Interstellar travel?

[Akka]

How are you proving that the characteristic "with life" is a common characteristic like "human-ness" rather than a unique characteristic like "warpus-ness."

Because life is a general process, not a uniquely assembled individual. Processes, by their very definition, are not unique instances.

 

[Timsup2nothin]

Because life is a general process, not a uniquely assembled individual. Processes, by their very definition, are not unique instances.

That's an awesome piece of pontification. I don't know which piece I am more likely to just accept as Akka given fact and engrave on a tablet; the "life is a general process" part or the "processes are inherently not unique" part.

Kidding aside that was a pretty good argument. The sticking point comes in the initiating of the process. While it seems to be verifiable by inspection that the process is not unique, unless proven otherwise the initiation of a process may be unique. As best as can presently be determined the process of "life" has exactly one point of initiation. Every organism known to exist, or known to have existed, is a derivative of that single point of initiation...or at least seems to be.

And that can turn this argument firmly against the likelihood of life elsewhere.

We know that at some location on the third rock from the sun, at some long ago instant, this process we call life initiated, and after much diverse evolutionary branching and circumstantial pruning this process of life became what we consider intelligent. Now, that is valid proof that conditions for the initiation of the process did exist, and we could theorize that basic mudballs orbiting stars are very unlikely to produce any genuinely unique sets of conditions, so since those conditions happened here they likely happened on many other mudballs.

But, where did these conditions disappear to? Again, by all indications all life as a process is derivitive from a single initiation of the process. Why did this process start once, and not continue to start? The circumstances, if they aren't unique and are happening on mudballs everywhere, should have happened repeatedly right here. But they aren't. Life the process started on earth once, and has apparently just ticked along ever since. Even application of the vaunted intelligence that has evolved in that process can't get it to initiate a second time, under any circumstances. However this process initiated, it appears very arguable that the initiation of the process is unique. No matter how repetitiously the process spreads and diversifies, there is only one known starting point.

 

[Akka]

While it seems to be verifiable by inspection that the process is not unique, unless proven otherwise the initiation of a process may be unique.

True, which is the point I answered in the previous post :

There is tons of things we don't know about life, but it's still made out of rather mundane elements that just require a set of factors which are barely on the "uncommon" side.
So unless we discover an especially incredibly rare and restrictive requirement, it's a given there is a big bunch of planets hosting life in our very galaxy, and probably hordes of planets with the potential.

As best as can presently be determined the process of "life" has exactly one point of initiation. Every organism known to exist, or known to have existed, is a derivative of that single point of initiation...or at least seems to be.

On the other hand, we know exactly one planet with the known prerequisite of life. So you can see it either as "a single occurence" or "a 100 % occurence"

But, where did these conditions disappear to? Again, by all indications all life as a process is derivitive from a single initiation of the process. Why did this process start once, and not continue to start? The circumstances, if they aren't unique and are happening on mudballs everywhere, should have happened repeatedly right here. But they aren't. Life the process started on earth once, and has apparently just ticked along ever since. Even application of the vaunted intelligence that has evolved in that process can't get it to initiate a second time, under any circumstances. However this process initiated, it appears very arguable that the initiation of the process is unique. No matter how repetitiously the process spreads and diversifies, there is only one known starting point.

I'm sorry, but what makes you think that life only started once on Earth ? There could have been millions of "false start", or there could have been dozens of "real start" which just converged/mixed together, or maybe the first step in the life process is still happening thousands of time per year but is just not noticed.

We don't know precisely the chain of events that led to life. We have some guesswork (some proteins/molecules spontaneously assemble in some sort of membrane in certain conditions for example, which could explain the first examples of cells), but we're still rather in the dark.

As said above, it could mean that there is some incredibly rare requirements for life to develop and we just happen to be the lucky winner, alone in the universe. But it's quite more probable that it's just a serie of events, and as we don't know several of them, we just don't notice them happening. We could have untold billions over billions of "first step life step" happening a bit everywhere in the oceans right now, but as the niche of "living cells" is already occupied, they simply don't get to do anything more noticeable.

 

[gozpel]

All though I appreciate your philosophical banter, this is not what the thread is about!

Manfred Belheim believes in facts, Warpus and Timsup2nothing are more open and other ppl have open and closed minds.

