Self-replicating alien probes could already be here

Jul 19, 2013 by Lin Edwards report
Artist's concept of NASA's Voyager spacecraft. Credit: NASA/JPL-Caltech

Mathematicians in Scotland calculate that "self-replicating" alien probes could already have explored our solar system and may still be here but undetectable to our current technologies.

Drs Arwen Nicholson and Duncan H. Forgan from the University of Edinburgh had previously calculated that if a Voyager-sized probe passing through the galaxy picked up speed using slingshots around stars it could travel 100 times faster than otherwise.

The slingshot technique uses the of stars or planets to "slingshot" a craft and boost its speed. The Voyager 1and 2 probes launched by NASA in 1977 used slingshot maneuvers around the planets they passed to pick up speed, and Nicholson and Forgan calculated that interstellar probes could use the same technique around stars.

The new calculations, reported in the International Journal of Astrobiology this week, expanded on the previous work by using "self-replicating" probes in the computer models to see how the self-replication would affect the timescale.

The robotic probes could explore our galaxy and self-replicate themselves from and gas, after which the parent and child probes would each set off for a different star, where they would look for and then self-replicate themselves again. The probes would therefore disperse themselves radially across space.

In all the scenarios the scientists looked at, exploration timescales were reduced when the probes were self-replicating, and they concluded that a fleet of self-replicating probes could travel at only 10% of the speed of light and still explore the entire Galaxy in the relatively short time of 10 million years. This is a tiny fraction of the age of the Earth and the scientists say the results reinforce the idea of the "Fermi Paradox."

The Fermi Paradox, proposed in 1953 by physicist Enrico Fermi, suggests there is a contradiction between the high probability that civilizations exist elsewhere in the Universe and the fact that there has been no contact between ourselves and other civilizations.

Dr Forgan said that the fact that we have not detected or seen any evidence of alien probes in the solar system suggests there have been no probe-building civilizations in the Milky Way in the last few million years or that the probes are so hi-tech we are unable to detect them. Another possibility is that probes could be programmed to make contact only with civilizations that pass a set measure of intelligence, which could be the ability to detect the probes.

Explore further: How ancient impacts made mining practical

More information: arxiv.org/abs/1307.1648

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User comments : 51

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StarGazer2011
2.7 / 5 (22) Jul 19, 2013
The maths is interesting (if a fairly trivial problem from a networking pov) but the Fermi Paradox is not invoked by the ideas.
If the probes were Voyager sized we wouldn't see them even if there were hundreds of them in the Solar System right now.
And depending on how often each star is visited by 'the swarm' in a traveling self-replicating salesman type sense its probable none would have arrived in the 500 years or so since the telescope was invented.
But its a cute way to spend some taxpayer money.
TheGhostofOtto1923
2.8 / 5 (16) Jul 19, 2013

"...that passed a set measure of intelligence"

-Yes when they became machine like the creature that sent the probes. The reason that the galaxy appears silent is likely because organic sentience is an extremely brief transitory phase.

The machine singularity which will succeed us will be interested in contacting others of it's kind in order to expand it's database of the state of it's environs. This communication would be directed, coherent, burst-packet and impossible to detect unless you were directly in it's path.

Perhaps this explains the 'wow' signal.

Why send probes? Maybe some forms of sentience could be a threat. Maybe intelligence is rare, but so what? A singularity could seed itself elsewhere in order to expand it's network. Why wait for organics to turn?

Ben bova explores this in his new book.
dogbert
1.4 / 5 (20) Jul 19, 2013
The Prime Directive and the Fermi Paradox. Wow.

A waste of time but I guess it provides the illusion of useful work.
Egleton
2.5 / 5 (23) Jul 19, 2013
Because the Earth is one organism with interacting components that have evolved together I believe that any alien intruding biology would be a "woopsie" moment.
As far as spending taxpayers money, they can have mine. I consider science to be great art. But I object to supporting the other many millions of non-contributing parasites.
visualhawk
2.8 / 5 (9) Jul 19, 2013
The Prime Directive and the Fermi Paradox. Wow.

A waste of time but I guess it provides the illusion of useful work.


