5 ms·

I'm sold on the whole UFO cover-up thing. If you peel back the social ridicule (very successfully induced by US government collaboration with Hollywood) and con

by brango 9y ago

I'm sold on the whole UFO cover-up thing. If you peel back the social ridicule (very successfully induced by US government collaboration with Hollywood) and consider the huge number of circumstantial reports from across the military and non-military it seems pretty clear there's stuff in the skies of non-human origin. Historical art suggests they've been flying for centuries. There's also the publicly acknowledged reports of NASA and various governments/military conducting investigations and spending millions of dollars in the process. Historically it would have been politically difficult for governments to come out and admit this - and when they did (like after Roswell) it was quickly retracted. Peel back the social conditioning and reconsider the likelihood of this given all the reports.

dsacco 9y ago
I’m open minded to what you’re saying, and I agree that dismissing alien contact due to popular zeitgeist is silly. But here’s my problem with what you’re saying: where did they come from then, and how did they get here? Why do we not have any evidence of their planet in any reasonable distance from Earth? Given what we understand about modern physics, we have three conclusions we can arrive at: 1. We fundamentally misunderstand physics, in particular the central concept that the speed of light is a hard speed limit on motion, and aliens are capable of arriving here faster than light, 2. The aliens have technology capable of arriving here from so distant a home world that they are either inconceivably long lived or else their entire society existed on a transport vessel for generations and generations, 3. Sightings of UFO are examples of popular hysteria, and aliens are not, and have never been anywhere near Earth. Given the available evidence, Occam’s Razor suggests #3. I understand that reports from distributed and disconnected sources can be encouraging, but realistically speaking it still presents insufficiently extraordinary evidence to me to abandon possibility #3.
- brango 9y ago
  Yeah #3 is certainly the most likely and is what I always assumed. But over time I've come to think that they are here. So probably the next most likely is #1. Maybe they just know more science than we do. Look how far we've come in the last 200 years. What if they have a few millennia on us?
  - LyndsySimon 9y ago
    What if it's some sort of psychological phenomenon, but one which has a physical manifestation? Yes, I know that that idea is pretty out there, but we're already talking about ideas that bend or break the known physical laws, so why not consider it? I honestly don't see it as being any less absurd than the idea that the speed of light is not a universal constant, an that is required for almost all hypotheticals involved extra-solar intelligence.
- ghostbrainalpha 9y ago
  Isn't it much more likely that an Alien society developed an artificial intelligence capable of exploring the universe AND self replicating. A satellite program like this could easily monitor distant parts of the galaxy without travelling faster than light, or require a generational ship.
- zamalek 9y ago
  > fundamentally misunderstand physics Keep in mind that we think we know how to reach a destination faster than light (although not travel faster than light). We just don't know how [edit: to build the engine] or even if it's a practical approach. What it shows is that physics does allow us to reach a distant star and return in a single lifetime. > inconceivably long lived I'm not sure about this one. That species would have had to evolve somehow, unless they solved the mortality problem or unless Earth-like evolution is not universal. Even if they could, given the timeframes, why would they visit? My point is that, yes, we don't have enough evidence to abandon possibility #3. We also don't have enough knowledge to abandon possibility #1 and #2. That being said, I'd wager that if ET has visited Earth less than 1% of the sightings are authentic - we aren't that interesting.
- ansible 9y ago
  I used to be fascinated with the UFO reports and such as a kid. However, I grew up, and learned physics. And then later I learned about things like Molecular Nanotechnology. Aliens, as popularly conceived, have not been here, and will not be coming here. Why? I'll explain. Space is big. Like, really big. The distance to the nearest star system is 4 light-years away. Even for a small object, it takes an enormous amount of energy to get going at a "reasonable" speed, like at some fraction of the speed of light. For an example of a more reasonably-sized object, Voyager 1 would take 70k years to get to the closest star system (4LY away) if it was headed in the right direction. But then you have to stop! If you accelerate up to 0.1c (very fast), you have to decelerate to arrive at your destination. This is where the rocket equation kills you. Even with super-mass efficient ion drives (which with our current technology provide very low thrust), accelerating your spaceship to a reasonable speed, and then have enough delta-V to stop at the destination requires an even more crazy amount of energy. If any aliens are headed to our solar system, we'd see their drive flairs from a long way out. The most efficient system is to use a light sail (really, a