If civilizations exist in our galaxy with levels of technology at least equal to our own, we might be able to detect some of them using radio telescopes. And if civilizations exist with technologies far in advance of our own, we might expect them to have colonized millions of habitable worlds in the Milky Way, and even to have visited our own planet. Yet there is no evidence in the astronomical, geological, archaeological, or historical records that extraterrestrial civilizations exist or that visitors from other worlds have ever been to Earth. Does that mean, as some have concluded, that ours is the only civilization in the galaxy? Or could there be a natural self-regulating mechanism that limits the intensive colonization of other worlds? In 1961 radio astronomer Frank Drake devised an equation to express how the hypothetical number of observable civilizations in our galaxy should depend on a wide range of astronomical and biological factors, such as the number of habitable planets per star, and the fraction of inhabited worlds that give rise to intelligent life. The Drake Equation has led to serious studies and encouraged the search for extraterrestrial intelligence (SETI). It has also provoked ridicule and hostility. Novelist Michael Crichton recently denounced the equation as "literally meaningless," incapable of being tested, and therefore "not science." The Drake equation, he said, also opened the door to other forms of what he called "pernicious garbage" in the name of science, including the use of mathematical climate models to characterize global warming. Crichton rightly pointed out that any numerical "answers" produced by the Drake Equation can be no more than guesses, since most of the terms in the equation are quantitatively unknown by many orders of magnitude.

But he is utterly wrong to claim that the equation is "meaningless." An equation describes how the elements of a problem are logically related, whether or not we know their numerical values. Astronomers understand perfectly well that the Drake Equation cannot prove anything. Instead, we regard it as the most useful way to organize our ignorance of a difficult subject by breaking it down into manageable parts. This kind of analysis is standard, and a valued technique in scientific thinking. As new observations and insights emerge, the Drake Equation can be modified as needed or even replaced altogether. But it provides the necessary place to start.

View: Full Article | Source: Astrobiology Magazine

WOW... what a humbling article... I agree 100%... it is almost like I have always known about Harrison's regulatory mechanisms but have never put those thoughts into words, and here we are with someone else doing the thinking for me... how lucky we would be to experience extra-terrestrial contact... but like the article suggests, it is a gained privilage and we by no means have any right to this galaxy or this universe since life evolves and is prevalent anywhere and everywhere that it possibly can be... therefore we must stop and slow our ever expansive and territorial nature because we are at a stage which warrants caution and light steps into the future in order to preserve our own intelligence in the hopes that our existance may be benificial to the universe which has spawned us... I guess we must seperate our emotions and tendancies into two categories, those which are instinctively primal and those which are intelligently induced in order to understand how to properly proceed into the furure... for primal insticts are those which were only necessary in the past and those which have no place in the future... If we don't discard these instincts then they will pull us back into our past, they will make themselves necessary again.

Always beware of the self-aggrandizing (Crichton) when he/she/they speak out against the humble (Drake).

Sure, there is "no evidence" if you just ignore all the evidence. The collections of data on landed UFOs with occupants nearby or inside is very good evidence that we are visited by hundreds of species of star-traveling humanoids. See UFOs, PSI and Spiritual Evolution, 2005, or, if you can find a copy, the technical monograph edited by Charles Bowen, The Humanoids, 1969.

Those who assume advanced civilizations would colonize the galaxy have been reading too much science fiction. Isn't it a bit absurd to assume that old species would behave like us? We would colonize the galaxy, if we could. But then we are only 40,000 years old. We are a primitive and brutal and uncivilized species, as proven by our wars, murders, rapes and child molestations. I am sure that intelligent species either outgrow that, or go extinct.

As for the Drake equation...even if it weren't a combination of unknowns, the fact of the UFOs and our star-traveling humanoid brethren shoots it down, and makes it irrelevant.

Cebrakon

Eloquent, but not practical.

We (The USA) had the technology to send people to the moon 36 years ago yet we haven't been able to expand that vision. Not only have we not been able to expand it, we have been drawn back.

It's not because the technology isn't available to expand. It is. It's because global conflict, nationalism, and religious extremism have won out versus human exploration.

If every country, religion, and person were to put aside their political, idealogical, and religious differences, we'd have set foot on Mars by now.

It has NOTHING to do with territorial conflicts. It has EVERYTHING to do with money. Money revolves around resources. As resources become less available, money follows suit.

We as a world have the technology now, and have HAD the technology to completely eliminate the dependence on fossil fuels, yet somehow oil still drives the world economy.

Territorial conquest is only secondary to the engine that drives it.

MONEY

Hmm...well, nothing new here.