A doco I saw tonight...

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Posted: Mon Feb 18, 2008 9:15 pm

Standard Procedure wrote:

Maybe the Martians many millions of years ago did something to cause their downfall. We might do the same...

If there ever were ever any "Martians" odds are they might not ever have made it out of the microbe stage. I think humans tend to expect that all life strives to evolve and become human someday. As far as anyone knows, of the 10 billion species that have sparked into existence and then sputtered out on earth, only one has ever become a city building, history writing civilization.

Most species never had the chance to wipe themselves out. They were probably out competed, or done in by environmental changes.

Baiting Guru Joined: 04 Jan 2006 Posts: 3193

Hekate wrote:

we can now build fairly accurate timescales for our species' progress.

I think you're probably right about humans; the timescale is too short to hide that sort of thing, but how about dinosaurs? If they had built an advanced civilization for say ten thousand years, how likely is it that we would miss it 60 million years later? Maybe we would expect to see something in the fossil record if they achieved a population of six billion, but if they died out before the industrial revolution, my untrained hunch is that it would be possible for it to not be evident.

Posted: Mon Feb 18, 2008 10:28 pm

Well, let's assume that what you said did happen, and that there is no material culture remains of those dinos' civilization, wouldn't there still be something, even the tiniest "WTF?" feature left in their biological remains, which we do have? Larger cranial capacities, more dextrous fingers/limbs, or whatever would look out of place for the typical "non-cultural dinosaur" morphology? Or, as with the "other appearance of humans" scenario, and the culture-using dinos were wiped out completely, then we'd still see at least something baffling in their predecessors which abruptly stops.

In short, it's as Hekate said, but applying to biology... it's very difficult to remove something from the historical record completely as there isn't just what's left behind but also what came before that leads (and gives us clues) to that 'missing' thing.

Posted: Mon Feb 18, 2008 11:13 pm

I was thinking hypothetically. Obviously there is fossil evidence to prove the progression of man. I guess I have a little too much time on my hands (Reading week at uni) to think about this stuff and ponder about our fate...

The point about radio waves turning into static within 1 or 2 lightyears has me wondering though. If NASA broadcasted a Beatles song from one of their satellites, how do you expect anyone to find us if that turns to nothing more than static in a lightyear or two?

Posted: Tue Feb 19, 2008 2:48 pm

Wow - this is quite an intelligent sounding thread - it won't last! Laughing

I'll have to think about the static thing - but I suspect that unless the aliens have technoclogy that can do things we can't conceive of, they wouldn't be able to track static back to us.

Baiting Guru Joined: 04 Jan 2006 Posts: 3193

The radio wave do not actually turn into noise. They just get so faint that they are indistinguishable from the background noise. There are ways to retrieve signals that are so faint, but TV signals are not good candidates.

@Otterfan, I am not being particularly serious, it is just an interesting thought experiment. Given that humanity has only been producing artifacts for 10k years, and most of those artifacts would not survive or be obvious in the fossil record, it seems unlikely that it would be easy to be sure that there was no brief dinosaur civilisation immediately before the K/T event.

The physical adaptions do have more chance of noticing such an event, but the fossil record is very sparse. Can you be sure that there was no single species of dinosaur in those few million years with the required adaptions? Can you be sure which adaptions would be necessary for such a civilisation, rather than just associated with ours? Are there perhaps alternative adaptions that may also lead to civilisation?

Posted: Tue Feb 19, 2008 4:22 pm

I agree, it's something to think about and speculate about, and you can get immersed in all the what-if aspects.

My point was, though, that if you have feature C which is essential for civilization (however you want to define that---let's for the moment say that the base requirement is that there is a material culture that is passed down the generations, allowing improvement, adaptation, etc). Whatever C is, you will have to see some path leading from non-C to C in the pre-C phylogenies of the 'civilized' species.

To be less abstract, and looking at humans, if we say that language is our feature C, then many of the biological adaptations took thousands of generations (or even longer) to arrive at the C state.
For example... the lowering of the larynx (claimed by many to be essential for human speech) didn't happen overnight. Broca's area in the brain has its analogue in the F5 area of monkey brains (implying that our common ancestor had that trait). The baso-cranial flexion unique to humans can be seen in our fossil ancestors as it develops through evolutionary time. The enervation channels and foramina that control speech muscles and lung control can be seen to increase in size from earlier pre-Homo ancestors through to ourselves. Categorical perception (being able to tell a /b/ from a /p/ and not hearing some strange blend in between) is present in many species of primates (and even alleged to be present in quails), showing that a common ancestor in deep evolutionary time had that feature already.

And so on.

All of these features have traces that can be found prior to the fully-fledged language-using species, in various states of moving gradually from pre-C to fully-fledged C states.

So too I would expect with the material culture dinosaurs. There would be something, however small and trivial, that would make dinosaur experts stop and go "Huh? What's going on here?" in the ancestors leading up to the material culture species. It would look strange because it looked either so out of place or seemed to imply a trajectory towards something grand but then disappeared, stopped abruptly and swallowed up in whatever scenario you propose was responsible for wiping out the actual material-culture species.

I think probably the only way you could have material-culture dinosaurs AND have them hidden totally would be if there was a sudden evolutionary leap from ordinary dinosaur to material-culture dinosaur in either one generation (very unlikely) or in a very small number of generations (which would rely on some extreme selective pressure and heck of a lot of good fortune mutation-wise---literally "hopeful monsters" [geeky joke for evolutionary theorists]).
That would be taking punctuated equilibrium to an extreme I doubt even palaeontologists would be comfortable with.

Posted: Wed Feb 20, 2008 1:06 am

thud419 wrote:

The radio wave do not actually turn into noise. They just get so faint that they are indistinguishable from the background noise. There are ways to retrieve signals that are so faint, but TV signals are not good candidates.

So I guess that an invasion from Omicron Persei VIII in 1000 years time for knocking Single Female Lawyer off the air is out of the question Very Happy

Interesting discussion that is happening...

Posted: Wed Feb 20, 2008 11:21 pm

Standard Procedure wrote:

... nothing that we create will last forever. ...

There's an old astronomer's joke about that:

Two planets meet each other in outer space. One planet says to the other: "Hey, I have homo sapiens." The other planet says: "don't worry, that goes away pretty quickly."