Voyager's 'Cosmic Map' of Earth's Location Is Hopelessly Wrong

https://www.forbes.com/sites/startswithabang/2017/08/17/voyagers-cosmic-map-of-earths-location-is-hopelessly-wrong/

by Alexey_Nigin • 9 years ago

40 66 9 years ago

forbes.com

putsteadywere• 9 years ago

I'm fine with that!

[0] https://en.wikipedia.org/wiki/Three_Body_II:_Dark_Forest

[1] http://abcnews.go.com/Technology/Space/stephen-hawking-alien...

new2993• 9 years ago

Yep, after reading the three body series I feel like I'm much more skeptical about sending out Earths location indiscriminately.

Spoiler: One of the central tenets of this book is that the most logical course of action for any alien discovering another life form, is to destroy it immediately. The story is pretty coherent, but if anyone has references to any scientific/theoretical work on this I'd be very interested in reading it.

iammyIP6• 9 years ago

'the most logical course of action for any alien discovering another life form, is to destroy it immediately'.

In that case i'd rather be destroyed than share a universe with such a species. I do not think the premise makes sense. It also makes no sense to compare it with the slaughter of native americans, since that has been done by apes in clothes.

Any interstellar spacefaring civilisation should be so advanced that it values construction over destruction.

pavel_lishin8• 9 years ago

I don't buy it, at least not as stated in the book. The axioms in the book are flawed, and there are some unspoken axioms that aren't explicitly laid out.

1. Destroying a civilization isn't risk free. If you destroy a nearby star system that harbors life, you better be sure that your weapon can't be traced back to you, by either any observers, or by the survivors. (See Forge of God & The Anvil of the Stars[1] for a study of the latter.)

2. If you do subscribe to the Dark Forest game theory, and do have what you believe is an untraceable weapon of some kind, there's no reason not to sterilize every star system around you. Why would you wait until you've detected life? Send out self-replicating Saberhagen Berserker[2] probes and sterilize the galaxy. (Be sure you've got a good Friend-or-Foe system in place.)

[1] https://www.goodreads.com/book/show/464609.Anvil_of_Stars [2] https://www.goodreads.com/book/show/582675.Berserker

Balgair• 9 years ago

Meh, I think, assuming communication is possible, the possible gained knowledge is of greater value in the long term.

New mathematics, new ways to see physics, new art and culture, etc. and most of it would have been nearly impossible to create de novo. An easy solution to prime number generation? Easily worth Italy in value, if not more, over the medium-long term. Multiply that by a planet and all of it's history.

Hell, the dumb accounting records of even a small municipality for a few decades from aliens would be worth at least a Luxembourg in terms of information you could glean from it. (Not to make it all about money, but to give the info some sort of value we can understand) An alien civilization would be astonishing in terms of it's value to science and culture, etc. Forget BC or AD in terms of marking time, it would be Pre-Contact and Post-Contact.

Why kill that? Why destroy the golden goose? That would be so stupid.

Ok, maybe come in in disguise, give them an internet type thing, glean every possible bit of data from it, then sterilize the civilization. Best of both worlds? (pardon the pun).

Still, the matter we are made of is only ~5% of the universe. Dark matter is about 20% and dark energy is about 75%. So, odds are that whatever the aliens are doing, it's in those realms. Realms we cannot even begin to think to access and modify yet. If anything, if they see us, we're acting like a goldfish stuck in a bowl to them, no threat whatsoever.

rmidthun• 9 years ago

It doesn't even need to be hostile to be trouble.

The Strugatsky brothers book "Roadside Picnic" (inspiration for game and movie "Stalker") is based on the idea that aliens came and visited Earth and ignored us completely.

However, they left behind a lot of weird and often deadly trash that people are scavenging.

sliken3• 9 years ago

Assuming A) that FTL is impossible and B) the galaxy isn't a mono culture. The established players will likely have an mutually assured destruction agreement not to fight among themselves. Defending against near light speed attacks is basically impossible... at least for planets.

Civilization inhabiting whatever their favorite star systems in the galaxy would have to deal with a few problems. One is that the size of the galaxy (100k light years) galaxy wide quite difficult. Another problem is that civilizations can go from pre-radio (before they are easy to detect) to mass energy conversion (allowing a decent fraction of light speed) within a few 100 years. One likely strategy would be to place sensors across the galaxy that would detect problematic aggressive/warlike civilizations and eliminate them.

