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A variable signal at heart of the Milky Way (sciencedaily.com)
330 points by wglb on Oct 12, 2021 | hide | past | favorite | 144 comments



This is the plot of "The Island" by Peter Watts! See https://rifters.com/real/shorts/PeterWatts_TheIsland.pdf


Thank you for posting that. Odd how it's so much different that most of Watts' writing. Normally I consider Watts to be in my category of "authors whose ideas are irresistible but whose writing style is tortuous" thanks to him fitting five or six metaphors and similes into every single paragraph, but that was an excellent read. I wonder if he intended it for a different audience than his usual. I wish I could get Blindsight and Echopraxia rewritten in that style.


To each their own. I always enjoyed the metaphors and ambiguity, even if it meant I have to re-read a page after going "wait, WTF just happened". Reminds me of poetry analysis or classic literature class. Understandingly frustrating if you just want to charge through and find out what happens.

Gene Wolfe is also a master of this style, although he employs less metaphor, more ambiguity, and unreliable narrators.


I totally agree. I like reading Watts's work in the rare cases when I don't like his science.

> Understandingly frustrating if you just want to charge through and find out what happens.

"the device of art is that of ‘making things strange’ and of making form difficult, increasing the difficulty and time taken to perceive, since the process of perception in art is an aim in itself and must be prolonged" (Viktor Shklovskii, 1914)


I'm glad I am not the only one who finds his writing challenging. I had to give up on Blindsight after only a few pages as I had no idea what was going on.


Which is sad because it really is an excellent plot, but ye gods is it a miserable read. There seems to be a correlation with how good an author is at world-building and plot-weaving and how much actually reading the work is a chore. Watts isn't the only one either. Peter F Hamilton's worlds are utterly enchanting but will make you want to hit him with his own books.


Interesting, I haven't noticed writing style being especially challenging. Mostly because I'm not a native english speaker and read a lot of fantasy/sci-fi/etc books in english. They _all_ start off like "and then gromulars grokled grampors and fiddled fibbles flamboyantly" for several chapters. Then two things start to happen at the same time -- 1: author gets tired of introducing new things in fancy ways and goes on with the plot, and 2: reader slowly gets used to terms and concepts that are relevant enough to be used in the rest of the book.


After ploughing through a few of Hamilton’s books I came to the conclusion that three out of every five words could be deleted without any damage to the plot whatsoever.

He’s got some good stories, but I gave up after realising that I really didn’t need to know what every character, no matter how minor, had for breakfast.


He also has the unspeakably irritating habit of starting every chapter with an in medias res moment for some bystander that isn't part of the plot. It's only after two pages of Fuckface McGee's afternoon stop at the tea shop do the significant characters walk through the door. Even that would be a minor issue, except he also changes which character is the narrative focus every chapter and you don't find out which one until they enter the scene. Every single chapter starts out with ten minutes of the reader not even knowing what planet the events are happening on and it's very frustrating. I tried the audio version but went back to the books because he uses John Lee for all his narration and I can't stand Lee's weird faux-Scottish accent that wobbles all over the place.


Agreed. Like WoT, desperately in need of a fan edit to do what his editors wouldn't.


> ... but will make you want to hit him with his own books.

One of the funniest things I've read recently. Literally laughed out loud. Thanks for sharing.


Alas, we - the audiobook people - are left without a recourse.


I found blindsight pretty easy as an audiobook when driving rom SF to seattle. Maybe being slightly inattentive benefitted me for that style of writing, but I didn't notice the metaphor heavy style.


Blindsight's not too bad, but Echopraxia really piles it on. For example, it takes nearly a full page to describe uneventfully passing through an entryway and it gets two similes and two metaphors.


I found that Echopraxia felt underwhelming - blindsight had a lot of great stuff, but I felt that Echopraxia didn't really deliver as a sequel.


What a coincidence that this pops up on HN as I’m halfway thru Blindsight. It’s somewhat of a relief to hear others find his writing style frustrating… I was starting to think I was just dumber than his normal audience


Neal Asher would be the counter point there.

His world building is amongst the best I've ever read and yet his writing is plain, crisp and clear.


robin hobb excels at world building and plot weaving while having a very pleasant prose style, as does lois bujold.


