A model that computes the fraction of the 'haystack' that SETI programs have collectively examined

September 28, 2018 by Bob Yirka, Phys.org report
Credit: CC0 Public Domain

Why haven't we found evidence of life anywhere but Earth? A trio of astrophysicists has revisited this question by taking a closer look at the "needle in a haystack" analogy. Their analysis involved creating a model to assess the amount of work that has been done searching for extraterrestrial life, the Search for Extra-terrestrial Intelligence (SETI) project, compared to how much is required before scientists can rule out the possibility that there is none. Jason Wright, Shubham Kanodia and Emily Lubar have written a paper describing their efforts and uploaded it to the arXiv preprint server.

While it might seem to people who are not space scientists that humans have done an awful lot of work searching for signs of on other worlds, the truth is quite the opposite. Back in 2010, well-known space scientist Jill Tarter compared the thus far to peering at a glass of water looking for fish while standing next to the still unexplored ocean. In their new effort, Wright, Kanodia and Lubar have created a model that they believe better frames the effort to date. Their model uses inputs such as the number of searches conducted and amount of space covered, and compares them to estimates of the size and intricacy of the galaxy and universe beyond.

In their work, the researchers focus on the more traditional types of searching methods—using telescopes and other advanced equipment to study signals that arrive here on Earth from other places. This, of course, rules out the possibility of already residing here on Earth or unexplained phenomena such as UFOs.

The researchers have found Tarter's analogy to be quite close to reality, though they would bump the sample size from a glass to a swimming pool. But they also note that another famous analogy might need modification. They suggest the might be more akin to searching for any one of multiple needles in a proverbial haystack, rather than just one. But they also note that all we really need to find is just the one.

Explore further: NASA is taking a new look at searching for life beyond Earth

More information: How Much SETI Has Been Done? Finding Needles in the n-Dimensional Cosmic Haystack, arXiv:1809.07252 [astro-ph.IM] arxiv.org/abs/1809.07252

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dirk_bruere
1 / 5 (1) Sep 28, 2018
The most likely conventional communications technique for interstellar distance is laser. The equipment need for transmission and reception is far more compact than for microwave.
antialias_physorg
2.3 / 5 (3) Sep 28, 2018
The most likely conventional communications technique for interstellar distance is laser. The equipment need for transmission and reception is far more compact than for microwave.

The most likely technique is an information pod. If you can go close to c then it's only marginally slower but a lot more secure than a laser, able to evade interference and also able to 'hit' a moving receiver (with a bit of a detour you can also make it immune to being traced to the origin).
You can also pack a lot more info into a pot than a laser. ("sneaker net" always beats direct line in terms of bandwith)

I find the (radio) based SETI initiative a bit bizarre. On the one hand it presupposes 'advanced intelligence' and on the other hand it requires those intelligences to be supremely dumb (i.e so dumb that they waste energy blasting information intended for spatially localized receivers over 720° spatial angle at vastly overblown power levels.)
barakn
2.3 / 5 (3) Sep 28, 2018
720° spatial angle? If you're trying to convey some sort of angular area instead of just an angle, use steradians.
dirk_bruere
3 / 5 (2) Sep 28, 2018
As Michael Hippke has shown, if using a star's gravitational focus then point to point comms using 1 metre optics is sufficient to get megabits per second per watt bandwidth.
rrwillsj
1 / 5 (5) Sep 28, 2018
Giant Laser guns/heliograph.
Shooting giga=tetra=peta wattage of energy beams. Sufficient to carry a message across dozens of light-years. Or further?

Who would you trust to aim it?

You do understand that sending, oh, say "Hello, fellow sophont! How's it hanging?" is your verbal message?

However, the method of delivery, the aimed, coherent, carrier beam? Is a whole different message in itself. "Look at what we can do! We can boil oceans and melt mountains and fricassee entire continents. Any damn time we feel like it! Watcha thinking of how cleverly we aimed this at your planet?"

Yes? No? You sure that's not the message you wanted the aliens to have to ponder?

You sure now? Cause I know what a destructive gaggle of monkey's you are! Offering sweet seductive words. Right before engaging in violent rape.
Hyperfuzzy
not rated yet Sep 28, 2018
The Title is Val( x/Infinity). Would it just be simpler to tabulate possible habitable domains and count of near domains?
antialias_physorg
2.3 / 5 (3) Sep 28, 2018
720° spatial angle? If you're trying to convey some sort of angular area instead of just an angle, use steradians.

