Why are we not already receiving alien transmissions?

[vspin]

The universe is very old and mind boggling enormous to say the least. One could imagine that there are thousands, if not millions of planets within transmitting range with greater intelligent life than ours, which leads me to my question.

What if some of those planets were beyond our intelligence 1 million years ago, shouldn't we now expect incoming transmissions from just one of those planets, or, are we just not listening with the right technology?

Sorry for my post. I'm an adult with a childlike curiosity.

 

[vspin]

I hope this is the correct forum for my post..

 

[ramparts]

Well, there are two possible responses. The cynical answer is that there is no other intelligent life out there, for whatever reason: the development of life is extremely rare, intelligent life has a tendency to self-annihilate before it gains the capability to communicate with other lifeforms, or other possibilities. The other answer, to which I personally subscribe, is that such signals are out there, but we just don't know where to look or what to look for. While it's possible that any alien signals would stand out clearly from all the astronomical signals out there, we just have no idea what an alien species' form of communication would be - what methods they would use, how they would encode their signals, and the like. Even if we are able to determine that a signal is from an intelligent civilization, we'd need to know where to look. The SETI project does this, but it is truly like finding a needle in a haystack: the signals wouldn't just show up, we'd need to have our telescopes pointed in the direction of a planet with life on it. We've begun that search (again, see SETI), but we've really only scratched the surface. There's a whole lot of cosmos left to check!

I think the last problem is probably the reason we haven't found anything so far. Without an idea where to look, it could take a long time before we stumble upon the right little patch of sky where ET is beaming their messages (or TV shows)

 

[JasonChapman]

The other answer, to which I personally subscribe, is that such signals are out there, but we just don't know where to look or what to look for. While it's possible that any alien signals would stand out clearly from all the astronomical signals out there, we just have no idea what an alien species' form of communication would be - what methods they would use, how they would encode their signals, and the like.

That's a good point one which I have been meaning to raise. Many scientists I have seen on Documantaries seem to be concerning themselves with radio signals. I think SETI needs to start thinking about another form of communication, perhaps something which could be right under our noses but we just haven't seen it yet.

 

[Couerl]

The cynical answer is that there is no other intelligent life out there, for whatever reason: the development of life is extremely rare, intelligent life has a tendency to self-annihilate before it gains the capability to communicate with other lifeforms, or other possibilities.

Hi ramparts, I don't think it is cynical to suppose that intelligent life is extraordinarily rare, even on a cosmic scale. I also don't think that radio waves would be uncommon or that any intelligent life would use them any differently than we do. Having scanned entire galaxies for such radio transmissions and coming up with zilch is a problem for us. It may be a bit like finding a needle in a haystack (I don't fully agree with that analogy), but if you're using a metal detector at least you'd know whether the needle was present or not and so far there only appears to be "hay" everywhere we've looked. The radio spectrum of Earth outshines the sun by many magnitudes and we have little problem detecting other stars radio spectrum's and so I can't fully fathom why we haven't heard anything as of yet unless I imagine that there is really not much out there to hear. In short, if entire galaxies show up blank I don't care what time scale we are discussing, probability is simply against us.

 

[dragon04]

Space is big. One thing to consider is that even if there are civilizations capable of interstellar transmissions, there's no guarantee that they're not just like us; they know of no other intelligent civilization.

So, without knowing who might be listening, how does a civilization send out messages? Do they send out weak signals omnidirectionally as our radio and TV broadcasts went out into space? Do they pick whatthey feel to be a likely spot and send a powerful, narrow signal (like was done from Arecibo in 1974) and hope for the best?

Also, remember that sending and receiving signals between worlds in space not only requires a Where but also a When. It does little good if right now today, ET's CQ passes through the spot where Earth was last week or where it will be on Friday morning about 9am. Tricky stuff when everything is in motion in 3 dimensions with respect to one another.

So we may never know that ET spent 33 years sending out daily signals only to have them all miss inhabited solar systems and gave up because their Enrico Fermi won the day.

What we're reasonably sure of is that there are no other civilizations within 100 or so light years omnidirectionally transmitting something we would understand to be communications of some sort. But maybe their I Love Lucy episodes passed us by 3 days or 3 centuries before the first radio was turned on. No way to know. And 100 light years isn't very much territory in our Galaxy. It's about 1/1000 of the diameter of the Milky Way.

*We may not be receiving alien transmissions because we're not at the right where in the right when yet.

*SETI may not be receiving alien transmissions because they're listening at the wrong frequency. That would be very unlikely because where SETI listens happens to be a fairly radio "quiet" place and likely the one where something would be transmitted. Or at least that's what they think.

*We may not be receiving alien transmissions because were "listening" with the wrong receiver. Maybe they transmit digitally and not analog.

