Chippy_boy
Well-Known Member
Where are you getting the 3 billion from? Are you presuming a certain distance? While I agree that we're extremely unlikely to communicate with any other sentient races in our time, I don't think that makes it a certainty that nobody knows about us. We could have easily made contact with a race 100 light years away, we still wouldn't hear anything back for another 90 years. Considering we're only now finding planets less than 40 light years away that can support life, it's a bit silly to exclude the possibility of sentient life in a exponentially bigger radius.
To keep the maths simple and to illustrate the point I simply assumed that at 10e+23 / 1m per second / 3600 /24/ 365 is 3 billion. Obviously you'd have to add on the time taken to reach us, so in fact it's many times longer than that in reality, but it served my point as it was.
The question and this answer related to how likely it is that intelligent life will find us by random chance. And that I think is so ludicrously unlikely as to be dismissed as per above.
How likely it is that we'll be found as a result of us announcing a big "hello out there" perhaps back in the 30's or 40's with the first TV broadcasts, is a different question. The answer is "not very", but of course it depends on how common life is, and beyond that how common is intelligent life, that's alive right now (and not long since deceased). But the chances of there being intelligent life on one of these nearby stars is very low, but not as ridiculous as above. As I say, in 1,000 years time the sphere of neighbouring stars will be 1,000 times bigger and the chances 1,000 times higher, so perhaps in time, there is hope.