Right, we simply don't know the conditions to generate a advanced civilization. We're certainly not it (yet) -- at least in terms of the characteristics we're expecting space-faring extraterrestrials to have.

There might be billions of worlds full of dinosaur analogs running around happily eating and growling till their star burns out...and that might be all that you can expect out of life in the general case when it happens.

"Why didn't the Dinosaurs develop space flight?" Why don't we? Again, in absolute terms of the characteristics we're requiring of an alien civilization, we're not really any closer (in measurable absolute terms) to visiting Vega than a struggling ape is. The furthest distance a human has ever traveled off of the Earth is very slight navigational/rounding error when going to another Star.

I think you don't give us enough credit :-) We have developed enough technology to leave the planet and walk around on our Moon. We are, perhaps within a decade, going to have that capability again but with a much higher level of base technology. While it would be unlikely for Dinosaurian satellites to have remained in orbit for millions of years, anything they left on the moon would still be there.

"There might be billions of worlds full of dinosaur analogs running around happily eating and growling till their star burns out...and that might be all that you can expect out of life in the general case when it happens."

This is the essence of the Fermi paradox I believe. (And I've ordered a copy of the book mentioned below, it looks intriguing) So what hypothesis could support billions of iterations of 'life' evolving into the multicellular form we see today and in our past, and so few evolving technology?

I totally agree it is a somewhat useless question to ponder but I can't help it.

> So what hypothesis could support billions of iterations of 'life' evolving into the multicellular form we see today and in our past, and so few evolving technology?

Probably just a function of environmental input and enough generations optimizing along directions that matter more for species propagation than a large, energy burning cognitive organ. Keep in mind, it appears that Human level intelligence seems to have (so far) only evolved maybe a handful of time maximum in planetary history...and AFAWK only along a fairly specific mammalian family line that happened to live on part of the planet with fairly specific thermal/environmental and energy availability properties.

On a planet slightly warmer than the Earth, the dominant species might be selected to have heat management organs we're not even aware of; or a planet with more landmass vs. ocean, the ability to handle dry climates; or a planet with two moons and higher gravity an efficient metabolism and ambulatory system...some kind of reptilian slug perhaps?

Are savannas necessary to culture space faringness? Or could a planet with no moons, shotgunned with equally dispersed Guam sized islands provide the necessary conditions?

It's useless, but an incredibly fun thought experiment.

I quite like Geoffrey Miller's theory that the human brain is primarily the result of sexual selection rather than natural selection - the hominid equivalent of the peacock's tail.

i find that theory to be unlikely to be true, because its usually not the smart guys but the buff guy that gets the prettiest girls (at least, that is the cultural belief).

Product of our culture more than anything. We'd all be buff if we barely ate and were outdoors/hunting all the time.

I disagree with your characterization of our accomplishments. Getting to the moon isn't just a matter of distance from earth's center, it's a fundamental difference in kind from anything done before by living things on this planet. We could, today, launch a craft in the direction of a star. It would eventually get there, it would just take a long time.

I think the distinction is that getting something going with enough velocity to escape the gravity well of the Sun, and in a vector the points it towards another star's gravity well is different than getting living representatives from a civilization around one star to another.

Philosophically, even an Ark ship, with technology capable of sustaining a population of humans for a million years wouldn't fit the bill since I'd argue that by the time the descendants arrive they:

a) would probably not be the same species anymore, having evolved over thousands of generations for ship life

b) wouldn't be the same civilization anymore, having developed their own micro-civilization in the intervening years -- they'd no longer be representatives from their home civilization...any more than I as an American can be a representative for the European civilizations I am descended from when I travel to Asia

c) their home population and civilization will have evolved and diverged from the Ark's population and civilization regardless of the Ark's conditions. Even if the population on the Ark was put into some kind of suspended animation for the length of the trip (preserving the both the original species and civilization) they'd be representing a species and civilization that no longer existed

One of the semi serious answers is you need a peculiar and somewhat unusual arrangement of land and sea to create a long series of oscillating ice ages every ten thousand years or so (to one sig fig), which is just the right wavelength to very strongly evolve intelligence and civilization. Without that intense adaptation pressure you don't get growth. With enough of it, you get us.

Interesting idea, I'd like to know more. Is 'The Ascent of Mind' by William Calvin what you are referring to?

http://www.amazon.com/exec/obidos/ASIN/0595161146/

My apologies, I messed up by not providing things to google for.

There is a hyper specific (perhaps overspecific) theory by a geologist named Matthias Kuhle with many publications from vaguely the 80s thru the 90s. He's probably the most "famous" of the proponents of the whole plate arrangement theory.

The general idea that plate tectonics causes the overall cycle of ice ages doesn't seem very controversial. What the geologist types seem to fight over a lot is Exactly which of numerous causes contributes Exactly what percentage of the positive feedback loop in Exactly which numerical model.

For example Kuhle has a lot of publications about the tibetan plateau being a great place to bootstrap the glacial positive feedback loop. There's others who get all excited about the precise location of the continents affecting the flow of ocean currents pushing warmth up north... The current that pushes warm water to England so its warmer than alaska, the current that used to flow over Panama but can't anymore, the current that used to not exist over the Bearing straits in Alaska but exists now. Then theres the other folks who get all wound up about continents being over a pole (like antarctica) or landlocking a polar ocean (like the other side, the north pole) leading to glaciers. There's something of a minority opinion about "really big continents with mountains in the middle covered in glaciers"... think America's Glacier National Park as visual model, other than its all melting right now.

I don't know anything about the book you linked to, although it's reviews make it look interesting.

That's all very fascinating! Thanks very much for the reply.

Upvote for dinosaur lasers alone.