Facts? We are newbies in this and are facing a black wall of space, well with little glittering stars all over the place. We know little, but we learn more everyday and let's continue on mankinds options to do this, instead of focussing on maybe aliens.

Theorizing with theorems or principals are ways that are not set in stone, it's like arguing about religious ideals and political ideas, where no one will win, as beliefs are set in stone.

We want to go out there, aliens or not. I believe there are a multitude of planets even in our galaxy, that could support us in one way or another. This is the first step of exploration, to find those planets. If there are alien life on these planets is a total different issue, my idea is totally focussed on how do we get out there?

So stop talking about aliens, as they do not exist....yet, and continue working on our way out of here.

But I have to give Manfred an applause for sticking to his beliefs, it made me laugh. But I am the only gozpel here. So stick with my quest please.

 

[red_elk]

It's possible we are the only life that ever arose in the universe anywhere, ever. But it's more likely that it also arose elsewhere. P(1) is just one singular data point while P(2) + P(3) + P(4) + P(5) + ... is a combination of probabilities. In some cases yes, P(1) will be more likely, if you set up your variables just right. But in most situations it wouldn't be. We have no idea which situation we are in, but we can't just assume we are in the situation where P(1) is more likely.

The conditions we have here on Earth seem to be fairly common in the Universe. Planet systems are seemingly abundant, our star is quite ordinary, the chemical elements which life on Earth is based on, are not rare too. Unless life was initiated with incredibly rare event, it's logical to assume we are not unique. So, if I had to bet my money on either outcome, I would bet on existence of extraterrestrial life somewhere too. But I doubt this can be strictly proven in mathematical sense.

 

[El_Machinae]

I will also say that "I suspect there is ET life". My next question is "will we discover evidence of life from an advanced civilization or a primitive life first?". I don't know. I cross my fingers on Europa, I cross my fingers on SETI. We're now looking for evidence of Dyson Spheres out there. And we're trying to use spectroscopic analysis to determine atmospheric composition of far-away planets.

I don't know what will get human civilization into space. We will have this slow plodding of expensive efforts, where we put token batches of people further and further out. But it looks like so much of the industry will be happening with robots, and I don't see a natural transition point to cause humans to follow them out. Maybe someday the technologies will advance enough such that small cults can go out and try to make it on their own. I mean, it 'probably' could even happen where they become independent(ish). But it's a slow process.

I don't see interstellar efforts being made except by wingnuts. Looking at economic growth, eventually it should become affordable to do it. But despite being 'affordable', you'd really have to want to. A generational journey is a huge investment.

The other scenario is humans hop-skipping through the Oort Cloud, very very slowly. Like island-hopping in the Pacific.

 

[Lexicus]

You think it evolved from something more primitive, that there were non-DNA (or non-RNA) based lifeforms, which are now extinct?

Yes. Perhaps several iterations. Viruses seem likely to be holdovers from this pre-DNA period.

Life the process started on earth once,

We don't actually know this. Everything on Earth today appears to have a common ancestor, but that doesn't imply a single origin event for life- just as the existence of mitochondrial Eve doesn't imply that she was the only human around when she lived.

 

[red_elk]

...just as the existence of mitochondrial Eve doesn't imply that she was the only human around when she lived.

It's safe to assume there was at least one man somewhere nearby

 

[timtofly]

On the off topic point of the wheel: it was a military technology that was only shared with the public at large after it's military usefulness was a mute point. In the middle east there were more warring civs, and the need for military maneuvers, than super civs in the Americas. The wheel used in moving goods was probably used in China as humans migrated in more peaceful patterns away from the warring civs. The issue was getting an axle produced that lasted long term and not just during a short battle scenario. Suitable terrain being a factor as well. Not just mountains, but keeping forrest and jungle growth cleared, would be another factor. Having an economy and the need to transport goods would be the driving factor for the luxury of wheels. There was a Trojan horse of course.

The idea is out there, that all good military technology was given to humans as an advancement in evolution. Not that technology evolved as the result of human evolution.

