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No, it's not. While I agree that it should be a late-stage hypothesis for simple Ockham's Razor reasons, there is absolutely nothing irrational nor supernatura

by api 10y ago

No, it's not. While I agree that it should be a late-stage hypothesis for simple Ockham's Razor reasons, there is absolutely nothing irrational nor supernatural about ET. Everything we know about life and about the universe, including the prevalence of Earth-sized and possibly Earth-like planets around other stars, makes ET an inductively obvious and very likely reality. It's not confirmed yet, but it's a hypothesis that belongs in the same category as the Higgs Boson prior to the LHC: according to rest of what we know ETs should exist and we should expect to find evidence of this in some form someday. It could come in the form of microbes or fossils on Mars, Titan, or Europa, or it could come in the form of a signal or even a probe or a spacecraft from the stars. The latter is IMHO no less likely. We exist and we send signals and space probes and pretty soon spacecraft. While we don't yet send these things very far, if we continue to develop as we have been we probably will someday. If we are a product of natural processes and those same processes are happening elsewhere (naturalistic metaphysics plus Kepler data says yes) then other things capable of sending signals or craft should exist elsewhere. Due to the age distribution of stars, some of them may have been around longer and therefore have had longer to evolve. If anything the persistent absence of ET would suggest to me that modern science's fundamental understanding of reality may be incorrect. Either the theists are right, we're in a simulation (which is virtually identical to theism when you think about it), or something else profoundly strange is going on. I attribute the intense skepticism of ETs to the silliness of much of UFO mythology. It's important to realize that the Rael cult and the abduction myth and so forth are a cultural phenomenon that has zero bearing on science one way or the other. Culture will take scientific ideas and hypotheses and run with them, and that's fine, but it shouldn't distract from reality or provoke an irrational backlash. Do we stop looking into "weird" possibilities in quantum physics because there are new agers who say silly things about QM? No, and we shouldn't dismiss aliens either. If we do we are actually letting pseudoscience and non-science dictate (in the negative) where science is willing to go.