*We may not be receiving alien transmissions because.... well because ET would rather not have us know they're out there. I think that to be unlikely, but there's something to be said for keeping quiet and unnoticed. Ask any prey animal.

*We may may not be receiving alien transmissions because there are none.

*We may not be receiving alien transmissions because they were blocked by our Sun or some other object between Here and There when the transmission took place.

That's not the full list I could probably come up with, but every one of them is possible. Who knows? We may have just been rung up by ET while I was typing this. SETI is privately funded and has scientists and others who are willing to carry out a search that may well never offer up any positive results.

The one answer I wouldn't want to have to post would be that we are not already receiving alien transmissions because we're just not listening. Fortunately for us, SETI keeps that one off the page.

 

[Couerl]

I was reading today that Seti@home has processed something like three-million years worth of data since it began (huge amount) and I still participate with my home machine, but to me time becomes a moot point where sheer volume is concerned and that sheer volume comes in terms of listening to entire galaxies at once. At any given time a galaxy should have at least one radio broadcasting civilization going and those broadcasts should be detectable by us and yet they are not.

 

[dragon04]

I was reading today that Seti@home has processed something like three-million years worth of data since it began (huge amount) and I still participate with my home machine, but to me time becomes a moot point where sheer volume is concerned and that sheer volume comes in terms of listening to entire galaxies at once. At any given time a galaxy should have at least one radio broadcasting civilization going and those broadcasts should be detectable by us and yet they are not.

SETI has been online more or less for 50 years under various names using various technologies. Whole SETI@Home (I'm a member too) has processed a bunch of data it's only data from the direction of a relatively small number of stars for a relatively short period of time.

There are on the order of 200 billion stars in our galaxy and almost all of them are so far from Earth that any signals sent may not have reached us yet, or may have passed us by.

I don't think people understand how downright lucky we will have to be to catch a transmission by being in the right place at the right time, and that presumes that some civilization or civilizations just happened beam out a signal we could both receive and understand at exactly the right time and in the right direction. Needles in haystacks.

I think another problem is that people apparently assume that alien civilizations know that we or our life bearing planet even exist. SETI isn't listening for a message custom designed to be received by Humanity. They're trying to pick up a transmission, any transmission broadcast as a cosmic message in a bottle.

There could be 10,000 broadcasting civilizations and maybe some of them talk amongst each other, but unless we happen to be in the way between two or more transmission points, how would we ever know? You can't just say that we "should have heard something by now". That would be like saying that since the Sun pumps out an uncountable number of Neutrinos and that trillions of them pass through Earth every second that because we don't have a bucket full of them, they must not exist.

 

[Astro_Robert]

Signal to noise ratio is a key issue for SETI. Yes we may scan vast portion of the sky, so did Galileo. Yet today we get a lot more out of our scans than he did. We are able to detect, and even resolve large planets orbitting other stars, whereas Galileo did not. Simply we have bigger telescopes and more sensitive cameras/detectors. Both are important, just think about Hubble, the mirror is the same yet the newer cameras take better pictures. SETI itself has also experienced this as the sugnals they process today are far more involved than what they processed 10-20 years ago.

By the same token we are at a serious disadvantage at the moment as we look for ETI signals. We do not know how strong or weak these signals may be. However, some have estimated that leaked radiation would be difficult to detect beyond a few dozen lightyears. Which implies that a civilization wishing to make contact would have to broadcast a narrow beam at all nearby star systems. Doing this without interuption would take a space based asset, or probably 2-3 such assets. That is a serious investment, one some may be too Xenophobic to justify the cost of making.

Finally, many potential civilations may decide that the round trip communication time is not worth it and so only resort to listening. If everyone listens and nobody sends, then there is no chatter to listen to. Hopefully however our imaging and spectroscopic capabilities will grow such that we can examine all nearby star systems directly.

In the meantime, I note that life on Earth seems to hold on almost wherever we look, so there has got to be more out there somewhere. As far as the distance to the nearest civilation, I think we are more likely to be living in the countryside than the city.

 

[FlatEarth]

Why send radio signals when you already have craft on Earth doing surveillance?

Apparently, they don't have a need to make contact with us, or they have decided it's not the right time. When they decide to, perhaps they will send us a signal from space because they probably know we are listening. What better way to make first contact? If so, the signal will likely originate within our solar system.

 

[5hot6un]

I'm with Dragon on this. The slice of time that we have been listening is minuscule on the cosmic scale.

I think SETI is important. But it's a very long shot that we will happen to be listening at the right time and place.

And is it not a bit arrogant to think that ET would develop and use RF communications technology as we have? People see the world as they are.

