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Could Giant Alien Structures Be Dimming a Far Away Star? (sciencemag.org)
sciencehabit quotes a report from Science Magazine: Astronomers and alien life enthusiasts alike are buzzing over the sudden dimming of an otherwise unremarkable star 1300 light-years away in the constellation Cygnus. KIC 8462852 or "Tabby's star" has dimmed like this several times before, prompting some researchers to suggest that the megastructures of an advanced alien civilization might be blocking its light. And now -- based on new data from numerous telescopes -- it's doing it again. "This is the first clear dip we have seen since [2013], and the first we have ever caught in real time," says Jason Wright, an astronomer at Pennsylvania State University in State College. If they can rope in more telescopes, astronomers hope to gather enough data to finally figure out what's going on. "This could be the first of several dips about to come," says astronomer David Kipping of Columbia University. "Many observers will be closely watching." KIC 8462852 was first noticed to be dipping in brightness at seemingly random intervals between 2011 and 2013 by NASA's Kepler telescope. Kepler, launched to observe the stellar dimmings caused when an exoplanet passes in front of its star, revealed that the dimming of Tabby's star was much more erratic than a typical planetary transit. It was also more extreme, with its brightness sometimes dropping by as much as 20%. This was not the passage of a small circular planet, but of something much larger and more irregular.
Assuming that it's a single regular ring around the equator of the star, and not a massive constellation of collectors eclipsing each other at seemingly random intervals because that's what was maximally efficient according to both energy capture, and launch costs, while slowly moving into more efficient orbits over the millennia using solar sailing.
It's not like there's no good reason to have anything but a blandly periodic function in a Dyson swarm
A Dyson sphere, much less a partial Dyson sphere with sporadic orbit makes no sense. Why build such huge things? With technology so advanced, there are plenty other ways to gets lots of energy. They could harvest cosmic rays or put quantum entangled particles inside stars to generate energy from the paired particles. A lot more fissile material must exist in the parts of a solar cluster that failed to ignite.
However, an armada of spacecraft heading straight here from that star would not only dim it, from our perspective, erratically but also dim more and more of it, as it draws near to us. While also highly improbably, I prefer this alternative as it just seems way more exciting.
Except that I'm pretty sure nobody has made that claim.
What has been said is: "What is being observed is consistent with a partially constructed dyson sphere, and thus far it is not consistent with any other explanation we've had".
Now it's possible that this recurrence will allow for more observations, allowing us to learn more - and narrow things down further. That could easily end up with "We're now quite certain that 1300 years ago there was a partially constructed Dyson sphere around Tabby's star". And the likely assumption that, right now, that sphere is complete (or the project failed and it was never pushed past halfway and there's just a few floating bits of scattered construction equipment now.
The thing is - until there is more evidence, even if something else fitted the observations the odds of it being a Dyson sphere is NO LOWER than that other thing. No, it really is not. We have absolute PROOF that intelligent life can exist in the universe. We have absolute proof that SPACEFARING life can exist in the universe. We have absolute physical proof that spacefaring life can CONSTRUCT things in space in the universe.
The absolute proof is that we're here and we've done ALL THOSE THINGS. We've also had the theoretical design for a Dyson sphere for 40 years, we're a long way from building one but there is no theoretical reason whatsoever why, with sufficient technology, it could not be done.
So lets say the new observations STILL fit a Dyson Sphere in progress but ALSO fits a "weird meteor cloud" or something - you have absolutely no grounds to assume the weird meteor cloud is more likely - in fact it's less likely since we've got no evidence that such a meteor cloud can form, no theory for how it may have formed and no evidence for their existence.
Jumping to "There is alien life" would be a mistake, but jumping to "there is NOT alien life involved" is the EXACT SAME mistake.
Right now, the available evidence is consistent with one thing that would require alien life to exist, and not consistent with anything else. This may change - but right now the odds are, very slightly, in favor of aliens.
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>No, but odds are good that it's possible, since intelligence is useful for all kinds of tasks.