laser sail). This is so you don't have to carry all that reaction mass with you, thus bypassing the rocket equation. And then there's a trick where you detach most of your sail, allowing it to reflect light back towards the ship for the deceleration half of the trip. But again, even for a small (like 1kg) payload, this requires a stupendous amount of energy. And we'd see them coming because they'd be shining a big, big laser in our direction. There are also Bussard ramjet drives, and other speculated technology, but these would all likely be slower because of the mass required to build it. Now simply flinging out a bunch of von Neumann replicators out in every direction would be much less obvious (though very slow), until the space dust starts building infrastructure in our solar system... but that's a talk for another day.
  - em3rgent0rdr 9y ago
    But maybe the UFO are really old machines (like millions of years old) in which case they can take all they time they need to travel and decelerate, such that wouldn't produce drive flairs.
    - ansible 9y ago
      Anything is possible, but that doesn't seem likely. It is helpful to think of what would aliens want from us that they can't get at home. Raw material, like in the mini-series V, Oblivion, Uplift War trilogy, etc? It is too expensive to ship matter anywhere. If you need a lot of it for a construction project, you'd be better off heading to the galactic core. Maybe they want our cultural uniqueness? But they could easily simulate many virtual worlds with different starting conditions, and poke around those without leaving the comfort of home. That would be much easier, especially after they get bored with humans. And if they have advanced molecular nanotechnology, it isn't just waiting millions of years for results. They are likely running at a much higher "clock rate" than we are now. You can run an uploaded mind much faster than a biological one. So these hypothetical aliens would instead be waiting billions of years of subjective time for their probes to find something interesting.
- lucozade 9y ago
  Not sure I agree with the analysis, although I do agree with the conclusion. We've only known there's a pervasive limit for a century. We've known for a few decades that the limit is quite subtle i.e. the violation of local realism. It's not at all difficult to imagine that there is more to know in this field. I mean, it took 200-odd years before Newtonian mechanics was supplanted. So there's form. Also, you don't need to go faster than light as long as you don't go back. If alien explorers are going at a decent fraction of light speed, they can get a fairly long way in a sensible timespan for them. Just not for the folk back home. My objection to the conspiracy theory idea is that it just doesn't make any sense. They drew huge pictures and built great monuments then got shy. They now play peekaboo with rednecks and the odd fighter pilot. Governments could be covering up alien tech from a long gone race but one that's still here? A race that they collude with but let out to do a bit of probing because, presumably, the government can't find bodies for them. So nah. They're not here but it's not technically inconceivable that they haven't been in the past or won't be in the future. It just doesn't seem very likely.
- yosito 9y ago
  4. Intelligent life has evolved on Earth, alongside (or before) humans, and has mostly managed to cloak itself from human discovery. Occam's Razor still suggests #3, but #4 is more likely than #1 and #2.
- egypturnash 9y ago
  4. The entire world is a simulation and UFOs are moving around in debug mode. The size of the simulation could be anywhere from the entire universe to the Solar System (or less, if you can come up with a plausible reason why the Pioneer probes appear to continue to operate despite being outside of a smaller simulation volume). Occam's Razor would throw that one out too of course.
- gfodor 9y ago
  There's a perfectly consistent explanation that doesn't really break Occam's razor unless you have huge assumptions about AI takeoff and the drake equation: - These are really old things - They are autonomous and are driven by some computing system/AI - They have the ability to harvest, store, and leverage an immense amount of energy and convert it into propulsion (or more specifically, allows the repositioning of the object's atoms in spacetime) in a way we don't understand but doesn't break the laws of thermodynamics and allows travel at near light speed for long periods of time. - Their purpose isn't to communicate back to the origin (since the speed of light) but to autonomously take interventional action at their destination upon arrival based upon observation (this is the part that should scare you and if I were to go out on a limb is the reason these things aren't disclosed) That's it. Speculation about their original origin is irrelevant with regards to assuming it's an extremely unlikely thing for unmanned autonomous agents to exist with (a relatively incremental) post-human level of technological capability. If anything, there are many variants of resolving the drake equation which would make it surprising to not see such things, since it would imply there was never AI takeoff anywhere or any mechanism to deploy long-lived, self sufficient, autonomous probes. I'd expect us to be able to construct primitive versions of this within 100 years.
mtberatwork 9y ago
