Astronomers: Please stop shouting out to the universe.

[WalrusLike]

Maybe that endless nitpicking is not pointless, it's meant to test whether the scenario is conceivable.

But it assumes that I have all day and nothing else to do... I dont. Lets not line by line nit-pick... why not choose a solid point and argue that....

Yes, and some of those are just plain wrong in the sense that first contact will never happen that way.

This is why I didnt want to debate it..... Did I, at any point, say that every sf scenario is plausible? NO... so the fact that some are not does not prove that they are _all_ unreasonable.

... I claimed that anyone capable of harming us could also find us without much effort.

Ok... lets agree on that... it still doesn't show that a) they are looking... b) they are looking here... or c) that whatever method they use works as well as simply receiving a targeted hello.

you also have to explain why they haven't bothered to look for us in the first place. (Or if they did, why didn't they succeed)

This is the area of imponderables that I don't want to go to... its too much like arguing how many angels fit on the head of a pin... all of our assumptions in this type of discussion are suspect.

No, what we do is......... You think I'm nitpicking here, right? But this is an important distinction.....These conclusions are actually often wrong.

Shoot me for stupidity... but I didnt understand this portion of your post at all. (I _know_ you want to reply... 'And thats why you are not qualified to speak on the topic....' )

Why not? They obviously care because they are willing to go some way to destroy us.

Again, angels on the pin... I am not going to speculate on the imponderables....

There are ways to look for technological civilizations.

Sure.. granted. But there still is a world of difference between being detected passively and going to a lot of trouble to actually get their attention.

The point is that while there currently, unarguably, is some possibility they have missed us... that drops to zero if we successfully say hello.

Actually it doesn't

Um... so do you reckon that if they have detected us there is still a possibility they haven't detected us?? A bit too existential an argument for me to follow....

But apart from that yes, it is more likely we will be found. The difference is minuscule but it is there.

And so we come back to... if the risk is small but the possible consequence is major... and you can avoid taking it (especially by simply NOT doing an action).. then do so.

...Some of the things you said proves that you are not on top of the relevant science nor too good in evaluating situations with extremely low probabilities.

Cant wait to see what those things are....

Maybe people are disagreeing with you because some of your assumptions (open or hidden) or your logic is wrong.

Its possible.... Have a look at my recent post... please feel free to point out any additional assumptions... or any flaws you see.

No, you only need to accept that the risk is low and that there are possible benefits.

Um... I am not advocating doing anything.... the ones who are shouting are the ones who should prove the risk/benefit ratio is favourable. Also they should consult with those affected.

I do believe that the risk is low and that you systematically overestimated it,

Yeah... I keep saying the risk is low. But I don't recall at any point estimating it.

...other negative consequences.... I don't like the idea of telling people what they can or can not do without a damn good reason and I certainly don't want societies to get into the habit.

Oh dear... a bit late now... the whole of society is premised on a number of implicit and explicit rules about behaviour. Take the one that you cant shout fire in a cinema. Your shout puts people at risk... you don't have the right to do it. Even if the risk is low....

Now we come to the 'By wanting to keep quiet till we know more, you are fearful and paranoid' point in the discussion....

...inspiring for kids to know that we are trying to reach others...[rather than] eying the universe with suspicion...

Not suspicion... caution. Suspicion is such an emotive word. I think a bit of caution for kids is not a bad idea... Do you encourage yours to wander off in a crowd? The risk is low..... Most people out there will be helpful and considerate.

You might think these are intangible and even unimportant

No.... intangibles can be very important.

I think the kids will be alright with 'we wont shout out just yet... we are still looking around the joint to see whats what'

[crosscountry]

I think you are right in that last paragraph. Sums me up exactly.


Also, haven't you repeated yourself enough?

[Ara Pacis]

Short answer: if you have to claim the burden of proof is on the other side, it probably isn't. And Ara Pacis was succinct because he stated the proposition without the proof.

Evidence for what, that the "Precautionary Principle" is defined such as it is? Perhaps there is confusion about who has the burden of proof because people here are confusing science and politics. The issue of "who speaks for humanity" is a political question, not a scientific one, even if scientists are involved. The point of bringing up the Precautionary Principle in such a policy debate as this is to make the participants realize that the present or proposed activity in question is, infact, an (as yet) undefended affirmative proposition because their activity is not actually supported by the status quo.

[Maksutov]

I was going to go with that, but there are a lot of innocent people down there. Wouldn't it be better just to give them laser guidance or GPS coordinates?

LOL!

