Laser cloaking device could help us hide from aliens

March 31, 2016
A 22W laser used for adaptive optics on the Very Large Telescope in Chile. A suite of similar lasers could be used to alter the shape of a planet's transit for the purpose of broadcasting or cloaking the planet. Credit: ESO / G. Hüdepohl

Two astronomers at Columbia University in New York suggest humanity could use lasers to conceal the Earth from searches by advanced extraterrestrial civilisations. Professor David Kipping and graduate student Alex Teachey make the proposal in a paper in Monthly Notices of the Royal Astronomical Society.

Several prominent scientists, including Stephen Hawking, have cautioned against humanity broadcasting our presence to intelligent life on other planets. Other civilisations might try to find Earth-like planets using the same techniques we do, including looking for the dip in light when a planet moves directly in front of the star it orbits.

These events – transits – are the main way that the Kepler mission and similar projects search for planets around other stars. So far Kepler alone has confirmed more than 1,000 planets using this technique, with tens of these worlds similar in size to the Earth. Kipping and Teachey speculate that alien scientists may use this approach to locate our planet, which will be clearly in the 'habitable zone' of the Sun, where the temperature is right for liquid water, and so be a promising place for life.

Hawking and others are concerned that extraterrestrials might wish to take advantage of the Earth's resources, and that their visit, rather than being benign, could be as devastating as when Europeans first travelled to the Americas.

The two authors of the new study suggest that transits could be masked by controlled laser emission, with the beam directed at the star where the aliens might live. When the takes place, the laser would be switched on to compensate for the dip in light.

According to the authors, emitting a continuous 30 MW laser for about 10 hours, once a year, would be enough to eliminate the transit signal, at least in visible light. The energy needed is comparable to that collected by the International Space Station in a year. A chromatic cloak, effective at all wavelengths, is more challenging, and would need a large array of tuneable lasers with a total power of 250 MW.

"Alternatively, we could cloak only the atmospheric signatures associated with biological activity, such as oxygen, which is achievable with a peak laser power of just 160 kW per transit. To another civilisation, this should make the Earth appear as if life never took hold on our world", said Alex.

As well as cloaking our presence, the lasers could also be used to modify the way the light from the Sun drops during a transit to make it obviously artificial, and thus broadcast our existence. The authors suggest that we could transmit information along the laser beams at the same time, providing a means of communication.

David comments: "There is an ongoing debate as to whether we should advertise ourselves or hide from advanced civilisations potentially living on planets elsewhere in the Galaxy. Our work offers humanity a choice, at least for transit events, and we should think about what we want to do."

Given that humanity is already capable of modifying transit signals, it may just be that aliens have had the same thought. The two scientists propose that the Search for Extraterrestrial Intelligence (SETI), which mostly currently looks for , could be broadened to search for artificial transits.

Explore further: What if extraterrestrial observers called, but nobody heard?

More information: The new work appears in "A Cloaking Device for Transiting Planets", David M. Kipping and Alex Teachey, Monthly Notices of the Royal Astronomical Society, Oxford University Press, in press. mnras.oxfordjournals.org/conte … 6/03/30/mnras.stw672 , DOI: 10.1093/mnras/stw672 , Arxiv: arxiv.org/abs/1603.08928

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Osiris1
4 / 5 (5) Mar 31, 2016
No wonder we have not found anybody.....all the others are maybe already using this technology or functionally similar technology so that they do not get found, and exploited. Steven Hawking and others wondered why we have not found other broadcasters. Maybe broadcasting is only done by the very young who have not learned the error of their ways yet?

