Why is SETI not receiving ET signals?

Quick note: 05/06/09 - Friends inform me that my idea has been picked up by Universe Today: "So Where Is ET, Anyway?" Just for the record, the following article you are about to read was published March 27th, 2004 - Will I get credit?
:-)

Why is SETI not receiving signals?

Seti - The Search for Extra Terrestrial Intelligence - has for decades now been scouring space for anything that resembles signals denoting sentient life for a significant amount of time without having received any transmission that could be perceived as emanating from an intelligent source.

This is a significant finding. In a Galaxy that has been around for billions of years, the argument that there are a plethora of super-civilizations populating its spiral arms and halo, is very persuasive. Should we not have received signals the moment we pointed a radar telescope into the heavens?

I find little credibility in the arguments that these civilizations failed to communicate with us because they either did not want to communicate with other species or that we are unable to understand their mode of communication.
True, many of these super-civilizations would fall into either of these two categories, however, many would not.
It is reasonable to assume that those that did - or do - want to seek out other intelligent life in the galaxy should have become very proficient at it, considering the age of our galaxy.

According to this reasoning we should be very unlucky to have missed some sort of extra-terrestrial broadcast that would be understood by us on some level as being transmitted from a sentient source outside our solar system.

Yet, wherever we point our listening devices, all we hear is the whisper and random crackle of natural events and background radiation.

What could the cause of this silence be? It is of course quite possible that we may yet discover a transmission or develop a communication process that we as yet cannot understand.

However, there may be another, and to many of us, a somewhat more chilling reason for this absolute absence: There is no-one there.
At a glance, such an argument seems ludicrous in the light if the billions of stars in our galaxy and the endless possibilities for sentient life to evolve from them.
However, what if we include another factor into to formula? What if nature is universal and plays by a set of rules that are inviolate throughout the Universe? What if these rules dictate that sentience is a temporary condition in any location, and is ultimately hardwired for destruction?

This is not so absurd an argument as it may seem at first glance. Consider the endless march of extinct species embedded in the fossilized history of our own planet, or how the existence our own species teeters on the brink of extinction in a furnace of thermo-nuclear war. The scenarios for our obliteration are many and varied, enough for us to realize that it is easy for our species to shed this mortal coil.

One of the remarkable observations one can make about the Force of Nature is that it more often than not presents phenomenon that are inter-related to the surrounding environment. Evidence for this can be observed by observing say, the beaver. The beaver removes trees around a body of flowing water and builds a dam. Eventually, the dam creates a blockage that over the years starts to silt up. This new environment becomes home to a host of other creatures, but for the beaver, the environment becomes untenable and it has to move on.

A stork hunts frogs in a pond. When the frog supply is exhausted, the stork has no option than to search for food elsewhere or perish.

In both instances, we can observe an inevitable sequence; these would appear to be the rudiments of an unchangeable law that would come under the heading of the Force of Nature. We can see that echo-systems are dependent on one another, that they force change upon one another. Only some sort of undefined Law of Change, seems unchanged.

However humbling it seems, it would be foolish to believe that Homo Sapiens are not an inherent part of this universal system.

If we could stand back and look at our behavior on a global level and ask, "What is the single greatest impact we are having on the universe?"
The answer is obvious.
Our species is reintroducing carbon into the biosphere that has been covered over by consecutive eons of time. The oil and coal that we extract, seemingly for our own purposes, is much like the beaver building a dam. We unknowingly trigger unintended events that may not be conducive for the existence of our species, but may be of great benefit to the system as a whole. What if, in performing this inevitable action, we would have fulfilled our role - the byproduct of which - may be that our species is slated for extinction?

Our species has a biased sense of time; we see our collective actions upon the planet as a disastrous event for the biosphere. However, let us consider a worst case scenario and extrapolate:
We extinct ourselves in an apocalyptic thermo-nuclear war. All our cities burn, filling the biosphere with huge amounts of carbon and high levels of radio-activity. There is significant die-off of flora and fauna.
Indeed, a grim picture.
But now, consider such an event through a time-span of our planet. The eon between the mass extinction of the dinosaurs and the present is a mere 1/70th of our planet's existence - or to put it in another way, roughly one year out of the lifetime of a human being. If the planet were alive and cared about its biosphere, it might consider this span of time a mere inconvenience.
Within this time-scale, let us consider the ramifications of our massive thermo-nuclear extinction: The biosphere would have access to all that carbon we extracted in the form of coal and oil. Carbon that, until we came along, had been silted under, trapped away from interacting in the biosphere as it once had.
The radiation would ensure accelerated random mutation allowing for a greater variety of species to proliferate.
In short, come back 65 million years later, and our species handy-work could be appreciated in all it's glory; a richer, more varied and active biosphere for the Earth.

This cannot but help force the question:

What if this is the sole purpose of sentience? That this is an inevitable pattern of extinction by civilization-building species repeating itself endlessly, for ever, everywhere in the Universe - An infinity of species evolving sentience, fertilizing their biospheres, then self-destructing? There would be no super civilizations, merely a temporary emergence, like a blossoming flower.

If this were so, it would be a reasonable answer to the question, why is The Search for Extra Terrestrial Intelligence not receiving signals?

Stephen Goodfellow