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SETI puts a considerable effort into finding extraterestrails under the assumption that they want to be found and are intentionally putting out a enough radiation in some way for us to detect them. Recent upgrades allow them to detect relatively nearby extraterestrails by eavesdropping on their normal communications.

 

But what if the extraterestrails do not want to be detected? It has been hypothesized that extraterestrails might want to smack down any up and coming civilizations to prevent competition. This might cause them to want hide or to simply not wanting to be bothered by primitives.

 

If we assume that extraterestrails are really hiding then how could we detect them? What would we look for to detect ET's if they are not actively broadcasting or if they are actually hiding?

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Nothing strange about this topic Michael! Moved to Anthropology because....

 

...think about it: what if you replaced the word "extraterestrails" with say, "African Pygmies" or "Big Feets"?

 

Why would you want to hide? In another thread around here, one motivation (ours) would be to avoid being noticed by Borg-like "civilizations".

 

No wonder those Pygmies hide....

 

To get a man's attention, just stand in front of the TV and don't move. He'll talk to you. I promise, :)

Buffy

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Nothing strange about this topic Michael! Moved to Anthropology because....

 

...think about it: what if you replaced the word "extraterestrails" with say, "African Pygmies" or "Big Feets"?

 

Why would you want to hide? In another thread around here, one motivation (ours) would be to avoid being noticed by Borg-like "civilizations".

 

No wonder those Pygmies hide....

 

To get a man's attention, just stand in front of the TV and don't move. He'll talk to you. I promise, :)

Buffy

 

it would seem to make sense for primitives to hide instead of look for the big guys. Of course to all depends on how easy star travel really is, and what a civilization a thousand or a millions years ahead of us could do or would want to do. From the stand point o find sight wouldn't the native Americans have wanted to hide from the Europeans?

 

Contrary to modern belief the native American weren't all that inferior to The Europeans. If not for the small pox and religious fear the Americans could have kicked the Europeans back into the ocean easily. Of course hind sight is always 20/20 If the Europeans had waited another couple hundred years it might have been the native Americans who visited them instead of the other way around.

 

If ET's hide from each other due to concerns like interstellar conquorers or simply not wanting to be influenced by superior beings then how do we find them? I think one idea was that a really advanced civilization would enclose their entire star and would be detectable as a source of infrared radiation instead of a star.

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If you watch enough Star Trek episodes, I think it becomes clear that beings hide from both the higher and lesser "others," albeit for different reasons. I think ST also shows that there's always someone higher up on the "intelligence/power" scale! :)

 

Very good, Captain. There is hope for you. Perhaps in several thousand years,

your people and mine shall meet to reach an agreement. You are still half-savage, but there is hope. We will contact you when we are ready, :)

Buffy

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If you watch enough Star Trek episodes, I think it becomes clear that beings hide from both the higher and lesser "others," albeit for different reasons. I think ST also shows that there's always someone higher up on the "intelligence/power" scale! :)

 

Very good, Captain. There is hope for you. Perhaps in several thousand years,

your people and mine shall meet to reach an agreement. You are still half-savage, but there is hope. We will contact you when we are ready, :)

Buffy

 

Since it's obvious we cannot hide, yet, and no one seriously wants to hide anyway these days. How do we go about finding them? A civilization that uses energy will always show some sort of signature. We leak radio waves into space and have been doing so significantly for at least 75 years. So what do we look for if they aren't trying to signal their presence and they are trying to hide?

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Shortly we shall have the capability to carry out spectroscopic analysis of terrestrial planets around other stars. Monitor the atmospheric composition of these planets to identify changes analagous to the anthropogenic changes in the Earth's atmosphere.

 

Search for EM signatures associated with interstellar star drives.

 

If you wan't to remain hidden you probably want to know what others are doing. therefore conduct a search of the solar system for robotic alien monitoring systems.

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Shortly we shall have the capability to carry out spectroscopic analysis of terrestrial planets around other stars. Monitor the atmospheric composition of these planets to identify changes analagous to the anthropogenic changes in the Earth's atmosphere.

