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Active SETI?

madurobob

Philosopher
madurobob
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I did a moderate search of the forums - didn't find this discussed. Feel free to direct me to the thread I've missed if I've done so.

I've seen a few articles lately questioning "active-SETI". In case you are not aware, this involves intentionally beaming signals to potential sources of intelligent ET life as opposed to simply "listening" for signs of intelligent ET life - AKA Passive-SETI (google "Active SETI" for many links).

The articles I've read are generally against Active-SETI for what I see as two general reasons:
  1. The ETs will get the signal, visit us, and eat us (or otherwise do mean things to us).
  2. No significant public discourse has taken place and those involved in Active-SETI are speaking for all of Earth with no real mandate to do so... and the aliens might get the signal, visit us, and eat us (or otherwise do mean things to us).

I think the latter argument is valid and should be explored. I don't want just any nutcase beaming "free lunch!" signals to Andromeda. But can there really be a meaningful worldwide conversation? I think that even if the WW consensus were to NOT send such signals, they would end up being sent anyway.. so why not at least try to control the message?

Do you think we should be involved in Active-SETI and if so, what should be the message?
 
Sounds like a scam to me. We're already sending billions of electromagnetic signals in all directions. Why would it be necessary to add another?
 
bokonon said:
Sounds like a scam to me. We're already sending billions of electromagnetic signals in all directions. Why would it be necessary to add another?
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Yes - I had this thought as well. Decades of radio and TV signals, not to mention private communications are bouncing through space already. I assume that the targeted signals of Active-SETI are intended to be more intense and thus more likely to be detected and understood.
 
Free lunch signals? That's a long way travel for lunch. How long would it take for the signals to reach Andromeda? Would we still be alive by the time an answer was received?
 
madurobob said:
I've seen a few articles lately questioning "active-SETI".
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According to the book The World Without Us, some scientists tried beaming a signal in the seventies and public reaction was extremely negative for reasons of people not wanting our location broadcast.

Explaining that we were broadcasting anyway did little to change public perception.
 
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drkitten said:
As has been pointed out, that genie is out of the bottle.
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Right. So, why the recent spate of articles? There have even been resignations at SETI over this issue.

From this article:
We can not assume that we already have been detected or that detection is inevitable. Extraterrestrial civilizations might not be looking for the kinds of signals we normally radiate. More importantly from a policy perspective, our leakage signals may be below their detection threshold. An Active SETI signal much more powerful than the normal background emitted by the Earth might call us to the attention of a technological civilization that had not known of our existence. We can not assume that such a civilization would be benign, nor can we assume that interstellar flight is impossible for a species more technologically advanced than our own.
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ETA here too:
This widely-held supposition was, in fact, decisively disproved years ago, in a paper written by Dr. Shostak himself! In fact, even military radars and television signals appear to dissipate below interstellar noise levels within just a few light years. Certainly they are far less visible -- by many orders of magnitude -- than a directed beam from any of Earth's large, or even intermediate, radio telescopes.

Moreover, this reasoning is illogical, since METI's whole purpose is to draw attention to Earth by dramatically increasing our visibility over whatever baseline value it currently has. If it's already "too late," then what are they aiming to achieve?
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madurobob said:
LDT (Long Damn Time)


We? Perhaps not me, but humans generally? Maybe. Question is, should we be inviting the evil ETs to lunch in the distant future?
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Who's to say the ETs are evil? Or that they would even want us for lunch?
I suppose if those two things are based on how humans behave we're in trouble. If we discovered a planet within our reach would we invade and eat the inhabitants? Damn right!
 
sinclairmcevoy said:
Who's to say the ETs are evil? Or that they would even want us for lunch?
I suppose if those two things are based on how humans behave we're in trouble. If we discovered a planet within our reach would we invade and eat the inhabitants? Damn right!
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Well, obviously the point is we don't know what their disposition would be. They may take one look at our history and decide to blow us up as a protective measure. They may invite us to tele-port to their planet made entirely of marshmallow and chocolate. But, with us completely in the dark on this point, should we actively pursue contact?
 
We can not assume that we already have been detected or that detection is inevitable. Extraterrestrial civilizations might not be looking for the kinds of signals we normally radiate. More importantly from a policy perspective, our leakage signals may be below their detection threshold. An Active SETI signal much more powerful than the normal background emitted by the Earth might call us to the attention of a technological civilization that had not known of our existence. We can not assume that such a civilization would be benign, nor can we assume that interstellar flight is impossible for a species more technologically advanced than our own.
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My question is, what kind of signals would these ETs be looking for? What would these active SETI signals look like that would make them more obvious than, say, AM signals, which have been broadcasting for about a century?

