And that's just for life. — Relativist

Keeping in mind the different kinds of life that have occurred on this planet, it appears that many "notions" of life should be qualified as life-like-us. Once free of that parish-pump idea, the possibilities for life increase by a lot. And where there's life there's the possibility of evolution. Life is thought of variously as divine, magical, mysterious. More likely it is simply a very possible mix of the right chemicals and some energy, and not even a lot of energy. Thus given enough chances, inevitable; and given a universe's number of chances, frequent.

In terms of the local universe, imo any thought of constraint on the possibilities of life must be reckoned provincial and a provincialism reinforced by the blunt fact of distance.

Keeping in mind the different kinds of life that have occurred on this planet, it appears that many "notions" of life should be qualified as life-like-us. Once free of that parish-pump idea, the possibilities for life increase by a lot. And where there's life there's the possibility of evolution. Life is thought of variously as divine, magical, mysterious. More likely it is simply a very possible mix of the right chemicals and some energy, and not even a lot of energy. Thus given enough chances, inevitable; and given a universe's number of chances, frequent.

In terms of the local universe, imo any thought of constraint on the possibilities of life must be reckoned provincial and a provincialism reinforced by the blunt fact of distance. — tim wood

That life is improbable is supported by the fact that we're nowhere close to figuring out abiogenesis. This suggests it requires a narrow set of conditions.

It is not the possibility of intelligent life that I'm arguing, it is its probability. Only one species developed our level of intelligence on earth, and I see no reason to think that was inevitable. (If intelligent design is true, then it may indeed be probable, but I'm very skeptical of that).

Absolutely it's probable there's other intelligent life somewhere in this vast, old universe. The issue is whether or not it exists close enough to us (in both time and distance) to even be detectable. For the reasons stated above, I think that's highly improbable. If you think I'm wrong, give me some basis to think it's probable.

Only one species developed our level of intelligence on earth, — Relativist

Copied from our friend the 'net:

"Apart from our species, the gallery features eight other kinds of human: Homo habilis, Homo rudolfensis, Homo erectus, Homo antecessor, Homo heidelbergensis, Homo floresiensis (nicknamed 'the hobbit'), Homo neanderthalensis (the Neanderthals) and the recently discovered Homo naledi."

That's an error by a factor of at least eight, right here, in the last few hundred thousands of years. As to "goldilocks" conditions, I commend to you a little research on life forms on earth before the "oxygen catastrophe." And current life forms by thermal vents in the deep ocean. To my way of thinking, more interesting than the brute fact of life is what about being alive that makes life keep on - or might that be an evolutionary accident as well?

It's logically possible, just like it's logically possible we could work magic, or summon demons, if we just had the right incantation. There's really not much difference, when we start considering possibilities that contradict science that is as well established as relativity. — Relativist

Events that are unexplainable by current science is usually indistinguishable from magic. Or do you think our scientists know all about the universe already?

The best guess is that conditions need to be similar to earth's: goldilocks zone orbiting a star liquid water, heavy elements in sufficient abundance.

And that's just for life. We humans are the unlikely consequence of a series of environmental/evolutionary accidents- so the probability of life with similar intelligence seems quite low. — Relativist

https://www.littlepassports.com/blog/space/how-many-stars-are-in-the-universe/

https://access-ci.org/billions-and-billions-of-stars/

Considering that the Milky Way, our home galaxy, has over 100 billion stars in it.

100% = 100,000,000,000
1% = 1,000,000,000
0.1% = 10,000,000
0.01%= 1,000,000

If we count only one hundredth of one percent of the stars in the Milky Way as possibly having a planet in the Goldilocks zone, that is still a million planets that might contain the elements of life. If we count only one hundredth of one percent of those as possibly containing life, that still leaves us with a hundred possibilities. Obviously the one percent possibility of there being intelligent life on any of those planets could explain us being here. And all of those without looking outside of our galaxy.

Even if there may be life with such intelligence, it's not inevitable that it would be inclined toward science and technology - particularly the relevant technology that would make itself known, or travel - instead of making its lives richer in other ways, or self-destructing (like we might). — Relativist

That is what I have been saying all along, We might just be the poor people in the neighborhood and so they ignore us.

That's an error by a factor of at least eight, — tim wood

Hardly. None of them had a human level of intelligence.