Think of what we have done to our own species when we 'discovered' new continents.
dbsi
5 / 5 (4) Mar 31, 2016
But you need to know where they are - or spend a good 2 TWh.
kochevnik
1.5 / 5 (11) Mar 31, 2016
Perhaps they already found us. Sapiens seems to have gone through recent rapid evolution that could be alien genetic engineering. This might also explain the blood purification rituals and messiah-creation ceremonies practiced even now by catholics. There are ancient rituals worldwide that seem designed to make some kind of royalty, analogous to the way a beehive makes a new queen with royal jelly. These seems to have been a synchronization of cultures worldwide about ten millenia ago. This blood purification technology (what survives) seems to lie at the core of secretive mystery religions and modern occult
Zzzzzzzz
4.4 / 5 (7) Mar 31, 2016
you cannot hide gravity
rderkis
4.3 / 5 (3) Mar 31, 2016
If they are clocking it's like a do not disturb sign. We value our privacy (freedom) so high we would fight to keep it. Perhaps we should respect their do not disturb sign. Or expect a fight.
I would guess a type 3 civilization could do whatever they want with gravity.
Osiris1
2.8 / 5 (5) Mar 31, 2016
Would rather use those big lasers for Big Honkin' Space Guns to shoot down North Korean missiles with stink bomb nukes.on top.
big_hairy_jimbo
3.8 / 5 (4) Mar 31, 2016
So what exactly are the resources on Earth that these aliens are so interested in, that they couldn't find it in other systems?? Maybe Life itself is a resource they are after, but WHY?? Surely any aliens sophisticated enough to get here, have NO NEED for anything on this planet??? Sure they could enslave us, but for what purpose? Aliens no doubt have machines that can work better than us. Perhaps they would like to use us as sport, such as in the Predator movies.
Anyway, I think we are being a bit big headed to think highly intelligent aliens want Earth. Us humans can't stop that urge to always be on the defensive or offensive. Maybe the aliens just want to wipe us out, so we don't wipe them out hehehe See even I'm thinking militarily now.
Psilly_T
2.4 / 5 (5) Mar 31, 2016
If you use your imagination earth has a lot of resources any civilization would envy. Our entire solar system could be harvested by an advanced enough civilization. But earth also contains a lot of information. Countless species to catalouge and all the crap that we have left here. Maybe there are aliens or AI civilizations that go around and collect data as well as resources. *shrug* my vote is on making the earth look "inhospitable" with the smaller KW beam
simzy39
3 / 5 (2) Mar 31, 2016
If you use your imagination earth has a lot of resources any civilization would envy. Our entire solar system could be harvested by an advanced enough civilization. But earth also contains a lot of information. Countless species to catalogue and all the crap that we have left here. Maybe there are aliens or AI civilizations that go around and collect data as well as resources. *shrug* my vote is on making the earth look "inhospitable" with the smaller KW beam

Yes, but if we can easily get SETTI to search for the artificial light/cloaking...then can't the aliens also do that? It seems kinda like we're screwed either way. If it's possible to cloak, and possible to search for those who are cloaked then we can't do anything about it.

I agree about the cataloging. Earth probably has lifeforms with wanted cells or features, like the jellyfish that can be immortal.
jimhawtree
2.8 / 5 (4) Mar 31, 2016
I've noticed that many good people like to share resources, music, artwork, etc. I like those people; it's beneficial to me and to them, to communicate with them. But if someone tries hiding themselves or hiding other details about them, that is treachery and deception — why would I want to help someone like that, or let someone like that, help me? Treachery and deception are dangerous traits.
koitsu
5 / 5 (4) Mar 31, 2016
If they have the technology to cross unfathomable distance to harvest our resources, one might think they'd also have unfathomably more advanced methods of locating "exploitable" planets as well.
Steve 200mph Cruiz
5 / 5 (4) Mar 31, 2016
It would have to be a constant laser.
If we knew of an enemy alien civilization that was a threat, they would probably know about us already.
Since we dont know which direction the aliens are, we have no idea when to turn the laser on and off.
The laser would also have to spread in order to completely hide the planet. We don't transit in perfect geometry, we could appear at any latitude in the solar disk depending on which star is looking at us.

