The idea of the potential of other pre-historical societies developing being unlikely was brought up as there is no trace of industrial activity in the geological record, that is making the assumption that a technological race would have to develop in the same manner that we did. Keep in mind that much of our development and the traces we’ve left (and are leaving) behind have been the result of conflict among ourselves, and greed. The choices of another species on this planet may have been more biologically harmonious and based on simple curiosity, rather than one-upping the neighboring tribe, or even just the guy next door. But that Cobra-La-esque speculation aside, the assumption that our society’s way is the only, or likeliest way, just because its the only example we have, seems like a circular self-serving logic error.
I’m glad you found this episode as stimulating a we did Linton, and thank you for the encouraging words.
To this point I would simply state that any emerging intelligent species on the planet would leave behind a complete fossil record, and clear evidence of their rising civilization – if only in the form of spearheads or primitive pottery. And we’ve found nothing like that in all of the archaeological digs spanning thousands of years – everything we’ve found (and we’ve found irrefutable evidence of our current evolutionary model dating back to trilobites and beyond) conforms to the conventional model that humans represent the first civilization to arise upon the Earth.
I suppose that some intelligent fish species –might- have been able to arise undetected by archaeology, but even that seems a stretch, because we have lots of areas that are now above ground, that we formerly beneath the ocean, and no pre-human civilization of any kind at all has been detected.
It really comes down to this: we now have every reason to believe that technological civilizations have arisen billions of times throughout cosmic history, randomly distributed throughout the galaxies. So the only reason we wouldn’t expect them to send devices here, is if interstellar travel is impractical for all civilizations no matter how advanced they become.
But as marduk points out, we already have the capability of sending small probes to other stars – we just haven’t done so yet, because the time and energy issues seem too impractical and costly. Certainly that’s going to change – the fastest speeds attained by human technology are growing asymptotically, and, we already have a compelling theoretical argument that presents the credible possibility that one day our technological capability will surpass the speed of light to a theoretically arbitrary degree, while also circumnavigating the problems of time dilation and the energy consumption problems associated with the very primitive rocket principle that we depend on today.
So if we simply extrapolate based on what we know about our own technological and scientific progress, it’s easy to see that many interstellar civilizations have already likely arisen throughout the observable universe, and making a trip to see what us zany humans are getting up to may be as easy to them as taking a ferry across the river is for us.
Fermi was right to ask the question “where is everybody?” Where he erred, is that he didn’t look up to see them in our skies, and he dismissed the untold thousands of accounts from all the people who did and witnessed an extraterrestrial device passing overhead.
Gene brought up the point of why haven’t we heard the E.T.’s? The follow up to that was all on point. The likelihood of us picking up any sort of signal, intentional or otherwise indicating another society seems unlikely, and that is just assuming that those potential societies would communicate in a similar method. I’ve made this point before, but it bears restating, that it is exactly this argument that makes the chances of an alien race stumbling upon us terribly unlikely. Yes, like us, they could scan for potentially habitable planets, and hop over to go “wow look at that” (and that is where the ETH has the strongest argument for me), but when I weigh the probability of that, against, the likelihood of another species having developed right here, maybe even millions of years before us, right here just seems more of a probable than the possibility of what might be out there. ‘Cause there are a heck of a lot of giant brains on this little world constantly observing the great out there and picking up wondrously near imperceptible things like gravity waves, and yet nothing that has made us go “hey that looks like the traces of a civilization”
I would argue that because we don’t yet have the technological capability to detect evidence of exosolar civilizations, that the absence of that data is meaningless.
As we discussed on the show, picking up radio signals from a civilization like our own 20th-Century civilization is impossible for our best modern technology – and the chances of such a civilization going through that same era at basically the exact same time that we did, is indistinguishable from zero.
And as we’re seeing right now, there are vastly more efficient, lower-energy methods for transmitting information. So we’re becoming harder to detect as time passes. Any civilization even more advanced than ours will broadcast even weaker signals than we do today, because technological advancement is directly proportional to
efficiency.
I’m hopeful that one day we’ll have a space telescope of sufficient size and clarity to detect artificial light on the dark side of exosolar planets, emitted from civilizations of arbitrary sophistication, because as we’ve seen on the Earth so far - cities grow in brightness each and every decade –
and it will probably always be practical to light cities at night. So the "night-time artificial lighting footprint" of a civilization may span the entire existence of that civilization.
But we may also detect atomic tests from exosolar civilizations – I would think that the power of those signals would propagate much further than the comparatively weak radio and television station broadcasts from the 20th Century. And as Chris pointed out on the show, it sure as hell seems suspicious that we were inundated with ufo sightings not long after we detonated our own nuclear bombs for the first time. If I were an interstellar civilization picking up atomic blasts from some backwater solar system, I know I’d send some probes to covertly monitor that planet to see what the lunatics there were doing to their own planet and ecosystem, or to see if they’d simply annihilated themselves at the first opportunity.