LOL and a good way of getting through some dreary winter days with a bottle of whiskey.
lkdjfsd
2.3 / 5 (3) Jul 19, 2013
Am I the only one that thought of roaches?
cantdrive85
1.2 / 5 (21) Jul 19, 2013
Total waste of thought, must be nice to live in a fantasy world paid for by others.
rug
2.9 / 5 (18) Jul 19, 2013
@cantdrive - I think you just described yourself.
RichTheEngineer
1.7 / 5 (12) Jul 19, 2013
Well, I guess then by Fermi Paradox, we'll never know, because we'll never develop the capability to detect alien probes before we destroy ourselves.
krundoloss
2.9 / 5 (13) Jul 19, 2013
I love all this psuedoscience where people come up with unprovable conjecture. Anything is possible, dont write a paper about it. It would seem that a highly inteligent race is capable of anything. They can build robots, they can build artificial DNA that grows new forms of life, they can do anything because we dont know how much longer they have been at it. We have just gotten started with technology, and we can already do amazing things. The things that some hypothetical race with a few million year head start can do, is seemingly limitless. Its fun to think about!
tadchem
1.6 / 5 (13) Jul 19, 2013
"...may still be here but undetectable to our current technologies."
In other news, DARPA is reportedly working to incorporate dark matter into a coating mixture, expected to be the next major advance in Stealth Technology.
Jo Blas
2.6 / 5 (5) Jul 19, 2013

LOL and a good way of getting through some dreary winter days with a bottle of whiskey.


Except in Scotland, they drink whisky. (the spelling matters to a whisky drinker ;-)
baudrunner
2.2 / 5 (19) Jul 19, 2013
Am I the only one that thought of roaches?
No, you're not, lkdjfsd. Why mechanical probes, and not biological ones? Insect species are all intent on a single and unvarying purpose, and many of those species have a hierarchy whose workers report to a single authority. Insects can reveal the existence of all the life forms that they depend on for their existence, which makes them a marker for analytical purposes. Alien civilizations could conceivably know all about the nature of life on a planet simply by analyzing insect telemetry.

lkdjfsd
2.7 / 5 (3) Jul 19, 2013
baudrunner, interesting response, I didn't consider that. I wonder how advanced mechanical probes could get before they are indistinguishable from life? Cool.
Yarking_Dawg
4.2 / 5 (13) Jul 19, 2013
The hostility some of the commentators express to an interesting thought piece is astounding. There is no way of knowing which kind of thought piece will spark and intuitive leap (Einstein anyone?), or where it will catalyse. Watch James Burke's connections and think again about what you know.

And for those of you who ignorantly bitch about wasting tax money, you need to learn a few things.

One, university mathematicians are poorly paid, and spend most of their time teaching. You get more than fair value for money just from the classed they teach to the engineers and such around the world.

Two, this specific bit of research was about the implications of self-replication, which is highly relevant to nano-tech applications and this example was to demonstrate the scale of the impact of self replication. Not at all a waste of time or money.
MandoZink
4.5 / 5 (8) Jul 19, 2013
Am I the only one that thought of roaches?
No, you're not, lkdjfsd. Why mechanical probes, and not biological ones?

Hmmm. My cats may be killing off perfectly good alien probes just for the fun of it.
HealingMindN
3 / 5 (4) Jul 19, 2013
Am I the only one that thought of roaches?
No, you're not, lkdjfsd. Why mechanical probes, and not biological ones?

Hmmm. My cats may be killing off perfectly good alien probes just for the fun of it.


You mean the little white mice? My cats have one as a pet.
VendicarE
2.9 / 5 (8) Jul 19, 2013
"Am I the only one that thought of roaches?" - foofie

Apparently yes..
tomkennedy
5 / 5 (2) Jul 19, 2013
This is an interesting exercise. I wonder though at the value of sending probes out so far. Once they got thousands, even hundreds of LY away, radio contact would be impossibly slow. A probe could make a world-shattering discovery and the host world would not know about it for hundreds, or even thousands of years.
Slick
4.3 / 5 (3) Jul 20, 2013
Science fiction has been talking about this for years, with von Neumann machines and the berserker machines.
ccr5Delta32
1.4 / 5 (9) Jul 20, 2013
If self replication machines are to explore the galaxy and replicate using only materials found locally while having all the information contained within a single molecular size unit ,they might well converge on something alot like DNA . Beautifully circular ! , Biology makes machines makes biology
Guy_Underbridge
2.6 / 5 (5) Jul 20, 2013
I distinctly remember a self replicating probe of interstellar origin pass through this solar system about 14 million years ago.

