I think you may be confused by an oversimplification of Occam’s Razor: “Extraordinary claims require extraordinary evidence.” That’s not actually how you derive a prior—the very word “extraordinary” implies that you already have experience about what is ordinary and what isn’t. If we really throw out all evidence that could tell us how likely aliens are, we end up with a probability which (by the usual method of generating priors), depends on the information-theoretic complexity of the statement “There are aliens on earth.” Which in turn depends on how precisely you define the word “aliens”. Aliens that fly around in saucers are more likely than aliens that fly around in saucers and want to probe our butts. And aliens that fly around in saucers and probe our butts are more likely than aliens that fly around in saucers and probe our butts and are abducting our politicians one by one to replace them with reptilian impersonators. Every extra caveat makes a statement less likely. Every extra belief you take on is one more way that you could be wrong. This is why you need to justify all your beliefs.
I don’t think that generic aliens should be considered especially improbable a priori—before the evidence is considered. I think that they are unlikely a posteriori—based on the fact that we don’t see them. I think that any intelligent space-faring life would be busy building spheres around stars (if not outright disassembling the stars) as quickly as they spread out into the cosmos. So we’d notice them by the wake of solar systems going dark. At the very least, there’s no reason to think that they would hide from us, which is what these scenarios tend to require (though I haven’t watched the documentary).
I’m not sure what you’re trying to say about the black swan. What a bayesian would do is assign a prior probability distribution over possible colorations of swans (say 1⁄2 white, 1⁄2 black), then calculate, based on the fact that ey has seen, say, a million white swans in a row, what the probability is that the next swan ey sees will be black. Needless to say, ey will be very surprised if the next swan actually is black. But this is a good thing, because, for the same reason, ey was very unsurprised by the previous swan, which was white, as well as swans number 999,999 and 999,998 and 999,997 and so on.
“I don’t think that generic aliens should be considered especially improbable a priori—before the evidence is considered. I think that they are unlikely a posteriori—based on the fact that we don’t see them”
Citation?
There’s plenty of evidence for non-man made, non-hoaxed, non-astronomical, non-weatherrealated unidentified flying objects according to studies made by the US and French military:
The black swan example was just a general pondering.
“I don’t think that generic aliens should be considered especially improbable a priori—before the evidence is considered. I think that they are unlikely a posteriori—based on the fact that we don’t see them. I think that any intelligent space-faring life would be busy building spheres around stars (if not outright disassembling the stars) as quickly as they spread out into the cosmos. So we’d notice them by the wake of solar systems going dark. At the very least, there’s no reason to think that they would hide from us, which is what these scenarios tend to require”
This is very speculative to me. I don’t think we can use it as evidence for or against.
Even if you could rule out man-made and weather-related causes for some UFOs, that wouldn’t imply that they were caused by an extra-terrestrial civilization either. Some UFOs may still be unexplained, but all that means is that we don’t know enough about them to say what they are.
That said, I don’t think you can rule out weather and human craft. Others have already explained why I find the “primary” evidence unconvincing.
This is very speculative to me. I don’t think we can use it as evidence for or against.
Let me put it this way. My guess of what an interstellar civilization would look like makes predictions about what it would be like to encounter that civilization. Those predictions are not satisfied. This is strong evidence that no extra-terrestrial civilization (as I understand the term) has made it anywhere near us.
One of the reasons you were downvoted is that you asked us to evaluate evidence for “Aliens”. But that is impossible until you explain what you mean by “Aliens”. Obviously, there is something about these UFO sightings that makes you think they are more likely to be caused by aliens than by weather. Which implies that you think you know something about aliens that makes them a better explanation.
So what is it that you think you know about these “Aliens”?
“Even if you could rule out man-made and weather-related causes for some UFOs, that wouldn’t imply that they were caused by an extra-terrestrial civilization either.”
I agree. But in the cases of grey beings emerging from UFOs we can at least conclude that grey beings can occupy UFOs, if we trust primary evidence. This would be a massive discovery in itself, so why don’t we hear about it? We don’t have to conclude they come from outer space—who knows, they maybe live underground. Lets not speculate on that as we have plenty of interesting observations to delve into already—little gray men emerging from airborn thingies is HUGE in itself.
