Is it a rare fluke here ? No it finds a foothold in every possible environmental niche include harsh ones Extremophile - Wikipedia
Extremophiles are fascinating critters, but I just want to make sure that nobody jumps to the wrong conclusion about them, because that’s easy to do. What they show us, is the marvelous adaptive power of life
once it has a foothold in a favorable environment – i.e., after a thriving biosphere has arisen, it’s very difficult to sterilize a planet via natural catastrophe and whatnot. What extremophiles don’t show us, is that life can
arise in harsh conditions: if that were true, then we’d see a vibrant ecosystem on Mars, or Venus. I wanted to point that out on behalf of the casual reader, because it’s a common misunderstanding.
Is this likely to be a universal imperative ? It seems like it might be.
I’m not comfortable with the phrase “universal imperative,” because it feels reminiscent of the “intelligent design” argument. But we certainly now have firm empirical grounds to conclude that the prevalence of organic chemicals and favorable planetary conditions throughout the universe provide ideal conditions for the emergence of life. And if life gets started on only 1 in 10 well-situated Earth-like planets, which seems like a reasonable ballpark estimate given what we now know, then there are
at least 2-4 billion independent biospheres
in our galaxy alone. If intelligent life arises within only 1 in 1,000,000 such biospheres (which I feel is an unjustifiably low estimate), then at least 2-5000 intelligent sentient species have arisen within our galaxy.
I’d like to make another important point here, which most people overlook because it’s easy to miss unless you’re an incurable physics junkie like myself. The metric propulsion concept that we’ve seen with Alcubierre’s work (and which we’ll see more about in the years ahead) is a radical game changer regarding the significance of cosmic-scale distances. There is no known theoretical upper limit for the speed that one could attain via such a system. Last week I did a back-of-the-envelope calculation to arrive at an order of magnitude estimate for the metric expansion of spacetime during cosmic inflation – which might suffice as a substitute for an upper velocity limit, in lieu of a theoretical argument. It came out to roughly 10,000 billion billion times the speed of light, or in long form, 10,000,000,000,000,000,000,000 times the speed of light. To put that in perspective, at that speed it would take .000145 second to reach the edge of the observable universe (a distance of roughly 46 billion light-years).
But beyond that, a metric propulsion system obviates the significance of the cosmological horizon, because it uses the same underlying mechanism as the Hubble expansion. In practice, this means that a metric-propulsion device could not only leap the vast distances between stars and galaxies – but it could reach far beyond the observable universe, which we now know is only an infinitesimal fraction of the known universe (by our best current estimates, the universe appears to be infinite, or in astronomical parlance, “flat”).
So if one is predisposed to thinking of the observable universe as “our” universe, then one could confidently say that extraterrestrial species with metric spaceflight capabilities could arrive here from “beyond our universe.” Because the “cosmic event horizon” (and also the event horizons of black holes) are readily traversable using a metric propulsion system, once one can produce an adequate magnitude of spacetime deformations. Such are the mind-boggling spaceflight capabilities, once a civilization transcends engineering within the context of special relativity, and begins engineering with general relativity instead.
I'm going to jump into the deep end here and add a thought or two, even though I am neither as well-versed in these issues as Thomas, Constance, Mike, Trajanus, and Burnt, nor as intellectually capable as you lot. I'm going to focus my observations on the back-and-forth between Burnt and Thomas to keep things manageable and so I don't have to keep name-dropping everyone else engaged in this lively and interesting discussion.
