No alien civilizations? After analyzing two decades of data SETI@Home produces 100 signals “worth a second look”
For more than two decades, from 1999 to 2020, the Search for Extraterrestrial Intelligence (SETI) project asked millions of people worldwide to loan it the use of their computers so the project to could analyze twelve billion signal detections that were of interest.
After 10 years of work, the SETI@home team has now finished analyzing those detections, winnowing them down to about a million “candidate” signals and then to 100 that are worth a second look. They have been pointing China’s Five-hundred-meter Aperture Spherical Telescope, a radio telescope referred to as FAST, at these targets since July, hoping to see the signals again.
Though the FAST data are not yet analyzed, [computer scientist and project co-founder David Anderson] admits he doesn’t expect to find a signal from ET.
At the link the SETI team outlined the many reasons, all quite reasonable, for the failure to detect any obvious signals from alien civilizations. The universe is vast, they only looked at a very tiny slice, the variations of signals are many, and the amount of data was still so gigantic analyzing it was endlessly time-consuming. Moreover, they might have been looking at the wrong wavelengths, and there is even the possibility that advanced civilizations simply don’t broadcast at any wavelengths.
Nonetheless, the project was not a failure. It showed it was possible to use a lot of home computers to create the equivalent of a super-computer. The technology and volunteer system it developed has since been used by other scientists on projects like looking for clouds on Mars and studying galaxy types.
The big question remains unanswered however. Considering the numbers of stars in the galaxy, and the recent data that shows most have planets, it seems strange that there have been so few candidate detections, and even these are questionable. Could it actually be the case that we are the first sentient intelligence species in the Milky Way?
There always has to be a first. That humanity might be that first is a mind-blowing thought.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
For more than two decades, from 1999 to 2020, the Search for Extraterrestrial Intelligence (SETI) project asked millions of people worldwide to loan it the use of their computers so the project to could analyze twelve billion signal detections that were of interest.
After 10 years of work, the SETI@home team has now finished analyzing those detections, winnowing them down to about a million “candidate” signals and then to 100 that are worth a second look. They have been pointing China’s Five-hundred-meter Aperture Spherical Telescope, a radio telescope referred to as FAST, at these targets since July, hoping to see the signals again.
Though the FAST data are not yet analyzed, [computer scientist and project co-founder David Anderson] admits he doesn’t expect to find a signal from ET.
At the link the SETI team outlined the many reasons, all quite reasonable, for the failure to detect any obvious signals from alien civilizations. The universe is vast, they only looked at a very tiny slice, the variations of signals are many, and the amount of data was still so gigantic analyzing it was endlessly time-consuming. Moreover, they might have been looking at the wrong wavelengths, and there is even the possibility that advanced civilizations simply don’t broadcast at any wavelengths.
Nonetheless, the project was not a failure. It showed it was possible to use a lot of home computers to create the equivalent of a super-computer. The technology and volunteer system it developed has since been used by other scientists on projects like looking for clouds on Mars and studying galaxy types.
The big question remains unanswered however. Considering the numbers of stars in the galaxy, and the recent data that shows most have planets, it seems strange that there have been so few candidate detections, and even these are questionable. Could it actually be the case that we are the first sentient intelligence species in the Milky Way?
There always has to be a first. That humanity might be that first is a mind-blowing thought.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Our own civilization is a case in point for some-thing;
– We started broadcasting high-power AM radio signals in the 1930’s followed by TV and FM, but those emissions have been in decline for the past 2 decades.
From the outside looking in, and given that you can’t actually watch I Love Lucy at 50 light-years out, but you can detect the carrier signal, it would appear we are slacking off big time. Whatever that would imply to our future alien overlords.
That’s Fermi’s Paradox for you!
But I admit, this is how I am inclined to think. It could be that life is extremely rare, and intelligent life, even more so. Perhaps even once in a galaxy is beating the odds as it is?
I could be wrong. There could be a number of advanced civilizations out there in the neighborhood and there is a good reason why we simply cannot detect them (assuming that we have not done so and are not keeping it a secret from the public) — something like the Dark Forest Hypothesis, or whatever.
Space is very large, on the upside the average distance between stars in our Galaxy is about 4 light-years.
I seem to recall the SETI people broadcast a high-powered message from the Arecibo dish in 1974, but they sent it toward some galaxy 25,000 light years away.
