Why SETI won't detect anything?

While I don't mean to be deflatist, I had a thought as to why SETI will not detect ETI via radio waves or non-laser light emissions (presuming laser must be technologically generated).

Given that we earthlings have only been playing with radio since Hertz in 1888, our civilisation had been generating 'detectable' radio for around a 110 years.

By detectable I mean a non-random signal which has some pattern such as a carrier wave and repetitive modulation etc.

I recall a few years ago the news of quantum encoded light transmissions, which could, via quantum entanglement detect any eavesdropping (if my recollection is correct).

At the time I conjectured that all intelligent species would discover this, and hence change to light signals to preserve the integrity of their communications.

More recently we have the likes of ultra wide band radio which in theory appears to be random noise. If you add either sophisticated encryption or, in the immediate future, some form of quantum encoding, then the signal should be undetectable.

Given the development of prototype quantum computers, we will obviously need more reliance on quantum entanglement photonic communications to ensure integrity.

All the above means that from 1888 to say 2028 we, as a technological civilisation, will have been radiating pseudo ' intelligible ' signals for only 150 years.

Should this be representative, that intelligent species are only detectable during their 'industrial revolutions', we have no chance of detecting these fleeting signals.

My Sci-Fi side says I hope otherwise, or that the Vulcans are about to get our early radio/TV [isn't it great that they speak english...]

So why am I wrong?

Detecting signals not intended for us would be difficult for several reasons. These reasons might well include the ones you mention. The general idea of most SETI efforts is to detect a signal made as easy to detect as possible, and very possibly beamed in our particular direction. It is assumed that they will either know of our presence and general technological level, or at least realize that our system has a planet suitable for fostering the development of intelligent life. It is also assumed that they wish to contact us. Michael

Without getting all high tech. I agree with you. RADIO waves as we use them is way out of date. No ET would use our communication system for longer than necessary. In our own case 135 years.

So if we want to listen for ET, we need to look at visible light, and invisible spectrum.

If I was ET and wanted to send a message. I would use the the reverse system of how we find planets orbiting stars. Anybody interested. contact me. Or buy the book I wrote. Cheers from down under.
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Gus in Melbourne Downunder

I would think seti needs a small sub project to analyse random noise/background noise too, that should not be difficult just to run it for a few years because discarding it as random noise may be setis greatest mistake it may not be random at all, but generated by anther type of radio instrument why should they assume that it should be exactly like ours, why discard it .
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We choose to go to the moon and to do other things, we choose to go to the moon not because its easy but because its hard. kennedy

We need to collect and study many orders of magnitude more workunits than we do now. Pointing the scope at one little area of sky no larger than a lunar mare for a minute or so isnt going far enough. We need to study many areas of the sky almost continuously.
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A couple of thoughts.

First, can light be trusted for satellite communications? There is a problem of cloudy days, atmospheric dispersion, and so on. Yet, satellite communications appears necessary for a global communications newtwork, at least for general purposes, because the high captital cost of point to point optical communications would be prohibitive. Furthermore, an advanced civilization probably has some extraterrestial communications needs as well, such as 'talking' their moon bases or the like, which probably cannot be satisfied by optical based technology. So perhaps radio is not so obsolete, and never may be so.

Second, it seems that seti is itself a study of random noise, which is (obviously) the dominant signal in the data we process. And whereas I agree that we need to receive, process, and analyze dramatically more data than we today, I become disillusioned that the existing approach remains so bogged down with day to day difficulties and setbacks. There seems to be no way this project can meet the challenge of "orders of magnitude more workunits", without a significant restructuring.

Here is anther reason why seti doesnt detected anything that can be perceived as intelligent communication, Its that over vast distances of space several 10-100 light years something interesting is happening to the electromagnetic signal that we are all searching for. Below i try to show you what is actually happening to it but take it as a cumulative effect until the signal reaches earth.

Under the photon theory of light, a photon is a discrete bundle (or quantum) of electromagnetic (or light) energy. Photons are always in motion and, in a vacuum, have a constant speed of light to all observers, at the vacuum speed of light (more commonly just called the speed of light) of c = 2.998 x 108 m/s.

Basic Properties of Photons
According to the photon theory of light, photons . . .

* move at a constant velocity, c = 2.9979 x 108 m/s (i.e. "the speed of light"), in free space

* have zero mass and rest energy.

* carry energy and momentum, which are also related to the frequency nu and wavelength lamdba of the electromagnetic wave by E = h nu and p = h / lambda.

* can be destroyed/created when radiation is absorbed/emitted.

* can have particle-like interactions (i.e. collisions) with electrons and other particles, such as in the

COMPTON EFFECT

So you can see that by the time radio waves reach us they most likely will be destroyed or distorted beyond simple repair ,unless off course we can mathematical taking into effect every possible distorting agent in outer space and the number of possible electron collisions work on every spike that we detected which would actually be a near impossible task,given the amount of computing power we would need.

