New SETI Study: Why We Might Have Been Missing Alien Signals (seti.org)
- Reference: 0180932038
- News link: https://science.slashdot.org/story/26/03/09/0654222/new-seti-study-why-we-might-have-been-missing-alien-signals
- Source link: https://www.seti.org/news/why-seti-might-have-been-missing-alien-signals/
> Stellar activity and plasma turbulence near a transmitting planet can broaden an otherwise ultra-narrow signal, spreading its power across more frequencies and making it more difficult to detect in traditional narrowband searches. For decades, many SETI experiments have focused on identifying spikes in frequency — signals unlikely to be produced by natural astrophysical processes. But the [2]new research highlights an overlooked complication: even if an extraterrestrial transmitter produces a perfectly narrow signal, it may not remain narrow by the time it leaves its home system... "If a signal gets broadened by its own star's environment, it can slip below our detection thresholds, even if it's there, potentially helping explain some of the radio silence we've seen in technosignature searches," said Dr. Vishal Gajjar, Astronomer at the SETI Institute and lead author of the paper.
The researchers created "a practical framework for estimating how much broadening could occur for different types of stars" — and accounting for space weather — by "using radio transmissions from spacecraft in our own solar system, then extrapolated to other stellar environments."
The study's co-author (a SETI Institute research assistant) suggests this coud lead to better-targetted SETI searches. (M-dwarf stars — about 75% of stars in the Milky Way — actually have the highest likelihood that narrowband signals would get broadened before leaving their system...)
[1] https://www.seti.org/news/why-seti-might-have-been-missing-alien-signals/
[2] https://iopscience.iop.org/article/10.3847/1538-4357/ae3d33
Re: (Score:2)
They might just be hiding. There is a good argument to say that we should avoid being detected, because there is no way of knowing what the reaction might be. First thing we know of it might be the planet killing asteroid mysteriously headed our way.
Re: Is there alien intelligence out there? (Score:2)
We have been marked by the galaxy as an invasive species to be shot on sight.
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The only thing that was created was the myth of god by mankind! So any any and all attempts to understand the universe referencing god are just bullshit!
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Just because we don't understand or experience other higher or lower realities does not mean they do not exist. Besides, we have evidence that they do, it's just that fundamentalists refuse to consider examining the evidence and refuse to question thier own assumptions and beliefs.
That is unless anyone has definitive and incontrovertible proof to the contray. I'm sure we'd all appreciate seeing it.
No, eh. I didn't so.
The truth is we don't understand the nature of reality or our place in it as well as we wil
Re: (Score:1)
[1]https://en.wikipedia.org/wiki/... [wikipedia.org]
[2]https://en.wikipedia.org/wiki/... [wikipedia.org]
[3]https://en.wikipedia.org/wiki/... [wikipedia.org]
[4]https://en.wikipedia.org/wiki/... [wikipedia.org]
[5]https://en.wikipedia.org/wiki/... [wikipedia.org]
[6]https://en.wikipedia.org/wiki/... [wikipedia.org]
[1] https://en.wikipedia.org/wiki/Near-death_studies
[2] https://en.wikipedia.org/wiki/Theology
[3] https://en.wikipedia.org/wiki/Theism
[4] https://en.wikipedia.org/wiki/Spirituality
[5] https://en.wikipedia.org/wiki/Reincarnation#Reincarnation_and_science
[6] https://en.wikipedia.org/wiki/Western_esotericism#As_higher_knowledge
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We are alone. This is our private server.
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that's a lot of empty rack space for one private server
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> that's a lot of empty rack space for one private server
Room for expansion, perhaps?
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> We are alone. This is our private server.
I have sometimes heard new game players say that, then I ask a few questions and it becomes clear that they are on a company server. But the game is so large that they have just not met any other players yet. Can be unfortunate if it is a PVP server... 8-}
Re:Is there alien intelligence out there? (Score:4, Interesting)
> God created a vast universe He isn't happy with JUST us.
This was Giordano Bruno's (1548-1600) argument, which got him burned on a stake. If Copernicus was right, and Earth revolves around the Sun, then all the other stars are other suns, with other planets revolving around them and other humans on planets. Hence, he said: "Your God is to small for the Universe."
Bruno's Book (Score:3)
De Immenso et Innumerabilibus On the Infinite and the Countless By Giordano Bruno Of Nola
is essential reading. It sounds like 1950's sci fi.
Re: (Score:2)
The Milky Way is home to about a billion civilizations more advanced than us. We are late to the party.
Fortunately space is really big, or we would be them.
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> God created a vast universe He isn't happy with JUST us. That is one argument.
Interestingly, in one of the Gnostic Gospels, Jesus is quoted as saying when he departed that he had to go visit "sheep of other folds, that you know not of".
(paraphrasing from memory)
Re: (Score:2)
While I cannot know everything about the entire Milky Way, what I do know is in our current solar system, only one planet has life much less human life. Some moons might be able to sustain life under a thick surface of ice; we have yet to confirm that. In the Milky Way, the vast majority of planets detected so far are gas giant which cannot sustain human life for sure. From an initial assessment, your assertion that the galaxy was made for humans does not pass a logical test.