“So what is it that you think you know about these “Aliens”?”
It’s not that I know anything about aliens. It’s that more earthly explanations are completely implausible in many cases.
“That said, I don’t think you can rule out weather and human craft.”
In which cases? Just all cases, a priory? Or did you go through all previous sightings and came to that conclusion in every one case? Maybe others did the study for you, so you could provide a reference?
little gray men emerging from airborn thingies is HUGE in itself.
Um, no. A short guy in a grey suit stepping off a helicopter is a little grey man emerging from an airborn thingy.
Or did you go through all previous sightings and came to that conclusion in every one case?
No. I don’t see the point in digging through all the reports, when the reports I have heard about have been so underwhelming. I was skipping around, watching bits and pieces of the video you linked, until Manfred pointed this out:
The geiger counter reading is reported as “10 times background,” which sounds impressive if you’ve never held a geiger counter, but really just means a nearby rock had some potassium in it, or a dozen other possibilities.
So they basically lied. I actually haven’t ever held a geiger counter, so I had no way of knowing this. If asked to explain it, I would have had to admit that something weird was going on that I couldn’t explain. Except there’s a perfectly mundane explanation, and the only reason I was confused is because I was misled about the significance of the reading in the first place. After that I didn’t see the value in watching the rest of the documentary.
So I have a better idea. You tell me what you think is the single most convincing incident, and I will tell you,
How convincing I find the report on its own, and
How convincing it would be, assuming that there were thousands of similar, equally reliable reports.
“I don’t think that generic aliens should be considered especially improbable a priori—before the evidence is considered. I think that they are unlikely a posteriori—based on the fact that we don’t see them. I think that any intelligent space-faring life would be busy building spheres around stars (if not outright disassembling the stars) as quickly as they spread out into the cosmos. So we’d notice them by the wake of solar systems going dark. At the very least, there’s no reason to think that they would hide from us, which is what these scenarios tend to require (though I haven’t watched the documentary).”
is at best secondary evidence and thus shouldn’t be weighted as high as primary evidence such as sightings or knowledge of time+space-correlating weather balloon flights.
I think you may be confused by an oversimplification of Occam’s Razor: “Extraordinary claims require extraordinary evidence.” That’s not actually how you derive a prior—the very word “extraordinary” implies that you already have experience about what is ordinary and what isn’t. If we really throw out all evidence that could tell us how likely aliens are, we end up with a probability which (by the usual method of generating priors), depends on the information-theoretic complexity of the statement “There are aliens on earth.” Which in turn depends on how precisely you define the word “aliens”. Aliens that fly around in saucers are more likely than aliens that fly around in saucers and want to probe our butts. And aliens that fly around in saucers and probe our butts are more likely than aliens that fly around in saucers and probe our butts and are abducting our politicians one by one to replace them with reptilian impersonators. Every extra caveat makes a statement less likely. Every extra belief you take on is one more way that you could be wrong. This is why you need to justify all your beliefs.
I don’t think that generic aliens should be considered especially improbable a priori—before the evidence is considered. I think that they are unlikely a posteriori—based on the fact that we don’t see them. I think that any intelligent space-faring life would be busy building spheres around stars (if not outright disassembling the stars) as quickly as they spread out into the cosmos. So we’d notice them by the wake of solar systems going dark. At the very least, there’s no reason to think that they would hide from us, which is what these scenarios tend to require (though I haven’t watched the documentary).
I’m not sure what you’re trying to say about the black swan. What a bayesian would do is assign a prior probability distribution over possible colorations of swans (say 1⁄2 white, 1⁄2 black), then calculate, based on the fact that ey has seen, say, a million white swans in a row, what the probability is that the next swan ey sees will be black. Needless to say, ey will be very surprised if the next swan actually is black. But this is a good thing, because, for the same reason, ey was very unsurprised by the previous swan, which was white, as well as swans number 999,999 and 999,998 and 999,997 and so on.
Anyway, I found this amusing.
“I don’t think that generic aliens should be considered especially improbable a priori—before the evidence is considered. I think that they are unlikely a posteriori—based on the fact that we don’t see them”
Citation?