Funny, I found Hobb (Assassin trilogy) torturous and Watts (Rifters) quite easy to read.


yeah, i guess a lot of it is a matter of taste. i find hobb's style very engaging and readable, and there are other popular writers like c j cherryh and david drake whose style i have a hard time getting into. (not read watts; from what i've heard of him i suspect his sf will have too many horrific elements for me.)


If you enjoyed that, you might also like Aphyr's spiritual "sequel" to this story, Needlepoint: https://aphyr.com/posts/349-needlepoint



> The brightness of the object also varies dramatically, by a factor of 100, and the signal switches on and off apparently at random. We've never seen anything like it."

A signal-emitting star being temporarily obscured by massive objects passing close enough to block the signal in our direction, or smaller objects at a further distance? Asteroids? Planets? Other stars? Dwarf stars? Maybe it's a crowded system, which may look like randomness.

If I'm standing on one side of a busy road with a lamp aimed at you and you're on the other side observing the light, the seemingly random passage of vehicles will make the signal look random.


I wonder if it is some sort of variation on a double pendulum problem.

https://en.wikipedia.org/wiki/Double_pendulum

Where the system is very chaotic and incredibly hard to model, so it appears to be random.

Perhaps this is a complicated multi star system that contains a pulsar and the complex orbits are creating these seemingly random flashes of light.


See also The Three-Body Problem

https://en.wikipedia.org/wiki/Three-body_problem

And it's also the name of a great book that might be appropriate here...

https://en.wikipedia.org/wiki/The_Three-Body_Problem_(novel)


Traffic doesn't look random - you'd quickly note patterns in it. Ditto for movements of celestial objects.


Does that hold true for something so far away? The number of objects that might pass through our line of vision only once during our life time seems as if it would uncountable.


The thing about outer space is that it's impressively empty. Any objects obscuring a visible star are most likely in its system. So, even for something this far away in a crowded system, we should be able to tell in a couple decades.


Doesn’t this ignore the vast number of systems between us and the visible star?


It doesn't. Imagine the night sky. What do you see? I see stars, that are bright dots on black background. That is, to a first approximation the overwhelming fraction of the area of the sky actually doesn't actually have a star. Now, the obvious error in that is the Milky Way, which is kind of a faint bright smudge. The non obvious error is that some things I see as stars really aren't. In both cases you can get a telescope and see that, upon closer inspection, this is actually a bunch of stars on black background, that were close enough to seem to be one star, or a smudge. As you point ever stronger telescopes at those, you discover that many smudges and stars are in fact bunch of individual stars (but some stars are actually singular stars and some smudges are nebulas). More annoyingly, when you point those telescopes at the black background, you notice more individual stars on black background. Now, you'd think you know the pattern and can do it ad infinitum. But you can't, because at some point the black background is resolved to the point of, well, the background radiation at the edge of the visible universe. And some of the bright dots turn out to be dense clusters and galaxy cores, where we can't make out individual stars.

But, as far as I understood, we have catalogued tens of millions of stars we have a clear view of. And when something passes between our system and a visible star, it's often (usually?) an exoplanet in that star's system, of which we've discovered almost five thousand.


The light is polarized, as I understand that very much excludes an ordinary star in such a system.


Dyson sphere.


Dyson swarm.


The pattern probably wouldn’t be random then.


Maybe it's still under construction


Maybe it's Morse code


Maybe it's Maybelline


"Random" is a very loaded word. If you were looking at some arbitrary nth digit of pi it would look random to you as well.


Some people will describe any non-periodic signal as random.


Compressed or encrypted data should also look random.


Would these bodies cause detectable lensing?


I don't think that explains the rotating polarization.


Maybe the source's rotation axis is responsible for this.


It would have to be spinning pretty darn fast to affect polarization of light in a detectable way.


Mr Wang and an international team, including scientists from Australia's national science agency CSIRO, Germany, the United States, Canada, South Africa, Spain and France discovered the object using the CSIRO's ASKAP radio telescope in Western Australia.

I just love how international Science is.


Business as well nowadays as software engineering teams can be easily distributed and travel and employment within EU is a non-issue. I have team members (at least) from Finland, Sweden, Estonia, Belgium, Romania, China, Germany, UK, New Zealand, Spain, Ethiopia - within company the interaction expands to teams and nationalities from US, France, India, Poland, Croatia...