If these ETs are looking for foreign signals, in the same way that we are, and are capable of interstellar travel, why would the strength of the signal matter? I'm sure they would have the capability to detect very low level signals. AM radio broadcasts are obviously not of natural origin (the signal doesn't look like stellar radiation or anything like that) so why wouldn't these interstellar traveling ETs be able to figure out that we're here anyways?

Bah, thats a lot of questions that I don't think anyone except The Doctor can answer.

ETA: Damn I didn't read madurobob's edit.
 
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Uncle Vanya said:
My question is, what kind of signals would these ETs be looking for? What would these active SETI signals look like that would make them more obvious than, say, AM signals, which have been broadcasting for about a century?
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I certainly don't know the technical answer. But, the quoted text points to a key issue, I think. That is, the point about the detection threshold. As an analogy: I can walk all around in my yard and see yellow-jackets if I am looking for them. But, if I'm not looking for them I often only notice them when I'm stung - when they want me to notice.

So, I think its a question of sending an undeniably obvious signal as opposed to a lower magnitude, less obvious signal.
 
madurobob said:
Well, obviously the point is we don't know what their disposition would be. They may take one look at our history and decide to blow us up as a protective measure. They may invite us to tele-port to their planet made entirely of marshmallow and chocolate. But, with us completely in the dark on this point, should we actively pursue contact?
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No, I don't think we should pursue contact. It's a bit like sticking your arm down a dark hole and not knowing what may be living in it.
If we ever receive an answer or at least affirmation of someone else out there, then what?
 
sinclairmcevoy said:
No, I don't think we should pursue contact. It's a bit like sticking your arm down a dark hole and not knowing what may be living in it.
If we ever receive an answer or at least affirmation of someone else out there, then what?
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I agree that it is worrisome. Kinda like an online dating sight: you know there is something on the other end, but you don't know what it is, if its intelligent or how palatable is its appearance or personality.

But... I think its guaranteed that Active-SETI will continue. And, as technology advances, more and more laymen will have the ability to do this from their backyard (as an aside: Great business oportunity! Build a radio antenna in your backyard and charge people a fee to broadcast their message to any specific point in the universe they choose! Get in on the ground floor!). So, since this sort of activity will continue and accelerate, should/could it be monitored and regulated?
 
madurobob said:
But... I think its guaranteed that Active-SETI will continue. And, as technology advances, more and more laymen will have the ability to do this from their backyard (as an aside: Great business oportunity!

So, since this sort of activity will continue and accelerate, should/could it be monitored and regulated?
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You've answered your own question. Regulating or monitoring this is largely impossible, and therefor trying to do so would be a foolish waste of resources.
 
madurobob said:
Decades of radio and TV signals, not to mention private communications are bouncing through space already.
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Ah -- but the amount of radio power that's actually escaping Earth is shrinking.

Why?

Because we've been getting better at saving power, by sending radio signals only where we want them to go.

In the 1940s, to get a radio signal to the other side of the globe, you had to send out an enormous amount of power in the A.M. band and hope enough of it bounced off the ionisphere for someone on the other side of the Earth to receive it. Today, you send a much-lower-power narrow beam signal at a geostationary satellite, which relays your signal (also on a low-power narrow beam) to its destination station on the ground. Similarly, broadcast television has been largely replaced by cable TV (which produces no detectable stray signals at all) and digital satellite TV (which beams all its energy at the ground).

If we don't start intentionally sending signals out for aliens to pick up, the Earth might go "dark" from an interstellar perspective before the century is out!
 
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drkitten said:
You've answered your own question. Regulating or monitoring this is largely impossible, and therefor trying to do so would be a foolish waste of resources.
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Yes, I see your point. There is little that can be done done to adequately regulate it and sitting around wringing our hands worrying about it does no good. But, ignoring it may not be the best way to go either. - at least to read what folks like David Brin have to say.

But I gather from your response that you feel ignoring it is, in fact, the best alternative at this point. I've not come to that conclusion yet.. but I may be there soon.
 
madurobob said:
Yes, I see your point. There is little that can be done done to adequately regulate it and sitting around wringing our hands worrying about it does no good. But, ignoring it may not be the best way to go either. - at least to read what folks like David Brin have to say.

But I gather from your response that you feel ignoring it is, in fact, the best alternative at this point. I've not come to that conclusion yet.. but I may be there soon.
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By no means should active SETI be ignored, there is great potential in it. Although it is true that some fear that after we alert them, they come here and eat us, other, less cowardly souls have made plans.

Once SETI comes to our welcoming beacon, we can eat them.

A new delicacy arrives.

But wait! There's more. Our law does not recognize SETI, only humans and animals. SETI, therefore, are animals with no property rights. You see, it is all so simple if you think it our the right way. Whoever welcomes them here, not only gets to eat them but also gets to keep the flying saucers.;)

Now how would you like that, to have one of those parked in your front yard. Just put out the lawn chairs, break out a couple of six packs, light up the barbecue grill, and watch the fun start.
 
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