Originally posted by: Doboji
Well if you consider the fact that life has existed on the planet earth for almost 4 billion years, and intelligent life has only existed for what?.. 10,000 years?... and we've only gotten into space in the last 50 or so years.
The parameters for a hi-tech intelligent life containing planets outside of earth gets narrower and narrower the more you look at it.
They are:
Earth like planet, in the appropriate orbit, with a stable sun.
Very likely billions like this
Life coctail chemical reaction
Within those billions there could easily be millions like this. Heck, Venus and Mars either are or were close
Evolution in the direction of intelligent life
Evolution has no direction. Reaction to stimuli is very probable in life, infact it is perhaps a definition of life. Intelligence is just a very complex reaction to stimuli, one which has an obvious survival benefit.
Societal evolution in the direction of high technology
Tools are the main survival benefit of intelligence, so with one the other is likely, to be able to "justify" the resources needed to have intelligence evolutionarily. A species that has the capacity of originality to invent tools, matched with the capacity for communication and the preservation of knowledge through generations, (arguably present in most "higher" mammals) will lead almost inevitably to the elaboration of those tools.
Cultural curiosity for space
IMO, to have the capacity for originality to be able to invent tools, general curiosity as an in-born trait is requisite
Appropriate fuels present on the planet.
Life is basically a powerplant, with the ability to convert energy and store it. The chemical complexity needed to evolve higher life would leave on the planet the resources needed to have fire, and eventually steam power. Magnetic materials would need to be present in order to protect the budding life from solar radiation, which could easily lead to the discovery of electricity. Also, the sheer time it would take in order to evolve intelligence would leave generations of dead organisms in the earth, with all the chemical complexity they had when they were operating powerplants. Much like what happened here. They could have fossil fuels. How likely they would be able to extract this easily would be a matter of geology, which I don't know enough about to guage any kind of probability. Even without, they have the basics for development of industry and electricity. And remember that they will have wind and water power.
Matching time period to us..... Universe is what? 11 Billion years old? All of the above would have to exist in parallel to our current existence.
It's quite likely that they would evolve at nearly the same time as us. Based on my limited knowledge of cosmology, the universe has had about two generations of stars born. In the first generation, most of the universe was made up of Helium and Hydrogen. Heavier materials were only dispersed through the universe after that first generation of stars died, spreading the heavier atoms that were born in their cores due to fusion throughout space. Thus, planets can only exist around second-generation stars like our sun
In short... it's just very unlikely. The universe is not infinite