Its always been that way, you read about how scientists in Germany and the Uk and France secretly wrote to each other during WW1 sharing their latest thoughts and discoveries.


For most things related to looking into space nowadays, we need a distributed team so we can cover the sky around the clock. It would be bad if we miss a 1 minute event "because it's daylight on our side".


it might be bad for optical telescopes, but not radio telescopes fortunately

I think it's more about sky coverage - which parts of the sky can be viewed from which telescopes at any given moment. that would require international collaboration


Surprised nobody has yet mentioned the book/movie "Contact" here.


What were you expecting exactly.


New random number generator!

"The brightness of the object also varies dramatically, by a factor of 100, and the signal switches on and off apparently at random. We've never seen anything like it."


Cloudfare famously uses images of a wall of lava lamps as a random number generator (https://blog.cloudflare.com/randomness-101-lavarand-in-produ...)

Makes me wonder if photos of the sky are sufficiently random to be used this way? Does the image vary enough and does an attacker see a sufficiently different view even if really physically close? Etc.


It’s more useful to take a sensitive detector and crank the sensitivity to maximum and put it in the dark. The randomness inherent in high iso noise on a cmos camera sensor is actually quite random. Adding actual stars to it might only decrease the randomness you might be able to see from the night sky without a telescope, in this case a radio telescope.


Camera sensors have the same amount of noise regardless of ISO. It's just that bigger or better-engineered sensors have less noise period, so less is revealed as you raise the gain (ISO). I might have written a little about this: https://ko-fi.com/post/What-the-heck-is-ISO-A-sensitive-ques...

The ideal for this would be an old sensor with lots of noise since anything new would have very little visible at any ISO. Maybe even the sensor in the camera they use for the lava lamps!

A lava lamp has the benefit of being fully analog. There's no way to exploit it to make it predictable without physical access to mess with the chemistry to make the blobs stop moving around, and you'd have to do it to all of them without anyone noticing the blobs stopped blubbing. The camera on it 24/7 would make this a bit hard.


The source of your randomness matters much less than insuring that your adversary doesn't have access to it, and that you collect enough entropy from it. As long as you have a good lower bound on the amount of entropy per unit time that your source generates, and the source is secure, the physical details of the source don't really matter.


That sounds like a non-trivial energy expenditure. Hopefully it's part of their office heating plan.


It looks like there's 100 lamps. If they have regular 20W bulbs in them like any lava lamp, then that's just 2kW being used for this. Not nothing, but in an office it might as well be. That's less than a single AC unit. If you want to save energy in an office start by switching off equipment at night.


It also helps serve the needs of millions of websites. This is like the mileage of a freight train: you have to look at how many tons it carries in that distance compared to alternatives. That's 2KW for easy true randomness. They have to get it some way, and this is probably the most efficient option for their purposes.


From the end of the blog post, the LavaRand project was never actually used as a primary source of random numbers.

>Hopefully we’ll never need it. Hopefully, the primary sources of randomness used by our production servers will remain secure, and LavaRand will serve little purpose beyond adding some flair to our office. But if it turns out that we’re wrong, and that our randomness sources in production are actually flawed, then LavaRand will be our hedge, making it just a little bit harder to hack Cloudflare.

So, no, it isn't serving a purpose for millions of websites. It's 2kW of lamps running as a backup in an office nobody is going into right now to even look at.


Yes, it is. I'm not sure what you think that post says, but it means LavaRand is currently serving a purpose in production. The whole point is to add more randomness to their other methods to protect against exploits or failures in the implementation of those methods. This is like the drives in a RAID setup. All those drives are a waste of power if you only care about when things work right. The point is to provide safety when things break.

The previous paragraph:

>> "LavaRand is a system that uses lava lamps as a secondary source of randomness for our production servers. A wall of lava lamps in the lobby of our San Francisco office provides an unpredictable input to a camera aimed at the wall. A video feed from the camera is fed into a CSPRNG, and that CSPRNG provides a stream of random values that can be used as an extra source of randomness by our production servers. Since the flow of the “lava” in a lava lamp is very unpredictable,1 “measuring” the lamps by taking footage of them is a good way to obtain unpredictable randomness. Computers store images as very large numbers, so we can use them as the input to a CSPRNG just like any other number."