> Peel back the social conditioning and reconsider the likelihood of this given all the reports. Well, for starters, it would require an extraordinary number of people to keep such a secret [1], so not really as probable as you may think. But it's still fun to think about. [1] https://www.pbs.org/newshour/science/math-formula-charts-the-lifespan-of-hoaxes https://www.pbs.org/newshour/science/math-formula-charts-the...
gooseus 9y ago
Links to credible sources or GTFO. That was rude, I know, but remember that the evidence required is proportional to the claim. Extraterrestrial machines literally flying within our atmosphere is an extraordinary claim and requires more evidence than a huge number of circumstantial reports. I imagine the claim like a hole in the ground that needs to be filled with nice clear evidence in order for people to swim in it comfortably. These circumstantial reports are like a bunch of 12oz cups and the hole you're trying to fill is more akin to a lake than a puddle.
- cmroanirgo 9y ago
  As per previous comment of mine, https://news.ycombinator.com/item?id=15966698 https://news.ycombinator.com/item?id=15966698 See http://siriusdisclosure.com/ http://siriusdisclosure.com/ countless testimonies, videos and proofs.
ohyes 9y ago
Ok. If it’s an extraterrestrial, how did it get here? There’s no evidence that FTL is possible and even if it were it would probably require huge amounts of power. We’d notice it being used. We may as well be saying that these are angels from heaven, I guess is my point. There are tons of reports of ‘divine’ stuff happening as well, but jumping to God existing being a likelihood is not something an objective observer would do. What I really want to know is what the alien technology is that makes all of these videos grainy and impossible to make out details in, and how did Bigfoot acquire it?
- 0xFFC 9y ago
  In a totally unrelated comment, I want to say, one reason why I find the UFO thing interested is in hypothetical situation if we can have proofs of existence of aliens, all those nonsense, ridiculous religions (like Islam, Christianity, Judaism, etc) would be horseshit to common people. With a simple question of : “Why your God only sent his prophet to earth?”
  - dragonwriter 9y ago
    > one reason why I find the UFO thing interested is in hypothetical situation if we can have proofs of existence of aliens, all those nonsense, ridiculous religions (like Islam, Christianity, Judaism, etc) would be horseshit to common people. With a simple question of : “Why your God only sent his prophet to earth?” How is that question substantively any different than “Why your God only sent his prophet to the Middle East?” If the Abrahamic religions (not even to mention all the religions that don't rest on a singular preeminent emissary, which don't have this problem at all) can survive and thrive in the face of the latter question, the former isn't much of a challenge.
    - 0xFFC 9y ago
      >How is that question substantively any different than “Why your God only sent his prophet to the Middle East?” Nice question. I remember when I was 12,13 and lived with my family (in religious country) I have thought about the exact same question. I think you are totally right.
corobo 9y ago
Why though? Why would an alien species just do atmosphere drive-bys? Why wouldn’t they pop down and say hello? Why on earth would NASA, SETI, SpaceX, etc cover up the biggest scoop (biggest FUNDING scoop) of Earth’s history? Why wouldn’t any of the other LEO piercing countries in the world grass it up? Thousands of people working in each of the space-faring countries, all keeping quiet about it. Why would the US, Russia, China, probably even North Korea agree on this one thing? Alright guys we are all agreed on not telling the plebs about the aliens? Ok cool, back to the war then lads. If you can answer why, I’m down to clown on your theory.
- briffle 9y ago
  When we send scientists to document and study the penguins in Antarctica and their march to lay and sit on eggs, do we have the scientists go walk down to where they are, measure them, interact with them, etc? Or do we spot them from a distance, as discretely as possible, so that we don't disturb the subjects, and don't bias the study of their interactions?
  - shedaemon 9y ago
    Remember "Occam's Razor?" It is so incredibly difficult to travel through interstellar space that "aliens" is not the simplest explanation. Any civilization so advanced that it could bridge such distances in space to study earth would definitely have the technology to be undetectable. They'd have molecular sized drones collecting info. They wouldn't be detectable on radar. And it certainly wouldn't be the aliens themselves travelling, collecting data, it would be thousands of tiny robots. A more logical explanation is that this phenomenon is terrestrial in origin. The object from the pilot's video in 2012 was tracked and seen for several weeks by a Navy ship. Where are those records? Maybe this whole thing was an experiment to see how the military responds to an advanced piece of equipment. The fact that the object appeared on radar at the pilot's rendezvous point 60 miles away is very suspicious.
  - em3rgent0rdr 9y ago
    Exactly. Sci-fi writers have contemplated this. Advanced civilizations might consider cultural contamination of a relatively-primitive civilization so bad that they'll strive to avoid it (e.g. Star Trek's Prime Directive).