 

[hobbsyoyo]

Sure, but if there's so many sparefaring civilizations out there, they must be all dying out or stopping their expansion.. or hiding. Or there aren't so many space faring civilizations out there

Or we just don't know how to detect them yet. Or they may be exceedingly common on the scale of the universe but rare locally. If there is only one intelligent species for every 10 galaxies, there will still be a ton of intelligent species but we'll have a hard time spotting even one with our current technology.

The inconceivable size of the multiverse means it is near-certain there is another warpus out there somehwere.

We don't know there is a multiverse.

I look at the possibilities of life on other planets this way:

If you have a (nearly) infinite number of monkeys typing on typewriters, one will eventually reproduce the works of Shakespeare. If you have a nearly infinite (lets just say an uncountably large) number of planets in the entire universe, there is almost a certain probability that since life has arisen once, life will arise again somewhere else. It may not look like something we're used to, but it will be life. There are simply too many stars out there with potential planetary systems to not have at least a percentage of them in the "Goldilocks Zone" capable of sustaining life, and or liquid water. That percentage, on a universal scale could mean billions of planets capable of sustaining life. If you assume our planet is the only planet out of the billion or so that may exist able to support life, the probability of life occurring is 1/1,000,000,000 x 100 = 0.000001 %. Those are ridiculously low odds for life to have developed on earth, and I've possibly done my math wrong.

In any case, I find it presumptuous and arrogant for humans to assume that Earth is the only planet in the cosmos to have developed and sustained life.

Incidentally, it's become a theory that octopi are from outer space:

http://www.newsweek.com/alien-octopuses-outer-space-930942

https://www.theaustralian.com.au/ne...s/news-story/61c54641ceb4dbf0c9da927e5a7de49e

Not sure I believe this one, but given my statistical theory, it's slightly credible, assuming that the DNA or eggs survived outer space, re-entry, etc.

The goldilocks zone is useful for looking for Earth-like planets but as we've seen with Europa, there are potentially many other types of habitable planets that not only don't conform to the goldilocks zone hypothesis but would also be very hard to inspect for the presence of life. A few kilometers of ice (or rock) is really good at hiding what might be lurking in the oceans beneath it.

 

[Manfred Belheim]

I look at the possibilities of life on other planets this way:

If you have a (nearly) infinite number of monkeys typing on typewriters, one will eventually reproduce the works of Shakespeare. If you have a nearly infinite (lets just say an uncountably large) number of planets in the entire universe, there is almost a certain probability that since life has arisen once, life will arise again somewhere else. It may not look like something we're used to, but it will be life. There are simply too many stars out there with potential planetary systems to not have at least a percentage of them in the "Goldilocks Zone" capable of sustaining life, and or liquid water. That percentage, on a universal scale could mean billions of planets capable of sustaining life. If you assume our planet is the only planet out of the billion or so that may exist able to support life, the probability of life occurring is 1/1,000,000,000 x 100 = 0.000001 %. Those are ridiculously low odds for life to have developed on earth, and I've possibly done my math wrong.

The point is that the odds of it occurring here don't come into it because it's already an established fact, and we're only here to talk about it because it happened. The odds could be so low that it would only happen once in a billion trillion universes, but the people on that world would still be sat there having the same conversation.

Imagine a forest of trees coming into Autumn. The chances that you could point to any single particular leaf and predict, exactly to the second, when it would fall off the tree, and exactly which square inch of the ground it would fall onto, are infinitesimal. That doesn't mean that if you observe a leaf falling and it hitting a particular spot on the ground at a particular time that you've witnessed a spectacularly unlikely event.

I realise that that example is kind of backwards, but it's just an example of how it's easy to misunderstand exactly which probability we're talking about and therefore estimate it completely wrong. The question isn't "how likely was life to evolve on Earth", but "given that life did evolve on Earth, how likely is it to evolve anywhere else", and the simple fact is we have no idea because we don't have the information to work that out.

This article articulates exactly what I've been trying to say.

This is a fairly common thing you can use statistics to study. You just ignored the explanation I've typed up because the conclusion doesn't agree with your worldview or whatever. You could have at least tried to reason through it and show me which step I took you through you think is incorrect.

It's a lot easier to just say "Nope, I'm right, you're wrong" I guess, yeah.

Apologies if it seemed rude, but I wasn't trying to be dismissive or hand wave it away, I was just saying that I think your starting premise is wrong so that going through the rest of it wasn't going to reveal anything. For pretty much the same reason I said to Lemon above, because you're looking at the probability of the wrong thing.