I can imagine a line from a Jerry Bruckheimer remake of a Steven Spielberg movie:

Alien attacker: ET phone homing beacon!

[eburacum45]

For myself, I do agree with your points, and it is dangerous to shout into the endless void in the way that we do; but the fact that radar is so much louder than our shouts makes it fairly pointless to worry about deliberate transmissions.

If we do detect an alien civilisation in the next few decades, one likely method would be a chance detection of their radar- they might use high powered active sensors to protect themselves against meteor impacts, for example. And if our planet develops similar anti-meteor technology in the near future we will be sending even stronger artificial radiation out towards any hypothetical eavesdroppers.

But a radar signal carries very little cultural information- we couldn't tell if a radar beam was coming from a race of intelligent lichen or a race of intelligent coke machines. Perhaps sending out a few data-rich messages might demonstrate to these hypothetical eavesdroppers that we are Mostly Harmless.

Or such messages might just whet their appetites.

[eburacum45]

On the other hand, we might miss out on joining the 'Intergalactic Internet'. Interstellar travel is likely to be so difficult that perhaps no civilisation ever acheives it; however there may be a rich, yet fairly safe, flow of ideas and data from star to star between innumerable very different species. By remaining silent, we might miss out on all that.

[WalrusLike]

...the fact that radar is so much louder than our shouts makes it fairly pointless to worry about deliberate transmissions....

Thanks for the support... But I appear not to have convinced you that the radars are not as bad as targeted signals.

Was I wrong when I said that radars are generally intermittent and tend to be roughly in the plane of the eclipse [edit:bloody spell checker... gotta watch that... I started with 'ecliptic'] and therefore are not a guarantee that everyone out there sees them?

Whereas with a deliberate signal someone has gone to a lot of trouble to pick likely systems in whatever direction and targeted them? In other words in directions that may not normally have many, if any, radar beams. I could be wrong... but no one has pointed out the error, if there is one, in this sidebar of the argument.

In a way I feel I must be right since there would be no need to go active if our radar beams were already doing a good job of letting everyone know we are here. Apparently the active seti folk think they need to do more to get ETs attention.

[Noclevername]

Was I wrong when I said that radars are generally intermittent and tend to be roughly in the plane of the eclipse and therefore are not a guarantee that everyone out there sees them?

Yes and no. Radars are usually aimed at specific Solar System bodies, and everything in the Solar System is in a Solar orbit, constantly moving. Unless you for some reason are aiming radar at a star, it'll never hit the same patch of sky twice.

[WalrusLike]

Yes and no. Radars are usually aimed at specific Solar System bodies, and everything in the Solar System is in a Solar orbit, constantly moving. Unless you for some reason are aiming radar at a star, it'll never hit the same patch of sky twice.

Um. I think the original radar fella was talking about military radars... but the astronomers' ones have roughly the the same constraints... if they are not aiming in the plane of the ecliptic they are not going to hit too many planets ....

Not saying there are none ever aimed elsewhere... just that the vast majority would be roughly in the plane of the ecliptic... and in fact, there is a bias towards the 'top' half of this imaginary, roughly ecliptic, plane. Most radars are in the northern hemisphere.

[eburacum45]

Astronomy radars would be in the plane of the ecliptic, but military radars would scan over a respectable fraction of the sky. The one near me scans mostly towards the east, which would be roughly in the plane of the ecliptic, but the one at Thule will be pointed north, so will often send beams out of the plane of the solar system.

Actually, this might not be so bad, as many nearby Sun-like stars which might be expected to hold life-bearing planets are in the Southern Hemisphere. Alpha Centauri, Tau Ceti, Epsilon Indi, Epsilon Eridani, Delta Pavonis, Gamma Pavonis, Nu2 Lupi...

[Van Rijn]

Ok... I will bite. Yes that is all true... although your assumption that they will be looking for O2 spectral lines is perhaps off base if they have a different chemistry. (Silicon perhaps???)

The point would be to look for indicators of things that are out of bounds for simple chemistry. There is far too much oxygen in Earth's atmosphere without some active process to sustain it.

Also, that is one of the simpler ways to find life, the sort of thing we can expect to do within a few decades. The theoretical possibilities of telescopic observation go far beyond that, and even far more impressive ideas (such as interferometric arrays of telescopes with an effective diameter of millions of miles) would be pretty simple compared to the technology needed for interstellar attacks.

But, again, it doesn't matter... even if they see life is here they might not know we are intelligent (I am not too sure of that myself ... that one never gets old.... ) The spectral lines can be detected further out than the emissions.

