SoylentNews is people
SoylentNews
An arXiv preprint suggests that evidence of intelligent (or trashy) life could be found by looking for space junk:
Its author, Héctor Socas-Navarro, spends most of his time at the Canary Islands Institute of Astrophysics in Spain studying the sun. But he was struck by a weird side effect of the ring of active and retired satellites circling Earth: it's a little bit opaque. And the more satellites we throw up there, the more opaque it gets. He realized that if we—or any technologically advanced aliens out there—build enough satellites, they'll eventually become dense enough to leave a faint shadow around the planet when it passes in front of a star.
And that's awfully convenient given that one of the best ways we have of spotting alien planets is by staring at their stars and waiting for tiny dips in brightness as planets pass in front of them. Essentially, Socas-Navarro's new paper proposes, if aliens have put enough satellites into orbit around their planet, we'll be able to spot the faintly opaque bubble before and after we spot the brightness dip of the planet itself.
The scale of the endeavor would be a real challenge for the aliens, however, since this idea relies on between 10 billion and one trillion satellites. "It's like building the pyramids," Avi Loeb, an astronomer at Harvard University, told New Scientist. "Each building block is easy, but putting it together is the hard engineering task."
(Score: 2, Interesting) by milsorgen on Thursday March 08 2018, @10:40PM (6 children)
Even if feasible I would assume that the timeframe a developing civilization would create large amounts of potentially dangerous debris would be a very short one. Either they would use their resources more effectively or they would come up with a way to remove the potential impactors from orbit. Thus leaving a very narrow window of time to hopefully observe another intelligent lifeform, I guess it boils down to how ubiquitous life is out there.
On the Oregon Coast, born and raised, On the beach is where I spent most of my days...
(Score: 5, Insightful) by NotSanguine on Thursday March 08 2018, @11:38PM (5 children)
I'd go even farther than that. The issue isn't just the vast distances involved in seeking out such debris. Given the enormous time scales of the universe, should a civilization leave their space junk lying around, its' orbits would almost certainly (unless it was an incredibly large mass of junk) have decayed within a few million years, leaving nothing we could actually detect.
Consider the possibility that a species of dinosaur achieved sentience 75-100 million years ago. Even if they had a technological civilization, all traces of them would be completely eradicated (well, except possibly extremely long half-life artificial radioactive elements like P239) by now. Polymers would merely be carbon deposits. Any alloys would long ago have been degraded to their initial elements, any structures on the earth would have been completely destroyed/eroded away.
As such, if we can't definitively say (and we can't) whether or not there was a previous technological civilization *on the Earth*, the likelihood of discovering remnants of one around another star are vanishingly small.
No, no, you're not thinking; you're just being logical. --Niels Bohr
(Score: 0) by Anonymous Coward on Friday March 09 2018, @10:44AM (2 children)
We find footprints and even eggshells pretty regularly... Surely a technological civilization would leave artifacts more durable than that. Metal might corrode, but ceramic and glass should last over geological timescales, not to mention stone tools or fossilized bone tools, or the "footprints" of machinery. Now, if they were just sentient but only used that ability for social interaction had no technology, then of course we could only infer that if we found a skull.
(Score: 2) by maxwell demon on Friday March 09 2018, @12:00PM
The point is, they were so intelligent that they eventually came to the conclusion that littering the planet is a bad idea, so they collected all the artefacts in middle America, where they then destroyed them with a meteorite they directed towards earth for that purpose.
Unfortunately they were still not intelligent enough to recognize the big error in their calculation, which led them to choose a much too big meteorite, causing their own extinction. ;-)
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by NotSanguine on Friday March 09 2018, @04:54PM
Volcanism [wikipedia.org] (think the Siberian traps), plate tectonics, massive space rocks, and possibly even a large thermonuclear exchange could certainly obliterate just about any trace of a civilization over such long time scales.
Any of the major mass extinctions [worldatlas.com] (and conceivably others less massive) could have been caused by many things, even devastating nuclear exchanges. And over the time scales we're talking about (aside from, possibly, the Cretaceous), we'd likely be unable to identify such events.
Glass? Ceramics? Metal works? Given the geological processes at work, it's entirely possible (especially if a technological civilizations was concentrated on coastlines) that the ruins of such a civilization would be completely recycled via tectonic plate movements, with all evidence having been cycled through the Earth's mantle.
I'm not saying that such a thing happened, I'm merely suggesting that it could have, illustrating the difficulty in identifying the remains of a another hypothetical civilization around another star. Especially given the even longer time scales (10 billion years?) and vast distances involved.
Does that mean I think we shouldn't try? No. On the contrary, I think we should try to gather as much information about our universe as possible. Discovering such debris would be exciting, if incredibly unlikely.
No, no, you're not thinking; you're just being logical. --Niels Bohr
(Score: 2) by HiThere on Friday March 09 2018, @05:58PM (1 child)
The concentration of metals in ores is something that takes a long time. The dinosaurs isn't far enough back. Now if the trilobites had a technological civilization, I don't think we'd detect it unless they left traces on the moon, and we have explored enough there to rule that out...but the plausibility is quite low. The dinosaurs were (nearly?) evolved enough, but there were too many big ones for it to be plausible. (Just consider trying to fence out an apatosaurus.)
So I'm rather certain that we're the first technological civilization on Earth.
I guess I should have read the article, since people are talking about fragments and derelict civilizations, etc., but my first thought was that a topopolis should be rather detectable. The problem, though, is that it wouldn't be planet centric, but solar centric. Still, the inner rings would need to be as close as feasible to derive maximal energy/area from solar power, and that would mean it would need to be highly reflective to maintain a livable temperature inside. This should result in a sustained radiation spike in certain frequencies that would otherwise be hard to explain. There should also be certain effects in the heat spectrum...I don't want to say infra-red, because that's making assumptions about the habitable temperature of that lifeform. Still, it would obviously be easier to detect creatures that preferred a high temperature over those that preferred a lower temperature, unless the inner rings were automated.
I really doubt that a civilization that had been long in space would remain planet centric, so I have my doubts about their entire scenario. Still...if they *did* find one that way...well, I'd need to revise my thinking.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by HiThere on Friday March 09 2018, @06:08PM
1) We haven't explored the moon enough. I don't know how I left out that "n't".
2) Reading the article I see that they're proposing certain particular orbits, and only a very slight advance over our space capabilities. I find it hard to believe that this would be detectable, but they say they've calculated it, and certainly polished metallic objects are a lot more reflective than asteroids. I do think they're assuming that the targets would stay at approximately our level of space advancement for an extended period of time, however, and I find that implausible. We're going to either rise or fall, and soon. If we fall, we probably won't be able to get back up. If we rise, then I think the topopolis is more probable than dense clusters around the planets. (More probably, it will be something nobody's thought of.)
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.