I think we are the only game in town
https://phys.org/news/2026-01-complex-life-planets-orbiting-galaxy.html
Until recently there was no evidence of any planet existing outside of our solar system.
Finding a planet populated with life having similar technology, at an equivalent timeline to our world is a real long shot.
Admittedly, I’m neither a scientist nor an engineer but always enjoy the reality check provided on BtB, if I’m missing something.
“Whatever that would imply to our future alien overlords.”
“Finally! I’ve filed noise complaints, but do the cops do anything?! Nooooo!”
One of the 100 messages said, “Your planet is scheduled for destruction to put in an intergalactic bypass. You had 50 years to file a comment at the galactic office for bypass construction on Alpha Centauri. It’s not our fault you didn’t bother to file. The construction will now proceed.”
the WOW signal might have come from 31/Atlas, would have required about a GW of power and they came from nearly the same spot, which is a 100:1 coincidence
so in theory it could have been a “anyone there?” test to see if someone here could generate a braking laser within a few decades
it’s now heading right for the Jovian Hull boundary, which is also probably just a huge 1000:1 coincidence
unless it drop something off there, of course :)
but realistically as others have pointed out, in a flat infinite universe, the weak anthropic principle has unlimited power to explain our lonely presence, and it seems every day we learn another way our Sun and planet are unique
there’s life out there, just probably not in our observable universe, and far less likely to share our galaxy
on the plus side, everything we can reach is ours for the taking
“Space is very large”
one distressing conclusion from our latest interstellar visit is that there could be fleets of miles-long alien vessels quietly wending amongst the outer planets and we just wouldn’t even see them unless they made a light
heck, we wouldn’t even know 3I/Atlas was here except for the halo of gas and dust, even at closest approach the core is smaller than the pixels on Webb
It is possible that the existence of even one advanced civilization in the entire universe might be a statistical long shot.
Define “Civilization”.
Civilization does not necessarily indicate technology that would be used in parallel, broadcast and be detectable by both humans and others.
And of course, then there is the overlapping time X’s distance X’s existence part of the equation. A similarly technologically enabled civilization may have existed 1 billion? 5 billion? years ago and their ability to send or receive a communication has long ago passed by planet earth.
Someone here on BTB please seriously explain the sometimes-observed phenomenon reported and documented regarding: UFO’s, USO’s, UAP’s, “Tick Tac’s” throughout more recent and much older recorded history.
*Foo Fighters / WW2: “The first sighting of a foo fighter was reported officially in November 1944, by the crew of a Bristol Beaufighter plane on a night mission over the Rhine. The crew included radar observer Donald J. Meiers, intelligence officer Fred Ringwald, and pilot Edward Schlueter. They reported seeing about 8 to 10 orange glowing objects that moved at a fast pace and followed their aircraft.”
*Rendsham forest incident: http://www.ufoevidence.org/cases/case279.htm
*UFO turns off 10 nukes: https://wonderfulengineering.com/retired-usaf-captain-says-a-ufo-turned-off-10-nukes-and-sent-a-message-wtf/
I asked a buddy (with 3 PhD’s, that alone is amazing) who served in the Airforce at these nuke installations about these reported incidents. I expected him to tell me that they were a hoax or some kind of test. Nooooooo, it happened.
*USO Canada: https://youtu.be/K8TMq0gwCv8?si=u8ChRiVbgkHlhJAE
*Travis Walton incident: https://www.kjzz.org/the-show/2025-07-03/his-arizona-ufo-abduction-story-became-legend-after-50-years-hes-sick-of-attempts-to-debunk-it
I could go on.
Information? Disinformation?
Maybe we are looking in the wrong direction for other civilizations in the universe? Maybe “others” exist at a level we are unable to properly detect, comprehend and understand?
We are assuming that “others” are just like or very similar to us in how they exist and experience the universe.
Anyone?
I am one of those aliens you’ve been looking for. Your problem isn’t that you are looking in the wrong place, you are looking in the wrong way. The heavens are lit with our communications but they are not enabled by modulation of the electromagnetic spectrum. Listening for drums or looking for smoke signals will yield nothing.
Regrettably, viable technologically advanced planets are rather rare– on average about three to five per galaxy. Our surveys across several galactic clusters have shown that most hitech planets (>80%) die out, not because of war or pestilence (or errant asteroids), but mainly because they stop reproducing. A techno-cide of sorts. Occasionally a hitech civilization will develop exogenetic intelligence (ie, machines) which carries on before the indigenous bio-intelligence regresses to a primitive state or vanishes all together. Thankfully, your galaxy is presently spared such entities with which, I’d advise, you hew to the dark forest hypothesis.
