you never know...
there could be another colony in our galaxy, thats more advanced than us in some ways, but less advanced in other ways.
no, not with the knowledge today,
from measurements of the Cosmic Microwave Background, the whole Universe is aprox 13,7 bill. years old.
Observations of the first generation of stars in our Milky Way that formed soon after the end of "Dark Ages"
this was aprox 13,2 bill. years ago.
Our SOlar System is aprox 4,6 bill. years old.
the earth is aprox 4.55 bill. years old
and we humans exist aprox 160.000-250000 years.
what does all means?
to build us (humans) in our galaxy it took aprox 4.6 bill. years,
so in other words, the ET's out there in our Galaxy should be at the same
level what we are now, nothing was build earlier (maybe in other galaxys)
but they are way to far away anyway to get an signal in our life-time.
Since at least 1900, our first radio signals have traveled a distance of 129 light years.
Since our galaxy measures about 100,000 light years across, these signals have traveled
only about 1/1,000th the width of the Milky Way.
That would mean there are maybe 30 to 100 stars that would have picked up our Radio signals noise by now.
And remember, those stars, needs planets where life can exist, and allready build radios...
like i said, we need another 100000 years to get sure if we are alone.
We are the first, at the beginning, like maybe others in our galaxy.
otherwise we should allready made contact.