It was a Tuesday.
alfie_null
3.8 / 5 (5) Jul 20, 2013
The hostility some of the commentators express to an interesting thought piece is astounding.

My guess would be sour grapes. To them, it sounds like these researchers are having fun and being paid for it. Makes me wonder what sort of positions these detractors hold. Perhaps doing stuff they hate, yet having no alternative. Perhaps not themselves having the skills or intellect to do science as a career.

An obvious question is: how much money could be saved by not spending it on endeavors like this? How does that compare with how much money we spend on other things?

The framework within which science is worked is reasonably good at ensuring resources (money) are spent efficiently. Unlike, for instance, executives for some of our less-than-efficient corporations, few scientists get rich off their work.
TheGhostofOtto1923
2.3 / 5 (8) Jul 20, 2013
This is an interesting exercise. I wonder though at the value of sending probes out so far. Once they got thousands, even hundreds of LY away, radio contact would be impossibly slow. A probe could make a world-shattering discovery and the host world would not know about it for hundreds, or even thousands of years.
As the host will most likely be an effectively immortal machine intelligence it would no doubt have different perceptions of time.
machinephilosophy
1.4 / 5 (9) Jul 20, 2013
What about the trillions of future self-replicating alien probes that time-traveled to 2013 and are now living in my closet?
Mayday
2 / 5 (4) Jul 20, 2013
Not to worry. A civilization advanced enough to send a galaxy-wide probe network is likely searching for concentrated resources -- something the heaven's natural processes seem quite good at. They will likely be driven by commerce and/or conquest, not grad-student thesis or science grants. They'll likely want whole planets made of gold or diamond or whatever it is they value. Our system will be little more than a backwater gravel bin to them; which is a good thing. I suppose we do sit on a core of solid iron -- but I think it best we keep that quiet.
Ens
Jul 20, 2013
This comment has been removed by a moderator.
Eikka
2.3 / 5 (6) Jul 20, 2013
How would they deal with the problem that they need to slow down as they approach each star, or they'll just shoot through a cloud of dust and rocks at 10% of the speed of light, unable to capture anything without destroying themselves in the impact?

The requirement to slow the probe down in order to replicate it meanst that they start with essentially zero speed from each solar system, so the slingshot advantage is lost. They can't at the same time slingshot themselves around the galaxy and gather materials to replicate, because they're moving at relativistic speeds relative to the stuff they're trying to gather up.

Trenchant
2.1 / 5 (7) Jul 20, 2013
This will happen the same day undetectable self replicating alien monkeys fly out of my ass. Heyyy... wait a minute...
Hev
3 / 5 (4) Jul 20, 2013
Anything could be around that no one can detect. However if aliens have discovered us they must have superior technology to us, and history shows what happens when people are invaded by others with a more advanced technology, as in Australia, America etc. We should keep quiet for now.
ValeriaT
1.3 / 5 (12) Jul 20, 2013
Mathematicians in Scotland calculate that "self-replicating" alien probes could already have explored our solar system and may still be here but undetectable to our current technologies.
Yes and mathematician in another countries already calculated, that the Sun is rotating around Earth and/or that Earth is a hollow sphere (Euler). Does it mean something? It's evident, the mathematicians are really allowed to publish whatever BS today without single evidence (..I see, I forget, these aliens probes must remain "undetectable" for these models being valid). It brings the "predictions" of "undetectable particles" of string theory on my mind - the fact we found none serves as an indirect evidence of these theories.
marraco
1.6 / 5 (7) Jul 20, 2013

And depending on how often each star is visited by 'the swarm' in a traveling self-replicating salesman type sense its probable none would have arrived in the 500 years or so since the telescope was invented..

There is nonsense in abandoning a system, if the probe has self replicating capabilities.

Space travel is so expensive that, from an economic viewpoint, once a star is reached, the first priority should be to assure the permanency of the probe, or the investigation facilities.
marraco
2.2 / 5 (10) Jul 20, 2013
The information theory says that efficiently coded messages must be indistinguishable from random noise.

