?
1. This probability may not be impressing, but it cannot be interpreted as absolute zero in any way.
2. This is made with the assumption that the civilization in question is of class III - it has survived for the whole life-span of the Galaxy.
3. Is there any civilization existing for sure in the Galaxy at present: absolutely yes - ours. How much are we expected to survive as such (not because of the Drake Equation, but because of the 2000 sq.km of self-ignited coal mines in the Gobi Desert, for example) - having in mind that we will hardly survive in the next 100 ÷ 1000 years, our lifespan as a civilization is not more than 200 000 years.
4. If the average life-span of a civilization is 200 000 years, how much is 0.001 of 13.8 BN divided by the average life span - to get the approximate number of possible existing civilizations: 69 (the number is too beautiful not to be true)
In various times throughout the existence of the Galaxy there might have existed 50 ÷ 70 in various time and in various parts of the Galaxy.
Does anyone of them made it (have succeed to become a civilization of class III) - we don't know but most probably not, for otherwise we would be watching their TV shows from space emissions. Really?
Yet, if they have succeeded to survive for 200 000 years, they must have had radio and TV shows in the last 50 ÷ 200 years, which is a lot of RF pollution in space & time - it should be seen everywhere. Nothing of the kind. Our own radio and TV shows and any other RF pollution that we have made so far are within a range of a sphere having diameter of approximately 50 lys (around the SS) - but the question is: are they recognizable at present as RF signals coming from a civilization? Can we, with our own equipment decode them right now if we catch them somehow from the remote edge (which is actually mission impossible)? I doubt, for the red shift of the RF emissions (and it doesn't matter whether due to expansion of the Universe or to something else) has transcoded them throughout transmission by something like a one-time pad, in other words our RF signals are already unrecognizable as such ... even to us. If they are cryptoanalytically unbreakable to us, then how exactly do we expect for the aliens to recognize and find them, in the first place ... before 'reading off' the code?