SETI & Anomalous Signals

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Anonymous

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#92
i supose so but with out the fibers the point being there are lots of ways to communicate over large distances so why limit yourself to radio only?
how would we communicate with another solar system?
i doubt we would only use radio signals.
 
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Anonymous

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#93
I've looked into x-ray and gamma lasers but there are many technical difficulties, possibly solvable by high tech, possibly not... to minimise spread of the beam,
a blue or ultraviolet laser might be best, although molecular and dust clouds might block them...
there could be strings of interstellar relays as well to boost signals, but these would soon run out of energy.
Quantum entanglement can apparently be used to boost signals travelling at light speed, so might be useful.
Wormhole tech (if it works) could allow high speed broadband connections but would be undetectable.
 
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Anonymous

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#94
is there a colour that isnt very common in the night sky?
It's not so much colour as wavelength. Any wavelength which is uncommon in the night sky will be uncommon because it is strongly absorbed by interstellar gasses/dust.

Therefore in a way it makes sense to use the most common 'colours' as these are the ones which will travel furthest with the least absorption.

The probelm with lasers of course is deciding which direction to point them in.
 
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Anonymous

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#95
it isnt a question of traveling the greater distances,we are only talking of one solar system to another not between galaxies but a one of the exact colour it would be when recived,so u dont have to scan the entire spectrum as for possible interference coundnt u use a similar system as the internet protocol which compensates for an unreliable connection
 
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Anonymous

Guest
#96
detection

back to the point though seti has been conducting a very narrow search of the sky given the possabilities why do they keep banging the radio drum its been how many years
try something else et may not use radio
 
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Anonymous

Guest
#98
the entire electromagnetic spectrum even trying just one other alternative is a start,i just think radio is too weak sky use microwaves dont they?
 
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Anonymous

Guest
#99
Another thing to look for is the infrared emission of a high tech civilisation- the average solar collection swarm should emit recognisable waste heat energy above the background radiation and over several light seconds in diameter...
so if there are any Kardaschev 1 or 2 civilisations up there we should see their waste heat if not their comm lasers.
 
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Anonymous

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results

there you go within a couple of days already there is a case to show that there are lots of possibilities for seti to consider instead of trawling over the same stuff
just how long have they been at it and how much of the tecnology they developed is used by there goverments to intercept foreign communication etc
 

DerekH16

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Re: results

Tin Finger said:
there you go within a couple of days already there is a case to show that there are lots of possibilities for seti to consider instead of trawling over the same stuff
just how long have they been at it and how much of the tecnology they developed is used by there goverments to intercept foreign communication etc
The reasons that SETI keep 'trawling over the same stuff' are that 1) it's something they can do, technologically, rather than tap laser-beam comms between 2 distant galaxies/solar systems, and 2) they can afford it.

How long have they been at it? Can't remember offhand, the SETI website could probably tell you.

As for their technology being used to 'intercept foreign communications' - the software isn't particularly sophisticated, so it would be like asking the CIA to crack mirror handwriting, and the hardware points straight up from Arecibo - there are no known foreigners up there. In fact, SETI is looking for them! :)

ET may not use radio comms., but since it's the only thing that we can reasonably search for, we may as well search....
 
A

Anonymous

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Tin Finger said:
it isnt a question of traveling the greater distances,we are only talking of one solar system to another not between galaxies but a one of the exact colour it would be when recived,so u dont have to scan the entire spectrum as for possible interference coundnt u use a similar system as the internet protocol which compensates for an unreliable connection
IIRC (and someone more knowledgable than I please correct me), but the the protocols involve a fair amount of "handshaking" which would slow things down a bit if we were trying to communicate over distances of light years. Pinging the other end would be fun, though. ;)

What you would probably need to do is to stick a fair bit of error correction code into the signal, thus reducing the data rate. Though if you're limited by "c", this might not be much of a problem. It would be an interesting calculation to work out the link budget between a notional transmitter on, say Barnards Star, and a receiver on the earth. I might get back to you with an answer on this. :)
 
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Anonymous

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hardware

what about the computer systems used to scan millions of frequencies at once yes the softwares simple but the hardware they developed i think could be used to spy
the Arecibo isnt the only telescope that has ever been used to do setis work
look at http://www.jb.man.ac.uk/research/seti/
 
A

Anonymous

Guest
Jodrell's well worth a visit if you have the chance. It's probably 12 years since I was last there, but it had a good visitors centre, and on a sunny day you can go for a wander around the arboretum. (The have a scale model of most of the solar system in there. IIRC it was one hell of a walk to get to Jupiter ;) )

The sort of technology that you talk about isn't only used for SETI. There are other applications in astronomy and elsewhere that have a use for it. Curious fact though, IIRC some of the technology used in the Hubble Space Telescope had its heritage in the non-civil world.
 