So civilizations that are peaceful, grow slowly, don't ruin their planet, and don't set off nukes in their atmosphere might get a pass. Maybe even an invitation into the galaxy wide community once they figure out anti-matter/mass conversion.

However the ones launching nukes might just get eliminated before they become hard to contain. If the typical window from pre-ratio to a growing thread takes a minumum of 200 years they might well spread a sensors to be within 100 light years of any planet. That would need something like 250k to cover the milky way. That way the problem is eliminated within 200 years and before they can spread far enough to be hard to contain.

MikkoFinell• 9 years ago

Yeah broadcasting our location is a horrible idea until we know whats out there.

new2993• 9 years ago

Because it's a forbes article, I guess this may be a pain for anyone using Adblockers. In summary:

The Voyager disk contained a "map" showing where Earth is. They used pulsars to identify Earth's location. However, since the launch of Voyager we've discovered that there are probably a billion pulsars in the Milky way. We've also discovered that they somewhat unpredictably change the direction in which the pulses are directed. Making it unlikely that Earth's location can be identified using this map.

Nice article, shame about the invasive Ads Forbes uses...

iammyIP6• 9 years ago

worked fine with ublock origin firefox 53

devy• 9 years ago

worked fine with latest uBlock Origin on Chrome 60

georgeecollins• 9 years ago

Not to be anti-science, but it is worth taking into account that there are a lot of things we think we know now that may turn out to be wrong. Particularly things that are far away in space and time, where the points of data are few. Popular articles discuss the latest theories as "now we know this to be true." I'm thinking articles about details of the Dinosaurs or the size of distant planets. It may be right, but it could be revised with new knowledge.

cmurf• 9 years ago

That's not anti-science, that's the whole point of science. It's the willingness to incorporate new information. The current understanding is always understood to be based on currently available information. I'll take it over religion any day, which is: there is nothing more to be learned about our origin, nature, purpose and future, the founding documents do not get changed or updated as new information is acquired, we can only invent new excuses for the ever increasing incongruence.

godshatter• 9 years ago

Wouldn't they just look at the nearest star first? On the scale of light years, it's so close to us it's extremely obvious where it came from, and will be for many thousands of years. Just backtracking it's course should be enough for a much longer time after that. Sure, millions of years from now it might be harder to figure out, but we'll be long gone by then. They can come bother our descendents, whatever form they might take. For the period of time our civilization is likely to survive if aliens stumble upon it, they will be able to find us rather quickly.

rm_-rf_slash2• 9 years ago

Depends on how far it goes and if any other gravitational forces act on it along the way.

Sometimes I wonder if the decision to turn Voyager around to produce the photo of the "pale blue dot" will someday end up fucking with aliens who couldn't imagine another species who would launch a deep space probe backwards.

Semiapies• 9 years ago

Perhaps all intelligent species take star system selfies.

tinus_hn• 9 years ago

Reaistically once you go far enough the only things to see that you couldn't see before are behind you. There isn't much blocking the view of the distant objects (and we're never going to get a close-up of them) once you leave the earth's atmosphere so once you reach the edge of the solar system the only things that are interesting to look at are behind you.

Chaebixi• 9 years ago

IIRC, Voyager's camera is on a movable arm. The probe itself has never "turned" and always has its antenna dish pointed at Earth.

New Horizons had a different design and works more like you describe; where the whole probe has to turn to point the camera.

SolCitizen• 9 years ago

Good, Why would we want potentially dangerous aliens to easily find us?

bhouston• 9 years ago

I have faith that they could decode it if they were sufficiently advanced.

antihero• 9 years ago

It'll probably land on some planet filled with ape like creatures that use it to beat each other but hey, we tried.

eutropia• 9 years ago

If by land you mean 'burn up re-entering their atmosphere' then sure. But of course, then those same ape like creatures will just use the meteor omen as a means to justify beating each other ;)

rbanffy2• 9 years ago

It's only a matter of time until someone notices we have a very weird spectral emission peaking around the TV and FM radio broadcast frequencies...

vixen99• 9 years ago

And anyone recalling the film 2001 will know what signals they'll be picking up ...

(for those who haven't seen it, 'they' receive images dating from the 1930s or thereabouts with a certain someone making what is today, an unacceptable (for most of us one hopes) salute)

pavel_lishin8• 9 years ago

I believe you're thinking of Contact, not 2001.

pcardoso• 9 years ago

It was Contact, not 2001.

wl• 9 years ago

The free space path loss from Earth to Alpha Centauri (4.4 ly) is ~345 dB at 100 MHz (FM broadcast). Our broadcast signals, with their relatively non-directional radiation patterns, are well below the thermal noise floor long before they reach anyone who might be listening for them.