Peak Detectability (Score:2)
In our experience of a single planet, we can see a greater reason. We have passed the peak of our detectability to outside civilizations. While we still radiate some narrow band signals, there are fewer than there were a few decades ago. The first world countries no longer beam out carrier based television signals. The current methods of TV transmission would be undetectable without prior knowledge of the details of the modulation methods. Our navigation no longer uses the powerful narrow band LORAN, the re
Re: (Score:2)
"The first world countries no longer beam out carrier based television signals"
Sorry, what? If you think digital TV signals dont use carriers think again.
"The current methods of TV transmission would be undetectable without prior knowledge of the details of the modulation methods"
BS. Look on a spectrograph and digital signals - even ones with multiple carriers - stand out like the proverbial sore thumb from the background noise. If that wasn't the case the military wouldn't have to use methods like spread s
Re:Peak Detectability (Score:5, Informative)
In ATSC8VSB 0.5% of the power is in the pilot tone, the rest is spread over the entire bandwidth as subcarriers. Analog TV put 70% of the signal into the single frequency of the carrier. Add in doppler shifts from planet rotation and the perspective from space of seeing all stations on all the channels, and you would be left with a sight rise in the background noise, not a detectable signal.
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Subcarriers are still carriers and if the signal was undetectable it would also be undecodable.
SETI Is Stoopid (Score:2)
They haven't a clue. They're too stoopid to realize that alien communication technology is undetectable. It uses quantum entanglement and gravitational brainwaves for the bearer channel. It also uses unbreakable alien encryption technology.
Aliens are LTFAO at SETI and their primitive attempts.
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Sadly yes, aliens advanced enough to travel at FTL speeds obviously don't use primitive radio waves.
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There are no FTL speeds. No exceptions.
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> just keep the poor busy with cheap entertainment and use shock and awe to distract and confuse us
People are already being entertained buy the unending revelations from the Epstein files.
And shocked, though not particularly awed.
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> What if this latest adventure in Iran is just a smokescreen
Call it by its proper name, Operation Epstein Fury!
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Other similar stars were here in this galaxy for 8 billion years before the Sun even formed - twice as long as then to now. Inception of life as we know it on Earth was effectively instant upon planet formation, which was contemporaneous with solar ignition.
Waste of time (Score:2)
Weak signals over a long distance. You may as well try to listen to people whispering in China from the US.
(Why would a civilization dedicate a large amount of resources, say 1,000+ nuclear power plants, to send a very narrow signal into the void hoping for a billion+ to one chance of hitting our little planet at a time we are listing - Not before the Romans or after we're cooked. Engineers start with: how can I send the message with as little cost (materials, power, etc) as possible? If they over enginee
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They might do it for other reasons, however. Say to communicate with a generation ship en-route to a distant star. But it *does* make it a lot more unlikely.
Re: (Score:1)
Maybe they're looking for the heat signature of crypto mining.
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> Why would a civilization dedicate a large amount of resources, say 1,000+ nuclear power plants, to send a very narrow signal into the void hoping for a billion+ to one chance of hitting our little planet at a time we are listing,
The assumption of SETI is not that alien civilizations are doing that necessarily on purpose to contact us. The assumption is that signals are sent out on purpose or inadvertently as the humans send out signals all the time through entertainment and communication broadcasts.
Required signal strength ? (Score:5, Interesting)
I'd be interested to see some analysis of how strong of a signal an alien civilization would need to be transmitting for us to have any chance of detecting it with our networks of radio telescopes.
Sure we can hear Voyager's weak signal, which is impressive, but in the galactic scale of things it is right beside us, only just having left our solar system.
Any potential aliens are much, much further away ... On a scale where our sun is a grain of sand, the closest star is another grain of sand 600 miles away, with radio signal strength weakening according to an inverse square law.
Of course it's almost certain that the closest alien civilization (assuming one exists) capable of radio transmission isn't so conveniently close by, and if it was on the other side of our galaxy (100,000 light years away, not just 4), then what sort of transmitter power would they need to be using? The inverse square law is brutal.
What if the nearest civilization if not even in our own galaxy?
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I don't think we have any reason to suppose that we're the only technological civilization within 300 light years. OTOH, within 4 light year the odds are quite good that there aren't any.
That said, I wouldn't want to guess how far it is to the closest other technological civilization...not without a better estimate of the lifetime of such civilizations. (My guess is that they're typically pretty short, but that it's possible to build enduring ones...but that this requires moving parts of the civilization
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I expect that life itself is not rare - that the universe is teaming with life, but maybe only at simple prokaryotic cell type of level. The emergence of "life" (self encoding self-replicators) from non-life seems somewhat inevitable when a few conditions are in place.