But unfortunately it's not. In the analogy given in the comment I responded to, these lava lamps are a locomotive burning fuel while not actually moving any load. Sure it's there to "serve a purpose" if the primary breaks, but that doesn't mean it's doing any work when the primary is functioning just fine.


This is the check on the primary. It moots the concern of whether or not the primary is working. You could turn them off, but then the system is open to all the vulnerabilities known and unknown this mitigates.


It’s probably not literally the most efficient, but it is very good publicity. It is deliberately displayed behind the reception as a talking point.


It's definitely not the most efficient. Let's get that straight. Even within the space of "cameras pointed at chaotic systems", it's trivial to imagine less energy intensive chaotic systems than a rack of heaters convecting molten wax.


2kW still seems like a lot compared to just putting the cameras in a lightless cardboard box, which will work just as well.

This is energy spent because it looks cool, not because it's effective.


Why even use a camera? Use an avalanche diode and sample the noise.


Of course. I'm just pointing out the inefficiency by noting a minimal modification that would use less power.

An even more minimal modification would be to use those USB-powered "glitter" lava lamps. The idea that 2 kilowatts of heat being dumped into molten wax represents some kind of efficiency optimum is completely absurd.


Stop using your computer, its a non trivial energy expenditure


If they use heating at all (and not just AC) and have a thermostat as everyone else it would automatically account for the extra heat and not run the furnace as much. This is also why a blanket ban on incandescent lightbulbs is silly.


A blanket ban on incandescents is not at all silly. Your underlying assumption, that 100% is the peak efficiency for electricity to heat, is false.

Heat pumps.


Fair enough, I haven’t considered that. I would still prefer a tax or something over an all out ban but that’s a different conversation.


why tho? given that there are more efficient ways to produce light and heat and there are drop in replacements for incandescents?

Do you just prefer blackbody spectrums?


Yes on spectrums, I’m also sensitive to flicker and it’s hard to find LEDs that consistently don’t (I understand that it can be done with some circuitry - but then again I could just not use LEDs).


Late to the party, but using low watt incandescent bulbs to stop small compartments from freezing in winter is a classic off grid cabin and camper van trick.


IANAC but any sufficiently secure RNG implementation should be inherently wasteful.


It doesn't need to be inherently wasteful. A reverse-biased diode provides a completely unpredictable source of noise while also taking extremely little power.

Or cranking up the sensitivity of a sensor.

Or reading the low bit of an ADC.

All of these provide good entropy sources without being wasteful.


it's not _actual_ lava you know? Probably not significant


You can never be sure... https://dilbert.com/strip/2001-10-25


I like to tell people who play the lottery they should go for 1 2 3 4 5 6 as it's just as likely to come up.


That is not a good strategy. That pattern is just as likely to come up. However, should it come up, you are almost guaranteed to split the pot.

The best strategy is to not play. The second best strategy is to minimize the chance of splitting the pot.


But it's bad advice compared to a random selection because these are all numbers with meaning for people. Many people who enter lotteries use meaningful numbers such as days of birth. So 1 2 3 4 5 6 is just as likely as any set of numbers to come up but if you do win you're more likely to be sharing the jackpot with other people who chose the same set.


But does it really matter? If you selected another number on that basis and then 1 2 3 4 5 6 won, you would still be kicking yourself as splitting the pot is better than no pot at all.


You have the same chance of hitting right combination if you enter 12345 or a random number chosen by a wall of lava lamps. But you have lower expected return since more people will use 12345 than your particular random number.

Expected return being size of the pot you can win multiplied by probability of winning. It's the first number that is lower when everybody has the same bright idea at once.


It does really matter. It's certainly better to have x% chance to win y, than x% change to win z, for z < y. Psychologically, if you assume you lose (and you're "kicking yourself") then avoid betting on popular sets, because it's better to miss a chance to win $100 000 (10 way split) that you would get by betting on a popular set, than to miss a chance to win $1 000 000 that you would get by betting on a unique set.


My favourite of the Dilberts!



It’s sending pi, but we missed the first quadrillion digits.


All compressed data looks like random noise. If it didn’t, then it wasn’t compressed enough.


An RNG that all your friends and enemies also have access to


If that's intelligent life, they could then attack our encryption!