Some day the technology will exist to directly observe small rocky exo planets and the signatures of life will found in the light some of them reflect.

ET is out there. But it is far more likely that ETs are plants and animals.

 

[Antwerpo]

The reason why we don't receive signals is because we are not looking for them. SETI searches for humans in space not aliens. Aliens to SETI need to have had a scientist with the ideas of Marconi or a story builder like George Lucas to be able to be using the right equipment so we could detect them. And let's be honest only on earth someone could put Jar Jar Binks in a movie and still be allowed to make another movie

 

[ZenGalacticore]

One of the many reasons we are listening, instead of transmitting, is because any artificial signals we may receive from sources likely scores (that's 20s) or hundreds of light-years away, would indicate that those transmitting civilizations had high-tech, focused, radio-transmitting capability scores, if not hundreds or even thousands of years ago.

IOWs, any civ that could transmit to us from as near as say, 200 light-years distant, would've had that capability at least 200 years ago. (And most likely much earlier.) Therefore, they would most likely be orders of magnitude more advanced than we on every conceivable level.

Hence, this is why we listen, instead of jabber.

 

[bdewoody]

The third article today over in Space.com sums it up. The distances are just to great for us to be able to communicate with other intelligent life. The present generation has been exposed to so much sci-fi babble about ftl travel that some of them actually either believe it is already being done or that it is just around the corner. Maybe a breakthrough will be made in the not too distant future but I'm not holding my breath. I doubt that we will leave or solar system anytime in the next 500-1,000 years. I hope I'm wrong but I wouldn't put any money on it.

 

[chesterhotels]

There is life out there but they are avoiding us. /*Spam Link Removed, Poster Banned*/

 

[kelvinzero]

Well, there are two possible responses. The cynical answer is that there is no other intelligent life out there, for whatever reason

Actually there would be something very depressing about finding a signal from an intelligent species just sitting on some world a thousand lightyears away. Picture this conversation. (1000 years between each reply)

Alien: Hello.

Man: Hello!.. um.. you gave me a bit of a fright. How long have you been standing there?

Alien: Well.. you know how the universe is about 13 billion years old right? Well if you guessed my age to be some average way through that period, eg 6.5 billion, yeah thats about right.

Man: Wow! This is amazing! You must know just about everything! Are you an intergalactic civilization? Have you visited us?

Alien: Um.. no.

Man: No...?

Alien: It would be pretty silly to call from here If we had visited you, wouldnt it. I mean, if we could visit you, we could have colonized every system within a thousand light years. We'd be calling from the bus stop down the road.

Man: So.. you have just sat there.. for six billion years..

Alien: Hey, it isnt as easy as you think, being this old. You youngsters think you can just zip across four lightyears to a neighboring star system in the wink of a millennium? When you get to our age, you know that these things just aren't practical. The distances are too far, colonies always die out before they can build their own arks.. and then there is the schnerpal.

Man: ...The.. shnerpal?

Alien: You will undertand that when you reach your first billion. Just rest assured there is a very good reason we decided not to go anywhere or colonize anything.

Man: Um.. can we speak to someone else?

Alien: They will give you the same answer.

 

[bearack]

Just imagine trying to thread a needle in New York, while the needle is Melborne, Australia. We aren't even a spec in the vastness of Googols of planets. Other species might look at our tiny sun and think there absolutely is no life in our solar system. Speculation of course.

 

[fastman50]

I guess I had said this one time or another and still have the same opinion and its this. if we have the technology to have voyager1 &2 do what they are doing and the capabilities of the hubble as well i am sure we could have communicated by now with life if it exists out there in space long before now....Although this is a touchy question due to religion or non religious views I don't beleive we will ever come in contact with another lifeform outside of this planet. Now to question some of the intelligent life right here on earth?????? :lol:

 

[6075]

Why are we not already receiving alien transmissions?

Probably because each civilization has its own Hawking-like prophet, who intimidates the poor aliens...

 

[a_lost_packet_]

The universe is very old and mind boggling enormous to say the least. One could imagine that there are thousands, if not millions of planets within transmitting range with greater intelligent life than ours, which leads me to my question.

What if some of those planets were beyond our intelligence 1 million years ago, shouldn't we now expect incoming transmissions from just one of those planets, or, are we just not listening with the right technology?

Sorry for my post. I'm an adult with a childlike curiosity.

There is no need to apologize for true human curiosity. Without it, we wouldn't discover much of anything of any significance.

There are a variety of reasons why we have not yet confirmed a radio transmission. Many are listed above by other posters.

Perhaps the most poignant reason one should consider when musing on the subject is that using our technology today, it would be nearly impossible for us to receive anything other than a specifically directed radio signal intended to be received. Most popularizers point to the obvious "radio leakage" of television/radio into space as the means by which we would detect another civilization or how we, ourselves, would be detected. That's not very likely.