I find Thomas' line of reasoning articulate, reasonable and full of merit. I also agree with Burnt that quite a large number of assumptions are being made. Thomas, it seems to me, is arguing strictly from the scientific method standpoint to support the ETH. A perfectly rational and compelling approach and if one chooses to subscribe to that technique he makes a very strong case. Robert (Burnt), on the other hand, IMO, is coming from less a scientific angle, and more of a philosophical approach, as it pertains to the ETH. His approach (to me) is a classic Pyrrhonian position of "let's suspend judgement" because we really don't "know" anything. Not that the ETH is incorrect, per se, but simply that he is unwilling to accept, as such, any of the individual hypotheses that traditionally make up the bulk of the ETH in total. Those assumptions (hypotheses), based on cumulative observations of real physical phenomena over time (by Robert himself, even), that Thomas so eloquently lays out in his argument, are not ones Robert is willing to accept given the philosophical underpinnings of his approach to the topic. Thomas and Robert are speaking two different languages. Or, to bring the religious metaphor into it, two different belief systems and never the twain shall (probably) meet.
Regardless, I find the whole discussion intellectually stimulating and feel privileged to be around such thoughtful and intelligent people. Thanks for the serious thought and effort you put into this thread, and the forum in general. I, for one, really appreciate it.
Welcome to “the deep end” Chris – and thank you for the kind words and thoughtful contribution. I think you’re right: I feel like Robert and I are talking past each other, and it must be due to some underlying philosophical disparity that I don’t understand, because clearly the facts are on my side (haha…just kidding around).
I feel like I should point this out though, to avert any personal misunderstanding: I’m a strong adherent to the adversarial debate method. I think that we all have an obligatory responsibility to the significant effort we’ve put in to parse the data and arrive at our viewpoints, to represent them and to defend them vigorously – like a lawyer defends a client. So if I get strident, that’s why. It’s not a personal attack; it’s just me playing the game of Meme Wars, because I see the realm of ideas as a kind of ecosystem – and the best idea should always win, because that’s how human civilization slowly but surely advances.
And to anticipate a common rebuttal that gets trotted out about now "The vast distances" rebuttal, Let me say this.
When the Europeans "discovered" America and Australia The native peoples had no way of traveling the vast distances from Australia and America to England and Spain.
Oh they could make short voyages using their technology, paddle up a river or to nearby islands, their equivalent of our moon landing and mars probes etc.
But they could not traverse the vast oceans. It wasn't that it was impossible, it just wasn't possible with their level of technology. The Europeans with their more advanced vessels could do it, But they couldn't.
The native Australians would have been wrong to assume Europeans couldn't be visiting them because they themselves didn't have the ability to travel from Australia to England.
That’s a good “toy model” argument, but in fairness, it is a little cavalier about the fundamental leap that we’re discussing: in the spacefaring scenario, building a bigger/better “boat” isn’t going to get the job done. Practical manned interstellar travel calls for an entirely new technology, which we don’t have yet. So I can understand why people get stuck on this part – it is a sticky issue.
But this is where a strong science background comes in handy. Historically, and fairly routinely, the most exotic, subtle, and perplexing theoretical predictions of our most reliable physical theories (both quantum field theory and general relativity) – which at first seemed far beyond the grasp of any foreseeable human technology…suddenly appear in the headlines not long after they’re first discussed in the theoretical literature. It takes a fairly long-term and intimate familiarity with these kinds of experimental breakthroughs to really appreciate the tangible inevitability of that transition from theory to experimental confirmation - and it doesn’t help matters one bit, that the least proficient members of the scientific establishment are always the most vocal critics of such efforts…until they actually happen in the lab. So the general public is almost always surprised when they do.
And this is the same pattern that we’re seeing play out again right now, with respect to the theoretical prospect of a gravitational field propulsion mechanism. Our best theory says that it’s attainable, but there are still hurdles which appear to be insurmountable to the average Joe. So the general public remains unconvinced regarding its inevitability, and they’ll once again be surprised when it actually happens. But it will. It could take longer than we’d like, because it is a very substantial challenge to our present-day technology, and there are still some significant challenges to work out theoretically. But I have faith in human ingenuity, because to date, human ingenuity has prevailed in these kinds of situations again and again and again, without exception. Or the theory that made the prediction gets overturned, which just doesn’t seem likely – GR has passed every test with flying colors (to the tune of observational precision levels from one part in a few thousand, to one part in >10^20).
