More than meets the eye

Scofflaw

pH wrote:

There are reasonable estimates that even without ftl a species *should* be able to colonize a Galaxy in a timeframe of the order 5m to 50m years, which given current estimates of the age of the the universe is a tiny proportion of the time available to have done so.

As far as I know, nobody has addressed Fermi's paradox satisfactorily, if intelligent life is reasonably common and the universe 14 billion years old then it *should* be all over the place.

http://en.wikipedia.org/wiki/Fermi_paradox

On the other hand a certain number of people have side-stepped it by pointing out that (a) there is no requirement to colonise the Galaxy, and/or (b) we have no evidence that it hasn't been done.

cordially,
Scofflaw

Demetrius

Hmmmm...well to side-step that, you could say that all life as we know it (if as a species it is to survive and reproduce) usually moves into many areas that were previously uninhabited, so the question remains-why aren't they here?

As regards radio signals and how we have only been listening for a short while...why aren't we picking up signals from hundreds, thousands, millions of years ago? Surely, if the galaxy is teeming with life as we know it, then maybe there should be signals bouncing ever which way. So why is it so quiet?

I know that I am sort of projecting my ideas of what this "life as we know it" should be doing ie colonising, sending beacons and transmissions for signs of life, whatever.

humanji

Well there's the fact that we can't say for sure what life elsewhere is like, or how their technology could develope. They may have been sending signals to Earth for thousands of years, but we don't have the facilities to pick up the signal.

Then there's also the argument that maybe the UFO conspiracists are right and contact has been made here already, but considering how war-like humans are in nature, why would they want to have anything to do with us?

And finally, since our most powerful telescopes still only see the stars of most solar systems and not the planets themselves, it'll be a long while before they are powerful enough that we can see a little green in his underwear, sitting in his back garden drinking bear and wondering if there's life outside of his world

Anyway, didn't NASA find bacteria or something on a meteroite a while ago? Can't remember if anything came of this. Does anyone know?

coffee_cake

http://www.nasa.gov/centers/ames/news/releases/2001/01_11AR.html
http://www.nai.arc.nasa.gov/news_stories/news_print.cfm?ID=193

looks like it, yeah

Demetrius

They found calcium carbonate deposits, which are similiar to the type of deposits that certain bacteria produce in certains on Earth (I think in certian hot-springs in Australia?) on a chunk of rock found in the Atlantic which came from Mars. Seemingly, a big meteor crashed into Mars, flining out bits of Martian rock which ended up crashing to Earth.

It wasn't conclusive evidence though. Some scientists say that the deposits were made by bacteria on Earth after the meteorite crashed here for the metorite had been on earth for quite some time.

5uspect

Demetrius wrote:

Hmmmm...well to side-step that, you could say that all life as we know it (if as a species it is to survive and reproduce) usually moves into many areas that were previously uninhabited, so the question remains-why aren't they here?

Isn't the whole problem with the Drake equation that no one can decide what the odds for intelligent life are? There may very well be lots of life out there, it just never had the evolutionary pressure to become highly intelligent like humans and develop technology. Human like intelligence occurring just once (as far as we know) on this planet.

If a form of life could exist in deep space and not be tied to planets then you would have a very interesting point.

Demetrius

Whoops-looks like I got it wrong according to Bluewolf's link.:) Damn, I thought it was calcium carbonate...

Son Goku

5uspect wrote:

Isn't the whole problem with the Drake equation that no one can decide what the odds for intelligent life are?

The Drake equation was always a bit dodgy/pointless, in the sense that it's merely a statement of how probability works rather than an equation with actual content.

Scofflaw

Demetrius wrote:

Hmmmm...well to side-step that, you could say that all life as we know it (if as a species it is to survive and reproduce) usually moves into many areas that were previously uninhabited, so the question remains-why aren't they here?

Actually, if you look at a map of human habitation on the earth, you can see that we restrict ourselves pretty much to the comfortable environments. If we have the technology to get to another planet, it's easier and pleasanter to colonise something nice.

Demetrius wrote:

As regards radio signals and how we have only been listening for a short while...why aren't we picking up signals from hundreds, thousands, millions of years ago? Surely, if the galaxy is teeming with life as we know it, then maybe there should be signals bouncing ever which way. So why is it so quiet?

Possibly because radio communication is a short step before you start using quantum-entanglement instead?

Demetrius wrote:

I know that I am sort of projecting my ideas of what this "life as we know it" should be doing ie colonising, sending beacons and transmissions for signs of life, whatever.

Quite specifically Western ideas...even the idea that technological progress is a goal is a Western idea.

cordially,
Scofflaw