5 ms·

"When we update this prior in light of the Fermi observation, we find a substantial probability that we are alone in our galaxy, and perhaps even in our observa

by V-2 5y ago

"When we update this prior in light of the Fermi observation, we find a substantial probability that we are alone in our galaxy, and perhaps even in our observable universe (53%–99.6% and 39%–85% respectively). ’Where are they?’ — probably extremely far away, and quite possibly beyond the cosmological horizon and forever unreachable." Opinions like these (I stop one step short of calling them findings, as this is speculation either way) resonate with me. I'm, too, more convinced by the Rare Earth hypothesis, and I find it quite plausible that we're indeed the sole sentient lifeform in the Universe - at least throughout the time of our existence. This belief never gained me much popularity though. And this is what I'm fascinated about - how badly a lot of people take to this view. Even seemingly rational individuals seem to have some deeply ingrained, emotional need to defend the belief in ETI. My personal theory is that this emotional mechanism is actually of religious nature; just in disguise. It's very telling that the most popular narratives involving ETI are usually quasi-religious. The aliens would typically "teach us how to live in peace" (if we're willing to sit down and listen, of course), or turn away from us in disgust (for our sins), or scold us for our poor moral judgment and deeds; generally trap us in shame. Or they'd be quite diabolical and bring all sorts of plagues upon us, giving us a taste of our own medicine for we're wicked. But the eschatological component is rarely absent either way. Even this sceptical paper uses biased language through and through, consistently referring to the belief in the prevalence of ETI as "optimistic", and calling the opposite belief "pessimistic". But why?