The case for advanced civilizations being rare is from looking at the earth (a sample of one, but still ...). Earth is almost as old as the universe. Simple life here arose almost immediately about 4B years ago, but it took another 2B years fo
Re: (Score:2)
Voyager has a tiny radio transmitter that's much weaker because of a limited power budget. The earth itself has much more powerful transmitters that would be far easier to receive. Radio stations are transmitting at multiple kilowatts to reach a city, but it's several orders of magnitude greater than what Voyager could transmit.
The other problem is as we moved from analog to digital transmissions, our radio emissions moved from artificial "not natural signals" to more noise-like. Indeed, many modulation tec
Communications (Score:2, Funny)
Just tattoo the insides of rednecks' assholes, who usually get abducted, with messages for the aliens.
That's wishful thinking (Score:3)
Taking into account the vastness of space and time, the constraints imposed by physics, and the relatively short existence of individual biological species, chances are any advanced civilizations will be too far from us either in space or in time (or both) for us to detect. Unless humans prove to be an exceptionally long-lived species (which is a very doubtful proposition, given their inveterate stupidity) the most likely scenario is one in which humans will go extinct without ever finding out whether or not other advanced civilizations exist, have ever existed, or will ever exist.
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Well, you gotta at least try...
Maybe SETI should rethink their whole approach? (Score:3)
I am pretty sure that SETI is looking at the problem the wrong way.
If all you have is a 1950ies radio antenna, what would you make of today's mobile phone signals? Would you recognize them as being artificial?
Already in the 1960ies, Polish SF author Stanislaw Lem in his essay "Summa technologiae" doubted the idea of "techno signatures" in radio signals. His argument? With better technology, we are better able to use the bandwidth of our signals, and with better usage of the bandwidth, the required signal-to-noise ratio gets lower, and the signal looks more and more like white noise to someone not knowing the technology. Additional, the power requirements to transmit a signal gets lower and lower too, and much less signal is wasted into space. The time frame in which electromagnetic waves from artificial sources look noticeably different from natural radiation is very short, it was less than 100 years for the human civilization.
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> If all you have is a 1950ies radio antenna, what would you make of today's mobile phone signals? Would you recognize them as being artificial?
Absolutely. I think you are misunderstanding the difference between being able to interpret content of signals with being able to tell if a signal is artificial or naturally occurring. As humans have been listening to the Universe for decades now, there is a huge catalog of naturally occurring signals.
Yeah, not necessary (Score:2)
We don't even have the ability to detect our civilization from the distances involved.
Dang it, Querellionix hang up the phone (Score:2)
your dad was trying to use the intergalactic modem to contact Earth. I swear, you kids. . .
maybe... (Score:2)
the aliens have become very good at hiding their existence from self-immolating viruses.
No one is signalling... (Score:2)
It is very unlikely that we will pick up a signal sent our way.
1. The other civilization would have to deliberately send a strong, narrow signal to our star. Why would they do that? See comment below about detectability: maybe they actually would, if they could detect us, but they cannot.
2. e would have to be looking at the exact moment that they send the signal. Consider the time periods involved: our planet has existed for billions of years, and only for about 1/10000000 of that time have we had the cap
Arrogance (Score:2)
Because it is our arrogance to think that signals must exist in the electromagnetic realm. We DO NOT know the ins and outs of the universe. Physics is NOT how things work. It's what we show and demonstrate and wrap math around. We've had, what a couple hundred years in using radio signals to communicate. The trilobites had MILLIONS of years to work on their understanding of the universe, and thinking that we would be able to find a millennia of EM usage historical representation of trilobite technology
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If you have discovered something that replaces EM radiation, please let us all know when you have collected your Nobel prize for physics, having successfully re-written the majority of it.
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> Because it is our arrogance to think that signals must exist in the electromagnetic realm.
As opposed to what? EM is the science we know. I do not know of human ability to detect other realms. For example subspace communication is an FTL system that exists in Star Trek and other franchises. It is theoretical at best.
hohum (Score:2)
Give it up, already.
Frequency Spikes? (Score:2)
"_spikes in frequency_ — signals unlikely to be produced by natural astrophysical processes..."
Then how are we able to detect lightning spikes on an extrasolar planet 124 light years from Earth?
[1]https://www.snexplores.org/art... [snexplores.org]
[1] https://www.snexplores.org/article/planets-lightning-storms-are-nothing-earth
Re: (Score:2)
"lightning spikes on an extrasolar planet "
Nope, it's aliens.
Seriously, that research is ten years old. Have we not looked at this radiation source since ?
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An average lightning bolt generates 1 megawatt of radio frequency energy. The earth has 40 million lightning bolts a day. This planet has 500 times that many. That is a lot more energy than any radio signal man has ever created. I'd guess more than man has created in 100+ years!
Re:Frequency Spikes? (Score:4, Informative)
Lightning spikes are not narrow-band.
You are misinterpreting the words. A frequency spice means a signal, which has a high power in a very narrow range of frequencies. A lightning is a very high power in a short amount of time. Those are two different types of phenomenon.
Re: (Score:2)
And the obverse:
If we can detect lightning from a planet 124 light years from Earth, and see no other potential communications from intelligent life, we should probably be looking closer at those lightning signals.
Notsayinitsaliensitsaliens.