I know some will argue that the compton effect only affects high energy photons will beyond the frequencies we are searching, but there is no doubt that electromagnetic radiation or radio waves do interact with atoms on there way .A practical example here on earth is the reflection of radio waves from one part of the world to the other.
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We choose to go to the moon and to do other things, we choose to go to the moon not because its easy but because its hard. kennedy

Have you any evidence that decimetric radio waves (the kind they expect to find in SETI work) can initiate Compton scattering? Compton scattering typically occurs at at energy levels of 100KeV or higher. Decimetric radio waves have an energy level of about .00001 eV. That's one trillionth the energy to accomplish the same process. Refraction of high frequency radio waves by the Earth's ionosphere is not an instance of Compton scattering. If it were, higher and higher frequencies would be refracted more and more efficiently. this is not the case. Above a certain frequency which varies, but typically falls between 15 and 30 MegaHertz refraction becomes less and less efficient, to the point that the radio waves simply pass through the ionosphere unhindered. Michael

I stated below that refraction of radio waves is not an issue of compton scattering , but evidence that radio waves do in fact interact with atoms. Radio waves we are searching for too interact with electrons /atoms on there way to earth and most likely something similar occurs that i can say for sure , its logic. But for the seti guys who have access to all kinds of labs can test to what extend that interaction takes place and at what distances radio waves lose most of there energy that they cant be picked up due lose of energy to that kind of interaction. Again i would like to say i am not a physists , just thinking may be i am wrong. Anther example is the voyager spacecrafts correct me if i am wrong ,the transmission from the one that is so far away has to be amplified by other space crafts behind so we can pick the signals from the first imagine these are not even a light year away.
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We choose to go to the moon and to do other things, we choose to go to the moon not because its easy but because its hard. kennedy

Wouldn't be a hoot if the ET we are looking for are in an evolutionary development equal to our own cave painting or drumming signal stage? So many of us (me anyway) really want ET to be superior to our own civilization.

We should be careful what we wish for. We could be demolished to clear the way for an inter-galactic bypass. Never can tell if a Vogon Constructor Fleet is listening in. A civilization that broadcasts a steady stream of "reality" TV and Three's Company re-runs deserves little more.

Would you want to visit us?

Wayne
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ET is out there and is transimting on many frequencies, for that i am sure. But the problem is we are not picking there transmission. What i write requires serious investigation and thought , but the problem for seti is mostly financial but seti can still over come this by the following way.

What i sincerely believe is that we should also pay attention to the fact that the entire solar system is in some kind of bubble and at the edge of that bubble
there various layers . If i recall the bubble is called the Heliosphere and with in that bubble at the edge there is alot of dynamics going on, like layers such as termination shock, heliosheath, heliopause, bow shock heliospheric current sheet. I am wondering if thats not what is preventing us from picking the signals, Its true that radio signals do cross the heliosphere but at what magnitude of strenth should they be able to do that? Has seti ever investigated ? because the voyagers are out there and are sendind data ,all seti has to do is get some of it and determine if there is any impendance by all these dynamics at the edge of the heliosphere. What i see in they near future would really require funds ,but one possiblity is sending a serious of satelites with some kind of radio amplifies on board about 3, i would say .1)one out side the heliosphere 2) close to the edge 3)the other in the middle between us and the edge.On that day ,i believe we shall tune into the et Broad band with millions of radio trans missions per sec.

dynamics at the edge of the heliosphere
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We choose to go to the moon and to do other things, we choose to go to the moon not because its easy but because its hard. kennedy

not to be off topic here but you guys realize that the individual that brought up the subject has failed to even reply to anything here. This makes me wonder if someone was just trolling the forums and looking to stir the pot
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Proud member of TSWB.

End terrorism by building a school

I never heard of a troll who posts once and is never heard from again. I thought they were supposed to thrive on the attention that continued dialog with them provided. Any number of things could explain a person's failure to continue participating in a forum. Michael

You assume this troll wants to talk to anyone. He's stirred the pot and now he can just watch everyone else bang heads. This way he's plays the innocent poster while getting his jollies. Had he any real interest in the topic he's have at least mentioned something in another post. This hasn't happened. thus Troll
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Proud member of TSWB.

End terrorism by building a school

Howdy folks,

It's a good topic-Let's actually discuss it.

Maybe we wont detect anything because of the following possibilities:

Let's assume that there are Aliens somewhere in our Galaxy that are time-coincident (transmission-wise and techno-wise) with us.

Maybe we have "detected "aliens in the sense that we have found and stockpiled thousands of promising locations. Perhaps one of these is from a true alien transmission. We won't know because we didn't go back and check the location. With the Arecibo dish it is probably the case that few if any locations are checked again for anomalies on a recurring basis.

We may also fail because the aliens are beaming on a time-recurring pattern that we miss because we don't return to their sky sector with any regularity.

We may fail if the civilizations are, say, farther away than 100 light years or so and they are not beaming towards Earth on a regular basis.

We may fail because we dissipate our resources by having multiple, competing efforts at SETI. If we could write down the best SETI search modality --could we fund it, are we funding it, could we fund it if we pooled our efforts.

What do you all think ??
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Thats true its a good topic, we are actually thinking of better ways and all the obstacles in our way.Some are true others are not but if we are to do such a difficult task with no funds lets put our minds and thoughts together, It will work out in the end its a good project and we shall pick them.In new frontiers of science you dont get discouraged over a few years of work but encouraged to work harder instead.
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We choose to go to the moon and to do other things, we choose to go to the moon not because its easy but because its hard. kennedy

Hi SKILDUDE and others. The reason why have not put up any further messages is simple.
Most of the replies are far to complex for my little brain.
To add comment out of context would have been wrong.
One more thing.
I'm on dial up, and only come onto these message one every 3 months or more.

Thanks to all those who put up interesting points of view.
Cheers from Gus Downunder


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Gus in Melbourne Downunder

so are you GUS or ME who is it?
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Proud member of TSWB.

End terrorism by building a school