If there is a paranoid star faring species, why would they wait for intelligent species to develop? It would be far safer (from a paranoid point of view) to keep any discovered life down to the level of bacteria (if that).

They have some assumptions in back of em....
I assume:
[LIST][*]That we cant know at this point for sure whether they have detected us

And that's my key point of disagreement: I expect that, assuming one existed, any technological species that cared could have detected and followed the development of life on Earth since long before we learned to use fire. If there was a paranoid species, I expect that they would have taken care of the "Earth problem" long ago.

[Kaptain K]

Maybe they don't have our chemistry and so don't look for the same life signs.

They don't have to be looking for any life signs at all to notice a planet with 21% free oxygen in its atmosphere! It would be a screaming red flag that something strange is going on here. It would be just as obvious as finding free chlorine or fluorine in a planetary atmosphere. Such electronegative elements simply do not occur as free elements naturally.

[WalrusLike]

....21% free oxygen in its atmosphere...screaming red flag...

This is the problem with long threads... you end up having to say the same thing over and over. Its not the fault of anyone.... not many of us have the time to read from the beginning if it is many pages long...

This was me a little while ago:

(Yes I know that any atmosphere that is chemically out of balance must have a driving process... Take the methane on mars... but that doesn't mean it is life.... and even if it is.. its unlikely its intelligent)

So... yeah... I know we stick out in this system because of our atmosphere... but as of this moment... as far as I know... we don't have any idea how many planets may have a similar situation. It could be, for instance that life evolves ubiquitously... so our atmosphere might not be as big a flag as you suggest. And the vast bulk, of the myriads of intelligent life forms, might be methane breathers... so who knew that a poison like oxygen, could have supported intelligent life... never woulda thunk it.

The whole point here is that we naturally tend to make assumptions about our own situation and figure everyone else must be the same. I can recall hearing definitive statements from respected scientists (who I fully believed at the time) that life would definitely require liquid water... that boiling water wouldn't support life... that sunlight, directly or indirectly, was the one absolute necessity for life.

I remember reading that there were 'theoretical' limits to the amount of bandwidth that could be gotten out of a copper wire... and now we routinely far exceed those 'limits' because of limitations in thinking of the scientists of the day.

So once again... it is dangerous to make any assumptions about alien intelligence. (dangerous in the sense that we will feel embarrassed if we are way off mark as often happens in a science as it explores new fields.... and dangerous in the sense of global catastrophe if we have made assumptions about alien behaviours and the worse case scenario, to our surprise, turns out to be true.)

Its hard to say global catastrophe without sounding dramatic... but its a small, non zero risk with a potentially disastrous consequence that is easy to mitigate... at least to some degree.

[WalrusLike]

I assume:[list][*]That we cant know at this point for sure whether they have detected us.

..And that's my key point of disagreement: I expect that..... any technological species that cared could have detected ... life on Earth.. long before...fire....taken care of the "Earth problem" long ago.

Ok... so if that is your key disagreement.... if you were to read:

Firstly lets assume that there _is_ one out there who would wish us harm and has the capability... they may not know we are here. They may not be looking. They may not have looked in this direction. They may not look for the signs that we exhibit. Unless a civilisation is communicating with modulated gravity waves they wont notice them. (Ok that's unlikely but it is an example of a whole class of possibilities.)

Maybe they figure any intelligent race will be sending out probes to nearby systems.. so their normal policy is to just wait for them. Maybe they don't have our chemistry and so don't look for the same life signs. .... Maybe their technology is such that they expect everyone will be using some comms technique we haven't thought of yet. (Or do you think that all of physics is now done? Like the folk back in the early 1900's)

The point is that while there currently, unarguably, is some possibility they have missed us... that drops to zero if we successfully say hello.

So... Do you think that every single one of the possibilities I mentioned above have absolutely _no_ chance of being applicable? (and realise of course that I am only some dumb bum from down under... so that list is not an exhaustive one... or maybe even the best one) If you _do_ think that.... then what can I say...

But if you agree that there is _some_ chance that a belligerent, capable species might not know about us till we shouted at them then you would inevitably advocate silence. Unless my logic is faulty.

[eburacum45]

I know we stick out in this system because of our atmosphere... but as of this moment... as far as I know... we don't have any idea how many planets may have a similar situation. It could be, for instance that life evolves ubiquitously... so our atmosphere might not be as big a flag as you suggest. And the vast bulk, of the myriads of intelligent life forms, might be methane breathers... so who knew that a poison like oxygen, could have supported intelligent life... never woulda thunk it.