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Anonymous

Guest
who would find it

if any nation found such a signal do u think they would tell us?
or would that nation try to use such contact to gain some kind of advantage over there rivals?
or possibly to guide public oppinion during a war that was going badly didnt america use the moon landings to boulster public oppinion of the govenment during the vietnam war.
 

Jerry_B

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SETI research isn't bound to just one country, so it's unlikely that just one country would only have access to any given signal.
 
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Anonymous

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There is a written protocol to be followed, if contact is made...
Though whether it would be followed is debatable.
 
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Anonymous

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While trying to find a reference to the SETI protocol, I found this.
(the top ten links for my search were related to amazon. Grr. mumble. Information superhighway.. home shopping channel more like...)

http://www.coseti.org/radobs01.htm


It's brief but informative.
 
A

Anonymous

Guest
light

i never thought that anyone had thought of the light / et thing
finding out that they had and science or 21st centuary church had discounted it out of hand without even simple consideration well its true to form science is lost in its dark age ,again!
the earth is flat etc :sob:
 

rynner2

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Scientists work out why we haven't heard from the aliens May 8 2003




The Western Mail - The National Newspaper Of Wales


ALIENS may be sending each other secret messages buried in background noise, it was claimed yesterday.

Two scientists have come up with a possible solution to the long standing puzzle of why, if alien civilisations are out there, no one has ever picked up signals from them.

The Fermi paradox, first posed by the physicist Enrico Fermi, is still one of the strongest arguments against the existence of intelligent aliens.

But Walter Simmons and Sandip Pakvasa, from the University of Hawaii at Manoa, have worked out how the aliens could be hiding.

First the signaller splits the message into two parts, so that its photons are sent in opposite directions to mirrors far from the home planet.

The mirrors redirect the signals to the intended receiver, who recombines the photons to reconstruct the message.

Neither the intended receiver nor any eavesdropper would be able to locate the home planet of the sender. Furthermore, it would be impossible to detect the message at all without extremely sophisticated technology, New Scientist magazine reported.

To recombine the beams and recreate the message you would need to detect the arrival time of the photons extremely accurately to identify pairs of photons split by the sender.

Mr Simmons said, "Such photons are distinguishable from the background of stellar photons because they arrive very close together in time. But any eavesdropper, like us, might not realise this and see only the background."

Jonathan Rosner, a physicist at the Enrico Fermi Institute in Chicago, said, "The proposal is ingenious." But he said it was hard to tell if the method could work in practice
icWales
 

rynner2

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Counting on Distant Worlds: Math as an Interstellar Language
By Douglas Vakoch
Special to SPACE.com
posted: 07:00 am ET 08 May 2003

If some day we receive an information-rich signal from another star, no one expects it to be written in English, Chinese, or Swahili. Instead, researchers engaged in the Search for Extraterrestrial Intelligence (SETI) often suggest that mutual comprehension will come through the language of math.

Imagine for a moment an extraterrestrial civilization that can build radio telescopes and transmitters, and thus signal its existence across interstellar space. Wouldn’t such a civilization’s knowledge of the physical universe overlap at least in part with our own?

Mathematics, it has been argued, provides a common language for talking about this shared scientific understanding. As physicist and philosopher Sundar Sarukkai notes, "Nature, for scientists, is universal in the sense that the laws of science hold in any region of the universe. Their belief that nature is written in the language of mathematics actually reflects their belief that mathematics is a universal language."

If in fact all extraterrestrials capable of interstellar communication have something like the science we are familiar with, would they describe their science in a form we could understand? Would extraterrestrial intelligence, living on worlds that differ from ours physically, biologically, and culturally, nevertheless share with us a common language of mathematics?

Parallel Lines of Development?

Surely, many have argued, the ability to build a radio telescope requires a capacity to count and to recognize that 2 + 2 = 4. The Dutch mathematician Hans Freudenthal started with this assumption to create an interstellar language called Lingua Cosmica — the language of the cosmos, published in 1960. Freudenthal’s step-by-step tutorials begin with basic counting, then progress through arithmetic to increasingly complex forms of mathematics.

If extraterrestrial savants can follow our descriptions of long division, shouldn’t they be able to follow a refresher course in hyperbolic geometry as well? Or might there be extraterrestrials, in some ways even more technologically advanced than we, who never ventured beyond the three dimensions of Euclid’s conceptual world?

Sarukkai, a researcher at the National Institute of Advanced Studies in India, suggests that mathematics on other worlds may differ considerably from ours. He is not convinced by the argument that something as basic as counting will lead to the convergent evolution of mathematics on Earth and on distant planets: "Even if numbers or counting can be a common genesis, who is to say that calculus is a universal, necessary consequence of mathematical thought?"