 

This might show a civilization comparable to ours but a really advanced civilization could and probably would stop and reverse all the changes we have made like pollution. I would like to think an advanced culture has disposed of planets completely but this would be speculation.

 

Search for EM signatures associated with interstellar star drives.

 

Wouldn't we have to know what an interstellar drive was first?

 

If you wan't to remain hidden you probably want to know what others are doing. therefore conduct a search of the solar system for robotic alien monitoring systems.

 

I really like this one a lot but short of going out and physically inspecting every body in the solar system how would we detect them?

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  • 5 months later...

I have a question about SETI.

 

From what I've heard, it seems the search might be fairly restrictive in its verifying patterns. I have got an impression they have been listening for a very basic pattern of a single frequency that is repeated for hours at a time.

 

If my impression is correct, wouldn't that basic, simple, repeated pattern be more indicative of a natural phenomenon? Wouldn't sophisticated communication be more varied? Are we really interested in finding the most boring life in the universe?

 

I hope my impression is wrong.

 

--lemit

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From what I've heard, it seems the search might be fairly restrictive in its verifying patterns. I have got an impression they have been listening for a very basic pattern of a single frequency that is repeated for hours at a time.
SETI assumes that some – not necessarily all or many, but at least a few – ET civilizations want to be discovered by listeners like us, so purposefully make an effort to make it easy for us.

 

An obvious way to do this is to send a strong signal at a frequency where natural sources are weak. On such range of frequencies is about 1420 MHz to 1640 MHz, known as the “water hole” because it falls between the emission line of unexcited hydrogen and OH. It’s not the only “quiet band”, but an easy one for radiotelescopes to monitor, so SETI focuses most of its listening on frequencies in this band.

 

If my impression is correct, wouldn't that basic, simple, repeated pattern be more indicative of a natural phenomenon?

SETI doesn’t look only for repetition of changes in amplitude at a given frequency – an initial indication EM radiation isn’t naturally generated noise – but for the amplitudes to be mostly of two values, indicating binary data, and also that the signal originates from a single location.

 

Once such a signal is found, again assuming it was sent with the intention that we be able to read it without too much, SETI looks for sequences such as counting, lists of the primes in order, and similar data that would be almost certain evidence of an artificial, intelligent source. A signal consisting of a number of bits that’s the sum of two or three prime numbers is another strong indication of an artificial signal, and additionally that the signal is a 2 or 3-D pixilated image with dimensions of its prime factors.

 

SETI occasionally sends signals of the same kind it’s looking for. The 1974 “Arecibo message” is a famous example. It’s 73*23=1679 bits long.

Wouldn't sophisticated communication be more varied?
Yes. Since sending EM signals over long distances is energetically costly, everyday “real” communication is likely to be both directional and compressed. Compressed data appears nearly random, and would be difficult to distinguish from noise.

 

Again, SETI assumes that we’d be receiving a signal intentionally created to allow us to detect and decode it, not overhearing everyday communication.

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I always think that nobody has contacted us is a sign that there is intellegent life out there. :shrug:

I mean, if you came to earth, and watched our tv broadcasts from your ship, what would you think of us?

I doubt the though "I would really like to meet them" would cross your mind.

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I always think that nobody has contacted us is a sign that there is intellegent life out there. :shrug:

I mean, if you came to earth, and watched our tv broadcasts from your ship, what would you think of us?

I doubt the thought "I would really like to meet them" would cross your mind.

 

I love that! I should have thought of it.

 

Congratulations!

 

It's great to have you around here.

 

--lemit

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SETI puts a considerable effort into finding extraterestrails under the assumption that they want to be found and are intentionally putting out a enough radiation in some way for us to detect them. Recent upgrades allow them to detect relatively nearby extraterestrails by eavesdropping on their normal communications.

 

But what if the extraterestrails do not want to be detected? It has been hypothesized that extraterestrails might want to smack down any up and coming civilizations to prevent competition. This might cause them to want hide or to simply not wanting to be bothered by primitives.