Oh, haha, is THAT what's going to do it? :)


Yes - They want our Bitcoins!


And here I thought intelligent life meant actual intelligence.


What if other people use the same signal?


We have found OnOff!

Beware the Emergence...


Love Vernor Vinge. Too bad is not as proficient as other world building science fiction authors, but if the pattern is correct, he should drop a new Zones of Thought book pretty soon.


He is probably in my top 5 after Stephenson and Gibson. He can't write aliens at all though. I skipped the alien half of a A Fire Upon the Deep (ok, skimmed) and missed nothing. The other books I tried by him were notably worse than that and a A Deepness in the Sky.

As usual in these posts, recommend authors/books. Forever War is ok for central concept, author is meh. Haven't read anything decent recently.


I can't tell if you're saying you like or dislike A Deepness in the Sky. From my perspective it's among the most thoughtful portrayals of a truly alien species I've encountered (trying hard to be respectful here and not include spoilers for those who have not read it)


> I skipped the alien half of a A Fire Upon the Deep (ok, skimmed) and missed nothing

You mean you still liked the book. Hard to know whether you missed something if you skipped or skimmed it. I read this over 10 years ago but the aliens are what I remember most


s/proficient/prolific/ ?


I've pretty much given up hope.


The part about the telepathic doggies was a downward slide anyway.


Have to disagree, the acoustically linked evolved hivemind concept was pretty mind opening for me.


Acoustically linked __furries__. Pretty neat concept, really.


Can't hold this against him; he wrote the book way before furries were a thing.


We might not have gone by that name, but we’ve been around at least since the ancient Egyptians drew a dog head on someone’s body and called them Anubis.

And the name probably dates to 1980-ish: https://www.flayrah.com/4117/retrospective-illustrated-chron...


My first thought as well. Hope we can visit those spiders one day.


Lem's His Master's Voice comes to mind.


It comes up every now and then… but there were some theories that these completely random but strong signals could be from a “light sail beam emitter” that is very far away and that the randomness just depends on where they’re going.


Do you have a source?


The paper that calculated the rough size of the object that could be pushed by one of these random pulses was fascinating and was posted to Hackers News a few months ago, but I'm struggling to find it. I would like to read it again, and would appreciate if anyone has the link.

The gist of the paper was that these beams would be plausible to push an object in the order of magnitude of the size of a spacecraft. But the calculated energy levels of the emitter (as we observe it) would require something like a dyson sphere, which would mean that if it were actually a light sail emitter, we'd expect a highly sophisticated civilization.


This one estimated a beam emitter "on the scale of a large rocky planet":

https://arxiv.org/abs/1701.01109

(my highly sophisticated approach to finding academic papers about outlandish alien technology is to search on Loeb).


The original article about the find, that was published in The Astrophysics Journal (linked at the bottom of the article): https://iopscience.iop.org/article/10.3847/1538-4357/ac2360

And open access version at ArxiV.org: https://arxiv.org/pdf/2109.00652.pdf


"Astronomers have discovered unusual signals..."

There are lots of 'unusual' radio waves in the universe; astronomers discover them almost daily. May of them are variable. But there's that word 'signal' again. Crap science journalism likes to play on the connotations, the suggestion of purpose, of meaning. Dictionary says: "An indicator, such as a gesture or colored light, that serves as a means of communication."

"the astronomers tried to find the object in visual light. They found nothing." Fairly usual for radio objects. That's why they were missed until Reber came along.

An interesting anomaly, I get that. Rouses the curiosity. Just stop with the 'signal' please, until it fits the case.



It mentioned its possibly a pulsar, it could just be a pulsar and magnetar https://en.wikipedia.org/wiki/Magnetar


I'm not saying it's aliens...but...


Anyone have a universally working link to access to the paper ?

https://iopscience.iop.org/article/10.3847/1538-4357/ac2360

[edit] Found : https://arxiv.org/abs/2109.00652

Is there some of the signal available so we can analyse the randomness for possible order ?


Someone forgot to unplug the microwave in the kitchen again


Waiting for the James Webb telescope to take a peek!


Is 'signal' the appropriate word, here? An astronomical term of art?

Signal usually implies intent, doesn't it?