TheOtherHobbes 5y ago
It's not religious. If anything the opposite is true. Believing we're the only intelligent life in the universe is an epic violation of the Copernican Principle. There are so many other explanations for Fermi Silence - from the reality of extremely limited sampling to the creeping suspicion that we're too mediocre and underdeveloped to recognise truly intelligent life - that grand assumptions about our specialness seem more than a little premature. None of this requires aliens who will teach us anything, one way or the other. It requires aliens who ignore us because we're about as interesting as a termite mound. And once you've seen a few billion of those, you've more or less seen them all.
- V-2 5y ago
  "Believing we're the only intelligent life in the universe is an epic violation of the Copernican Principle." Not necessarily, because the principle collides with observer bias in this case. I don't think it's valid in this context. "There are so many other explanations for Fermi Silence" Of course. I'm not concerned about the explanations themselves though - more about the emotional dimension; the attachment to the underlying idea. Lots of people seem to yearn for the ETI to exist at all. They'd be fine with any of the explanations you mentioned to be true, as long as the core concept is protected. "None of this requires aliens who will teach us anything, one way or the other." My point is not that they would, or that it's a logical scenario. My point is that humans exhibit a strong cultural need for this type of narrative. I'm interested in this anthropologically, so to speak. I don't really care about the actual aliens (or the lack thereof).
  - marcus_holmes 5y ago
    I find the theological aspects fascinating. If there are alien races, do they get their own Jesuses (Jesii?), or did we get the only Son of God? If there are multiple Jesii, are they considered to be the same person (to make the Trinity) or is the Trinity a little larger than 3? Did all the Jesii occur at the same time? Or at the same developmental point of the alien race (assuming a standard civilisational progression for all species)? Are there sapient, spacefaring aliens who have yet to have their own Jesus, and are therefore still in the "virtuous pagans" category? I realise this is kinda poking holes in Christian theology (always fun), and there are these kinds of questions for all religions. Can an alien reach Nirvana through meditation? Are there alien Buddhas? Are there Mecca-equivalents on all inhabited planets, or do aliens need to know the direction to our Mecca to pray? The woo-woo "aliens are gonna come and teach us how to be better humans" is less interesting, I think. The underlying psychological need for some beneficent parental authority figure to come and solve our problems is almost too obvious.
    - tom_mellior 5y ago
      > Jesuses (Jesii?) Pet peeve, honed by endless discussions on Slashdot in the late 1990s: -ii is not a Latin plural marker. -i is a Latin plural marker which can correspond to a singular -us. Plurals can look like -ii, but only if the singular word ends in -ius. That's simply because you replace -us by -i, and if there was an i before the -us, then there will be an i before the -i. (Example: the gladiator's sword, gladius, becomes gladii. But one of those i-s is part of the stem already.) Neither Jesus nor virus end in -ius, so their plurals can definitely, certainly, 100% never be Jesii and virii. They also happen to be words that end in -us but belong to declensions that don't use -i for the plural at all. (So no Jesi and viri either. "Viri" is a Latin word but means something else.) And on top of that IIRC virus is uncountable in Latin and Jesus is irregular even for the declension it sort of belongs to, and are proper names even countable? Thank you for coming to my TED talk.
MauranKilom 5y ago
Man, this is exactly why I dislike this paper. Somebody reads abstract and conclusion section, sees those probabilities, and then runs with them, possibly forming an entire world view around that. But there are such massive asterisks that should be attached to these numbers which are completely absent in that kind of presentation. The ~50% probabilities from the paper are not fundamentally more founded in reality than "Did another planet in our galaxy develop intelligent life yet that attempted to communicate? I don't know, so let's assume 50% either way. Therefore, we are alone with 50% probability." Should that number be 50%? Or 10%? Or 99%? You're choosing some prior there. So does this paper, and the priors chosen gravely affect the result. Of course, the paper has more intricate math and more solid reasons for their priors, but fundamentally it is still just assigning almost arbitrary probability distributions to parameters that we have no grasp on. Specifically (see my other comment), the numbers that they get primarily depend on the choice of prior distribution for the abiogenesis rate, which overshadows all other parameters. It has such massive error bars (>200 orders of magnitude by their own account) that arriving at a concrete probability (in the way that you understood it when reading the paper) is somewhere between misleading and a lie, because it's more or less just a projection of that prior into a single number. In other words, I'm convinced they could have easily arrived at probabilities like 0.1% or 99.9% by reasonably varying their prior distribution for that parameter alone.
- tom_mellior 5y ago
  > In other words, I'm convinced they could have easily arrived at probabilities like 0.1% or 99.9% by reasonably varying their prior distribution for that parameter alone. In other other words, this reading of the paper also confirms the general point it makes: The Drake equation is garbage-in garbage-out. There is no way to determine what numbers to plug into it. So let's just drop the whole unscientific nonsense.
misja111 5y ago
> I'm, too, more convinced by the Rare Earth hypothesis, I think you are misinterpreting the conclusion of the paper. The conclusion is that there is "a substantial probability that we are alone in our galaxy". This extra probability is because of the extra uncertainty within our estimates of the parameters in the Drake equation. But "substantial probability" is something entirely different than being sure.
eternalban 5y ago
C. G. Jung, Collected Works, Vol. 10, Civilization in Transition: Flying Saucers: A Modern Myth of Things Seen in the Skies (pg. 320 of pdf) http://cista.net/tomes/Carl%20Jung%20Princeton%20imprint/10%20Civilization%20in%20Transition%20%20(Collected%20Works%20of%20C.%20G.%20Jung,%20Volume%2010).pdf http://cista.net/tomes/Carl%20Jung%20Princeton%20imprint/10%...
mrkramer 5y ago
Also this from abstract: "we find a substantial ex ante probability of there being no other intelligent life in our observable universe" The keyword is "observable" universe what about probability of life in unobservable universe. When we discovered microscope and telescope only then you could say that we started "observing" something. Modern science is only 100 years old and we can not even imagine what would be invented and discovered for 50 or 100 years.

by V-2 5y ago

TheOtherHobbes 5y ago

It's not religious. If anything the opposite is true. Believing we're the only intelligent life in the universe is an epic violation of the Copernican Principle. There are so many other explanations for Fermi Silence - from the reality of extremely limited sampling to the creeping suspicion that we're too mediocre and underdeveloped to recognise truly intelligent life - that grand assumptions about our specialness seem more than a little premature. None of this requires aliens who will teach us anything, one way or the other. It requires aliens who ignore us because we're about as interesting as a termite mound. And once you've seen a few billion of those, you've more or less seen them all.

