Originally posted by Orkojoker
There are not an infinite number of grains of sand on Earth, but for all intents and purposes there may as well be. I feel that the same goes for stars in the universe. I would speculate that there are quite a few planets out there that are practically indistinguishable from our own, and that there are quite a few more that are indistinguishable from any other particular planet you might pick.
I agree, but agreeing that solar systems in our galaxy are common throughout we still see a much more limited chance of a planet with complex life on it. The reason is because there are basically three conditional needs required and when any of the three are lacking we might still get some kind of simple life, but complex life, intelligent life, is seriously inhibited.
First the planet would need to have an orbit basically in the band of life or "Goldilocks Zone” and this would be the distance from the sun to offer temperature ranges for complex life, next the planet’s gravity would need to be within a limited band once again for complex life to thrive, and lastly the planet would need to be stabilized to a certain degree along with a liquid core over a long period of time. This is because life takes time and complex life is rather far down the path.
I read a while back about an interesting theory on how a solar system needs a very large planet such as Jupiter to provide the right gravity offset for a solar system to actually form. Right or wrong though this theory has it merits and it does put light on the fact that there could be many other stipulations needed for that perfect situation to happen that we find ourselves in.
As far as intelligent life goes, I don't think we really have any idea how rare or common it might be. It would certainly be odd if intelligent life were the only thing in the universe of which there was only a single example, considering that there are billions and billions of everything else.
So far on earth after playing around with life for 4.5 billion years the human race is unique with their overall abilities and that says a lot in my book of perception, but being even more simpler than that is the fact that simple life comes first and life progression is not fast. We also need to understand that complex life is a living and breathing chaos theory, in that we start with simple life forms and they continually break away from order with complex life just a result. This doesn’t mean that complex life is better for in many ways it isn’t since the more complex it gets the more fragile it becomes.
With that said, one needs to ask the question as to whether intelligence is really needed or is it a random direction in the chaos theory of life.
If we had, say, 100,000 life-bearing planets that we could examine of which none had what we would call intelligent life, then I would suppose that it's pretty uncommon. But our sample size so far is 1, which is pretty meaningless when it comes to drawing conclusions. We could just as easily look at the fact that 100 percent of the life bearing planets we know of harbor intelligent life and conclude that intelligence is an inevitability once life begins. Either way we're working with some pretty scant information.
Actually it is 9 or 10.... and so far in our neck of the woods we had a 10% chance that the right planet was put into the right orbit. Mars and Venus as two great examples of planets just slightly outside of the right orbit and size.
We have 300 billion stars to work with inside our galaxy and out of that number we would need to subtract the stars that are unuseable, such as too new, old small, large etc. Then assuming thata solar system is more of a norm than not we would still have a good number of perfictly good stars that do not have planets.
Anyway we look at it we are going to eliminate a good chunk of that 300 billion. Now we continue to cause further eliminations by suggesting out of all these solar systems we still need a planet within the Goldilocks Zone and of the right density etc. Anyway you look at it and the number of 300 billion stars is greatly reduced once we add in all the requirements.
Now we need to create life on this planet and it needs to evolve into complex life with intelligence somewhere into there too, and oh they need to have the physical capabilities to use that intelligence such as we do, as in if it is an intelligent sponge I don’t see it building rocket ships. Lastly that just right race of intelligent ship builders needs to live long enough to reach the stars, and as I said before complex life is also fragile life.
But suppose there is another quality out there, let's call it "superness" for lack of a better term. Perhaps species that are super are as fundamentally different from intelligent species like us as we are from, say, fish or insects. In other words, superness is to intelligence as intelligence is to nonintelligence. Of course this is speculation, but can we think of any reason why there would be one and only one such fundamental dividing line in the hierarchy of life?
Could be, but we do have intelligence as a known factor, and we have yet to see other factors like this or factors that do not fit within the laws of physics. But I like to break things into simple and complex life and you are talking about maybe a third catagory.
