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> the Drake Equation is a religious statement. That is, it is a creative speculation

Creative speculation is not religion just as thought is not superstition.

Creative speculation + experimental verification = science

Creative speculation + certain belief without evidence = religion

Creative speculation + allowing uncertainty = reasoning

Creative speculation + action = decision making

Creative speculation + business implementation = startup

"The Drake equation basically says what anybody who has looked up at the night sky knows intuitively: there are a lot of stars out there, and it's extremely unlikely that we're all by ourselves."

Further reinforcing your core point, it can also tell you that we are. You don't have to be that painfully conservative with the numbers to come with one or fewer per galaxy. For instance, 50% of stars having planets may be a brutal overestimate, a lot of stars are in multi-star systems or other situations in which there are no stable orbits, resulting in any initial planets getting ejected very quickly if they form at all. 2 Earth-like planets per star is a bold statement, depending on the exact definition of "Earth-like", we only have one in our system and if you read past the propaganda in the planet finding press releases they aren't coming up with all that many other "Earth like" planets yet. Yes, that's because they still can't see them, but the press releases convey a false sense of how the search is going when they do things like call a planet with a surface gravity of 3 or 4 G and a surface temperature beyond rock's liquification point a "Super-Earth". 10000 years is a bold estimate for how long a civ will be around and communicating, certainly. I actually am against the self-loathing that some circles find fashionable but 10,000 years is a long time. I consider these numbers generous and it still only comes up with 10.

It's missing some terms, too. Irregular galaxies [1], approximately 25% of the galaxies out there, are thought to be entirely unable to support complex life because basically all the stars in such galaxies will take a system through a region of the galaxy with too much radiation and sterilize the planets every few tens of millions of years. I mean this only as an example, you can go on naming more fairly reasonable criteria that eliminate half or more stars from contention for quite a while (star types, star galactic orbits, other galaxy attributes, even before we get to planets we can eliminate a lot).

To brutally abuse notation, the night sky is O(n^3) in size, if the probabilities of developing civilization are O(2^n)-type it doesn't matter how large the sky is. Big numbers fall fast when you multiply independent probabilities together, and it's not sophistication to just give up and declare there must be a lot of other civilizations out there; it's still a mathematical copout. We don't know.

[1]: http://en.wikipedia.org/wiki/Irregular_galaxy

I agree with your poing, but Mars is earth-like and it could have carried life ...

There is evidence that Mars once carried liquid water on its surface, it's formed out of the same materials (carbon, hydrogen, water) and had all the elements needed for life. Mars lost its liquid water because (contrary to earth) it lost its atmosphere because it also lacks active plate tectonics (also, contrary to earth).

So our solar system has 2 earth-like planets ... with one that became a desert and died, but that was once very much like Earth, with some people still hoping to find microscopic life at the poles.

That's not too shabby. Basically it is considered that if a planet holds liquid water, then it can carry life (liquid water implies other things, like the presence of an atmosphere). Bigger solar systems may contain even more earth-like planets, but I agree: an average of 2 is way too high.

EDIT:

Also, one other thing: if Mars wouldn't have lost its atmosphere, then oxygen would have spread faster than on earth, because the planet is smaller, which means the transition from microscopic life to macro would have been faster.

Or the oxygen would have just managed to kill everything.

Venus is also very Earthlike (potentially much more than Mars in the past) and could have had liquid water and life before the runaway greenhouse effect.

That's what I meant by "it depends on your definition of Earth-like". Mars and Venus are at least debatable, many of the planets being reported as "Earths" in the media aren't. (Yet. I freely acknowledge this will change, and soon. I have no doubt that we will find rocky planets of the approximate right size in the approximate right orbit in the near future. Getting a bead on their chemistry and such is going to be a lot harder for a while, though, but we'll crack that too, eventually.) I tend to favor "actually capable of supporting life" but the equation doesn't seem to actually require that.

Mars has the strike against it that it is arguably on the frozen side of the zone of life. Earth is actually already on the somewhat cold side and has spent a fairly large portion of its life as an ice planet; some have speculated that our frequent ice ages have contributed to our diversity of life by moderately predictable periodic mass extinctions, but of course this is just a theory in all the bad senses of that phrase. Venus is possibly too far on the hot side but I have an easier time envisioning life on a relatively hot planet than a relatively cold one. We have extremophiles here on Earth and who knows what they'd be able to evolve into if they weren't in such a small niche? Whereas cold really puts a stopper on life; a critter can evolve that can survive being frozen and possibly even carry on simple life functions but only at a very slow rate, and for all we talk about how fast and robust life is it does not take very much slowdown of life before you can't get an intelligent civilization evolved before the sun ceases to support life. Life is thought to be ~3.5 billion years old here, and it's hard to pin down exactly how long the sun could sustain non-intelligent life but it could be as little as ~1 billion years. Cold life has a real challenge getting to intelligence in time. (Also why I don't spend any time wondering about life in nebulas; they may be a science-fiction staple but at the rate they could live they don't have enough time to evolve into anything interesting before the heat death of the universe.)

> It's the same as a couple of cavemen sitting on a hill talking about thunder as being large rocks falling from a cliff in a faraway valley.

Those cavemen are doing rudimentary science. They've come up with a testable theory that explains an observed phenomenon of the natural world. If they were to conduct surveys of the cliffs within hearing distance before and after thunderstorms, they'd eventually falsify the theory.

> It just does it in a way that makes us feel like we're receiving some sort of imparted scientific wisdom

If that is the way people choose to see it, that is not Drake's fault. It sounds like you and dantheman really only have a problem with the bullshit "religious" implications some poor souls wish to divine from a dry bit of math.

The Drake equation is not a religious statement until you fill in faith-based numbers.

My only problem is that it gives people some senses of rigorousness, without actually providing it. I could say the chance of extraterrestrial life is .4% pulling that number out of the air, and you can use the Drake equation and get .99% but you know what -- both are made up #s and yours is in no way more accurate than mine, but because of the use of an equation people will think it has scientific merit and is more rigorous.