UHF television broadcasts fare even worse because they have a much wider bandwidth and an even greater free space path loss.

throwaway1X23• 9 years ago

While I cannot put a label on it right now (but surely it has a name, read about it somewhere), it is some kind of paradox that sufficiently advanced civilizations will broadcast themselves openly and detectably only for a very very tiny fraction of time (tens of years are nothing on intergalactic, interstellar or even planetary scale).

We quickly learned that blasting long-wave analog voice signals to the skies and expecting the reflection behind the horizon is pretty inefficient and moved to shorter, shorter and shorter waves. Not only you don't need to blast local radio stations in local language to the other side of the planet, having hundreds of computer wireless networks in one apartment building means that it actually shouldn't broadcast more than a few walls away in order for multiple networks to coexist even with time-division multiplexes and collision avoidance magic.

So, in about a hundred years, we discovered RF, we then started by blasting long-wave radio stations using ionosphere as a mirror, gradually moved to more and more local frequency bands, we then launched satellites to wirelessly ping across the ocean, only to hide the signals back under the sea and ground using fiber optics for practical reasons (bandwidth, latency), we went from analog to digital and we started encrypting just about everything. In the end, we will produce mostly random noise with ultrashort reach.

Next step - we will enclose Sol with Dyson sphere and disappear completely :)

sliken3• 9 years ago

How about atomic bombs? Or early radar (powerful, very low bandwith, and not particularly directional).

Basically how far away could the most power signals from earth be heard?

Should be several magnitudes more powerful than a FM broadcast, while being significantly lower bit rate.

rbanffy2• 9 years ago

Won't the added emissions from all transmitters amount to something more easily detectable? How much does the Sun emit in the same frequencies?

pavel_lishin8• 9 years ago

On a long enough timescale, isn't our own solar system expected to change? It's not exactly proven to be stable, and several theories of its formation include radical changes after periods of stability. (Jupiter is supposed to have wandered all over the place.)

ourmandave• 9 years ago

Hopelessly wrong. Why? Does it assume parsec is a unit of time instead of distance?

moomin• 9 years ago

I think this would make a good basis for "The Orville: The Motion Picture".

V'ger is found in the middle of space utterly lost.

fapjacks4• 9 years ago

I don't think "hopelessly wrong" is correct, but we live in the era of clickbait titles, so of course it's not correct. Also, how "long term" is he talking? Because sure, in a billion years, provided Voyager isn't swallowed up by a star, the map is not going to be useful. I actually designed (and got) a tattoo based on this design, except that I updated the data on my version with data from newer astronomical catalogues, in particular a 2002 Australian survey that updated most of the p-dot values for these pulsars. Decoding the original period/p-dot values and locating the pulsars from the catalog data wasn't too hard, and some time after that effort but before I actually got the tattoo, I discovered a work online in which someone else had also decoded the p-dot values and found which pulsars they used. I compared his list to my own and was happy to discover we'd found the same. I also re-encoded the p-dot values which originally had Voyager's "launch date" with the value of my birthdate. I dropped a couple of the pulsars because the 1969 data was very far off from the 2002 data, crossing some imaginary error threshold in my mind enough to be dropped from the map. I personally believe the p-dot values are sufficiently precise as to be uniquely or nearly uniquely identifier data for the pulsars, I mean in the fantasy universe in which this actually amounts to something. It's estimated there are 200,000 pulsars in our galaxy. Surely ET has a computer he can use? Again, in this imaginary universe where ET finds Voyager (or me) and really sets out to crack the code, and we're not using some stupid scenario in which it's found in a billion years...

sliken3• 9 years ago

It's not that ET doesn't have a computer, it's that without omniscience they won't know which of those 200,000 pulsars were pointing at one of 100 billion stars way in the past.

Unless they already orbit all 100 billion stars, but even then it's 100,000 years to collect the data.

Basically with 200k pulsars sprinkled among 100B stars sprinkled over 200,000 light years it's very easy to get lost. A list of frequencies gets less useful over time. You saw a pretty big difference in the data between 1969 and 2002. Imagine the differences in 100k years.