The fact is that it has happened here. You can't deduce the probability of something happening based on just one example of that thing happening, if you have no other information to go on at all, which we don't. All you can say is that it's non-zero.

Even if, say, there are 10^30 habitable planets in the Universe, but the probability of life evolving on any one planet was something like 10^-1000000000000000000, it could still happen because that's a non-zero chance. In that case the life on that planet would almost certainly be the only life in the entire universe. Alternatively the probability of life evolving on any one of those planets could be 1 in 10, in which case life would be abundant in the universe.

But any individual species on any of those worlds in either universe would know exactly as much about the existence of any of the others (i.e., nothing) and they would all be having the exact same conversation as this. Like I said the question isn't "what are the odds of life evolving exactly once", it's "given that it has evolved at least once, what does that tell us about how often it might have evolved elsewhere", to which the answer is "nothing at all unfortunately".

If you have a die in your hand and you have only thrown it once.. and you have no idea how many sides there are on the die.. but you know what number came up when you threw it. you are still able to say things about certain statistical properties of the situation.

I don't think you are at all. I mean, if you somehow knew that the sides of the die were all sequentially numbered and started at 1, and you rolled 574383983, then you could say that there must be at least 574383983 sides and so therefore your odds of rolling that number again on any given roll couldn't be greater than 1 in 574383983. But if any side could have any number between 1 and infinity on it, regardless of how many sides there were, then you couldn't make any predictions at all. If you think you could I'd like you to show how because I'd definitely learn something

Well, you think wrong
There is tons of things we don't know about life, but it's still made out of rather mundane elements that just require a set of factors which are barely on the "uncommon" side.
So unless we discover an especially incredibly rare and restrictive requirement, it's a given there is a big bunch of planets hosting life in our very galaxy, and probably hordes of planets with the potential.
And that's just with the version of life we know of, so not counting the potential different way life can emerge.

Sorry, no. We don't know the mechanism for abiogenisis so can't say how likely that is from an analysis of the mechanism itself*, and we have no statistical information on life/non-life on other planets to infer anything empirically. So you're saying it depends on factors which are not uncommon, but you don't actually know that at all because no-one does (yet).

And I wasn't ignoring any other potential forms of life that could have emerged in a different way, but again that's just another thing we know nothing about the reality of, so again we can't say anything about how likely that may or may not be. Whatever it is. An unknown unknown if you like.

*although as I've said before, if there's been some breakthrough there that I've not heard about I would love to be informed about it.

Manfred Belheim believes in facts.

I mean, as a summary, I'll take that any day.

 

[hobbsyoyo]

But we do have enough information to make highly informed guesses.

 

[Manfred Belheim]

But we do have enough information to make highly informed guesses.

If we do I would genuinely love to know what it is because I don't know of any and I haven't seen any presented yet :/

 

[Lexicus]

If we do I would genuinely love to know what it is because I don't know of any and I haven't seen any presented yet :/

And as we all know, your ability to Google things rather than complaining on here that you don't understand them is legendary.

 

[Manfred Belheim]

And as we all know, your ability to Google things rather than complaining on here that you don't understand them is legendary.

Why are you being a dick Lexicus? You've already said yourself that you can't make any inferences on the properties of diamonds based on a statistical sample of one diamond*. That's pretty much the entire argument I'm making so I'm not sure why you're finding it so offensive. I really am just saying two things:

a) You can't do any statistical analysis with a sample of 1.
b) We don't know enough about how abiogenisis works/worked to assign any reliable measure of probability to it.

I think "a)" is pretty slam dunk (not everyone in this thread agrees, but you have done) and I don't think me saying that I'm willing to be corrected on "b)" if anyone knows any better (which no-one has yet) counts as "complaining about not understanding things".

I also linked to a Forbes article saying exactly the same thing I'm saying. I'm not saying that counts as a definitive word on the matter or anything, but it's not from some Creationist website or anything like that and at least shows I'm not just pulling this entirely from my backside. Yeah we disagree a lot in other threads, but that's no reason to be an antagonistic jerk in this thread. Engage with what I'm actually saying or urinate off please.