As to "goldilocks" conditions, I commend to you a little research on life forms on earth before the "oxygen catastrophe." — tim wood

The most well-supported hypothesis is the Universal Common Ancestor, which implies life began under exactly one environment. The oxygen catastrophe was a consequence of life that was already present, and changed the environment - sending evolution into another direction. There are a host of environmental changes that occurred in the evolutionary sequence from abiogenesis to humans, and thus many accidents that collectively/sequentially led to our existence. As I said, we're improbable.

Events that are unexplainable by current science is usually indistinguishable from magic. Or do you think our scientists know all about the universe already? — Sir2u

You're conflating "unexplainable events" with fanciful possibilities.

If we count only one hundredth of one percent of the stars in the Milky Way as possibly having a planet in the Goldilocks zone, that is still a million planets that might contain the elements of life. If we count only one hundredth of one percent of those as possibly containing life, that still leaves us with a hundred possibilities. — Sir2u

We could only possibly look for such planets within a relatively short distance from us: a sphere centered from earth out to a fraction of the volume of the Milky Way. I would not be much surprised if we DID find life eventually, but intelligent life seems many orders of magnitude less probable.

Obviously the one percent possibility of there being intelligent life on any of those planets could explain us being here. And all of those without looking outside of our galaxy.

Detecting life outside the galaxy seems extremely far fetched. 1% probability of intelligence developing seems grossly optimistic. On earth, only 1 out of 8.7 Million species have a human level of intelligence.

More pertinent: I see intelligence as just one (complex) trait that life can possibly develop out of an uncountably large number of possible traits. This implies an extremely low probability.

You're conflating "unexplainable events" with fanciful possibilities. — Relativist

And you are conflating unknown possibility with improbable probabilities. I think you missed the point.
“Any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clarke

Earths scientists still do not know a lot about earth itself, no one can say what might be possible in other parts of the universe. Even if the laws of the universe are standard, we still do not know all of them.

We could only possibly look for such planets within a relatively short distance from us: a sphere centered from earth out to a fraction of the volume of the Milky Way. — Relativist

So how can anyone be so sure that there are no other intelligent beings out there?

Detecting life outside the galaxy seems extremely far fetched. 1% probability of intelligence developing seems grossly optimistic. On earth, only 1 out of 8.7 Million species have a human level of intelligence. — Relativist

A million stars is only about one tenth of one percent of the stars in the Milky way. Once again, we still know very little about our own planet

https://www.the-sun.com/tech/12417100/bluestreak-cleaner-wrasse-self-awareness-mirror-study-japan/

More pertinent: I see intelligence as just one (complex) trait that life can possibly develop out of an uncountably large number of possible traits. This implies an extremely low probability. — Relativist

But even low probabilities are not the same as impossibilities.

Hardly. None of them had a human level of intelligence. — Relativist

Sweet Jesus! They were all human - just not like you! Unique common ancestor? Life began "under exactly one environment"? I think you need to be a little more precise in what you write. I'll buy the proposition that so far, existing life appears to share a common ancestor, although deep sea thermal vent life may disprove that. But that is silent on life that may have existed before and disappeared. And it leaves open the question of what "exactly one environment" is. Maybe life developed in multiple environments and then interacted. The problem is that you have guesses and an apparent bias, all of which you think is knowledge. And it isn't. Maybe they're good and educated guesses, but not knowledge.

And you seem to be limiting life to earth-like life - and that's absurd on its face.

And you are conflating unknown possibility with improbable probabilities. I think you missed the point.
“Any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clarke — Sir2u

Maybe you don't realize what I was talking about. I was referring to faster than light travel and traveling through hyperspace. The former is physically impossible if General Relativity is true. GR is one of the best established, and most verified, theories in physics establishing it as a law of nature, describing something fundamental about the universe.

Regarding hyperspace- that's pure speculation that it both exists and is traversible. Again, it's logically possible, but there's no basis to consider bare possibilities like these as plausible.

Clarke's claim doesn't apply. He was referring to unexplained things we observe. We haven't observed FTL travel or hyperdrive. It's not an excuse to treat the implausible as plausible.

Earths scientists still do not know a lot about earth itself, no one can say what might be possible in other parts of the universe. Even if the laws of the universe are standard, we still do not know all of them. — Sir2u

We are able observe galaxies at the edge of the visible universe, and have encountered no evidence inconsistent with GR. If there are island universes beyond ours (another speculation) it's moot to the discussion because they are clearly out of reach.

But even low probabilities are not the same as impossibilities. — Sir2u

Of course, but l'm talking probabilities.

There is a broader epistemological issue regarding how we treat possibilities. If you're going to take one bare possibility seriously, then shouldn't you take all of them seriously?