V-2 5y ago
"Believing we're the only intelligent life in the universe is an epic violation of the Copernican Principle." Not necessarily, because the principle collides with observer bias in this case. I don't think it's valid in this context. "There are so many other explanations for Fermi Silence" Of course. I'm not concerned about the explanations themselves though - more about the emotional dimension; the attachment to the underlying idea. Lots of people seem to yearn for the ETI to exist at all. They'd be fine with any of the explanations you mentioned to be true, as long as the core concept is protected. "None of this requires aliens who will teach us anything, one way or the other." My point is not that they would, or that it's a logical scenario. My point is that humans exhibit a strong cultural need for this type of narrative. I'm interested in this anthropologically, so to speak. I don't really care about the actual aliens (or the lack thereof).
- marcus_holmes 5y ago
  I find the theological aspects fascinating. If there are alien races, do they get their own Jesuses (Jesii?), or did we get the only Son of God? If there are multiple Jesii, are they considered to be the same person (to make the Trinity) or is the Trinity a little larger than 3? Did all the Jesii occur at the same time? Or at the same developmental point of the alien race (assuming a standard civilisational progression for all species)? Are there sapient, spacefaring aliens who have yet to have their own Jesus, and are therefore still in the "virtuous pagans" category? I realise this is kinda poking holes in Christian theology (always fun), and there are these kinds of questions for all religions. Can an alien reach Nirvana through meditation? Are there alien Buddhas? Are there Mecca-equivalents on all inhabited planets, or do aliens need to know the direction to our Mecca to pray? The woo-woo "aliens are gonna come and teach us how to be better humans" is less interesting, I think. The underlying psychological need for some beneficent parental authority figure to come and solve our problems is almost too obvious.
  - tom_mellior 5y ago
    > Jesuses (Jesii?) Pet peeve, honed by endless discussions on Slashdot in the late 1990s: -ii is not a Latin plural marker. -i is a Latin plural marker which can correspond to a singular -us. Plurals can look like -ii, but only if the singular word ends in -ius. That's simply because you replace -us by -i, and if there was an i before the -us, then there will be an i before the -i. (Example: the gladiator's sword, gladius, becomes gladii. But one of those i-s is part of the stem already.) Neither Jesus nor virus end in -ius, so their plurals can definitely, certainly, 100% never be Jesii and virii. They also happen to be words that end in -us but belong to declensions that don't use -i for the plural at all. (So no Jesi and viri either. "Viri" is a Latin word but means something else.) And on top of that IIRC virus is uncountable in Latin and Jesus is irregular even for the declension it sort of belongs to, and are proper names even countable? Thank you for coming to my TED talk.

MauranKilom 5y ago

Man, this is exactly why I dislike this paper. Somebody reads abstract and conclusion section, sees those probabilities, and then runs with them, possibly forming an entire world view around that. But there are such massive asterisks that should be attached to these numbers which are completely absent in that kind of presentation. The ~50% probabilities from the paper are not fundamentally more founded in reality than "Did another planet in our galaxy develop intelligent life yet that attempted to communicate? I don't know, so let's assume 50% either way. Therefore, we are alone with 50% probability." Should that number be 50%? Or 10%? Or 99%? You're choosing some prior there. So does this paper, and the priors chosen gravely affect the result. Of course, the paper has more intricate math and more solid reasons for their priors, but fundamentally it is still just assigning almost arbitrary probability distributions to parameters that we have no grasp on. Specifically (see my other comment), the numbers that they get primarily depend on the choice of prior distribution for the abiogenesis rate, which overshadows all other parameters. It has such massive error bars (>200 orders of magnitude by their own account) that arriving at a concrete probability (in the way that you understood it when reading the paper) is somewhere between misleading and a lie, because it's more or less just a projection of that prior into a single number. In other words, I'm convinced they could have easily arrived at probabilities like 0.1% or 99.9% by reasonably varying their prior distribution for that parameter alone.

tom_mellior 5y ago
> In other words, I'm convinced they could have easily arrived at probabilities like 0.1% or 99.9% by reasonably varying their prior distribution for that parameter alone. In other other words, this reading of the paper also confirms the general point it makes: The Drake equation is garbage-in garbage-out. There is no way to determine what numbers to plug into it. So let's just drop the whole unscientific nonsense.

misja111 5y ago

> I'm, too, more convinced by the Rare Earth hypothesis, I think you are misinterpreting the conclusion of the paper. The conclusion is that there is "a substantial probability that we are alone in our galaxy". This extra probability is because of the extra uncertainty within our estimates of the parameters in the Drake equation. But "substantial probability" is something entirely different than being sure.

eternalban 5y ago

C. G. Jung, Collected Works, Vol. 10, Civilization in Transition: Flying Saucers: A Modern Myth of Things Seen in the Skies (pg. 320 of pdf) http://cista.net/tomes/Carl%20Jung%20Princeton%20imprint/10%20Civilization%20in%20Transition%20%20(Collected%20Works%20of%20C.%20G.%20Jung,%20Volume%2010).pdf http://cista.net/tomes/Carl%20Jung%20Princeton%20imprint/10%...

mrkramer 5y ago

Also this from abstract: "we find a substantial ex ante probability of there being no other intelligent life in our observable universe" The keyword is "observable" universe what about probability of life in unobservable universe. When we discovered microscope and telescope only then you could say that we started "observing" something. Modern science is only 100 years old and we can not even imagine what would be invented and discovered for 50 or 100 years.