We should be searching unnatural noise on radio signals, instead of structured information. Today's approach is wrong.
Andrew Palfreyman
2.2 / 5 (13) Jul 20, 2013
Because the number of habitable planets in this galaxy alone is likely in the billions, and the fact that the oldest advanced civilisations in it may be over 8 billion years our senior, the Fermi Paradox becomes especially poignant. One way to explain it, it occurs to me, is that the galaxy is "policed" - either by some general agreement, or by some sort of fiat - to prevent our casual contact with other species. Thus our first contact will be a regulated, orchestrated event.
Eikka
3.1 / 5 (7) Jul 21, 2013
may be over 8 billion years our senior, the Fermi Paradox becomes especially poignant. One way to explain it, it occurs to me, is that the galaxy is "policed" - either by some general agreement, or by some sort of fiat


It can't be very effective, since it takes hundreds of thousands of years just to get a text message to cross the galaxy. How would this "intra-galactic" society communicate to the effect of policing the galaxy?
Job001
1.4 / 5 (10) Jul 21, 2013
Reject the hypothesis, given an unprovable unfalsifiable hypothesis. The motive of funding bias without accountability provides a fair hypothesis for unfalsifiable proposals. Unfalsifiable efforts should be unfunded.
Sinister1811
1.9 / 5 (9) Jul 21, 2013
I'm still waiting for the Black Knight to self-replicate. ;)
Andrew Palfreyman
2.2 / 5 (14) Jul 21, 2013
It can't be very effective, since it takes hundreds of thousands of years just to get a text message to cross the galaxy. How would this "intra-galactic" society communicate to the effect of policing the galaxy?
The assumption you make is that spacetime cannot be "gotten around" with wormholes or stargates or something else. I submit that the physics of a culture many billions of years older than our own may well have a couple of tricks up its sleeve that haven't yet occurred to us. FYI, our galaxy is about 50 KLY in radius.
PacRim Jim
1.4 / 5 (9) Jul 21, 2013
An infinity of things undetectable by our present technology could already be here.
That's called wild speculation.
zefal
4.2 / 5 (5) Jul 21, 2013
I have passed this said level of intelligence, and thus see alien probes all around me, which my lesser fellow humans won't believe me when I tell them.
JMu
5 / 5 (3) Jul 22, 2013
This article reminded me of Arthur C. Clarke's "Starglider" alien probe described in his 1979 novel "The Fountains of Paradise", though I can recall no suggestion that it was self-replicating, though perhaps self-repairing. I've thought that all of Clarke's major novels - starting with "Childhoods End" in 1954 - are actually explorations of the various possible means of contact with extraterrestrial civilisations.
TheGhostofOtto1923
2 / 5 (8) Jul 22, 2013
need to slow down
Ever hear of aerobraking? They could use the outer layers of a stars atmosphere as well as gas giants such as Jupiter and Saturn, to reduce velocity. They might need more than one star system to do this.

Hardened machines with ablative shells could withstand the stresses. Von bhilai machines can also be microscopic, nano-sized.
TheGhostofOtto1923
1.5 / 5 (8) Jul 22, 2013
'Von neuman machines' - fucking spellcheck
GSwift7
2.5 / 5 (8) Jul 22, 2013
Ever hear of aerobraking? They could use the outer layers of a stars atmosphere as well as gas giants such as Jupiter and Saturn, to reduce velocity. They might need more than one star system to do this


I don't think you're understanding the problem. It's a game theory problem. The probes would need some strategy of replication that maximizes the trade-off of momentum gained from slingshots against momentum lost from gathering up raw material. If you gather exactly enough material to self-replicate one time (with zero waste material) then you will lose half of your momentum relative to the star you're trying to use for a slingshot. I think you would want to avoid aerobraking. The problem would be collecting raw material for replication without losing any more momentum than you absolutely had to.

This might explain why we don't see alien probes. They're zipping through like a bat out of hell, so we never catch them in two frames from the same telescope. They look like noise.
TheGhostofOtto1923
1.8 / 5 (5) Jul 22, 2013
The problem would be collecting raw material for replication without losing any more momentum than you absolutely had to
I suppose it would depend entirely on their mission wouldnt it? A machine entity could observe over the course of time by sending billions of bug-sized probes which did not stop. But if they intended to stay and actually have an effect on the inhabitants, they would need to slow down.