Sweet Jesus! They were all human - just not like you! Unique common ancestor? Life began "under exactly one environment"? I think you need to be a little more precise in what you write. I'll buy the proposition that so far, existing life appears to share a common ancestor, although deep sea thermal vent life may disprove that. But that is silent on life that may have existed before and disappeared. And it leaves open the question of what "exactly one environment" is.

And you seem to be limiting life to earth-like life - and that's absurd on its face. — tim wood

Most of the species that were listed had brain sizes closer to chimpanzees than to humans. But OK, let's step back in the taxonomy. All are genus homo. So only one genus out of 300,000 genera. And the common ancestor of genus homo came to exist because of the environment in which some accidental, random genetic mutations happened to have a survival advantage. Same with its ancestry: a survival advantage at each stage in its evolutionary history.

So 1 out of 300K genera, but that doesn't really identify the probability that the specific series of random genetic mutations from its abiogenetic ancestor on down to the first genus homo, made the genus probable.

"Maybe life developed in multiple environments and then interacted. "
Speculation. The fact is, we haven't figured out how abiogenesis occurred, despite decades of work, so the set of conditions that can produce life is narrow enough to have escaped all our research.

Maybe life developed in multiple environments and then interacted. The problem is that you have guesses and an apparent bias, all of which you think is knowledge. And it isn't. Maybe they're good and educated guesses, but not knowledge.

OK, straighten me out to correct the bias you perceive.

Do you consistently treat propositions that are merely logically possible as worth giving serious consideration?

Or perhaps you can identify some epistemic warrant I'm overlooking that establishes the possibilities that you bring up as something more than a bare logical possibility?

I ask, because my "bias" is to give no consideration to propositions that are merely logically possible. I need something more, and that seems the most reasonable approach. That's why I don't take conspiracy theories seriously: someone jumps to a biased conclusion and then applies confirmation bias in seeking facts to support the theory.

It is logically possible there's an elephant in your backyard, but I doubt you would treat this possibility as worthy of consideration. Now imagine a person who's obsessed with elephants, who would be delighted to encounter one. He might give it more consideration.

And you seem to be limiting life to earth-like life - and that's absurd on its face. — tim wood

Sure, it's logically possible there are many ways life could arise. How do you factor this additional bare logical possibility into the analysis? It's also logically possible Yahweh directly created life on earth, and that this is the only way life can begin. Explain whether that possibility is worth equal consideration.

From your PM:

We haven't observed FTL travel
— Relativist
Sure we have. Demonstrations available in Youtube videos. — tim wood

Point me at such a video. I could only find videos and articles that support what I said. (Examples: https://youtu.be/BhG_QZl8WVY?si=U7OH2jr-APmkv8E3, https://en.m.wikipedia.org/wiki/Faster-than-light)

I hope you aren't confusing the universe's expansion with travel within the universe.

The problem as I see it is not that you're wrong, but that in speaking/writing informally - which we all do - you also fall into thinking and arguing with that same informality, which at that point becomes error. — tim wood

I'm perfectly fine with you exposing an error in my thinking. That's how we learn. In this case, it seems that we disagree regarding how much consideration we give to bare logical possibility, OR there's some factor I'm overlooking that shows these possibilities are more than merely logically possible.

Maybe you don't realize what I was talking about. I was referring to faster than light travel and traveling through hyperspace. The former is physically impossible if General Relativity is true. GR is one of the best established, and most verified, theories in physics establishing it as a law of nature, describing something fundamental about the universe. — Relativist

Ok, but I seem to remember reading about a time when gravity was an absolute law and then man found a way to overcome it and even use it to their benefit. Could it be in some way possible that humans are capable of overcoming or even utilizing other laws of the universe to their own benefit? And again we still do not know all of the laws.

I also seem to remember that Quantum physics is not entirely compatible with GR and that there are several theories being proposed to unite them. String theory proposes several dimension, which leaves quite a lot of possibilities for future discoveries.

Ok, but I seem to remember reading about a time when gravity was an absolute law and then man found a way to overcome it and even use it to their benefit. — Sir2u

You're conflating folk wisdom with a theory developed through the methodologies of science. Folk wisdom is a product of inductive inference (seeing no exceptions to observation) and assumed true without testing and with no attempt to establish a scientific basis for the assumption.

Scientific theories are developed through abduction: proposing hypothesis that explains something that lacks explanation, testing that theory against known facts, and making predictions that are beyond current empirical evidence - and then experimentally verifying those predictions. Relativity made a number of predictions that no one previously anticipated: the deflection of light by large gravitational fields,gravitational lensing, gravitational waves, black holes, red shift; time dilation, the big bang.

