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More Evidence That Aliens Aren’t Trying to Communicate With Us

Some SETI researchers believe the best way to detect aliens is to search the skies for their laser beams. In the largest survey of its kind, astronomers scanned 5,600 stars in search of these optical signals—and they found…absolutely nothing. Nada. Zilch. Here’s what that means to SETI and the ongoing hunt for alien intelligence.

In a new study accepted for publication at the Astronomical Journal, SETI astronomers Nathaniel Tellis and Geoffrey Marcy from the University of California Berkeley report that they were unable to detect optical signatures of advanced extraterrestrials in over 67,000 individual spectra produced by nearly 5,600 stars in the Milky Way Galaxy. Revealingly, around 2,000 of these stars are suspected of hosting warm, Earth-like planets, suggesting that advanced civilizations either don’t get into the habit of transmitting powerful laser beams across the cosmos, or they simply don’t exist. More practically, it means we should look for optical signals elsewhere, and expand our search to include an assortment of other potential alien signatures. Simply put, we’re not done searching for ET.

Listening for radio signals is so old school. All the cool kids are now searching for laser beams. (Image: Contact)

That said, the null result is undeniably discouraging. Laser signals would be an effective, cheap, and easy way for an advanced civilization to get our attention. Using technology similar to what we have today, aliens could deliberately transmit artificial infrared, visible, or ultraviolet emissions at our star. These directed signals could attract our attention by being continuous and abnormally powerful, or by containing tell-tale signs of artificiality, such as unexplained pulsing, or a string of binary data expressing some kind of mathematical phenomena (e.g. prime numbers or pi).

Prior to this study, SETI researchers had evaluated around 20,000 stars in search of optical signals at Harvard’s Oak Ridge Observatory, spending about 10 minutes on each object. Clearly, if the laser blinking frequency is longer than that, or if ET’s laser transmission station is temporarily out of service, we’re out of luck. Not surprisingly, nothing interesting has been detected thus far.

In an effort to conduct a more thorough review of the heavens, Tellis and Marcy analyzed a trove of data collected by the Keck 10-meter telescope and its high resolution spectrometer, HIRES, between 2006 and 2016 as part of the California Planet Search (CPS). The 5,600 stars included in the study, the majority of which are located within a distance of 300 million-light years, produced 67,708 individual stellar spectra, averaging 96 spectral signals per star.

“This study leverages the huge amount of data collected by the Keck telescope over decades, mostly as part of planet-hunting projects,” explained Penn State astronomer Jason Wright, who was not involved in the study, in an interview with Gizmodo. “That makes it sensitive to relatively low laser powers from thousands of the most nearby and interesting stars. It’s a great example of how SETI can ‘piggyback’ off of other science, looking for signals that might have been overlooked or thrown out because they were not expected or they look very similar to known sources of noise.”

Armed with this data, the researchers then set about the task of searching for spectral signatures that, in the words of the authors, “would be expected from extraterrestrial optical lasers.” The power of these lasers ranged from 3 kW to 13 MW, which isn’t extreme by any measure. Unlike radio signals, which dissipate over vast distances, laser light manages to hold its integrity as it travels through space. “We may imagine that beings more technologically advanced than humanity would be capable of constructing…laser launchers with power levels at least as high as those detectable here, for any of the 5,600 star systems we surveyed,” explained the researchers in their study.

An example of a false positive in a signal. This extraterrestrial laser candidate was found in an observation of TW Hydrae. The blip turned out to be heated gas in the protostellar disk around the star. (Image: Tellis and Marcy, 2017).

To analyze this decade’s worth of data, Tellis and Marcy developed an algorithm that was (at least in theory) able to discern a possible alien signal within the natural spectra of a star. If an artificial signal was directed towards Earth, 
it would be detectable as an unusually high number of protons compared with the background emissions of the star. The algorithm was configured to flag any occurrence of three consecutive pixels that exceeded the researchers’ thresholds.

“We searched our spectra for ‘brightenings’ of the star, relative to the light it is already emitting, that were both tight in wavelength and in space,” Tellis told Gizmodo. “Finding a signal that matched the instrumental profile of Keck HIRES would have almost unequivocally meant we were seeing laser light, as the normal stellar spectra contain only thermally broadened emission lines. This is one of the key advantages to using Keck, as it has high enough spectral resolution to distinguish the two.”

The thresholds were very liberal, resulting in an initial batch of 5,023 candidates. The researchers manually parsed these results (literally eyeballing the data), pruning the list down further and further as they pinpointed the source of each false positive. The most common sources of these false positives included cosmic rays, gamma rays, radioactivity from the observatory, molecules in Earth’s atmosphere, and emissions from the parent stars. Eventually, Tellis and Marcy had to concede defeat.

