
Voyager's 'Cosmic Map' of Earth's Location Is Hopelessly Wrong - Alexey_Nigin
https://www.forbes.com/sites/startswithabang/2017/08/17/voyagers-cosmic-map-of-earths-location-is-hopelessly-wrong/
======
new299
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...

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iammyIP
worked fine with ublock origin firefox 53

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godshatter
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_slash
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.

~~~
tinus_hn
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.

~~~
rm_-rf_slash
That's a good point. It would be nice to have an actual photograph of our Oort
Cloud, after all.

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putsteadywere
I'm fine with that!

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

[1]: [http://abcnews.go.com/Technology/Space/stephen-hawking-
alien...](http://abcnews.go.com/Technology/Space/stephen-hawking-alien-
contact-risky/story?id=10478157)

~~~
new299
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.

~~~
pavel_lishin
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](https://www.goodreads.com/book/show/464609.Anvil_of_Stars)
[2]
[https://www.goodreads.com/book/show/582675.Berserker](https://www.goodreads.com/book/show/582675.Berserker)

~~~
ufmace
Trying to spin up axioms and theories about the game theory of whether or not
to destroy alien species seems hopeless to me. There's so many parts of it
that hinge on what is or isn't possible to know and do in the first place. It
could easily swing either way based on countless factors we know nothing
about.

I'm far from saying for sure that something like that is definitely true, or
even more likely than not. But it seems reasonably cautious to me to not
arbitrarily broadcast out to the universe our location and rough technology
level. We have no idea what might be out there or what its capabilities and
thought patterns might be. Or rather, it seems hopelessly naive to me to just
go ahead with such broadcasts, confident in our theories that nothing could
possibly go wrong.

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1001101
It's a bit anthropocentric to ascribe human utility calculus to alien behavior
motivation.

~~~
ufmace
Indeed, even if our "game theories" are perfectly reasoned by our logic and
the technology available to us, there's no telling what kind of logic and
thought patterns an alien civilization might use, and what different types of
technology they might have.

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fapjacks
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...

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sliken
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.

~~~
fapjacks
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.

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georgeecollins
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
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.

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bronzeage
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
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.

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throwaway1X2
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].

~~~
sulam
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).

~~~
throwaway1X2
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! :)

~~~
sulam
I'm picturing an alien researcher saying:

"well, clearly it comes from a solar system orbiting a G-class star. There are
45,000 of those within a reasonable range based on the rate of micro-pitting
on the protected vs unprotected surfaces. It seems to have been launched with
an engine powered by hydrocarbons, and clearly they have been recently
experimenting with nuclear weapons. Let's identify a candidate star with a
habitable zone planet that shows signs of a run-away greenhouse effect and
global thermonuclear exchange. Because clearly they have self-extincted,
otherwise we would have already contacted them through other means."

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rbanffy
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...

~~~
wl
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.

~~~
throwaway1X2
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 :)

~~~
dogma1138
It's not a paradox but it's based on our own techonlogical progression which
is weird.

We are as a species 200-250,000 years old. For most of that time we did
absolutely fucking nothing as it seems. Even for the recorded history which if
we take the past 10,000 years then we still didn't made much progress as we
did in the past 100. And the weird part is that we still have small pockets of
population living like our ancestors 200K years ago.

In 100 years we went from horses to cars, to rockets and spaceships to the
internet and computers small enough to fit in our pockets.

The 20th century was weird as fuck as far as scientific progression goes.

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alistproducer2
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."

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pavel_lishin
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.)

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moomin
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.

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

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

~~~
eutropia
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 ;)

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

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