Agree completely with everything you've said, it's threads like this that really make you think and put the Paracast forum in a league of its own. It's a pity Usual Suspect isn't around at the moment he'd love this debate.
I agree. I sometimes despair over the debate tactics deployed at The Paracast forums, when the most cynical voices among us drown out the otherwise vibrant dialogue that we enjoy here. But bracing and sincere conversations like this one remind me of why I got so engaged here in the first place.
So in closing, I’d like to “call out” a kind of deeply dishonest rhetorical attack that we sometimes see around here, so we can all be aware of it and hopefully see less of it in the future.
I first noticed it when Paul Kimball kept using the phrase “space aliens,” even after I pointed out that this kind of language represents an intellectually bankrupt and grossly dishonest debate tactic. There’s absolutely no rational basis to object to the possibility, and in fact the now extremely high probably, of other technological species in this universe – so this tactic is deployed to make the idea
sound stupid. In practice, this falls into the same category of banal and ugly abuse of rhetoric that people like white supremacists use when they call black people “jungle monkeys” – failing to find any empirical or rational argument to defend their failed ideology, racists resort to this kind of rhetoric to dehumanize the targets of their outrage. There is
no place in civil discussion for this kind of vapid and hateful, purely rhetorical kind of attack. At a minimum, its use signals that the person exploiting this kind of language can’t defend their position rationally, but refuses to acknowledge that fact.
Another disingenuous rhetorical device that comes up on The Paracast show and these forums, is the phrase “nuts and bolts craft,” which is clearly used to ridicule the idea of physical craft arriving here from elsewhere. It sounds so 19th Century, doesn’t it? As if we’re talking about flying lawnmowers or something. But a predominant and widespread feature of ufo descriptions from eyewitnesses when they get close enough to look for such things, is the
absence of ordinary mechanical features like rivets, and seams, and so forth – aka “nuts and bolts.” To the contrary, we typically hear reports describing the unusually smooth, seamless, curving forms of these devices, which look strikingly advanced by our standards. In fact just this week we heard briefly about Jan Harzan’s fascinating personal account, and as he described precisely this kind of smooth seamless engineering, the fact that he saw what looked like a bolt in the landing gear, where a swivel would be an ideal place for a bolt no matter how advanced a craft may be, stood out to me as perhaps the only case I can recall where such a mundane feature was mentioned.
Usually in these rare reports where the witnesses can see these devices in close proximity, they tend to describe them as flawless surfaces that appear to have been either machined from a single solid block, or formed in a liquid state, because the absence of mechanical features is so striking. Therefore, I’m calling BS on this dishonest little phrase “nuts and bolts craft.”
We’ve also seen a similarly dishonest and empty straw man fallacy deployed against ETH advocates: accusations of a “religious” adherence to the ETH, with lots of talk of “belief” and “believers,” or ugly rhetorical mash-ups like “people who believe in space aliens” - another Kimball favorite.
I can’t speak for others, but there is no room in my cognitive process for the notion of “belief.” As I see it, “belief” is a lie: in reality there are only two categories – the things we know and the things we don’t know. And it’s perfectly reasonable to speculate on the basis of what we do know – in that case, it’s simply logical extrapolation: the fundamental force behind scientific advancement, “if this is true, then this should also be true – let’s find out.” But “belief” is ignorance masquerading as knowledge – people say “I believe xyz” when they don’t know, but wish to pretend that they know. And I find that loathsome because it fosters irrational conflicts of all kinds, and it places the personal ego above one’s own intellectual capacity. So I can’t even remember the last time I said “I believe” – and if I’ve ever used those words together like that, it’s been decades since, and I have no intention of ever doing it again.
To me, the ETH is a compelling and perfectly rational/defensible concept – a viable hypothesis, if not an actual theory: “belief” has nothing to do with it.