by brango 9y ago

dsacco 9y ago

I’m open minded to what you’re saying, and I agree that dismissing alien contact due to popular zeitgeist is silly. But here’s my problem with what you’re saying: where did they come from then, and how did they get here? Why do we not have any evidence of their planet in any reasonable distance from Earth? Given what we understand about modern physics, we have three conclusions we can arrive at: 1. We fundamentally misunderstand physics, in particular the central concept that the speed of light is a hard speed limit on motion, and aliens are capable of arriving here faster than light, 2. The aliens have technology capable of arriving here from so distant a home world that they are either inconceivably long lived or else their entire society existed on a transport vessel for generations and generations, 3. Sightings of UFO are examples of popular hysteria, and aliens are not, and have never been anywhere near Earth. Given the available evidence, Occam’s Razor suggests #3. I understand that reports from distributed and disconnected sources can be encouraging, but realistically speaking it still presents insufficiently extraordinary evidence to me to abandon possibility #3.

brango 9y ago
Yeah #3 is certainly the most likely and is what I always assumed. But over time I've come to think that they are here. So probably the next most likely is #1. Maybe they just know more science than we do. Look how far we've come in the last 200 years. What if they have a few millennia on us?
- LyndsySimon 9y ago
  What if it's some sort of psychological phenomenon, but one which has a physical manifestation? Yes, I know that that idea is pretty out there, but we're already talking about ideas that bend or break the known physical laws, so why not consider it? I honestly don't see it as being any less absurd than the idea that the speed of light is not a universal constant, an that is required for almost all hypotheticals involved extra-solar intelligence.
ghostbrainalpha 9y ago
Isn't it much more likely that an Alien society developed an artificial intelligence capable of exploring the universe AND self replicating. A satellite program like this could easily monitor distant parts of the galaxy without travelling faster than light, or require a generational ship.
zamalek 9y ago
> fundamentally misunderstand physics Keep in mind that we think we know how to reach a destination faster than light (although not travel faster than light). We just don't know how [edit: to build the engine] or even if it's a practical approach. What it shows is that physics does allow us to reach a distant star and return in a single lifetime. > inconceivably long lived I'm not sure about this one. That species would have had to evolve somehow, unless they solved the mortality problem or unless Earth-like evolution is not universal. Even if they could, given the timeframes, why would they visit? My point is that, yes, we don't have enough evidence to abandon possibility #3. We also don't have enough knowledge to abandon possibility #1 and #2. That being said, I'd wager that if ET has visited Earth less than 1% of the sightings are authentic - we aren't that interesting.
ansible 9y ago
I used to be fascinated with the UFO reports and such as a kid. However, I grew up, and learned physics. And then later I learned about things like Molecular Nanotechnology. Aliens, as popularly conceived, have not been here, and will not be coming here. Why? I'll explain. Space is big. Like, really big. The distance to the nearest star system is 4 light-years away. Even for a small object, it takes an enormous amount of energy to get going at a "reasonable" speed, like at some fraction of the speed of light. For an example of a more reasonably-sized object, Voyager 1 would take 70k years to get to the closest star system (4LY away) if it was headed in the right direction. But then you have to stop! If you accelerate up to 0.1c (very fast), you have to decelerate to arrive at your destination. This is where the rocket equation kills you. Even with super-mass efficient ion drives (which with our current technology provide very low thrust), accelerating your spaceship to a reasonable speed, and then have enough delta-V to stop at the destination requires an even more crazy amount of energy. If any aliens are headed to our solar system, we'd see their drive flairs from a long way out. The most efficient system is to use a light sail (really, a laser sail). This is so you don't have to carry all that reaction mass with you, thus bypassing the rocket equation. And then there's a trick where you detach most of your sail, allowing it to reflect light back towards the ship for the deceleration half of the trip. But again, even for a small (like 1kg) payload, this requires a stupendous amount of energy. And we'd see them coming because they'd be shining a big, big laser in our direction. There are also Bussard ramjet drives, and other speculated technology, but these would all likely be slower because of the mass required to build it. Now simply flinging out a bunch of von Neumann replicators out in every direction would be much less obvious (though very slow), until the space dust starts building infrastructure in our solar system... but that's a talk for another day.