pklausler 10y ago
If ETs are expected to be found, where are the Bracewell-von Neumann probes? If any tech civilization ever launches a self-replicating interstellar probe, it would only take a few million years for the probes to reach every system in the galaxy. The observed lack of B-vN probes implies that no tech civilization has ever done so. And the probability of any civilization capable of launching B-vN probles actually doing so seems very high -- we'll be able to do it ourselves pretty soon. You have to explain the lack of B-vN probes if you want to argue that ETs are/have been common. (Scarier thought: if B-vN probes are inevitable, so are berserkers.)
- api 10y ago
  Oh no I started a Fermi paradox thread! I don't have time for this but I'd suggest looking into other discussions on this. The Fermi paradox opens an entire monstrous tree of possibilities, but it's not quite as simple as "there are no VN probes therefore there are no aliens." My two favorites are: (1) Interstellar travel might just be too damn hard. Going fast enough to get there in a reasonable time seems to require insane physicists' nightmare propulsion systems like antimatter or fusion rockets or artificial black hole drives, while taking too long means cosmic radiation has too much time to cook both organic matter and electronics... or you can't build a power source that will last that long, etc. (2) The "uniform cooling hypothesis" -- maybe life is common but intelligences able to build (or become) VN probes are so far incredibly rare. Since the entire universe is (according to the leading theory) the same age, such things simply haven't happened yet. (1) and (2) could work together-- maybe there are pretty advanced aliens everywhere but so far very few are advanced enough to attempt interstellar flight. If the probability of interstellar flight is less than, say, once per galaxy per billion years, then we would not see VN probes. Neither (1) nor (2) rules out signals at all.
  - pklausler 10y ago
    I don't buy (1). B-vN probes don't care about transit time or cost. (2) is arguing for some kind of middle ground between "it's just us" and "lots of tech civs"; i.e., that life can get to the point of sending signals way easier than it can get to the point of launching a probe. But in our case the delta's just going to be a couple centuries, so no, that doesn't work for me either.
    - TallGuyShort 10y ago
      Both your points assume a lot of knowledge about the future.
      - pklausler 10y ago
        They're reasonable extrapolations from current capabilities. Build a self-replicating 3-D printer, make it capable of finding and refining raw materials on asteroids, slap it on a Voyager-like slow interstellar platform, and off you go. (Yes, I'm being glib, but it's not that much of a stretch.)
mrfusion 10y ago
I think you have a great point. Sorry you were downvoted. I too see science being silly about aliens and ruling them out of bounds for a hypothesis space. I see it like being on an island with no known wildlife. If you're trying to come up with hypotheses about why your food is dissapearing every night it would make sense to consider animals.
Udo 10y ago
Not sure why you're getting downvoted here. You are correct: there is absolutely nothing irrational or supernatural about ET, and when looking for it we should consider ET as an explanation for any given phenomenon with as very low priority. Most scientists agree that we should expect ET presence out there, it's just that opinions vary wildly about the probabilities involved.
- Almaviva 10y ago
  Say a 1080p monitor display is completely randomized, until it shows a clear visible five-pointed star. Given I'm looking at a star, what is the likelihood there is another one on the screen? Practically 0, I'd think. Why is the emergence of an intelligent civilization in the universe different, assuming I take a multiverse and the anthropic principle seriously? (In other words, given that a universe could have multiple intelligent civilizations, why is it the case that if I'm in a random sample with at least one, there is likely to be another?)
  - Udo 10y ago
    > Say a 1080p monitor display is completely randomized, until it shows a clear visible five-pointed star. Given I'm looking at a star, what is the likelihood there is another one on the screen? That's an unnecessarily convoluted example, a way of asserting that you think the probability of a technological civilization arising is vanishingly small, and taking into account the vast time intervals in question, therefore unlikely for more than one to exist simultaneously. Is that a valid point of view? Sure. It just means at least one of the factors in the Fermi equation is exceedingly small. Barring further evidence, that thesis may well turn out correct. But we still need to know what that inordinately small factor is, because we haven't found anything that fits the bill yet. Granted, there are big questions about the probability of things like abiogenesis, but over the entire history of science, arguments from exceptionality or uniqueness have almost always turned out to be incorrect.
    - Almaviva 10y ago
      > a way of asserting that you think the probability of a technological civilization arising is vanishingly small I have no idea one way or another. I wonder why many scientists are confident that extraterrestrial intelligent life exists though. Viewing through the lens of one example in a random (otherwise) unremarkable multiverse, it's not clear to me why this should be so.
corecoder 10y ago
You are right, it's a perfectly valid hypothesis, but it is an almost useless one, for at least two reasons. * It is improbable. Say I hear what appears to be a human being, but whom I cannot identify. It may be Roger Waters, there's nothing supernatural here, there's no reason why it couldn't be him. Yet, there are so many other people around that this hypothesis is totally useless: it very likely isn't Roger Waters, so I'm better off without it. * It is very hard to prove / disprove Intelligent, technologically advanced beings could very probably generate a wide variety of signals, so it is hard to prove that a certain signal cannot be generate by them; we also have no idea how the "typical" ET signal looks like, so the hypothesis doesn't really help us in furthering our analysis.
- thingexplainer 10y ago
  Regarding your first point, the trouble (at least in this instance) is that this logic doesn't apply when you're looking for Roger Waters and calling everyone in the phone book with his name. Each time someone picks up the phone it probably won't be the person you're looking for, but you certainly had reason to believe they could be. They didn't find a strange phenomenon and point out it might be ETI, in which case you're right, the hypothesis wouldn't make sense until you had ruled out basically everything else. They made a hypothesis about what ETI would look like, looked for it, and claim to have found things that could fit the bill.
- api 10y ago
  It's easy to prove if we were to ever receive, say, a string of Fibonacci numbers followed by their sum.
  - corecoder 10y ago
    Sure, and if we hear a very distinct voice singing and/or guitar or bass playing, we may identify Roger Waters. If we hear footsteps? Probably not Roger Waters.
M_Grey 10y ago
I'm skeptical of ET that: 1.) Is stupid enough to broadcast to a big, unknown universe 2.) Is alive and technologically capable at the same time we are 3.) That we're going to be around and looking to the skies for very long, relatively speaking. Personally I find some version of the Great Filter hypothesis very compelling.

by api 10y ago

pklausler 10y ago

If ETs are expected to be found, where are the Bracewell-von Neumann probes? If any tech civilization ever launches a self-replicating interstellar probe, it would only take a few million years for the probes to reach every system in the galaxy. The observed lack of B-vN probes implies that no tech civilization has ever done so. And the probability of any civilization capable of launching B-vN probles actually doing so seems very high -- we'll be able to do it ourselves pretty soon. You have to explain the lack of B-vN probes if you want to argue that ETs are/have been common. (Scarier thought: if B-vN probes are inevitable, so are berserkers.)

