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Existing Laser Technology Could Be Fashioned Into Earth's 'Porch Light' To Attract Alien Astronomers, Study Finds (mit.edu)
If extraterrestrial intelligence exists somewhere in our galaxy, a new MIT study proposes that laser technology on Earth could, in principle, be fashioned into something of a planetary porch light -- a beacon strong enough to attract attention from as far as 20,000 light years away. From a report: The research, which author James Clark calls a "feasibility study," appears today in The Astrophysical Journal. The findings suggest that if a high-powered 1- to 2-megawatt laser were focused through a massive 30- to 45-meter telescope and aimed out into space, the combination would produce a beam of infrared radiation strong enough to stand out from the sun's energy. Such a signal could be detectable by alien astronomers performing a cursory survey of our section of the Milky Way -- especially if those astronomers live in nearby systems, such as around Proxima Centauri, the nearest star to Earth, or TRAPPIST-1, a star about 40 light-years away that hosts seven exoplanets, three of which are potentially habitable. If the signal is spotted from either of these nearby systems, the study finds, the same megawatt laser could be used to send a brief message in the form of pulses similar to Morse code.
Any tribe that had such an idea in the 15th and 16th century would have been run over and destroyed before they even know what was happening.
Why would you assume the aliens will be any less brutal than the 16th century European explorers?
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
If we're not alone in the universe- I would like to know about our neighbours before they know about us.
Sending an unsolicited welcome beacon into the night could be catastrophic. If they're able to read it and respond they're probably more advanced than us. If they're more advanced than us they might not want to share the galaxy with another species who one day might evolve to challenge them or threaten them. There is no guarantee that any aliens out there would share our sentimentality to life. Or even want to meet alien species.
If their civilization has advanced far enough to be guided by Artificial Intelligence, certainly AI would decide the logical thing to do is remove a future threat before it becomes a threat. This isn't Star Trek, you can't guarantee that Mr. and Mrs. Greenface want to drink Romulan Ale with you and be best buds with you. Any species that survives to the space age needs some logic. Logic will tell you intelligent alien species could be a potential threat.
"That's the way to do it" - Punch
a star about 40 light-years away that hosts seven exoplanets, three of which are potentially habitable. If the signal is spotted from either of these nearby systems, the study finds, the same megawatt laser could be used to send a brief message in the form of pulses similar to Morse code.
So this would be an 80 year round trip ping time? Someone far away would also have to be looking our direction when we light it up. For argument's sake let's say we want to allow a 10 year window for someone to notice our beacon. This means that we would have to shine the beacon for 10 years and then wait up to 90 years for a response?
“Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn’t turn out so well.”
Well, if the laser is red, you can hardly blame the aliens for 'red light district' being an universal concept. And if it is not, then we should not risk advertising our present with other hues, either.
Basic prudence dictates that we do not attract attention to ourselves before knowing what that attention will bring along.
No good deed goes unpunished...
Read "The Three Body Problem" before you talk about this shit.
If you want a awesome book series about this exact type of thing, I recommend `The Three Body Problem`. It's a great book to get into (translated) Chinese scifi literature
What, nobody has posted the obligatory xkcd yet?
fish.
... and also, are you sure we're looking for the right thing? ants
http://www.geoffreylandis.com
That's indistinguishable from background noise a few light years out. Hence the entire point of this study on how to purposefully send a signal that is distinguishable at a distance.
No. Check your facts.
He's correct: our RF broadcasts are indistinguishable from background noise at even a few parsecs distance. The stars turn out to be a very very long way away.
There are two exceptions: the Arecibo planetary radar, and ballistic missile warning radars.
But the Arecibo dish is very rarely used as radar, and if it did by coincidence happen to illuminate a star with inhabited planets behind the planet it was looking at... it's likely that it would never point that direction again, ever. The aliens would see one bright blip--if they were looking with an Arecibo sized radio telescope at the right frequency at exactly the right time--but if they look again, nothing.
