Reply to this post:
How was it determined that it'd only take a million years to colonize our entire galaxy? Last I heard there were 400 billion stars in our
galaxy, you're telling me it'd only take a million years to colonize 400 billion star systems? I don't think so.
it is hard to imagine isn't it - the first time I heard the drake equation I had a similar response so i will explain to you what was explained to
me.
Let's build a timescale
This timescale is very rudimentary, the numbers may be wrong by several units, but the magnitude of each is rather well accepted by the scientific
community :
15,000,000,000 years ago : the Big Bang, the start of the Universe
10,000,000,000 years ago : formation of our Galaxy
5,000,000,000 years ago : formation of our Sun, Earth, and quite quickly afterwards, the start of life
1,000,000,000 years ago : life has evolved to organisms capable of leaving fossil record
500,000,000 years ago : evolution of vertebrate animals
100,000,000 years ago : reptiles are the dominant life form
50,000,000 years ago : mammals are the dominant life form
10,000,000 years ago : early hominids
1,000,000 years ago : Homo Erectus
200,000 years ago : Homo Sapiens
10,000 years ago : invention of wheel, agriculture, cities (this is the earliest moment at which I might be inclined to accept the emergence of
"intelligence")
500 years ago : Renaissance of the scientific method
100 years ago : modern (particle) physics
50 years ago : start of space exploration
let's extrapolate :
50 years from now : colonies on the Moon or Mars
500 years from now : extrastellar probes
1,000 years from now : manned extrastellar expeditions
10,000 years from now : extrastellar colonies
100,000 years from now : colonisation of large part of the Galaxy
1,000,000 years from now : colonisation of the entire Galaxy
If this last figure seems small to you, considering the vast interstellar distances, remember that the Galaxy is only 100,000 light years accross -
and with exponential growth to take into consideration, an average speed of 1/10th the speed of light should not be a major problem. In fact even with
slower than light ships the exponential population growth would soon push the colonisation bubble to almost light speed anyway. In a way a million
years is very generous, it could be done in a million years with current propulsion technology and generation starships. If technology advances at the
current rate and we break the faster than light barrier 25,000-50,000 years is feasible.
Now with the current age of the Galaxy/Universe - why hasn't this happenned already with a hypothetical extraterestial civilisation? Even if for some
reason our humble solar system isn't worth colonising why can't we see there vast engineering projects, why no fire citadels in the sky? It all
looks primordial so you have to think maybe we (intelligent life) is rarer than you think. Its hard to think of a advanced technological civilisation
that won't leave its mark over a significant portion of a galaxy.
and in answer to ugie1028
I have seen a Ufo and what I thought was a UFO. The first was when I was 18 and It turned out to be a Helium Ballon. The second was on a plane and I
have no idea to this day what it could of been. That is why I am so interested in this subject. You don't need to hit me in the face with one my
freind! I believe in the UFO phenomenom just not the Alien bit hope that clarifies things for you.
[edit on 1-12-2008 by oinkment]