This isn’t quite true. There are a lot of things involving biochemistry that still aren’t known, and the exact pathway to the first living matter is one of them.
Also, building chemical structures isn’t as easy as taking them apart. We’ve known the chemical composition of DNA for decades, but only recently have we been able to construct DNA chains to order.
The fact that we can, now, construct DNA chains suggests that, not very long from now, we probably will create a living cell from inert materials. Or…who knows? Maybe not. But this has nothing to do with how nature accomplished the feat, as nature had many millions of years to try different things.
In fact there may be multiple pathways to abiogenesis, and we may never know which one occured on Earth. If we ever find another planet with life we probably won’t ever know exactly how it happened there, either. But given enough planets to examine we might find a few examples of the process of abiogenesis in action, if we are very lucky.
Yes, beavers can build dams, and ants can ranch aphids, and birds build nests. But this is not the sort of technology that I was talking about. Perhaps I stated it poorly, it was late on a Saturday.
I was thinking about the ability to mine ore and turn it into tools for example. Global commerce lanes. Harnessing electricity. Things like that. If a blight hits the trees in the beaver’s domain it is not going to be able to relocate to a more favorable area, it can only move in a very limited range. An Alaskan beaver cannot relocate to Wisconsin unless they develop air travel. If a squirrel’s stored nut supply gets flooded out it will not begin importing French acorns. When the aphids in an ant colony die out due to whatever reason, the ants will not begin to buy grapes from Peru during the Winter.
We alone have demonstrated our ability to use tools and technology to the extent that we can live anywhere on the planet. Lower animals have skills that I would not describe as technology.
And it is this sort of technology that may be very rare, Perhaps non-existent. I am reasonably sure that life exists elsewhere, probably within our own solar system. But the sort of technology that allows a species to even look off-planet, to travel in a limited way off-planet, that is going to be rare or non-existent.
We find no signals or hints or other intelligent life not because there isn’t any, there must be. But the Sci-Fi consensus is that we are late to the party in a universe that is full of technological civilizations. I just do not see it.
And I am a both a participant and donor to SETI programs.
Interesting… I’d have said that intelligence is the choke-point, but once a species gets intelligent enough to chisel rocks and control fires, they sky is no longer the limit. I’d have said that stoneworking and fire are guaranteed entry-points to advanced technology: the first domino in the row has been tipped.
But advanced intelligence? I’m terrified that this is what may be horrifically rare in the cosmos. We’ll go out there and find algae mats on planet after planet, and maybe even the rare environment with megafauna… But flint-knappers and pyromaniacs? They might be only one in a trillion.
My point was that all the potential possibilities (Drake equation, etc) aside, the one big unknown is how “inevitable” is it that life will arise. There is no way to know or predict it. Maybe it would happen almost every time, maybe we are the one off.
I like the Drake Equation, but, really, all it does is break up the unknown into sub-unknowns.
Sort of like…What is the probability of salt? Well, if the probability of Sodium is x, and the probability is Chlorine is y, then the probability of salt can’t be more than x * y. It doesn’t really add anything to our knowledge; it just compartmentalizes it.
As a tangential question semi-on-topic, I often wonder why the dinosaurs never developed an intelligent, technological species. If intelligence of that sort (our sort) is common through the cosmos, the fact that they had 150 some odd million years to do it, yet didn’t, might be very telling as to its true rarity. There may have been some constraints in play which did not affect our evolution-it may seem to us to be a very viable and advantageous series of adaptations, but there may be some very good reasons why it has remained rare, at least on earth.
Could elephants (if they don’t go extinct of course) ever develop such a society? All they need are some dextrous fingerlike trunk extensions…
Disagree. Sub-dividing what we don’t know is often very useful; almost as useful as sub-dividing a task.
And indeed some of the unknowns are definitely firming up, such as the proportion of stars with planetary systems.