Not to mention that intelligence has all the earmarks of an evolutionary universal - a generic trick independently evolved several times. Octopi are as smart as cats - and the rest of the molusc kingdom is mostly things as stupid as clams (literally). Cats and Octopi didn't inherit their brains from a common ancestor (Their last common ancestor didn't have much of a brain) - they developed it independently.
So if intelligence can develop multiple times, independently, that fits the idea that it's so generically useful that evolution will favor it whenever a mutation arises that assists it.
Humans took it a step further, and so far the evidence suggests nothing else has done so except under influence FROM humans (literally - when interacting with us, their brains are pushed to learn to think a bit more like ours) which is to become self-referential. It's not just that we're smart, it's that we can think about WHAT we think, think about HOW we think - and even come up with ways to do it more effectively - that seems to be unique. And we took it one step further yet again. We didn't end at inteligence - we developed EXTELIGENCE, the ability to store our thoughts outside ourselves where they could outlive us. The first tool for this was complex communication: speech, which made it possible to convey our thoughts to others, and store it in their memories. The next step was writing, and so on and so forth until the current peak of exteligence: the internet.
Now these two things appear to be utterly unique to our species. We didn't just learn to use and make tools - but to share those techniques across societies, and allow others to improve on our progress over time. Since, here on earth, that looks like a uniquely human achievement - it's a lot harder to extrapolate that it will have happened elsewhere. At the same time - since it DID happen here at LEAST once - we cannot dismiss the possibility either. The odds of it being possible is 1. It has happened, therefore it is possible.
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There's a problem with that - you haven't explained the weird part. The weird part isn't the regularity, plenty of things orbit regularly. The weird part is that we can't see it. Every natural object we know off would, when absorbing light, heat up. 20% of a star's light output it s about 30 megafucktons (to use the proper metric unit) of photons. That will make that thing really hot, we'd be able to see that heat pattern.
Now perhaps we WILL see a heat pattern if we look with more telescopes now - but we've not seen one before. One possible explanation for whatever's blocking the light not heating up - is if that energy is instead being turned into something other than heat, like kinetic or electrical energy. That fits the dyson-sphere idea, but nothing we know of in nature.
I don't think we have enough information to rule it out, and it DOES fit the observed evidence. We don't have enough information to confirm it either - hopefully more information will let us settle on an answer.
And we don't need evidence of extraterestrial life to be forced to consider it a possibility - we have evidence of life in this universe. That alone proves that life is possible in this universe.
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Well that or we have to build it really, really thin....
Or, since matter can be converted into energy and vice versa - why not build the Dyson sphere out of matter made from solar energy ?
The thing is, we're talking thousands of years in the future. There is hardly a piece of technology in your life that wouldn't have been deemed impossible - even magical - just a century ago. Now imagine what it would look like to an Aztec ? To a Roman ?
We have no way of predicting what will be possible in a thousand years.
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You're linking to a paper published a year and half ago, if that's the correct explanation then why did Tabby send out a Twitter blast to a bunch of observatories, and why did they respond by looking at the star? It's a "family" of exocomets or planetesimal fragments, right? We've known that for a year and half, why redirect all of our telescopes to watch it when it happens again?
Oh, and why isn't that cloud of comets or fragments giving off any IR radiation that would be expected? And, if it's gas, why can't we measure the absorption to figure out which gas it is? You've read the article fully, so I'm sure you know the answers to those.
I did see an article which mentioned that the latest dip in brightness is similar to an event that happened 3 years ago, which is why they are predicting more dips this week. But the real interesting thing about that is, if there is in fact an object orbiting that star at a distance that it takes 3 years to go around, and it's capable of blocking this much of the light, then that object is larger than the star itself. If it was a cloud of dust, it would be radiating the IR that it is absorbing from the star. These are the kinds of things which make this star interesting, and even though you might be satisfied with that year and half old guess, astronomers aren't and they're still looking.
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