Could it be in some way possible that humans are capable of overcoming or even utilizing other laws of the universe to their own benefit? And again we still do not know all of the laws. — Sir2u

Once again, you're conflating logical possibility with plausibility. I also sense a bit of wishful thinking in there. Are you a theist?

I also seem to remember that Quantum physics is not entirely compatible with GR and that there are several theories being proposed to unite them. String theory proposes several dimension, which leaves quite a lot of possibilities for future discoveries. — Sir2u

Right - general relativity breaks down in the conditions of the very early universe, when the diameter of the current visible universe was around 1.5 meters (see this). But we're dealing with the universe in its current state - where no exceptions to relativity have have been discovered and many predictions have been confirmed.

In no special order.

Stopping light - one of several:
https://www.youtube.com/watch?v=-8Nj2uTZc10

Faster than light, Cerenkov radiation - one of several:
https://www.youtube.com/watch?v=Yjx0BSXa0Ks&t=169s

And quantum entanglement, which appears to be not only faster the light, but instantaneous. I think what you meant is that the speed of light in a vacuum is the speed limit for things, and information cannot be transmitted more quickly, although with entanglement that might require some qualification.

On intelligence, your comment was that

Only one species developed our level of intelligence on earth, — Relativist

.
I noted there were at least eight kinds of humans. And you replied:

Hardly. None of them had a human level of intelligence. — Relativist

. The most charitable thing to say here is that it appears you're confusing knowledge, certain kinds of knowledge, with intelligence, and that's just plain a mistake.

"Maybe life developed in multiple environments and then interacted. "
Speculation. — Relativist

Yup. Astute of you, or did the "maybe" give it away. The biases I find is that you appear to think of life as that which comports with your ideas of life, rather than restraining yourself so that your ideas of life might comport both with what life is and may be; and, that in mentioning survival advantages there seems more than a hint of teleology. Individuals may want to survive; to say that life wants to survive requires some elaboration to make sense - and teleology is just a sometines useful convenient fiction.

I understand a "logical possibility" as one not ruled out by, say, the law of non-contradiction. If you want to consider all of those, go for it. I think there are better uses for time and thinking. As to simple possibility and probability, consider: in our limited experience approximately at least one planet in ten evolves myriad advanced life forms, with at least one we consider pretty intelligent. If there are at least one trillion galaxies, each with about 150 billion stars, and the number of planets at least twice the number of stars and probably many more, then you do the math on the number of advanced life forms, and the number of those we would count as pretty intelligent or even very intelligent.

As you choose to mention my PM to you, it would have been nice also to include my point to you, that your arguments through lack of care and some rigor, become borderline nonsensical.

But somewhere above you observe that distances are such it's unlikely we're going to encounter any aliens any time soon - and that I agree with.

Stopping light - one of several:
https://www.youtube.com/watch?v=-8Nj2uTZc10 — tim wood

The speed of light (C) is a physical constant that corresponds to the light's velocity in a vacuum. The scenario in the video does not entail exceeding C, it entails slowing down light to a level that can be exceeded by non-light.

Faster than light, Cerenkov radiation - one of several:
https://www.youtube.com/watch?v=Yjx0BSXa0Ks&t=169s — tim wood

Same thing. It's described here::

"Cherenkov radiation ... is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium (such as distilled water) at a speed greater than the phase velocity (speed of propagation of a wavefront in a medium) of light in that medium[

And quantum entanglement, which appears to be not only faster the light, but instantaneous. — tim wood

Entanglement is instantaneous, but irrelevant to travel and communication. (see this).

On intelligence, your comment was that

Only one species developed our level of intelligence on earth, — Relativist

.
I noted there were at least eight kinds of humans. And you replied:

Hardly. None of them had a human level of intelligence. — Relativist

. The most charitable thing to say here is that it appears you're confusing knowledge, certain kinds of knowledge, with intelligence, and that's just plain a mistake. — tim wood

You got me: I was using an incorrect statistic, but my point stands that there's no basis to assume intelligence is probable. You ignored my more relevant point: the probability that the specific series of random genetic mutations from its abiogenetic ancestor on down to the first genus homo suggests intelligence is low probability.

The biases I find is that you appear to think of life as that which comports with your ideas of life, rather than restraining yourself so that your ideas of life might comport both with what life is and may be; and, that in mentioning survival advantages there seems more than a hint of teleology. Individuals may want to survive; to say that life wants to survive requires some elaboration to make sense - and teleology is just a sometines useful convenient fiction. — tim wood

My idea of life is pretty basic: molecules that self-replicate with some degree of accuracy. Do you have a less restrictive definition?