Ballistic missile warning radar would be more repeatable, but it sweeps small parts of near-polar sky with a repeat time of 24 hours. So, if they see the blip as the radar passes over their star, unless they look again exactly 24 hours later, again, they won't see anything.
And, at a hundred parsecs, even those signals are too faint to detect-- they're swamped by the background. The galaxy is 100 thousand parsecs across. So, no: most of the galaxy couldn't hear us even if they had Arecibo-sized telescopes listening.
http://www.geoffreylandis.com
"If they take the ship, they'll rape us to death, eat our flesh, and sew our skins into their clothing. And, if we're very, very lucky, they'll do it in that order."
-Zoe, Firefly (2002)
...when everything is a crime, everyone is a criminal.
"Of course they're cute NOW. But in a second they're going to turn MEAN and UGLY somehow and then there are going to be a million MORE of them! ... Jesus, didn't ANY of you watch the show!?"
-- Guy Fleegman, Galaxy Quest (1999)
It must have been something you assimilated. . . .
Wouldn't it be a better idea to focus the gigawatts of excess solar energy our planet is absorbing every day, and help fight climate change at the same time?
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
"Such a signal could be detectable by alien astronomers performing a cursory survey of our section of the Milky Way -- especially if those astronomers live in nearby systems, such as around Proxima Centauri, the nearest star to Earth"
The good people at MIT seem to have overlooked a small detail. Space is really big. Douglas Adams discovered this long ago- please bone up on your studies.
In order to scan the universe with your narrowly focused telescope, you need to be able to see a width of 360 degrees and vertically at 360 degrees. Virtually an infinite number of adjustments in both directions. In order to see the puny laser beam, you'd have to pause your telescope in that direction long enough to identify it and separate it from nearby noise; perhaps for a few seconds(10?) If every position of the telescope requires 'a few seconds', it would take an extremely long time to scan the universe.
From the other perspective- if you want to point your laser to every point in the sky, you have the same problem. A nearly infinite number of points, depending upon the width of the beam. If you are sending some kind of signal, let's say a burst that takes a few seconds (10?) in each direction, it would take an extremely long time to beam across the universe.
What are the chances that your beam and the telescope at the other planet will meet?
Infinitely small.
...omphaloskepsis often...
We are not ready for ET.
Here are some possible outcomes:
They are dangerous and if they come here they have better technology than we do - we're screwed.
They are nice beings, but correctly conclude we are not. They decide its better to eradicate us before we become the scourge of the galaxy - we're screwed.
They are curious but see no benefit in engaging with us directly
They are not curious and correctly conclude we have nothing to offer their more advanced society. The universe is a big empty place and there is space enough for everyone.
My personal favorite - faster than light travel is fantasy and they will never bother to come.
In any case, the likelihood that they are wondrous benevolent beings who want to give us all kinds of nice stuff without unintended consequences is basically zero. No need to attract attention. Do something useful instead.
Greed is the root of all evil.
"DON'T Pray. You never know what might be listening."
It would be a monumental effort, but perhaps a less dangerous method might be to set up the laser in the Centaurus system. That way, if any "bad people show up" (cf The Beastie Boys), they might not notice us. Too bad if there are any intelligent Centaurans, but they should have thought of this first and put a laser in OUR system.
Agreed.
Let me link you the Fermi Paradox: We're First, We're Rare, or We're Fucked.
https://waitbutwhy.com/2014/05...
Specifically Possibility 4: There are scary predator civilizations out there, and most intelligent life knows better than to broadcast any outgoing signals and advertise their location. This is an unpleasant concept and would help explain the lack of any signals being received by the SETI satellites. It also means that we might be the super naive newbies who are being unbelievably stupid and risky by ever broadcasting outward signals; and Carl Sagan's takeaway: “the newest children in a strange and uncertain cosmos should listen quietly for a long time, patiently learning about the universe and compa, ring notes, before shouting into an unknown jungle that we do not understand.”