There’s plenty of evidence for non-man made, non-hoaxed, non-astronomical, non-weatherrealated unidentified flying objects according to studies made by the US and French military:
http://en.wikipedia.org/wiki/Project_Blue_Book#Project_Blue_Book_Special_Report_No._14
most important highlights:
http://lesswrong.com/lw/ffd/struck_with_a_belief_in_alien_presence/7t4i
The black swan example was just a general pondering.
“I don’t think that generic aliens should be considered especially improbable a priori—before the evidence is considered. I think that they are unlikely a posteriori—based on the fact that we don’t see them. I think that any intelligent space-faring life would be busy building spheres around stars (if not outright disassembling the stars) as quickly as they spread out into the cosmos. So we’d notice them by the wake of solar systems going dark. At the very least, there’s no reason to think that they would hide from us, which is what these scenarios tend to require”
This is very speculative to me. I don’t think we can use it as evidence for or against.
Even if you could rule out man-made and weather-related causes for some UFOs, that wouldn’t imply that they were caused by an extra-terrestrial civilization either. Some UFOs may still be unexplained, but all that means is that we don’t know enough about them to say what they are.
That said, I don’t think you can rule out weather and human craft. Others have already explained why I find the “primary” evidence unconvincing.
Let me put it this way. My guess of what an interstellar civilization would look like makes predictions about what it would be like to encounter that civilization. Those predictions are not satisfied. This is strong evidence that no extra-terrestrial civilization (as I understand the term) has made it anywhere near us.
One of the reasons you were downvoted is that you asked us to evaluate evidence for “Aliens”. But that is impossible until you explain what you mean by “Aliens”. Obviously, there is something about these UFO sightings that makes you think they are more likely to be caused by aliens than by weather. Which implies that you think you know something about aliens that makes them a better explanation.
So what is it that you think you know about these “Aliens”?
“Even if you could rule out man-made and weather-related causes for some UFOs, that wouldn’t imply that they were caused by an extra-terrestrial civilization either.”
I agree. But in the cases of grey beings emerging from UFOs we can at least conclude that grey beings can occupy UFOs, if we trust primary evidence. This would be a massive discovery in itself, so why don’t we hear about it? We don’t have to conclude they come from outer space—who knows, they maybe live underground. Lets not speculate on that as we have plenty of interesting observations to delve into already—little gray men emerging from airborn thingies is HUGE in itself.
“So what is it that you think you know about these “Aliens”?”
It’s not that I know anything about aliens. It’s that more earthly explanations are completely implausible in many cases.
“That said, I don’t think you can rule out weather and human craft.”
In which cases? Just all cases, a priory? Or did you go through all previous sightings and came to that conclusion in every one case? Maybe others did the study for you, so you could provide a reference?
Um, no. A short guy in a grey suit stepping off a helicopter is a little grey man emerging from an airborn thingy.
No. I don’t see the point in digging through all the reports, when the reports I have heard about have been so underwhelming. I was skipping around, watching bits and pieces of the video you linked, until Manfred pointed this out:
So they basically lied. I actually haven’t ever held a geiger counter, so I had no way of knowing this. If asked to explain it, I would have had to admit that something weird was going on that I couldn’t explain. Except there’s a perfectly mundane explanation, and the only reason I was confused is because I was misled about the significance of the reading in the first place. After that I didn’t see the value in watching the rest of the documentary.
So I have a better idea. You tell me what you think is the single most convincing incident, and I will tell you,
How convincing I find the report on its own, and
How convincing it would be, assuming that there were thousands of similar, equally reliable reports.
As mentioned elsewhere, this kind of reasoning:
“I don’t think that generic aliens should be considered especially improbable a priori—before the evidence is considered. I think that they are unlikely a posteriori—based on the fact that we don’t see them. I think that any intelligent space-faring life would be busy building spheres around stars (if not outright disassembling the stars) as quickly as they spread out into the cosmos. So we’d notice them by the wake of solar systems going dark. At the very least, there’s no reason to think that they would hide from us, which is what these scenarios tend to require (though I haven’t watched the documentary).”
is at best secondary evidence and thus shouldn’t be weighted as high as primary evidence such as sightings or knowledge of time+space-correlating weather balloon flights.