I don't get why you bring up teleology. I earlier noted that if teleology is true, then life is more probable. However, I don't think it's true, and I've implicitly treated that as a premise in everything I've said.
Useful fictions are useful in helping to understand something, but are red herrings in a discussion where I've already indicated ~teleology is a premise.

Astute of you, or did the "maybe" give it away. — tim wood

You're verging on being rude. I'll give you the benefit of the doubt and assume you were trying to be funny, but try a little harder to avoid saying things that could sound demeaning.

I understand a "logical possibility" as one not ruled out by, say, the law of non-contradiction. If you want to consider all of those, go for it. I think there are better uses for time and thinking. — tim wood

Sounds like you agree with me that something more is needed than mere logical possibility to make it worth considering.

As to simple possibility and probability, consider: in our limited experience approximately at least one planet in ten evolves myriad advanced life forms, with at least one we consider pretty intelligent. If there are at least one trillion galaxies, each with about 150 billion stars, and the number of planets at least twice the number of stars and probably many more, then you do the math on the number of advanced life forms, and the number of those we would count as pretty intelligent or even very intelligent.

This is consistent with what I told you earlier:

Absolutely it's probable there's other intelligent life somewhere in this vast, old universe. The issue is whether or not it exists close enough to us (in both time and distance) to even be detectable. For the reasons stated above, I think that's highly improbable. If you think I'm wrong, give me some basis to think it's probable. — Relativist

As you choose to mention my PM to you, it would have been nice also to include my point to you, that your arguments through lack of care and some rigor, become borderline nonsensical. — tim wood

I chose to ignore the insult, but instead responded to the sense of what you said: "I'm perfectly fine with you exposing an error in my thinking."

The only error you've exposed was in my incorrect statistic about the number of "intelligent" species, and I acknowledged that. I could nitpick your claim about "1 in 10 planets have life", because we've examined some exoplanets as well. I saw no need to do that, because I think I understood the gist of your point.

Was it perhaps also the "speed of light" thing - that I didn't explicitly refer to the constant C (because I assumed it would be understood, given the context of FTL travel - flying faster than C). You could easily have said, "oh, you must mean the constant "C", because it's well known that light travels slower in a medium". So your making an issue of it seems disingenous.

But somewhere above you observe that distances are such it's unlikely we're going to encounter any aliens any time soon - and that I agree with. — tim wood

Then what is it that you disagree with me about? Is it just that I exercised "too little care" when I said only one species developed human-level intelligence, and/or that I didn't make it clear that by "FTL travel", I was referring to traveling faster than C?

Or the universe operates as suggested in the 3-body problem (the series hasn't reached this point yet). But I don't want to spoil the books or the series.

I've read the book; what do you mean "our universe operates as suggested ..."?

Replied via PM.

Scientific theories are developed through abduction: — Relativist

:gasp: That might work in Russia, not sure about the rest of the world though.

Once again, you're conflating logical possibility with plausibility. I also sense a bit of wishful thinking in there. Are you a theist? — Relativist

Ok. You are set in your way of thinking. You have no faith in humanities abilities to solve problems that are supposed to be unsolvable. Even though science is still young we have made great strides in understanding the universe.
As for wishful thinking, I think that there are many scientist that are STILL studying and investigating methods of FTL travel so maybe they are guilty of it. To me personal, I really don't care either way, I am too old to be able to take a trip to the stars.
And no I am not.

Right - general relativity breaks down in the conditions of the very early universe, when the diameter of the current visible universe was around 1.5 meters (see this). But we're dealing with the universe in its current state - where no exceptions to relativity have have been discovered and many predictions have been confirmed. — Relativist

I don't think I suggested that GR was in anyway wrong, But it is most likely still incomplete. Just as GR did not disprove Newton's theories, I would expect a newer theory to expand upon it. I cannot really believe that at some point in the future someone will not be able to complete a theory that explains everything about the universe and maybe show how FTL travel could be accomplished.

Edited

Something to think about.

https://uk.news.yahoo.com/scientist-disputes-big-bang-actually-171036722.html

Dark forest doesn't work because you can't hide the biosignatures your planet has been giving off for the last billion years.

From a distance I think technosignatures are more detectable – but I agree the so-called "Dark Forest" strategy can't work (and, due to interstellar distances, unnecessary).