That we appear to be alone in our little corner of this galaxy is both sad and a relief. Considering the distances involved it’s unlikely we ever be able to maintain communication let alone trade with them. And maybe that’s all for the best.
Here you go: Steve McQueen interviews a Martian: https://youtu.be/FQa71QtjoWM?si=NJBARrTOpJqtrsQN
Brace yourself, Wayne.
It has been clear since before I became a member of SETI (they once had a membership, like a museum), it was clear to me that SETI was futile.
1) As Robert noted, we could be the first. After all, someone has to be, why not us? (Aren’t we special). Therefore SETI is futile.
2) As Cryptonoetic noted, we may be looking in the wrong way. The electromagnetic spectrum (EM) may be an obsolete, long lag-time method, making communications virtually impossible. Therefore SETI is futile.
3) We may not be the first, but the first may have been recent enough that we still have not received their EM signals. Therefore SETI is futile.
4) There may be a “non-interference directive” in the same way as in the television show Star Trek. They may be out there, everywhere, but have not been allowed to visit us until we reach some form of technological, social, or psychological level that we are not allowed to even know about. Therefore SETI is futile.
5) Contact has already been made, but our highest leaders are not yet allowed to tell us or are afraid that the rest of us are not yet ready for the awful truth that we are not the center of the universe after all. Therefore SETI is futile.
6) We may be being visited by those who hide among us in order to study us before they announce themselves. Or maybe they hide in “duck blinds” to observe us without having to disguise themselves and risk exposure (as in the movie Cocoon). Therefore SETI is futile.
7) Technological advancement is hazardous, and civilizations destroy themselves at a horrendous rate, leaving very few other civilizations left to find us or for us to find. Therefore SETI is futile.
8) We really are special after all, and God made the world and the universe just for us (TallDave’s anthropic principle is just one scenario under this possibility). Forget about being first, we are the only one that will ever be. (Please don’t get a swelled head believing this one. It makes the head hurt. I know from personal experience. In addition, it makes the goal of making life interplanetary seem that much more important and that much more urgent.) Therefore SETI is futile.
9) Life is everywhere, and intelligent life is common, but we all were created at the same time (maybe 6,000 years ago, or maybe some non-religious amount of time ago) and so there has not yet been time enough to find each other. Therefore SETI is futile.
10) I Love Lucy proved that we are not the right kind of lifeforms that the rest of the universe wants to associate with, so they are making sure we don’t find out about them so that we don’t bother trying to talk to them. It is the “look the other way, don’t make eye contact” method of avoiding an unwanted conversation (as though they owe us some money, or something). They aren’t being judgmental, as they are above such petty things, but they have merely judged that they are better than we are. Therefore SETI is futile.
11) We accidentally found out about the cookbook, so they are waiting for us to forget about that warning to us. Darn those science fiction television shows! Therefore SETI is futile.
12) Life is violent in its struggle to survive, so they went to war with each other, destroying too many of them so that it is difficult to find the rest. (I don’t know how this is different from the more generic possibility #7, except that they destroy each other rather than themselves.) Therefore SETI is futile.
13) Per Peter Ryan, we are scheduled for demolition, as we were warned in a Douglas Adams book, but the bureaucracy takes more than 50 years to get around to the demolition. It may never get around to the demolition, because alien bureaucracy has had even longer to grow than it has among we earthlings. Therefore SETI is futile.
14) TallDave is right that the three interstellar visitors are versions of Rendezvous With Rama, and they have no interest in us at all. Our solar system is only a way for them to get from here to there, and vice versa. We are mere bugs of the universe that they ignore as we ignore our bugs. Therefore SETI is futile.
10) First contact will be “People of Earth, you got some ‘splainin’ to do!”
My guess is that more advanced civilisations will continue to use various forms of electromagnetic radiation like radio waves and light to transfer information because they are easy to produce, they can be controlled in very sophisticated ways, and the signal strength can be scaled up or down to whatever level is needed. Like the wheel, once you have it, it’s just too useful to ever give up.
But like us, those more advanced beings will want to make their transmitters as efficient as possible. As the first comment from wayne points out, Earth’s electromagnetic leakage has declined as technology has improved, and beings who are far ahead of us will have reduced the waste to almost nothing.