Speculatively,
Im sure we are just chimpanzees to aliens, they would laugh at our attempts to hide ourselves with a laser. Maybe they just dont need to talk to us, we have nothing to teach them by direct communication, only through quiet observation of our behavior.
Resources arent going to be an issue to creatures that understand everything about nuclear physics, they can probably make any element they need. Aliens dont plunder for treasure.
The energy it consumes to travel large galactic distances quickly is probably less than fusion
rderkis
5 / 5 (2) Mar 31, 2016
Quote
Resources aren't going to be an issue to creatures that understand everything about nuclear physics, they can probably make any element they need. End Quote

Not only could they make any element, they could combine them anyway they want.
I think there comes a point, with intelligence like ours currently is, where there is nothing more to learn of any significance. Sure maybe we don't know how often a certain individual of some alien species goes to the bathroom. But we will know just by looking at their genetic structure how often they should be going to the bathroom. :-) Perhaps just by looking at a planet we will be able to extrapolate everything common about it, including the life structures present, etc.
In other words there will come a time when exploration for knowledge is fruitless.
.
obama_socks
1 / 5 (5) Mar 31, 2016
So what exactly are the resources on Earth that these aliens are so interested in, that they couldn't find it in other systems?? Maybe Life itself is a resource they are after, but WHY?? Surely any aliens sophisticated enough to get here, have NO NEED for anything on this planet??? Sure they could enslave us, but for what purpose? Aliens no doubt have machines that can work better than us. Perhaps they would like to use us as sport, such as in the Predator movies.
Anyway, I think we are being a bit big headed to think highly intelligent aliens want Earth. Us humans can't stop that urge to always be on the defensive or offensive. Maybe the aliens just want to wipe us out, so we don't wipe them out hehehe See even I'm thinking militarily now.

- BHJ
If they're anything like us anatomically, they might want our women to procreate with because their own "women" have become sterile. Possibly too many GRBs. OR if the home planet has no men, they might want ME to sire their children
obama_socks
1 / 5 (5) Mar 31, 2016
No wonder we have not found anybody.....all the others are maybe already using this technology or functionally similar technology so that they do not get found, and exploited. Steven Hawking and others wondered why we have not found other broadcasters. Maybe broadcasting is only done by the very young who have not learned the error of their ways yet?

Think of what we have done to our own species when we 'discovered' new continents.

- Osiris1
So they are playing a game of, "Peek a Boo" with us, so we have to return the favor? It doesn't make any sense to pretend we're not here while using valuable resources/energy just to hide from someone that we're not even certain is 'out there'.
Unless, of course, THEY are here already living amongst us, and they have enemies who want to conquer them. Then it would make sense for them to set up a system with OUR resources. So if THEY are threatened by other aliens, then WE ALSO might be in danger of annihilation? Makes sense
Andrew Palfreyman
3.8 / 5 (4) Apr 01, 2016
April Fool !!
Guy_Underbridge
3 / 5 (3) Apr 01, 2016
Turn this on, then the aliens will wonder: 'Hey, where's that up-until-now uninteresting planet go?'
stezlaf
4.5 / 5 (2) Apr 01, 2016
This transmit dimming is just one means by which a planet can be detected. There are likely many other methods for detecting a distant planet that we have not yet discovered. To an advanced alien race, this "laser cloaking" technique could appear to be as silly as a baby covering its face, thinking that it makes him or her invisible.
antigoresockpuppet
3 / 5 (6) Apr 01, 2016
The elephant in the room is that an advanced civ would understand planet formation and know that there should be one where we are. An advanced form of Bode's Law or such. They probably would use perturbations anyway, and a laser won't hide that.

Hope AP is right, that it's an April Fool's joke. Pretty pitiful article if not. Not that idiots like Obama_Sucker would notice.
antialias_physorg
4.8 / 5 (4) Apr 01, 2016
April Fool !!

Yeah.

The Earth constantly transits with regard to some other star/planet out there. If they're also using space based telescopes then transits with respect to those would have to be taken into account. While we might figure out where planets are to point this at we would stand no chance to find space based telescopes (which might be anywhere)

Laser light is rather different from ordinary light (phase correlated). That would show up under the most simple analysis.

Plus while cloaking direct line of sight to the laser we'd be setting up a nice beacon for off-line of sight (due to scattering in the atmosphere). We'd be sending out very regular pulses at those angles.

(And as Zzzzzzzz notes: Microlensing is not affected)
compose
Apr 01, 2016
This comment has been removed by a moderator.
dbsi
5 / 5 (1) Apr 01, 2016
.... Is this 1 April article?