api 10y ago
Oh no I started a Fermi paradox thread! I don't have time for this but I'd suggest looking into other discussions on this. The Fermi paradox opens an entire monstrous tree of possibilities, but it's not quite as simple as "there are no VN probes therefore there are no aliens." My two favorites are: (1) Interstellar travel might just be too damn hard. Going fast enough to get there in a reasonable time seems to require insane physicists' nightmare propulsion systems like antimatter or fusion rockets or artificial black hole drives, while taking too long means cosmic radiation has too much time to cook both organic matter and electronics... or you can't build a power source that will last that long, etc. (2) The "uniform cooling hypothesis" -- maybe life is common but intelligences able to build (or become) VN probes are so far incredibly rare. Since the entire universe is (according to the leading theory) the same age, such things simply haven't happened yet. (1) and (2) could work together-- maybe there are pretty advanced aliens everywhere but so far very few are advanced enough to attempt interstellar flight. If the probability of interstellar flight is less than, say, once per galaxy per billion years, then we would not see VN probes. Neither (1) nor (2) rules out signals at all.
- pklausler 10y ago
  I don't buy (1). B-vN probes don't care about transit time or cost. (2) is arguing for some kind of middle ground between "it's just us" and "lots of tech civs"; i.e., that life can get to the point of sending signals way easier than it can get to the point of launching a probe. But in our case the delta's just going to be a couple centuries, so no, that doesn't work for me either.
  - TallGuyShort 10y ago
    Both your points assume a lot of knowledge about the future.
    - pklausler 10y ago
      They're reasonable extrapolations from current capabilities. Build a self-replicating 3-D printer, make it capable of finding and refining raw materials on asteroids, slap it on a Voyager-like slow interstellar platform, and off you go. (Yes, I'm being glib, but it's not that much of a stretch.)

mrfusion 10y ago

I think you have a great point. Sorry you were downvoted. I too see science being silly about aliens and ruling them out of bounds for a hypothesis space. I see it like being on an island with no known wildlife. If you're trying to come up with hypotheses about why your food is dissapearing every night it would make sense to consider animals.

Udo 10y ago

Not sure why you're getting downvoted here. You are correct: there is absolutely nothing irrational or supernatural about ET, and when looking for it we should consider ET as an explanation for any given phenomenon with as very low priority. Most scientists agree that we should expect ET presence out there, it's just that opinions vary wildly about the probabilities involved.

Almaviva 10y ago
Say a 1080p monitor display is completely randomized, until it shows a clear visible five-pointed star. Given I'm looking at a star, what is the likelihood there is another one on the screen? Practically 0, I'd think. Why is the emergence of an intelligent civilization in the universe different, assuming I take a multiverse and the anthropic principle seriously? (In other words, given that a universe could have multiple intelligent civilizations, why is it the case that if I'm in a random sample with at least one, there is likely to be another?)
- Udo 10y ago
  > Say a 1080p monitor display is completely randomized, until it shows a clear visible five-pointed star. Given I'm looking at a star, what is the likelihood there is another one on the screen? That's an unnecessarily convoluted example, a way of asserting that you think the probability of a technological civilization arising is vanishingly small, and taking into account the vast time intervals in question, therefore unlikely for more than one to exist simultaneously. Is that a valid point of view? Sure. It just means at least one of the factors in the Fermi equation is exceedingly small. Barring further evidence, that thesis may well turn out correct. But we still need to know what that inordinately small factor is, because we haven't found anything that fits the bill yet. Granted, there are big questions about the probability of things like abiogenesis, but over the entire history of science, arguments from exceptionality or uniqueness have almost always turned out to be incorrect.
  - Almaviva 10y ago
    > a way of asserting that you think the probability of a technological civilization arising is vanishingly small I have no idea one way or another. I wonder why many scientists are confident that extraterrestrial intelligent life exists though. Viewing through the lens of one example in a random (otherwise) unremarkable multiverse, it's not clear to me why this should be so.

corecoder 10y ago

You are right, it's a perfectly valid hypothesis, but it is an almost useless one, for at least two reasons. * It is improbable. Say I hear what appears to be a human being, but whom I cannot identify. It may be Roger Waters, there's nothing supernatural here, there's no reason why it couldn't be him. Yet, there are so many other people around that this hypothesis is totally useless: it very likely isn't Roger Waters, so I'm better off without it. * It is very hard to prove / disprove Intelligent, technologically advanced beings could very probably generate a wide variety of signals, so it is hard to prove that a certain signal cannot be generate by them; we also have no idea how the "typical" ET signal looks like, so the hypothesis doesn't really help us in furthering our analysis.

thingexplainer 10y ago
Regarding your first point, the trouble (at least in this instance) is that this logic doesn't apply when you're looking for Roger Waters and calling everyone in the phone book with his name. Each time someone picks up the phone it probably won't be the person you're looking for, but you certainly had reason to believe they could be. They didn't find a strange phenomenon and point out it might be ETI, in which case you're right, the hypothesis wouldn't make sense until you had ruled out basically everything else. They made a hypothesis about what ETI would look like, looked for it, and claim to have found things that could fit the bill.
api 10y ago
It's easy to prove if we were to ever receive, say, a string of Fibonacci numbers followed by their sum.
- corecoder 10y ago
  Sure, and if we hear a very distinct voice singing and/or guitar or bass playing, we may identify Roger Waters. If we hear footsteps? Probably not Roger Waters.

M_Grey 10y ago

I'm skeptical of ET that: 1.) Is stupid enough to broadcast to a big, unknown universe 2.) Is alive and technologically capable at the same time we are 3.) That we're going to be around and looking to the skies for very long, relatively speaking. Personally I find some version of the Great Filter hypothesis very compelling.