Sarukkai explains his skepticism: "Let us say we accept that numbers or representations of numbers will occur in extraterrestrials." By his analysis, this assumption gets us only part of the way to a shared understanding of mathematics as a whole. On Earth, Sarukkai says, math is "a specific human activity which discovers particular structures such as algebra, calculus, topology, group theory, and so on." Though extraterrestrials may be very good with numbers, they might do things with them that humans had never imagined. Similarly, parts of human math may be incomprehensible to extraterrestrials.

Having radio telescopes in common, Sarukkai claims, says more about shared patterns of thinking than about any underlying mathematics or technology: "If we begin with the assumption that the extraterrestrial folks have radio telescopes, then we are making an assumption about processes of their thought more than their language or even their technology. That is, what their having radio telescopes most importantly tells us is that these creatures reason in some particular way."

A Number of Meanings

In Sarukkai’s view, the attempt to identify universal languages reflects humankind’s long-standing uneasiness with ambiguity. Typically, ambiguity is seen as an obstacle to understanding the world, as reflected in the eighteenth-century philosopher Thomas Reid’s view that "there is no greater impediment to the advancement of knowledge than the ambiguity of words." As an antidote, scholars have been preoccupied over the centuries with finding languages that have fixed and definite meanings. "The search for 'universal' language or 'pure' language," say Sarukkai, "is part of human history in all civilizations. In part, this reflects an enormous distrust of ambiguity in meaning." Ironically, it is exactly the imprecision of any language that makes it work so well. As Sarukkai notes, "it is semantic ambiguity that allows individuals and societies to develop and flourish!"

If we cannot count on the universality of mathematics for interstellar communication, is there any hope of comprehending at least some of the meaning an extraterrestrial is attempting to convey? "Definitely yes," according to Sarukkai. But he doesn’t think we will stumble across a pre-existing universal language. Rather, we will need to invent languages for interstellar communication: "We always construct languages based on our needs, our capacities, and our traditions."

"I doubt we will ‘find’ a language ready for use," says Sarukkai. The key, in his view, is to expect some ambiguity as we attempt to bridge the vast distances that separate humans and extraterrestrials: "In looking for a language for interstellar communication, we should be looking not for one-to-one matching, but for some kind of mapping which allows us to understand ‘vaguely’ rather than with certainty."

Even gaining a vague understanding of the universe as seen by another civilization might help us expand beyond our parochial view of the world. And given the tremendous challenges of interstellar communication, living with ambiguity may be our only choice
link.
 
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Anonymous

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"The search for 'universal' language or 'pure' language," say Sarukkai, "is part of human history in all civilizations. In part, this reflects an enormous distrust of ambiguity in meaning." Ironically, it is exactly the imprecision of any language that makes it work so well. As Sarukkai notes, "it is semantic ambiguity that allows individuals and societies to develop and flourish!"
This must be some kind of joke!

Actually, he's right; ambiguity is what makes humour possible, and humour is vital in Human social interactions.
Mind you, there is no guarantee that aliens will have verbal humour, or even the sort of mammalian social grooming that has mutated into verbal comedy-
Aliens would probably have a completely different sense of humour - they might find prime number pairs amusing or something, or maybe unexpected or unusual fatal accidents.
 

intaglio

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Eburacum45 said:
This must be some kind of joke!
...or maybe unexpected or unusual fatal accidents.
Read Fortean Times "Strange Deaths" recently?
 

Mama_Kitty

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[email protected]

Anyone have it? Can you explain what a fast fourier is and why it takes so long to compute its transformation? My useful contribution will be to say that it all looks very pretty and we've done 124 data units. I guess it's just nice to know that my usually-idle PC has something useful to occupy itself with when I'm not wandering about on here.

Kitty.
 

Mike_Pratt33

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I have it, I'm up to 2884 Workunits now.

If I remember right a Fourier transform takes a signal and determines the frequency and amplitude of the radio waves that make it up. By analogy its like taking the sound of an orchestra and isolating the sounds of individual instraments.
 
A

Anonymous

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Re: [email protected]

KittyRice said:
Anyone have it? Can you explain what a fast fourier is and why it takes so long to compute its transformation?
And the fast fourier transform really is fast. If the size of the thing that you want to transform is N, then doing a Fourier Transform as it is normally defined takes N*N steps. The Fast Fourier Transform gives you the same answer in N*logN steps, which for large N is a huge improvement.

As an aside, the multiplication of two numbers of size N requires N*N individual multiplications. It turns out that this process can also be written in terms of a mathematical operation called a convolution. In turn, the convolution can be carried out using fourier transforms and then a simpler set of multiplications.

What the above means is that for large numbers it is computationally quicker/better to do the multiplications via the FFT than to use more traditional methods, and in fact a number of software packages do it that way. :)
 

rynner2

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Bump! Another one merged.. :rolleyes:


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