Translation SNAFU
Old_C_Code
3.7 / 5 (3) Sep 28, 2018
Plan for spacecraft weighing only a few grams to go to Alpha Centauri in 20 years.

https://www.newsc...entauri/

They (aliens technology) could be flying by all the time, but just very small and robotic.
PoppaJ
1.5 / 5 (2) Sep 28, 2018

I find the (radio) based SETI initiative a bit bizarre. On the one hand it presupposes 'advanced intelligence' and on the other hand it requires those intelligences to be supremely dumb (i.e so dumb that they waste energy blasting information intended for spatially localized receivers over 720° spatial angle at vastly overblown power levels.)


IMO: You are all incorrect. There is only one effective way to encounter ET communication. Entanglement, We will never hear from an "advanced" species until we can scan entangled states. What we will come across using our current method is garbled pieces of incoherent gibberish that we will at best be able to be attributed to artificial means. We need to stop thinking in terms of our limited ability and start thinking about what it takes to do things in real time.
antialias_physorg
3.4 / 5 (5) Sep 29, 2018
There is only one effective way to encounter ET communication. Entanglement

Please look up what entanglement actually is. It cannot be used for information transmission.
ShotmanMaslo
1.5 / 5 (2) Sep 29, 2018
it requires those intelligences to be supremely dumb (i.e so dumb that they waste energy blasting information intended for spatially localized receivers over 720° spatial angle at vastly overblown power levels.)


Who says the receiver has to be spatially localized? If there is intelligent life out there, then it could very well construct an omnidirectional beacon in order to contact other intelligent civilizations such as us. Also, any highly developed civilization probably does not care much about concepts such as "wasting energy". Energy is only seen as scarce by humanity because of our limited technology to harness it. The Sun is wasting yotawatts of it right now doing nothing but heating interstellar space. Might as well use it.
Anonym518498
1 / 5 (5) Sep 29, 2018
blah blah blah, ain't nobody there, total waste of taxpayer money
rrwillsj
1 / 5 (2) Sep 30, 2018
annoyingmousie as usual your indignant sputtering totally misses the point. Some congresscritters are being prodded by flying saucer worshipers to organize an official contact with the vaunted mothership.

Don't you crank cultists ever listen to one another? Isn't the illuminati suppose to be coordinating your lunacy?

Usually the gibberish would be ignored but I'm suspecting that some hustler has agreed to kickback some of what they can skim from the funding to a re-election campaign or two,

What are you besides a fleabitten rodent? Are you also some sort of commie agitator? Trying to interfere with the illgotten profits of an enterprising businessman? How UnAmerican of you!
Surveillance_Egg_Unit
3.7 / 5 (3) Oct 01, 2018

"This, of course, rules out the possibility of extraterrestrial life already residing here on Earth or unexplained phenomena such as UFOs."

Well, of course it is all ruled out. Not considered scientific enough. Totally fringe and kooky. Laughable.

The truth is that humans are too frightened to consider ALL possibilities, as such things would be too disturbing to the human psyche. In reality, the human race is not prepared for such an encounter with a race of beings who are so far advanced technologically, as well as psychologically.

One only has to read some excerpts from the physorg comments to realise that humans are still little more advanced than chimpanzees in their relationships with each other.

How would humans treat aliens from another star system? Would they run and hide? Would they take out their guns and knives to kill the newcomers? Would all humanity decide to use them as slaves? They already know what humans are like, and like to do. Word gets around.
rrwillsj
1 / 5 (2) Oct 01, 2018
oh segue, that is not fear you are hearing from all those about you... It's laughter! You must be a theosophist with flying saucers spinning wildly out of the Hollow Earth. With Elvis at the wheel, waving at you as he flies by!

Not all Ideas are equal. Hallucinogenic delusions are not equivalent to Rational Reasoning. No matter how loudly you tantrum at reality.
Surveillance_Egg_Unit
3 / 5 (4) Oct 01, 2018
oh segue, that is not fear you are hearing from all those about you... It's laughter! You must be a theosophist with flying saucers spinning wildly out of the Hollow Earth. With Elvis at the wheel, waving at you as he flies by!

Not all Ideas are equal. Hallucinogenic delusions are not equivalent to Rational Reasoning. No matter how loudly you tantrum at reality.
says rrwilliejoe

I am laughing also. Especially at you, williejoe
I don't recall mentioning "flying saucers". Do saucers fly - only YOU might know. And flying out of the "hollow Earth"? What a vivid imagination you have. And Elvis too? If I remember correctly, Elvis died many years ago. Unless you mean Elvis Costello - he is still living, I think.
The UFOs are mentioned in the article. I suggest that you take it up with the researchers.

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