Sadly not, this was posted on March 31. So it would be bad taste.
TheGhostofOtto1923
2.6 / 5 (5) Apr 01, 2016
Aliens no doubt have machines that can work better than us
No doubt aliens ARE machines which we will inevitably be replaced by in a very short time.

And machines would have no interest in conversing with us.

Kochevnik thinks aliens are engineering us. If so they may be wanting to hasten our transition into the machine state.

Out of all the languages spoken on earth, the English language is the best one for interfacing with machines.

Could this be the reason english-speakers won the world wars? Could this be yet one more example of planet-scale sociopolitical engineering?
antialias_physorg
3.7 / 5 (3) Apr 01, 2016
Sadly not, this was posted on March 31. So it would be bad taste.

Maybe not, depending on what timezone this was posted from and where the arxiv server is located.
Steve 200mph Cruiz
5 / 5 (2) Apr 01, 2016

Out of all the languages spoken on earth, the English language is the best one for interfacing with machines.

Why would that be? Just seems like an odd claim
TheGhostofOtto1923
3 / 5 (2) Apr 02, 2016

Out of all the languages spoken on earth, the English language is the best one for interfacing with machines.

Why would that be? Just seems like an odd claim
Ever have multiple translations on a single page? The English one is always the shortest.

English has a minimum of gender-based words and punctuation and umlauts and accent-ey-gues and so forth. It requires the smallest keyboard and the fewest characters to convey.

It's not odd it just never occurred to you.
gulfcoastfella
3 / 5 (2) Apr 02, 2016
I was going to claim "April Fools" on this article, but then I realized it was written one day too early. :(
Steve 200mph Cruiz
5 / 5 (1) Apr 03, 2016
What about those whistling languages? They can convey complex ideas, and you avoid a lot of the problems you talk about and I think they would mix well with machines
vladimir_ondrak
3 / 5 (2) Apr 03, 2016
For many years we searching for ET civilization... and nothig. What if they hide herself from "cosmical barbarians" - us, as good as they can ?
paris_arthur
3 / 5 (2) Apr 03, 2016
These so many things wrong with this article. Is it supposed to be propaganda, a joke or mindless page filler that gets clicks?.. I can't tell which.

I'd love to know why someone would publish this on a news site.

jimhawtree
3.7 / 5 (3) Apr 03, 2016
This article, and most of our assumptions about extrasolar civilizations, assume a 'wild West' scenario of a few isolated, lawless outposts. That seems unlikely in a universe 13 billion years old. What's more likely is everyone worked out 'Universal Laws' for peace and cooperation with each other that our earliest leaders rebelled against. In that case, we're in a remedial learning classroom that's locked until the standard lessons are completed. That's why we've had one bunch of arrogant, violent, secretive, treacherous, greedy leaders after another to show us what happens without these Laws. If aliens landed here and gave us advanced tech, it would be confiscated for secret 'black projects' for military use. You think aliens don't know that? (e.g. we discovered nuclear energy, and it's first use was on Hiroshima and Nagasaki) The only alternative is 100% honesty, humility, compassion for the weak and poor, and hiding NOTHING behind a 'fig leaf' — Now that's an 'alien' idea.
dbsi
5 / 5 (1) Apr 03, 2016
Sadly not, this was posted on March 31. So it would be bad taste.

Maybe not, depending on what timezone this was posted from and where the arXiv server is located.

@antialias_physorg: Your fine with this comment, since you posted it on 1. April....
and it's phys.org who is responsible for the story and dates published here. Besides, the server would need to be located east of Zurich or even the Gulf coast.
eric_in_chicago
5 / 5 (2) Apr 04, 2016
I think an extraterrestrial civilization would come here and blanket the planet with inter-dimensional nanobots that would transmit our recorded experiences as "virtual reality".

That's entertainment.

And, I am of the opinion that this is going on right now...
TheGhostofOtto1923
3 / 5 (2) Apr 06, 2016
What about those whistling languages? They can convey complex ideas, and you avoid a lot of the problems you talk about and I think they would mix well with machines
What countries with whistling languages were fighting in the world wars?

Mayberry as I recall was not directly involved.

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