A good way might be to impart all of their kinetic energy to a suitable asteroid, melting it and making it easier to use for replication.
Atomsk1
5 / 5 (4) Jul 22, 2013
Who's to say that these self-replicating machines arent molecular, biological machines, with the self-replication handled by specific combinations of guanine, adenine, uracil and cytosine and various proteins?
GSwift7
1 / 5 (3) Jul 23, 2013
This idea that all these magnetic fields exist devoid of the prerequisite electric currents and electric fields is ridiculous


Yes, that's the type of strategy a self-replicating fleet would need to employ. Something like scooping up a large asteroid and melting it with waste heat stored in your ship. Then use its materials for fabrication, and expell all the waste material out the back with high force to regain lost momentum from the intercept. Anyway, it's just hypothetical.

Who's to say that these self-replicating machines arent molecular, biological machines, with the self-replication handled by specific combinations of guanine, adenine, uracil and cytosine and various proteins?


Yeah, but as I just said, it's hypothetical. Specifics like technology and strategy are really moot. You've just gotta assume they worked that all out. In the course of a billion years, they could try many methods.
Eikka
2 / 5 (4) Jul 24, 2013
The assumption you make is that spacetime cannot be "gotten around" with wormholes or stargates or something else.


If they had that, then what's the need for self-replicating slingshotting probes? Just "hyperjump" your way around the galaxy.

FYI, our galaxy is about 50 KLY in radius.


50,000 years one way, 50,000 years the other way. 100,000 years to get a reply. By the time the interalactic police arrives, entire civilizations have risen and died, who have never heard of any of it, and thus wouldn't know about the whole deal about not contacting earth.
Andrew Palfreyman
1.4 / 5 (9) Jul 24, 2013
If they had [FTL travel], then what's the need for self-replicating slingshotting probes? Just "hyperjump" your way around the galaxy.
50,000 years one way, 50,000 years the other way. 100,000 years to get a reply. By the time the interalactic police arrives, entire civilizations have risen and died, who have never heard of any of it, and thus wouldn't know about the whole deal about not contacting earth.

You are correct about the common sense exclusivity of von Neumann probes and of FTL travel of some sort. But my assumptions are that The Galactic Cops have FTL travel, and that very old civilisations exist which keep all this humming along.

Also, when presuming FTL travel, all the galaxy statistics (e.g.how many Milky Way civilisations now have what ages) must be multiplied by roughly the number of galaxies in the universe, or about 200 billion. Suddenly it's a nigh-on certainty that they are out there, and the only resolution for Fermi is the cops!
TheGhostofOtto1923
2.1 / 5 (7) Jul 24, 2013
50,000 years one way, 50,000 years the other way. 100,000 years to get a reply. By the time the interalactic police arrives, entire civilizations have risen and died, who have never heard of any of it, and thus wouldn't know about the whole deal about not contacting earth
Except for a machine singularity which would never sleep, never die, and would measure time according to the rotation of the galaxy and the lifespan of its star.

THAT entity would have the patience to wait. And THAT sort of entity is the inevitable result of the emergence of intelligence.
adave
1 / 5 (1) Jul 24, 2013
Ok here is an interesting idea, a eukaryotic cell would make a good probe. It would evolve into intelligent life, explore the host system and send the seed cells on vectors to the next exoplanets. Returning cells would give what kind of information? Humanity would make a good alien probe. What a map would tell you are the genetic relationships between locations and the kinds of genetic material in the system. Thats the first generation. What is the only significant information you would want to find? So far we have only looked for habitable zones in other systems. There is also possible life in extremely cold zones where chemistry proceeds via tunneling near zero K and not temperature. Quantum based life like quantum computing might evolve thousands of times faster than high temperature life. The time of ultra cold life is at the end of the universe not the beginning. Science fiction can at least see the shadows of reality.
SURFIN85
1 / 5 (1) Jul 26, 2013
Question: if, using recombinant and eventually synthetic techniques, why would an alien society (or,eventually, us) choose to search millions of light years away for novel forms of life when they could ostensibly create whatever kind of life they want where they are? Could this be the solution to Fermi's paradox? Nah, too simple.