When and if we gain the technology to analyse the atmospheres of worlds in distant planetary systems, a whole new range of atmosphere types will no doubt be revealed to us. The mechanisms which could produce certain unusual types of atmosphere will no doubt be debated, but for certain types of atmosphere with very reactive components- for instance, oxygen, chlorine, perhaps fluorine - there must be an active process occuring to maintain that composition. Sometimes the active process will be natural, sometimes only biology would fit the bill.

Given sufficient observations of different worlds at long range, preferably reinforced by closer inspection by interstellar probe- an intelligent speces will gain the ability to determine whether a particular atmosphere is likely to be the product of biology, whether it is similsar to their own or not.

[Kaptain K]

So... yeah... I know we stick out in this system because of our atmosphere... but as of this moment... as far as I know... we don't have any idea how many planets may have a similar situation. It could be, for instance that life evolves ubiquitously... so our atmosphere might not be as big a flag as you suggest. And the vast bulk, of the myriads of intelligent life forms, might be methane breathers... so who knew that a poison like oxygen, could have supported intelligent life... never woulda thunk it.

1) Methane atmospheres are common - Jupiter, Saturn, Uranus, Neptune and Titan - just off the top of my head.
2) "Methane breathers" would breathe it for food, not as an oxidizer!
3) I did not say that oxygen (or chlorine or fluorine) would be a sign of intelligence. I said it would be an unmistakable sign of life. Those three elements simply do not appear "unattached" in nature! In fact, they are so active that they will even form compounds with the "noble gases" like neon, argon and xenon.

[Robonaut]

What? C'mon... you can't seriously believe this.

Um, yeah, actually I do. I just don't think that it would be that easy for an alien civilization to make enough sense of our myriad computer systems in order to hijack them.

Although, I can see them taking a look at Vista and deciding that we're well on the way to disabling our own computer systems and not bother sending their digital plague our way.

Seriously, though, even if an alien race could develop some sort of AI virus capable of infiltrating our systems, how are they going to get it here? I assume that they would have to hit a communications satelite with it and diguise it as a signal from an Earth computer, but aren't all the satellites pointed towards Earth? So how would they ever hit it with a signal?

Also, unlike the equipment used as part of SETI studies, I don't think that communications satelites are designed to pick up extremely weak signals--probably just the opposite, since they would be flooded by random signals from cellphones, radar, etc.

So, the aliens would have to hit the satelite with a signal as strong as a signal from Earth. From light years away. Good luck with that!

Besides which, we would more than likely notice a signal of that strength. So we would know where they are. Which I assume that they wouldn't want.

Maybe I'm completely wrong, though, since I'm not an expert on this stuff, but that's the way I see it.

[Van Rijn]

So... Do you think that every single one of the possibilities I mentioned above have absolutely _no_ chance of being applicable? (and realise of course that I am only some dumb bum from down under... so that list is not an exhaustive one... or maybe even the best one) If you _do_ think that.... then what can I say...

I think they're possible in the same sense as a backyard invisible elf is possible: Anything is possible, but I don't see any reason to take it seriously.

But if you agree that there is _some_ chance that a belligerent, capable species might not know about us till we shouted at them then you would inevitably advocate silence. Unless my logic is faulty.

Again, I don't think it is possible to be silent. If there is a paranoid and capable species, we couldn't hide and we probably wouldn't exist.

[Van Rijn]

When and if we gain the technology to analyse the atmospheres of worlds in distant planetary systems, a whole new range of atmosphere types will no doubt be revealed to us.

We've already begun to do that:

http://www.spacetelescope.org/news/html/heic0403.html

Of course, we'll need something like Darwin or the TPF to do a good job of that.

[WalrusLike]

I think they're possible in the same sense as a backyard invisible elf is possible...
Again, I don't think it is possible to be silent....

Fair enough...

I tried, and failed, to convince you. I wonder if I, (or those few others who spoke to my side of the debate,) have managed to change anyone's opinion... or bought it to anyone's attention who wasn't already aware of it.

Probably not....

[KaiYeves]

Don't worry. I'm the only ET here yet and it looks like the reaction to my report will be overwhelmingly positive!

[WalrusLike]

Don't worry....... reaction to my report will be overwhelmingly positive!

Thank God! or should that be 'The Prohets'... I keep getting my celestial overlords mixed up...

[KaiYeves]

I'm an Observer who works for The Council. That's all the information I'm privilaged to reveal to subjects of observation.

[FriedPhoton]

Um, yeah, actually I do. I just don't think that it would be that easy for an alien civilization to make enough sense of our myriad computer systems in order to hijack them.

