11 ms·

ET should always be the hypothesis of last resort. It is the modern equivalent of blaming the gods for a natural disaster.

by gjolund 10y ago

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.
pmarreck 10y ago
So you find it more probable that we are the only sentient life in the vast known universe? That would be the best proof of a(n absentee) God ever, basically. The one special planet deemed OK to magic-pixie-dust life onto! Which makes me presume it to be false.
- gjolund 10y ago
  That isn't science it is opinion. So far there is no evidence of life beyond this planet. Until there is that hypothesis should be viewed with skepticism.
  - kordless 10y ago
    We still have no idea what carries the force observed as inertia. While it may be a hypothesis that aliens exist, it's also a hypothesis that they don't. We know things have inertia, but have no idea why they do. We have a reasonable assumption that aliens exist. Proving they exist consists of finding an alien civilization, but proving they don't would include an exhaustive search of the entire universe. Inertia appears to be a universal force, but proving that would also require an fairly exhaustive search from everywhere in the universe.
  - rdlecler1 10y ago
    Sure, but if we're going to look let's look in those places that are generating the kind of evidence we'd expect to see which are showing interesting behavior.
  - stickfigure 10y ago
    It's a bit more than opinion, it's the Cosmological Principle: https://en.wikipedia.org/wiki/Cosmological_principle https://en.wikipedia.org/wiki/Cosmological_principle There's room for debate but it generally seems to match our observations. There's no a priori reason to believe that Earth is special in the universe since all the rest of our solar system / galaxy seem to be unremarkable.
- bbctol 10y ago
  No, they find it more probable that these particular signals are not aliens. It's not about whether or not you believe aliens exist, at all, it's about whether or not their the best explanation for any phenomenon. One day, we may get evidence for which there is no better explanation (say, a flying saucer landing at the White House with little grey aliens hopping out.) Right now, we do not have to use that hypothesis of last resort; it's still more parsimonious to think we just don't understand stars that well.

ET should always be the hypothesis of last resort. It is the modern equivalent of blaming the gods for a natural disaster.

by gjolund 10y ago

ET should always be the hypothesis of last resort. It is the modern equivalent of blaming the gods for a natural disaster.

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.

pmarreck 10y ago

So you find it more probable that we are the only sentient life in the vast known universe? That would be the best proof of a(n absentee) God ever, basically. The one special planet deemed OK to magic-pixie-dust life onto! Which makes me presume it to be false.

gjolund 10y ago
That isn't science it is opinion. So far there is no evidence of life beyond this planet. Until there is that hypothesis should be viewed with skepticism.
- kordless 10y ago
  We still have no idea what carries the force observed as inertia. While it may be a hypothesis that aliens exist, it's also a hypothesis that they don't. We know things have inertia, but have no idea why they do. We have a reasonable assumption that aliens exist. Proving they exist consists of finding an alien civilization, but proving they don't would include an exhaustive search of the entire universe. Inertia appears to be a universal force, but proving that would also require an fairly exhaustive search from everywhere in the universe.
- rdlecler1 10y ago
  Sure, but if we're going to look let's look in those places that are generating the kind of evidence we'd expect to see which are showing interesting behavior.
- stickfigure 10y ago
  It's a bit more than opinion, it's the Cosmological Principle: https://en.wikipedia.org/wiki/Cosmological_principle https://en.wikipedia.org/wiki/Cosmological_principle There's room for debate but it generally seems to match our observations. There's no a priori reason to believe that Earth is special in the universe since all the rest of our solar system / galaxy seem to be unremarkable.
bbctol 10y ago
No, they find it more probable that these particular signals are not aliens. It's not about whether or not you believe aliens exist, at all, it's about whether or not their the best explanation for any phenomenon. One day, we may get evidence for which there is no better explanation (say, a flying saucer landing at the White House with little grey aliens hopping out.) Right now, we do not have to use that hypothesis of last resort; it's still more parsimonious to think we just don't understand stars that well.