So, there will only be a few decades in the history of a civilisation – let’s call it “the Noise Window” – where it will be transmitting loudly and indiscriminately, before improving technology rapidly cuts down the leakage. The odds of us being able to listen with the right technology just at the time they’re doing that (or vice versa) do not seem very favourable!
AndrewZ wrote: “My guess is that more advanced civilisations will continue to use various forms of electromagnetic radiation like radio waves and light to transfer information because they are easy to produce, they can be controlled in very sophisticated ways, and the signal strength can be scaled up or down to whatever level is needed. Like the wheel, once you have it, it’s just too useful to ever give up.”
I agree that most fundamental technologies continue to be useful. We still use fire, despite its dangers (fire still burns down houses, and you really want to avoid fires aboard ships, airplanes and spacecraft).
Electromagnetic radiation (EM) has severe limits for long distance communication. It is bad enough waiting eight years for a reply from Alpha Centauri, but farther than that starts to become generational. EM will likely be used most for more local communications, such as within solar systems, or for reheating leftover pizza (or the space alien equivalent). Which reminds me, we use fire much differently than we did in the olden days, a century ago, when we used it directly to reheat our leftovers.
“So, there will only be a few decades in the history of a civilisation – let’s call it ‘the Noise Window’ – where it will be transmitting loudly and indiscriminately, before improving technology rapidly cuts down the leakage. The odds of us being able to listen with the right technology just at the time they’re doing that (or vice versa) do not seem very favourable!”
That makes a few interesting assumptions, and projects ourselves onto the space aliens. Since we only have a sample size of one civilization to examine, it is difficult to see potential alternate intelligences as behaving or advancing differently, but I am willing to give it a try, because I lied about the sample size.
Human/earthling civilization developed differently, depending upon the region of the Earth, and reviewing the definition of “civilization” I discovered that the word means the social and cultural development rather than the technological development. Fortunately, technology has an effect on the other two factors. This means that I am willing to consider certain social and cultural advancements as technological.
For instance, humanity and its tribalism appears to have formed in Africa, but the town/city technology appears to have formed in the Persian region with the invention of fixed-location farming. No more need to wander around to where the food is. These town/city technologies seem to have spread out from there, with the probability of some amount of reinvention in the Americas. It was in China and Europe that the Stone Age was left behind in favor of the Bronze Age. Eventually, Europe advanced technologically much faster than China. I blame two things: 1) the large multitude of tiny kingdoms always at war with one another, developing war technology in order to defeat the enemy’s previously developed war technology, and 2) crop rotation.
I love crop rotation. It is the fertilizer of the second millennium. No wonder England spread out so widely and ruled the world; they invented crop rotation (wheat, barley, oats: one prepares the soil for the next, as though fertilizing the field) and farmers were willing to violate English law in order to grow twice as much crop as they would otherwise be able to harvest (fallow fields were the law in England until about a hundred years ago). With all that extra food, the population exploded, people were available for non-farming work, such as military service, developing the next war technology to defeat the enemy’s previous technology, or industrial work (especially in the last quarter of the millennium). Meanwhile, Africa, Australia, and the Americas remained as Stone Age civilizations until the Europeans dropped by and brought their Steel Age war technologies that defeated the previous Stone Age technology.
With Europe being such a powerhouse of technological advancement, how was it that in the last quarter of the second millennium that North America became an even greater powerhouse of technological advancement? North America didn’t have a bunch of kingdoms always at war, creating the incentive to continuously develop the next war technology, so how did North America work that miracle?
My point here is that technology advanced in different places at different rates, and that is on the same planet. Other space alien intelligences may also advance at different rates, perhaps for social or cultural reasons. Different solar systems/planets may also develop at rates very different than each other, so how do the various intelligent life forms advance enough to ponder the possibility of space aliens that are available to talk to, if only they could get over their own versions of Fermi’s Paradox?
How many of them advance out of the Noise Window quickly (whatever “quickly” means in astronomical/cultural/social time), and how many stay in the Noise Window for a long time (whatever “long” means)?
The television show Babylon 5 started out seeming to be about the Third Age of mankind, but it ended by being about the Third Age of the galaxy’s intelligent life forms. The Ones that were, the Ones that are, and the Ones that will be. They all came at different times and developed at different rates.
”Could it actually be the case that we are the first sentient intelligence species in the Milky Way?”