 

If we assume that extraterestrails are really hiding then how could we detect them? What would we look for to detect ET's if they are not actively broadcasting or if they are actually hiding?

It may not be just that they do not wish to be detected.

 

Consider this analogy first. Say you would like to communicate with an ant. How would you go about it ? Forms of communication are very different. How would you get

your point across to a creature that is developmentally on a lower scale that ours. Now

reverse this; say we are the ants. How would we communicate with anyone out there ?

It may not be so much that they don't want to talk with. They not have the interest like

we what interest would we have conversing with ants.

 

Second, is the technology of communication. Who is to say that future civilizations wish

to modulate radio signals the way we do right now. Imagine a culture with 10,000 years

of technology advancements. Could we guess what types of communication is being sent

to us right now, only we don't know it ??? :Alien:

 

maddog

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I have a question about SETI.

 

From what I've heard, it seems the search might be fairly restrictive in its verifying patterns. I have got an impression they have been listening for a very basic pattern of a single frequency that is repeated for hours at a time.

 

If my impression is correct, wouldn't that basic, simple, repeated pattern be more indicative of a natural phenomenon? Wouldn't sophisticated communication be more varied? Are we really interested in finding the most boring life in the universe?

 

I hope my impression is wrong.

 

--lemit

I sometimes wonder about for a single signal. However the SETI of today does their search

on a target simultaneously search on about 6 Million (6,000,000) or more wavelengths.

They have built new machines to do this. I am not aware if the processing were to find

on some of those channels might sound like noise as a single frequency yet when put

together could make a bonafide signal by properly piecing it together.

 

I know that an FFT signal analysis is run on any capture signal on-axis, then off-axis. I

am not clear with simultaneous capture that whether multiple frequencies are correlated

or not.

 

maddog

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It may not be just that they do not wish to be detected.

 

Consider this analogy first. Say you would like to communicate with an ant. How would you go about it ? Forms of communication are very different. How would you get

your point across to a creature that is developmentally on a lower scale that ours. Now

reverse this; say we are the ants. How would we communicate with anyone out there ?

It may not be so much that they don't want to talk with. They not have the interest like

we what interest would we have conversing with ants.

 

Second, is the technology of communication. Who is to say that future civilizations wish

to modulate radio signals the way we do right now. Imagine a culture with 10,000 years

of technology advancements. Could we guess what types of communication is being sent

to us right now, only we don't know it ??? :Alien:

 

maddog

 

I think your ant analogy is a strawman. We are not ants. What we know about ants is the manifestation of our interest in ants.

 

Logically since we know that radio signal modulation works, any other suitably intelligent beings may also know it. Certainly we can and do guess about what we don't know, but it is always prefaced on what we do know. :help: :Alien: :doh:

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Consider this analogy first. Say you would like to communicate with an ant. How would you go about it ? Forms of communication are very different. How would you get

your point across to a creature that is developmentally on a lower scale that ours. Now

reverse this; say we are the ants. How would we communicate with anyone out there ?

It may not be so much that they don't want to talk with. They not have the interest like

we what interest would we have conversing with ants.

 

Second, is the technology of communication. Who is to say that future civilizations wish

to modulate radio signals the way we do right now. Imagine a culture with 10,000 years

of technology advancements. Could we guess what types of communication is being sent

to us right now, only we don't know it ??? :)

 

maddog

 

My favorite form of this argument is from Carl Sagan's book The Cosmic Connection from 1973. Although it's kindof obscure, and although I broadly disagree with SETI, I'll post it here just because I think it's beautiful:

 

We are like the inhabitants of an isolated valley in New Guinea who communicate with societies in neighboring valleys (quite different societies, I might add) by runner and by drum. When asked how a very advanced society will communicate, they might guess by an extermely rapid runner or by an improbably large drum. They might not guess a technology beyond thier ken. And yet, all the while, a vast international cable and radio traffic passes over them, around them and through them.
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