Even a single unknown gravitational interaction could throw the probe way off in speed/direction.

fapjacks4• 9 years ago

Well, I should be clear that the difference in data between 1969 and 2002 was due to measurement error in the original surveys, not due to some kind of actual movement. I have already conceded that over hundreds of millions or billions of years, the map becomes a jumble, but for the next few million years (or from a few million years ago), the map is definitely not "hopelessly incorrect" as the guy states. And actually the whole point of choosing 14 pulsars was so that you had plenty of elbow room for errors arising from e.g. one of the pulsars being flung far and wide by a rogue black hole.

With a computer and observations of "a fair percentage" of the 14 original pulsars, it would still be "fairly easy" to determine which pulsars we're talking about, because from the period alone, you can reduce the total number of candidates to a handful. And so from 200,000 pulsars, from the original 14 period measurements (or 11 in the case of my tattoo), you should be able to reduce the total pulsar pool down to perhaps a hundred or so candidates, just from looking at reasonable possible pulsar periods. Then you can permute through all combinations using a computer to determine which of the pulsars all shared the particular recorded period values at the same time. These values are so precise, and so varied in nature, that you could easily take all 200,000 pulsars in the galaxy, and sort out which 14 you were talking about, if you also could guess that the 14 values were all measured at the same time, that the precise moment chosen to record the period value had to coincide with the precise moment chosen for the other 13 pulsars. Only this select group of 14 pulsars will have had these precise period values at one time, even if many other pulsars in the galaxy have had a specific period value at some point in their history, and this is the genius of Carl Sagan's idea, since you then also can encode a specific time in the data (which happened to have been Voyager's launch date on the golden record, and my birthdate in my tattoo). I still concede that along enormous time scales, it would not be possible to do this, but Carl Sagan's original assertion is definitely not unreasonable across the span of a few million years or so, and a reasonably large enough survey of the galaxy.

qubex4• 9 years ago

Am I wrong in summarising that ”hopelessly wrong map” could also be read as ”a map and a calendar (provided the eventual receivers have good enough records of pulsars going back eons”?

fapjacks4• 9 years ago

I'll explain it from the start, even though you probably know some of this already. The period of a pulsar is the period of its rotation, so how fast it rotates. The "p-dot" of a pulsar is the speed at which the pulsar period decays over time, how quickly the spin rate slows (since everything is always slowing down). And so this is why you wouldn't need a calendar, because by observation, you can get both the period of the pulsar, and the pulsar's p-dot (just by measuring the period a handful of times and doing the math). So ET wouldn't need a calendar, they'd just need to have cataloged the same pulsars in at least a few different sky surveys. Or at least once, because if I gave you a period value of 0.34567890 (hypothetically ignoring units), this is enough information to reduce to the total number of candidate pulsars to one. Unless you want to talk about enormous time scales (e.g. millions of years), but then you'd still be able to reduce the total number of candidates to a handful since pulsars have wildly different periods (and p-dots).

So this is actually how the map "encodes" the launch date of the Voyager probe (and how I was able to change this data and encode my own birthdate in my tattoo): We measure the period of a pulsar at a specific point in time. The pulsar above with period 0.34567890 is a specific period that will change over time due to the natural slowing of its spin (it's p-dot). So all the periods "encoded" into the original map were December 1969. I identified the pulsars, updated the data (distance, direction) with data from the new sky surveys, then advanced the pulsar period value by the p-dot value between December 1969 and the precise date of my birth, then re-encoded those new period values into binary, placed them on the "new" map with updated direction and distance data, and got the tattoo.

I discovered all of this stuff in the research phase of my tattoo. I had some discussions with a handful of professors in the Astronomy department at UH -- where I was going to school at the time -- and for a time it became this "thing" that was well-known in the department. I'd go visit someone for the first time casually during their office hours and they'd mention they'd heard of my idea. Probably one of the best compliments I ever got was from an old engineer that had worked on the SSME (Space Shuttle Main Engine, one of the most complex machines ever made) who said that my tattoo was the nerdiest thing he'd ever seen. Felt good man.

throwaway1X23• 9 years ago

I'm not anywhere near being well-versed in astronomy, so I cannot judge how hard that problem actually is, but let me present a counterpoint/food for thought:

40 years ago, we launched a probe with what we though as of then as being a nice, permanent map of our location. Since then, we learned that there are many more 'beacons' in the universe than those we have chosen and pointed out in our 'map', and they change randomly or pseudorandomly, so with our current knowledge, receiving such probe with such map, we would be SOL to decode it.