That seems likely. If we weren’t the first the others would be here already
”Other space alien intelligences may also advance at different rates…”
This is the reason that explains the Fermi paradox: The speed of technology so far exceeds the speed of biology that the first technological civilization that arises will colonize the entire galaxy before any others can catch up.
Geologists say the Earth is four billion years old. If another similar planet formed somewhere else in the galaxy at the same time but advanced just 1% faster than Earth did, that planet’s creatures would have arrived at Earth when humanity’s ancestors were still lemurs. Likewise if it advanced just 1% slower, humanity will arrive at that planet while those creatures are still lemurs. The effect is even worse when you consider the 13-billion-year age of the galaxy.
I’ve heard of simulations that suggest only about 1-4 advanced civilizations are likely to form before the entire galaxy is colonized, with most runs accomplishing that with only one. Those are just simulations, of course, but the effect is real even if the simulations are uncertain.
So the Star Trek universe is unlikely to exist. The first creatures in a galaxy to invent the steam engine will likely colonize the whole thing.
Civilization refers to the building of towns and cities. By that standard, humans have been civilized for an absolute maximum of 10,000 years and significantly civilized for 6,000 years or less. The beginnings of modern industrial civilization go back only about three centuries. But before we were civilized, we were still around for tens of thousands of years as tribal nomadic hunter-gatherers. If the histories of any notional ETs are similar, there could well be other sentiences “out there” but they’re mostly still stuck in their “flint knives and bearskins” phase – to quote a famous fictional ET.
Looks like none of you believe in God. There will be wailing and gnashing of teeth.
Eric: The outer limits / phenomenon level of this “Other life and how it manifested in the universe” issue regarding anything other than black and white textbook science is a third rail subject to many in the high IQ engineering / rocket science / academic fields. As a general rule the stigma and potential ridicule is a powerful limiting factor in fully comprehending and understanding the issue.
But there it is all the same. IMO anyway.
There are some things that science just is unable to rationally in those terms explain.
https://www.sigma3ioc.com/post/ufo-s-extraterrestrials-ultraterrestrials
https://static.wixstatic.com/media/e691e8_fcf837f9d4da49e1a0f0b7f97a73df31~mv2.jpg/v1/fill/w_925,h_925,al_c,q_85,usm_0.66_1.00_0.01,enc_avif,quality_auto/e691e8_fcf837f9d4da49e1a0f0b7f97a73df31~mv2.jpg
Dick–
“Edith Keeler must die.”
https://youtu.be/dRIYBO-05K8?t=199
Eric–
“I Act as if God Exists”
Peterson / Akira (2018)
https://youtu.be/SG7mKcIVvQQ
Personally I do think thee are other advanced civilizations out there. Just to many possibilities.
But If they did or do come here I think they have better stealth tech than us and would never be noticed.
But sadly I think that there is no form of faster than light travel and no one has even shown up here.
Its up to us to colonize our local space with generational ships.
….and there is even the possibility that advanced civilizations simply don’t broadcast at any wavelengths…..
BOOM!HEADSHOT!
No, they’re not using analog based ANYTHING!!
“Its up to us to colonize our local space with generational ships.”
Not until you can control for 1G of gravity, constant radiation bombardment and a biosphere 2 like effect.
“Generational ships” are purely a Hollywood construct.
The human form / homo sapiens are of the earth and if those earthly conditions are not fully accounted for it seems to me that the only long-term result will be cancerous mutation and massive loss of musculature and bone structure. That is what the actual developing science actually currently supports.
Which does not mean that we will not be in space, to the moon and or Mars. But there are definitely hard lines to be drawn IMO.
The more I look into the subject the more I appreciate the uniqueness of planet earth and the sun that is orbits.
And there is something more going on that we are unable to fully detect and comprehensively understand.
…and one more thing (like det. Columbo):
Cotour nailed it.
High powered AM radio signals broadcast in the AM radio band 550 kHz to 1600 kHz never left the earth. The wavelengths are too long to penetrate the ionosphere and propagate into space. Only those signals around 30 mHz and above could propagate into space.
Cotour observed “And there is something more going on that we are unable to fully detect and comprehensively understand.”
If you look around, the evidence overwhelmingly supports this idea. As a teenager, I read “The Dancing Wu Li Masters”, and “The Tao of Physics”. “Zen and the Art of Motorcycle Maintenance” was required reading in high school. Also raised Southern Baptist, although non-practicing at the moment.
Point being, East and West both have it right; just different sides of the same coin. The approaches are complementary.