Life maybe, but probably not as we know it

The perennial issue of the possibility of life on other planets was in the news again with the report that estimated there might be tens of billions of planets in the Milky Way with the right (i.e. earthlike) temperature to support life.

http://www.guardian.co.uk/science/2012/mar/28/billions-habitable-exoplanets-milky-way

While it's always thrilling to think about alien life, and day dream about interplanetary communication, unfortunately any hope of such 'contact' effectively ruled out not by fancy and fascinating questions of whether life could evolve elsewhere, and how it might do so, but by the much more mundane and boring issue of scale.

As the Hitchhiker's Guide To The Galaxy said, "Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space". The problem to me is not that there might not be aliens, but if there are they are probably to far away to ever meaningfully interact with them. The Milky Way is up to 200,000 light years across, which means even if there is a distribution of life throughout the galaxy, the chances are the worlds would be several thousand light years away. This would mean even if we did get a signal from somewhere else, it would take many thousands of years for any signal of ours to get there, and the same time again to get a response. This would be a true intergenerational conversation, the only real-world example of which that I can think of is Julius Caeser finding a letter from an ancient Egyptian Pharaoh, and his reply being delivered to Hosni Mubarak.  And of course even if we did hear, and could return a "message", the odds are the original civilization wouldn't be around long enough to hear it. It's impossible to extrapolate from our own history general rules for how long a species, let alone a civilization, might exist, but it is reasonable to assume, from previous extinctions due to catastrophic events, and even our own unsustainable consumption of natural resources, that there is a limited 'window' during which any species capable of broadcasting an inter-stellar communication would actually exist, and that window would need to be exactly offset to our own window by the amount of time it takes for any signals to get here.
This is illustrated by perhaps the most insightful and deep element in the Star Wars movies, setting the events 'a long time ago, in a galaxy far, far, away'. Apart from being the ultimate disclaimer, it illustrates how much more advanced civilizations than our own, might be a possibility, but only in the distant past.

Overall i think there are 4 main points to consider when talking about 'aliens'.

1) What are the chances there is life somewhere else
Given the size of the universe, and the fact the life is at basis repeating regularities arising from the existing regularities of the universe, then I would think that it is a near certainty that life exists in many places, even if we might not at first recognize it as such
2) What are the chances of lifeforms we would recognize - i.e. animals
Again given that evolution is a regular process, then while it might proceed in different directions, at different rates, in other environments, it is reasonable to assume that if the starting regularities are similar, than some basic features, tendency to size, movement etc. would be common. So again it is highly likely that at somestage, somewhere, there are alien 'animals'
3) What are the chances of conscious life
This is a harder problem, since we don't know how or why we have consciousness, so can't determine how evolutionarily inevitable or likely it is. Personally I would be of the view that it is likely there is , at least one if of many, evolutionary chain of progression of the form reaction-movement-'intelligent' reaction-consciousness since only as part of such a chain does consciousness make sense, since I consider it too ingrained in us to be merely epiphenomenal. So the chances of this are also high, though of course the incidence might be significantly less than (2) and (1).
4) Would we ever interact with alien intelligent life
Unless there are ways to communicate and travel which circumvent the limitation the speed of light seems to place on distances between stars, then I think this last point is vastly less likely than any other, in fact as close to zero as is imaginable.
But of course the travel limitation only seems unlikely based on our current understanding of physics, and it would be arrogant to think this is anything but wildly imcomplete. Even still, the window of opportunity restriction would still apply, so overall I think the odds are between incredibly unimaginably unlikely, and not very likely at all.

At the end of the day, apart from the sensationalism, would proof of any of these points really matter?  (1) would be groundbreaking, but would it be any different from finding bacteria in volcanoes? (2) would be impressive, but any different from (1)? (3) Would be illuminating, since would show consciousness must have some inevitability to it, and be an insight into understanding how it comes about, but apart from confirming what we already suspect, unless we could examine a similar but different consciousness, just knowing about  it wouldn't help so much. Of course (4) , if at the impossible level of scientific fiction, would make a difference, since it would provide just the kind of similar but different examples of intelligent life that could help us understand better our own instance of it. But unfortunately this last point, the only one that really would make a difference, is impossibly unlikely.
ET phone home? Maybe, but if he could make the call, there'd probably be no one left around to answer it.

Napoleon Quote : understand the world of man's youth, understand the man

Napoleon said that, to understand a man, you have to know what was happening in the world when he was twenty