"Robert J. Bradbury" wrote:
>
> > Doug Jones <random@qnet.com> wrote:
> > Not quite, I think- the ETIs must only have been broadcasting at the
> > appropriate time vs distance. If a civilization 950 ly away
> > trancended 900 years ago, their "fossil" emissions would still be
> > wafting over us. This increases the number of possible hits
> > significantly.
>
> That's the problem with this group... Try to be brief and you
> get crucified... [I'm not sure if the converse -- Try to be complete
> and the message gets long and ends up DELed -- is true or not.] :-)
>
> Yes, I was aware of this. The problem is that as the distance
> increases so too do the power/antenna requirements. Our natural
> (unintentional) transmissions are designed for "domestic" consumption
> and are therefore not very powerful. For a similar civilization to
> detect them very far out is going to require an investment in a very
> big receiving antenna. The further away the civilization is the bigger
> the antenna needs to be.
>
> By the time *we* get to the point where we can hear "non-intentional"
> transmissions at 950 ly, we will likely be post-singlularity.
> [Please note that this is my gut-feel from reading the literature,
> a real physicist/astronomer would need to do the calculations so
> we could graph the detectable ranges for various transmission
> powers and receiver dish sizes.]
You are both wrongly assuming that all technological civilizations would have similar exponent courves in technological/population development. You are assuming that EVERY society will want to transcend, rather than just staying at a comfortable early 21st century level. You are also wrongly assuming that following a singularity by some percentage of the population that the rest of the population just dissapears.
Try thinking otherwise.