- em3rgent0rdr 9y ago
  But maybe the UFO are really old machines (like millions of years old) in which case they can take all they time they need to travel and decelerate, such that wouldn't produce drive flairs.
  - ansible 9y ago
    Anything is possible, but that doesn't seem likely. It is helpful to think of what would aliens want from us that they can't get at home. Raw material, like in the mini-series V, Oblivion, Uplift War trilogy, etc? It is too expensive to ship matter anywhere. If you need a lot of it for a construction project, you'd be better off heading to the galactic core. Maybe they want our cultural uniqueness? But they could easily simulate many virtual worlds with different starting conditions, and poke around those without leaving the comfort of home. That would be much easier, especially after they get bored with humans. And if they have advanced molecular nanotechnology, it isn't just waiting millions of years for results. They are likely running at a much higher "clock rate" than we are now. You can run an uploaded mind much faster than a biological one. So these hypothetical aliens would instead be waiting billions of years of subjective time for their probes to find something interesting.
lucozade 9y ago
Not sure I agree with the analysis, although I do agree with the conclusion. We've only known there's a pervasive limit for a century. We've known for a few decades that the limit is quite subtle i.e. the violation of local realism. It's not at all difficult to imagine that there is more to know in this field. I mean, it took 200-odd years before Newtonian mechanics was supplanted. So there's form. Also, you don't need to go faster than light as long as you don't go back. If alien explorers are going at a decent fraction of light speed, they can get a fairly long way in a sensible timespan for them. Just not for the folk back home. My objection to the conspiracy theory idea is that it just doesn't make any sense. They drew huge pictures and built great monuments then got shy. They now play peekaboo with rednecks and the odd fighter pilot. Governments could be covering up alien tech from a long gone race but one that's still here? A race that they collude with but let out to do a bit of probing because, presumably, the government can't find bodies for them. So nah. They're not here but it's not technically inconceivable that they haven't been in the past or won't be in the future. It just doesn't seem very likely.
yosito 9y ago
4. Intelligent life has evolved on Earth, alongside (or before) humans, and has mostly managed to cloak itself from human discovery. Occam's Razor still suggests #3, but #4 is more likely than #1 and #2.
egypturnash 9y ago
4. The entire world is a simulation and UFOs are moving around in debug mode. The size of the simulation could be anywhere from the entire universe to the Solar System (or less, if you can come up with a plausible reason why the Pioneer probes appear to continue to operate despite being outside of a smaller simulation volume). Occam's Razor would throw that one out too of course.
gfodor 9y ago
There's a perfectly consistent explanation that doesn't really break Occam's razor unless you have huge assumptions about AI takeoff and the drake equation: - These are really old things - They are autonomous and are driven by some computing system/AI - They have the ability to harvest, store, and leverage an immense amount of energy and convert it into propulsion (or more specifically, allows the repositioning of the object's atoms in spacetime) in a way we don't understand but doesn't break the laws of thermodynamics and allows travel at near light speed for long periods of time. - Their purpose isn't to communicate back to the origin (since the speed of light) but to autonomously take interventional action at their destination upon arrival based upon observation (this is the part that should scare you and if I were to go out on a limb is the reason these things aren't disclosed) That's it. Speculation about their original origin is irrelevant with regards to assuming it's an extremely unlikely thing for unmanned autonomous agents to exist with (a relatively incremental) post-human level of technological capability. If anything, there are many variants of resolving the drake equation which would make it surprising to not see such things, since it would imply there was never AI takeoff anywhere or any mechanism to deploy long-lived, self sufficient, autonomous probes. I'd expect us to be able to construct primitive versions of this within 100 years.

mtberatwork 9y ago

> Peel back the social conditioning and reconsider the likelihood of this given all the reports. Well, for starters, it would require an extraordinary number of people to keep such a secret [1], so not really as probable as you may think. But it's still fun to think about. [1] https://www.pbs.org/newshour/science/math-formula-charts-the-lifespan-of-hoaxes https://www.pbs.org/newshour/science/math-formula-charts-the...