“We found no such laser emission coming from the planetary region around any of the 5,600 stars,” conclude the researchers in their study.

This result would seem to strike a blow to the suggestion that advanced civilizations might last for thousands or millions of years, all the while sending hello messages to up-and-coming neighbors. If even a small fraction of the 2,000-or-so systems with potentially Earth-like planets surveyed had technological civilizations who took the time to deliberately beam megawatt-lasers towards us, we should have detected them by now.

“These results put an upper bound on the number of civilizations transmitting lasers at us while we were observing,” said Tellis. “It is only one type of communication, but we believe that for targeted communication, lasers are highly efficient.” That said, he admitted that lasers as a communication medium seem good to us at this time due to our relative youth, and that his team’s strategy relies on serendipity. “We have to ‘catch’ their broadcast,” he said. “Nevertheless, we believe it is a valuable result that the galaxy is apparently not teeming with such bright lasers.”

So either advanced alien civilizations don’t behave in this way (e.g. they hide their presence or engage in other activities), or they don’t exist. It’s also possible that technological civilizations are exceptionally rare in the galaxy (both in time and space), greatly limiting the ability of the researchers to detect a signal. As the authors of the new study admit, “We may begin to wonder if arguments along the lines of the so-called Fermi paradox have some merit.” Indeed, the eerie silence of space is getting louder with each new attempt to detect alien intelligence.

 

Source gizmodo.com

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46 Comments on "More Evidence That Aliens Aren’t Trying to Communicate With Us"

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And harvested

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Would you if you saw what’s happening among the humanoid species?

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Some alien species consider planet earth the isis of the solor system

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If I were. I conclude humanity to dangerous and not worthy of trust. No contact unless they’re threatening to destroy themselves!

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You wouldn’t be able to handle the rest

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Let’s just leave it at that

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There very strong and fast

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Hard to explain

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Aliens are in existing for several thousand years if they really want to communicate with us they should have done it to our ancestors…

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If they want to really communicate with us..then stop showing up at Night!!!!

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They already have

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People are always saying that aliens wouldn’t want to communicate with us because we did this or that. If aliens are that far away trust me, they’ll hardly know we exist, let alone everything we’ve ever done.

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The problem is stats and generalization which render hypothesis of numerous advanced civilizations. But what if the premise is faulty. What if our species which developed technology is a fluke a one off so to speak. Consider this of the millions of species evolved on earth only one developed technology, just one and that was a bit of a fluke. Individual species can be unique so although there are no doubt plenty of alien life out there one would not pin all you hopes on finding an alien humming bird, nor maybe a creature just as unique a being that… Read more »
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Well it seems that we that are already living in earth can’t get all get along

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You can’t prove a negative.

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Why would aliens talk to Us after all we are the people that used nuclear bombs on each other if I was an alien I wouldn’t speak to humans either

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Bro that’s different we’re talking about another civilization out of earth yoir talking about cavemen that’s us we are the cavemen with technology that’s all

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People are always saying that, but more than likely any civilization that had the knowhow to build great weapons would and would uesed them at some point and socially evolve past such things. Not saying that aliens wouldn’t look down on it, but they would view us in the same way we look at cave men. If there were cavemen still around do you not think someone would try to communicate with them?

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Y don’t dey wunna knw us Naya?

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Hahaha….

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No problem. …I like to do my bit !!!

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Aah G thanks hun…

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I’m only joking Martin…..I don’t know ….I’ll ask them next time I bump in2 them in the pub …..lol

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Because they don’t like you !!!!!

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So Y’s do I think dey don’t wunna knw is Naya?

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yes …..nasa already contected with aliens but cant tell to anyone…..they had find aliens theroy of binary language…0 1 …and make aa voice of..om …….and aliens also gives sign of of thier sound ..

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They know how humans think..if they show their selves maybe humans killed them and bring their bodies to a circus or freakshow for money..

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Begrijpelijk

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Hahaha

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Idd

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Tja

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Dyson

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Would rather us Not know they’re already Here.

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Nobody would wanne talk to aggresive monkey’s.. would you talk to a very hungry babboon tribe no didnt think so either

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Just a stupid would want to communicate with a selfdestroing race like ours..

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Earth has been “unfriended” by the universe …..

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No it just doesnt have universe facebook yet

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Can you blame them

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TAKE ME WITH YOOOOUUUUUU

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Seriously,if you were advanced would you take one look at us and turn the fuck around and try and forget what you saw?

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They’re like everyone else at a train wreck, watchin the carnage

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they have been living among us forever in stealth technolgy

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The Sombrero Galaxy…

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