But, 40 years ago, there was a term 'supercomputer' which meant an 80 MHz, 5 ton, >100 kW-eating monster. Nowadays, we carry billions of 150 gram glass slates in our pockets with 100-times the computing power, use it to play games, and we throw around desktop/rig computing power to shift balances between virtual bank accounts (PoW-based cryptocurrencies). What would be an unthinkable feat on the planet-wide energetic and hardware level back than, a grad student can do on their gaming device (CUDA etc.) nowadays as a semestral project, building on existing open-source libraries and published reproducible research.

What will be possible [on our humanity scale] in another 40 years? 400 years? 40000 years?

Wouldn't they just intercept the probe and immediately think, oh, species 5618 thought back then that a dozen of pulsars engraved on a metal disk would make a good map, how cute, let's run a configuration-search on our astronomical recordings and on next orbital period, a PhD student presents an interstellar-conference paper on three possible locations in the known history where and when the species 5618 would observe just this specific pulsar configuration recorded on the probe... Ok, what if they started recording the observable universe only after we recorded our map? They may not have the exact stellar configuration in their big data clouds, but using SETI-like-network, in another orbital period, they will simulate historical pulsar configurations back before they started recording them and extrapolate similar results. This is just a 'linear' prediction on our technology, but what about a complete paradigm shift? What if they can browse in a block universe just like we page through a book and can just rewind and fast forward looking in the spacetime searching for the configuration recorded on the probe?

Or, we will develop FTL in tens/hundreds/thousands of years, overtake the Voyager with spacecraft just like taking off a private Cessna at a local hobby airport, grab it as a historical artifact for the museum and launch a better map, or, we would know better by then and rather quietly destroy it, remain silent and be thankful it wasn't seen by anything (Hawking's position on contacting alien life).

An earth bound semi-fictional example: Say a secluded culture thinks that recording rains, droughts, good and bad harvests will benefit their children. Some time later they will find that they have a full Library of Alexandria of records and noone, never ever, in many human lives would sift through all the recordings to find anything useful. Some more time later they will even find about climate zones and think that their collected records are truly worthless and useless. On the other hand, if our current selves find such records - if they are fairly recent, we have complete satellite imagery of the place. We have pretty nice worldwide temperature, rain, air pressure recordings. If it is a bit older, we still have more sparse weather records, so with some effort, we can still search for their rain-drought patterns. We can carbon date it. We can or cannot see our atmospheric nuclear tests in their smelting. We can digitally cross-reference digitized historical written records from many cultures (probably not now, mind you, semi-fictional). We can manually cross-reference their observations with known folklore from around the world. We can drill Antarctica/permafrost layers to evaluate climate back then. We can date it before/after/around great extinction events, geological eras at least...

Just because we just realized that the IRL situation is much more complex than we thought, it doesn't mean that what we recorded back then and sent out is "hopelessly wrong" [and useless].

sulam2• 9 years ago

I agree with you, completely. In fact, more than completely -- it's likely that there are a large number of signals that we didn't even think of as signals that a reasonably intelligent, resourceful alien detective could use to find us. My mind immediately jumps to the specific chemical composition of the metals, for instance. Or perhaps remnant zodiacal dust grains that will certainly be on it. Even simple orbital backtracking is likely to be successful on any reasonable timescale (and for unreasonable timescales, who's to say we won't be very obvious in ways that are much, much faster to be received than Voyager).

throwaway1X23• 9 years ago

Excellent point, in the heat of many discussions whether even a studied being of the same species [human] would get the hydrogen state reference, it never occurred that even without decoding anything nor putting any styluses anywhere, just the mere possession of the record and, for example, analyzing primordial traces could give us away... And I mentioned the C14 earth-bound analogy, damn! :)

bronzeage• 9 years ago

The titles is wrong. The map is still in fact accurate, and not wrong as the titles suggests. It's just that it's totally useless because it's ambiguous. A more appropriate title would be "Voyager's 'Cosmic Map' of Earth's Location Is Hopelessly Useless".

logfromblammo• 9 years ago

It's like burying treasure in a forest, and using a dozen or so trees as your landmarks.

If you're standing on top of your cache, sure, the map makes sense, but if you're anywhere else at all, you would need to map every tree in the forest, and run a pattern recognition algorithm on them, hoping that none of the key trees have blown down or burned since the map was made.

alistproducer2• 9 years ago

Good. I'm not sure giving other species a map to our planet was such an awesome idea in the first place. Although, what if we just pissed them off more by giving them wrong directions? They might be like "we were going to come in peace, bu then you wasted so much of our time with those shitty directions that now all you base belong to us."

Voyager's 'Cosmic Map' of Earth's Location Is Hopelessly Wrong

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