That may not mean much to most people. However, the fact is that all the hype about "radio leakage" is mostly just that - Hype. Only a very, very few types of radio transmission, usually high-powered military grade radars intentionally scanning the solar system, would have even a slight chance of detection by any of the nearest supposedly habitable systems using technology we can understand or predict.

In other words - Getting "lucky" and picking up a stray radio signal is nearly impossible given what we currently know and are technologically capable of. Any signal we could actually detect would, most likely, be an intentional attempt by an alien civilization to transmit a very strong radio message that was intended to be received by a civilization in our specific solar system.

Even IF there are others out there, even IF they are near enough for us to receive a signal within our current window of detection, even IF we could recognize such a signal as being artificial and even IF they'd decide to use radio as a means of communications, there is the unmistakable necessity of that signal being intentional. Simple radio chatter from an inhabited world is not going to be enough to do the job given the distances involved as far as we understand it.

It's quite likely, given our understanding of "life", that other intelligences have existed or currently exist within our galaxy. However, as one can see, it is a very, very remote chance that we would detect an alien civilization that was not actively attempting to contact others. Even then, it is very difficult for us to say with any reasonable accuracy that such civilizations have not already attempted purposeful transmissions that were long before our ability to detect them. One certainly can't expect a civilization to repeatedly "ping" our solar system despite a continuing lack of evidence of our ability to respond, can we? They could have already messaged us as soon as 100 years ago and we wouldn't have known anything about it. The idea for SETI itself wasn't dreamed up until 50 years ago. Before that, we really weren't even looking.

 

[SpacexULA]

When was the last time you went to a art hill, and started talking to them, and offering them designs for the internal combustion engine?

We are not even yet a Type 1 on the Kardashev scale. We would not be much more interesting than an ant hill to a type 2 or 3 civilization, which is likely the only ones who would have the energy to transmit to us.

In the 1910s we would have only recognized a digital signal as being noise, what makes you think the transmisions from them would even be perceivable? The funniest thought is this.

If there is 1 alien intelligence, there are likely thousands. If you are a Level 1 society, you would be a fool to attract the attention of a stellarly close and aggressively expanding level 2 society.

 

[RikF]

One certainly can't expect a civilization to repeatedly "ping" our solar system despite a continuing lack of evidence of our ability to respond, can we?

I think we actually can expect that, depending on how many suitable planets are around in their vicinity. Maybe our planet is the only one they have ever seen that looks even remotely suitable, or the other suitable ones that may be around don't respond either. In an equally dense part of the galaxy as our part - how many suitable planets would be around?

Imagine if we found a planet around Alfa Centauri and sent a few messages - when would be a suitable time to give up and quit transmitting? It doesn't cost much and if there is no other planet around that looks suitable but there is one that really does look suitable, then why not continue and send them a beep once in a while? The procedure could be automated and they could just let it transmit in a regular interval.

 

[jimoutofthebox]

Perhaps we limit ourselves too much by looking just for electromagnetic communication. Perhaps we should be looking for other evidence of advanced civilization. Assuming that an advanced space faring civilization exist they are probably using some form of high energy particle propulsion system. Since the “exhaust” from such a system will travel unimpeded through the universe maybe we should be looking for a pattern of high energy particles that would have a pattern that would indicate that they are artificially generated. I’m not a physicist so I have no idea what to look for. Just an idea.

 

[Couerl]

One certainly can't expect a civilization to repeatedly "ping" our solar system despite a continuing lack of evidence of our ability to respond, can we?

I think we actually can expect that, depending on how many suitable planets are around in their vicinity. Maybe our planet is the only one they have ever seen that looks even remotely suitable, or the other suitable ones that may be around don't respond either. In an equally dense part of the galaxy as our part - how many suitable planets would be around?

Imagine if we found a planet around Alfa Centauri and sent a few messages - when would be a suitable time to give up and quit transmitting? It doesn't cost much and if there is no other planet around that looks suitable but there is one that really does look suitable, then why not continue and send them a beep once in a while? The procedure could be automated and they could just let it transmit in a regular interval.

Well no, we shouldn't expect to be "pinged", but we musn't underestimate "leakage" either.. 1-70 ly's out from earth, the brightest radio object in the sky is,... well,.. Earth!

 

[origin]

Well no, we shouldn't expect to be "pinged", but we musn't underestimate "leakage" either.. 1-70 ly's out from earth, the brightest radio object in the sky is,... well,.. Earth!

Are you sure about that? I was pretty certain the sun put out quite a bit more radio waves than the earth, and I thought that jupiter put out much more radio waves than the earth.