gooseus 9y ago

Links to credible sources or GTFO. That was rude, I know, but remember that the evidence required is proportional to the claim. Extraterrestrial machines literally flying within our atmosphere is an extraordinary claim and requires more evidence than a huge number of circumstantial reports. I imagine the claim like a hole in the ground that needs to be filled with nice clear evidence in order for people to swim in it comfortably. These circumstantial reports are like a bunch of 12oz cups and the hole you're trying to fill is more akin to a lake than a puddle.

cmroanirgo 9y ago
As per previous comment of mine, https://news.ycombinator.com/item?id=15966698 https://news.ycombinator.com/item?id=15966698 See http://siriusdisclosure.com/ http://siriusdisclosure.com/ countless testimonies, videos and proofs.

ohyes 9y ago

Ok. If it’s an extraterrestrial, how did it get here? There’s no evidence that FTL is possible and even if it were it would probably require huge amounts of power. We’d notice it being used. We may as well be saying that these are angels from heaven, I guess is my point. There are tons of reports of ‘divine’ stuff happening as well, but jumping to God existing being a likelihood is not something an objective observer would do. What I really want to know is what the alien technology is that makes all of these videos grainy and impossible to make out details in, and how did Bigfoot acquire it?

0xFFC 9y ago
In a totally unrelated comment, I want to say, one reason why I find the UFO thing interested is in hypothetical situation if we can have proofs of existence of aliens, all those nonsense, ridiculous religions (like Islam, Christianity, Judaism, etc) would be horseshit to common people. With a simple question of : “Why your God only sent his prophet to earth?”
- dragonwriter 9y ago
  > one reason why I find the UFO thing interested is in hypothetical situation if we can have proofs of existence of aliens, all those nonsense, ridiculous religions (like Islam, Christianity, Judaism, etc) would be horseshit to common people. With a simple question of : “Why your God only sent his prophet to earth?” How is that question substantively any different than “Why your God only sent his prophet to the Middle East?” If the Abrahamic religions (not even to mention all the religions that don't rest on a singular preeminent emissary, which don't have this problem at all) can survive and thrive in the face of the latter question, the former isn't much of a challenge.
  - 0xFFC 9y ago
    >How is that question substantively any different than “Why your God only sent his prophet to the Middle East?” Nice question. I remember when I was 12,13 and lived with my family (in religious country) I have thought about the exact same question. I think you are totally right.

corobo 9y ago

Why though? Why would an alien species just do atmosphere drive-bys? Why wouldn’t they pop down and say hello? Why on earth would NASA, SETI, SpaceX, etc cover up the biggest scoop (biggest FUNDING scoop) of Earth’s history? Why wouldn’t any of the other LEO piercing countries in the world grass it up? Thousands of people working in each of the space-faring countries, all keeping quiet about it. Why would the US, Russia, China, probably even North Korea agree on this one thing? Alright guys we are all agreed on not telling the plebs about the aliens? Ok cool, back to the war then lads. If you can answer why, I’m down to clown on your theory.

briffle 9y ago
When we send scientists to document and study the penguins in Antarctica and their march to lay and sit on eggs, do we have the scientists go walk down to where they are, measure them, interact with them, etc? Or do we spot them from a distance, as discretely as possible, so that we don't disturb the subjects, and don't bias the study of their interactions?
- shedaemon 9y ago
  Remember "Occam's Razor?" It is so incredibly difficult to travel through interstellar space that "aliens" is not the simplest explanation. Any civilization so advanced that it could bridge such distances in space to study earth would definitely have the technology to be undetectable. They'd have molecular sized drones collecting info. They wouldn't be detectable on radar. And it certainly wouldn't be the aliens themselves travelling, collecting data, it would be thousands of tiny robots. A more logical explanation is that this phenomenon is terrestrial in origin. The object from the pilot's video in 2012 was tracked and seen for several weeks by a Navy ship. Where are those records? Maybe this whole thing was an experiment to see how the military responds to an advanced piece of equipment. The fact that the object appeared on radar at the pilot's rendezvous point 60 miles away is very suspicious.
- em3rgent0rdr 9y ago
  Exactly. Sci-fi writers have contemplated this. Advanced civilizations might consider cultural contamination of a relatively-primitive civilization so bad that they'll strive to avoid it (e.g. Star Trek's Prime Directive).