"Signal" is used this way throughout physics. For example, CERN has an explainer on the search for the Higgs boson that says,

> When physicists search for a signal of the Higgs boson, they select particle collisions with observed characteristics similar to those a Higgs production would feature.

The "signal" comes from the process being studied, and the rest (at least whatever parts can be modeled stochastically) is "noise." One person's signal is another person's noise, depending on what each person is studying.

1. https://cms.cern/physics/higgs-boson-terms-and-definitions


Oxford defines “signal” as:

1. a gesture, action, or sound that is used to convey information or instructions, typically by prearrangement between the parties concerned.

2. an electrical impulse or radio wave transmitted or received.

The second definition doesn’t require intent.


If you take signal as simply “discernible from noise”, then it doesn’t require intent or a unique sender.


Just something that I started doing the last couple of years, searching for for ‘etymology of <insert word here>’ instead of definition. It usually leads to pretty interesting and informative results, particularly when a word selection feels strained.


I do this too and then talk through the interesting ones with my kids to encourage them to think about everything they encounter. e.g., this interesting theory for the origin of the surname "Kneebone" - https://en.wikipedia.org/wiki/Cornish_surnames#Anglicised_na...


Skip the search engine and just use etymonline.com


Wiktionary is excellent for this too.


Not necessarily. E.g. analyzing data from natural events is still "signals processing", even though there is no intent behind an earth quake etc.


I doubt it. E.g. the headline "New gravitational wave detector picks up possible signal" (1) does not imply intent, just measuring a definite event and not just noise.

1) https://www.livescience.com/gravitational-wave-detector-stra...


What's the frequency, Kenneth? What part of the spectrum are we even talking about here?


The ASKAP scans at 888MHz. From the paper, which luckily is publicly available:

> It exhibited a high degree (∼ 25%) of circular polarization when it was visible. We monitored the source with the MeerKAT telescope from 2020 November to 2021 February on a 2–4 week cadence. The source was not detected with MeerKAT before 2021 February 07 when it appeared and reached a peak flux density of 5.6 mJy. The source was still highly circularly polarized, but also showed up to 80% linear polarization, and then faded rapidly with a timescale of one day. The rotation measure of the source varied significantly, from −11.8±0.8 rad m−2 to −64.0±1.5 rad m−2 , over three days. No X-ray counterpart was found in follow-up Swift or Chandra observations about a week after the first MeerKAT detection, with upper limits of ∼ 5.0 × 1031 erg s−1 (0.3–8 keV, assuming a distance ∼ 10 kpc). No counterpart is seen in new or archival near-infrared observations down to J = 20.8 mag.

https://arxiv.org/pdf/2109.00652.pdf


I'm not asking if someone has access to https://iopscience.iop.org/article/10.3847/1538-4357/ac2360 and could upload the article on SciHub ...



Glad you didn’t asked!


the signal behaviour is curious


Aliens?


The black hole eating stars, one by one.


Like this person's guess, only speculation of what this actually is currently on the message board.

If you were going to put a signal (that was also a puzzle to be unlocked), seems like the center of the galaxy would be a good place to make it emit from. Kind of obvious place to look.

But yeah, would almost certainly fall into the black hole in the center in a couple million years or whatever.


Agreed that the center of galaxy is the best place to put up a billboard. Ha, what if that's all it was, an advert, "Be Sure To Drink Your Ovaltine." Galactic trolls, ha.

Is the signal's data available publicly? I wonder what the cryptanalyst community would think of it.

I would think that a intelligent species capable of placing a galactic billboard at the center of the galaxy would be intelligent enough to encode their message in an easy to decipher manner. Although, what does "easy to decipher" mean to a species with that technology. They may have stopped using any form of language that we would understand, generations ago.

Is math a universal language? Could an alien species use a number system that we wouldn't recognize?


Intergalactic number station makes sense. Starting to sound like an episode of Lost


I was also interested about the data (and cryptanalysis on it) – the best I could find with a quick inquiry was the original article published in The Astrophysics Journal: https://iopscience.iop.org/article/10.3847/1538-4357/ac2360

There is an open access version at ArxiV.org: https://arxiv.org/pdf/2109.00652.pdf


If I were to emit a signal for people (beings) to find I wouldn't make it so random. Or, I'd try and make it as regular as possible.




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