It’s true however that the only way we’ll be able to fill in most of the variables, is by actually visiting a large proportion of stars, at which point the equation is moot anyway. But in the meantime at least it’s a useful response to the common line of “there are lots of stars, and we know sentient life is possible, so sentient life must be common”.
The galactic core region is an unpromising long-term abode for life in any case, given the radiation from the central black hole accretion disk, the increased frequency of nearby supernova explosions, etc. Gamma ray bursts just confirm what we already know in that regard.
Unless the probes remain around for millions of years (a timescale in which they’d get scraped up pretty badly by micrometeorites and perturbed out of orbit unless their self-maintenance lasts far beyond the time necessary to survey the system and report home), they’re unlikely to be around at any given moment. For that matter, unless they specifically acted to make contact or were in the Earth-Moon system rather than anywhere else in the neighborhood, they’d be as effectively invisible as Russell’s Teapot.
Perhaps it may be inhospitable for naturally evolved life, but a reasonably advanced civilisation would find it relatively easy to protect itself from a supernova or GRB. If a space-faring civilisation can protect itself from cosmic rays, it could also have ways of dealing with short-lived peaks in radiation flux.
My apologies for unclarity; I like the Drake Equation approach! I love the fact that we can give very accurate estimates of certain of its terms.
I only meant that it can’t help us with the final answer, the “N” that the Drake Equation measures, because we don’t know the values of some of the terms.
e.g., I think the biggest “choke point” is the number of species that achieves advanced technology. But others might say that certain other values are the limiting values. (I’m VERY worried about the longevity of technologically advanced civilizations!)
Definitely, one of the niftiest things about Drake’s idea is that it allows us to focus our thoughts more narrowly on these kinds of analyses.
I only wanted to call attention to your “unless” clause. We’re only in the very early stages of self-repairing machines. It might be that self-maintenance technology can become good enough to permit multi-million year missions.
(At that point, we’d also likely be able to enjoy multi-million year lifespans. But…do we really want civilizations with multi-million year consensuses on societal goals? It sounds as if it would be extremely static, and violently hostile to creativity and innovation…)
Every advantage seems to come with a built-in disadvantage to help spoil it!
How long has it been since the dinosaurs roamed the earth? A few million years? Tens of millions? What sort of evidence (looking at what we do and make) would they have left, such that we could recognize it after that long?
Which is to say, how can we assume that they did not?
It may also be worth noting that abstract intelligence, at least as we know it, is not an evolutionary advantage in terms of species survival, which is the framework for natural selection. Homo Sapiens would have done just fine without intelligence, and there are those who would argue that the results of our development have pointed toward some pretty severe negative consequences from it.
We in fact may not be able to rein it in to the point that we can avoid extinction because of it, after but a few decacenturies.
If the civilization is advancing, even slowly, it just wouldn’t make sense to design probes to last for millions of years – a newer better probe can be sent every few thousand years even if travel is limited to a low percentage of c.
Given that, it’s entirely possible that the last alien probe passed through before the invention of the telescope. For that matter, as I noted in the earlier comment, there could be any number of them elsewhere (i.e. not orbiting Earth) in the solar system right now.
I think mammals were around during the time of dinosaurs, starting around 225 million years ago or so. It took that long to develop the human brain. Dinosaurs had to cope with multiple extinction events. It takes time for evolution to build increasingly complex things and competition over resources does seem to lead to more complexity. Intelligence isn’t necessarily the goal of evolution, but given enough time, intelligence is a form of complexity you might expect, given enough time and some luck.
That’s the problem. What we currently know of physics suggests that something like warp drive isn’t possible. It’s not science fiction, it’s fantasy. Barring some sort of revolutionary, turn-the-scientific-community-compeltely-on-its-head discovery, the only way we could ever interact with aliens 20,000 lightyears away is if we (or they) decide that it’s worth it to spend more than 20,000 years travelling to your particular star. That’s a heck of an investment to make.