*although, given that it's just an inert, repeating carbon lattice, you probably could actually.

Moderator Action: Disagreement is natural, but please disagree politely. There is no need for name calling. --LM

 

[warpus]

Or we just don't know how to detect them yet. Or they may be exceedingly common on the scale of the universe but rare locally. If there is only one intelligent species for every 10 galaxies, there will still be a ton of intelligent species but we'll have a hard time spotting even one with our current technology.

Yeah, you're right, those are both possibilities. IMO if there is such a small number of intelligent civilizations out there, most of them are probably hiding anyway. It just makes sense to (to me)

The conditions we have here on Earth seem to be fairly common in the Universe. Planet systems are seemingly abundant, our star is quite ordinary, the chemical elements which life on Earth is based on, are not rare too. Unless life was initiated with incredibly rare event, it's logical to assume we are not unique. So, if I had to bet my money on either outcome, I would bet on existence of extraterrestrial life somewhere too. But I doubt this can be strictly proven in mathematical sense.

Yeah, that's the thing.. Either life is super incredibly insanely rare, on such a level that it should never have happened anywhere.. but we got super lucky and so here we are, and nobody else is. We won the lottery of lotteries, we picked 581 numbers out of 581,168 * 10^87126 and we got all of them right.

Or probability of life occuring is such that it will pop up multiple times throughout the universe, whether it's 50 times per galaxy on average or 2 or 500,000

The second scenario is much more likely since it contains a multitude of various scenarios and doesn't involve us winning a crazy impossible lottery.

 

[El_Machinae]

Manfred, are you familiar with the example of the "bag with numbered marbles in it?" I think that's what warpus is leaning on while misunderstanding your point.

There are two bags, each with sequentially numbered marbles in them. One bag contains 100 marbles, the other a thousand.

You pull a random marble out of one bag. It's labeled a "eleven". One data-point.

Is it more likely that you pulled a marble out of the bag of ten, or the bag of one thousand? With your next draw from the same bag, what are the odds that you pick a "one"?

That's the statistical exercise they're drawing upon. They're positing two universes, one with only a small window in which life could appear or only with a long window in which life could appear. One where life has to begin in the first 100 billion years, or one in which life may begin in the first 1000 billion years. We pulled into the bag, and pulled out an "11" (or whatever).

I think it's a misapplication of that exercise to think this means that "there is probably other life", but I think that's what's being drawn upon.

 

[Lexicus]

That's pretty much the entire argument I'm making so I'm not sure why you're finding it so offensive.

Well you ignored the post I made showing how you, in fact, can draw some small conclusions even with a sample of one (I'm not sure application of the mediocrity principle counts as "statistical analysis" though).

I also linked to a Forbes article saying exactly the same thing I'm saying.

I've read that Forbes article (I read it quite soon after it was published as I also read the NYT piece it refers to); it doesn't address the arguments I've made either.

 

[EnglishEdward]

I suspect that primitive life is quite common.

Multi-cellular life is quite uncommon.

Complex mult-cellular life is rare.

Sentient life very rare.

And life with the ability to communicate across a galaxy, extraordinarily rare.

And the existence of sentient life with the ability to spread itself across the universe is speculation.

 

[Timsup2nothin]

I'm sorry, but what makes you think that life only started once on Earth ? There could have been millions of "false start", or there could have been dozens of "real start" which just converged/mixed together, or maybe the first step in the life process is still happening thousands of time per year but is just not noticed.

Life, the process we are familiar with, has persisted for a mighty long time. A sample size of one, but it doesn't argue for "the process started a bunch of times, but only one is still going." It also appears to be a divergent process rather than convergent.

Consider that my position in the argument really hasn't changed. It isn't that I'm committed to "life started once on Earth," any more than I am committed to "there is no life anywhere else." I started out challenging @warpus over his assumption that life is not unique, for which he had no evidence, and now I'm challenging the assumption (which I respect that you are not claiming as a fact) that these multiple starts that could have happened actually did.

I started out by mentioning the absurdity of two. As long as you have one and only one example you have to deal with the possibility of uniqueness, one way or the other. As soon as you have a second sample uniqueness as a possibility is eliminated. At that point, logically, no matter how long it took you to find a second example there are going to be more.