Although, I can see them taking a look at Vista and deciding that we're well on the way to disabling our own computer systems and not bother sending their digital plague our way.

Seriously, though, even if an alien race could develop some sort of AI virus capable of infiltrating our systems, how are they going to get it here? I assume that they would have to hit a communications satelite with it and diguise it as a signal from an Earth computer, but aren't all the satellites pointed towards Earth? So how would they ever hit it with a signal?

Also, unlike the equipment used as part of SETI studies, I don't think that communications satelites are designed to pick up extremely weak signals--probably just the opposite, since they would be flooded by random signals from cellphones, radar, etc.

So, the aliens would have to hit the satelite with a signal as strong as a signal from Earth. From light years away. Good luck with that!

Besides which, we would more than likely notice a signal of that strength. So we would know where they are. Which I assume that they wouldn't want.

Maybe I'm completely wrong, though, since I'm not an expert on this stuff, but that's the way I see it.

I was thinking of these arguments even as I wrote my last post. I was mentally attacking Earth from a distant star system. Yes, they would have to do it via microwaves, and yes those signals would have to be insanely powerful from the source to get here in any fashion that might be capable of hitting a ground station with sufficient power.

However, I do not think that it would be too difficult to bounce the signal off of another planet in the solar system and shoot it toward Earth to disguise their location. (And again, I'll concede that this would probably require a ridiculous amount of energy to get a decent signal in.)

There could be other ways of disguising the source and even the content of the signals if you'd be willing to step into a little, possibly impossible, science fiction. Imagine you have a signal entering a receiver on a ground station. From that point lets start moving backwards, but lets separate the signal using a Fourier Transform into separate parts. Individually the parts don't carry much of the original intelligence but combined they contain it all. So imagine transmitting these separate parts in such a way that each takes a separate path, bouncing off this astronomical body or that and arriving at the receiver, and only at the receiver, combined together in exactly the right place at the right time.

And barring any possibility of a sneak attack, it would be a simple matter for them to trick us into accepting their AI into our systems. All they'd have to do is send a signal strong enough for us to detect (much easier) that says "Hi, we're in the neighborhood and heard the party can we come in". They could feed us a line of bull about following the greeting message with an encyclopedia of their knowledge, which could be a revised, alienized version of our own crap sent right back to us, and we, in fear of missing out, would train all our receivers to listen. Every country on Earth would listen. The AI would get in one way or another.

Hell, they could transmit the DNA code for themselves (or the alien equivalent) and establish a physical presence here by telling us how to clone them. It wouldn't take more than a generation or two of polite nice behavior before we trusted them enough to let them wander freely and then they could begin their nefarious plan in person, right here on Earth.

Anyway, the point is, it would be far easier to attack us with information at the speed of light than it would to even do something as simple as throw rocks at us. Traveling here in person would be a complete waste of time and energy.

[Van Rijn]

I was thinking of these arguments even as I wrote my last post. I was mentally attacking Earth from a distant star system. Yes, they would have to do it via microwaves, and yes those signals would have to be insanely powerful from the source to get here in any fashion that might be capable of hitting a ground station with sufficient power.

So, somehow hypothetical ETs fifty light years away could have somehow known exactly how to compromise all of our technology today fifty years ago, and somehow do something we can't possibly do ourselves?

Hell, they could transmit the DNA code for themselves (or the alien equivalent) and establish a physical presence here by telling us how to clone them. It wouldn't take more than a generation or two of polite nice behavior before we trusted them enough to let them wander freely and then they could begin their nefarious plan in person, right here on Earth.

Anyway, the point is, it would be far easier to attack us with information at the speed of light than it would to even do something as simple as throw rocks at us. Traveling here in person would be a complete waste of time and energy.

That plotline has been done, in some pretty poor scifi movies. The assumption is that a bad ET could somehow manage to have known (remember they sent this some time in the past) so much about us that they could send exactly the information that we would use to destroy ourselves today.

[WHarris]

Don't worry. I'm the only ET here yet and it looks like the reaction to my report will be overwhelmingly positive!

Your report didn't read "Mostly Harmless" by an chance?

[KaiYeves]

Your report didn't read "Mostly Harmless" by any chance?

Actually, so far it boils down to "A few bad eggs, but all in all, a nice enough species."

[fotobits]

All I have to say is, "Don't panic."

[KaiYeves]

All I have to say is, "Don't panic."

You have no reason to.

[Ara Pacis]

You have no reason to.

Unless... somebody set up us the bomb.