SETI Redux: Joining the Galactic Club

May 24, 2010 by David Schwartzman
Alien telescopes could use the gravity of stars - using a technique called gravitational microlensing -- to help them view the Earth. Image credit: NASA

In this essay, David Schwartzman, a biogeochemist at Howard University in Washington D.C., explains why he thinks the aliens are out there, despite the fact that the search for extraterrestrial intelligence (SETI) has only found silence. He also outlines what we need to do for planet Earth to be initiated into the Galactic Club.

The Great Silence, the failure to detect signals of extraterrestrial intelligence (ETI) by the observational SETI program for the last 50 years, has continued to generate a lot of noise. I am not referring to the galactic noise which may hide a weak ETI signal, but rather all the old arguments revived again and again, ad infinitum. More books, more articles, more silence, more speculation. The latest is Stephen Hawking’s warning to Earthlings: keep silent or alien imperialists will devour us when they find out we exist. Has Hawking been watching too many Star Wars DVDs? Rather, I suspect the world’s greatest living theoretical physicist is having a laugh at our gullibility.

At first sight, Paul Davies in his new book The Eerie Silence proposes some fresh ideas. He suggests the approach of observational SETI - which tries to detect narrow-band signals directed at by an extraterrestrial civilization -- is probably futile, because the existence of a communicating civilization on Earth will not be known to any alien community beyond 100 light years. Instead, he argues “we should search for any indicators of extraterrestrial intelligence, using the full panoply of scientific instrumentation, including physical traces of very ancient extraterrestrial projects in or near the solar system. Radio SETI needs to be re-oriented to the search for non-directed beacons, by staring toward the galactic center continuously over months or even years, and seeking distinctive transient events ('pings'). This 'new SETI' should complement, not replace, traditional radio and optical SETI.”

But on second thought, maybe these ideas are not all that fresh. I’ve read these suggestions before in the SETI literature. Indeed, I found most of them cited in his footnotes. Nevertheless we should thank Davies for assembling them in his stimulating and lucid new book.

What are the possible reasons for the “Great Silence”? The following list is of course not original:

1) We are indeed alone, or nearly so. There is no ETI, nor a “Galactic Club” -- radio astronomer Ronald Bracewell’s name for the communicating network of advanced civilizations in our galaxy (GC for short).

2) The GC, or at least ETI exists, but is ignorant of our existence (as Davies has once again suggested).

3) We are unfit for membership in the GC, so the silence is deliberate, with a very strict protocol evident, “No Messages to Primitive Civilizations!” Only inadvertent, sporadic and non-repeated signals - for example, the "Wow" signal can be detected by a primitive civilization, with opaque signal content not distinguishable from natural signals or noise.

The first explanation is contrary to the subtext of astrobiology, the belief in quasi-deterministic astrophysical, planetary and biologic evolution. This view of life’s inevitability in the cosmos is a view (or, shall I admit, a prejudice) I heartedly endorse. Most scientists active in the astrobiological research program would support an optimistic estimate of all the probabilities leading up to multicellular life on an Earth-like planet around a Sun-like star.

I happen to be an optimist on this issue too. I have argued that encephalization - larger brain mass in comparison to body mass -- and the potential for technical civilizations are not very rare results of self-organizing biospheres on Earth-like planets around Sun-like stars. Biotically-mediated climatic cooling creates the opportunity for big-brained multicellular organisms, such as the warm-blooded animals we observe on our planet. Note that several such animals have now been shown to pass the “mirror test” for self-consciousness: the great apes, elephants, dolphins and magpies, and the list is growing.

But some, like my occasional collaborator Charley Lineweaver, an astrophysicist at Australian National University, are deep pessimists regarding the chances for other technical civilizations to emerge in the galaxy. He has argued, "humans and dolphins have 3.5 billion years of shared common ancestry. For 98 percent of our history, humans and dolphins were the same. The genes needed to develop those big brains had been fine-tuned over billions of years of evolution and were already in place." Lineweaver says that if advanced civilizations do emerge elsewhere in the galaxy, we can’t expect they’ll have human-like intelligence. This deserves an essay in itself.

But if the pessimists concede just one of the millions if not billions of Earth-like planets is the platform for just one technical civilization that matures to a planetary stage, advancing beyond our present primitive self-destructive stage, just one advanced civilization with the curiosity to spread through the galaxy, at sub-light speeds with Bracewell probes to explore and document an Encyclopedia Galactica, then what should we expect?

First, the galaxy should be thoroughly populated with surveillance outposts on a time scale much smaller than the time it took on Earth to produce this cosmically pathetic civilization we call the nearly 200 member nation states of the United Nations, with humanity now hanging under two self-constructed Swords of Damocles: the twin threats of catastrophic global warming and nuclear war.

Second, THEY, or at least their outposts, surely know we exist, since to believe THEY are ignorant of our existence is to assume they somehow bypassed us in their expansion into the galaxy, a scenario I simply find unworthy if not unbelievable for an advanced civilization, especially one in existence for millions if not billions of years. It is important to note that this conclusion is informed by present day physics and chemistry, not a post-Einstein theory that transcends the speed of light.

So we are left with option 3: the aliens are deliberately avoiding communicating with our primitive world. I submit this is by far the most plausible given our current knowledge of science and the likely sheer ordinariness of our chemistry and planetary organization.

Why would we be considered primitive? This should be a no-brainer, even for an Earthling. The world spends $1.4 trillion in military expenditures while millions of our species still die of preventable causes every year. Carbon emissions to the atmosphere continue to climb, even though presently available renewable technologies such as wind turbines exist and are sufficient to completely replace our unsustainable energy infrastructure. As J.D. Bernal once put it, “There is a possibility that the oldest and most advanced civilizations on distant stars have in fact reached the level of permanent intercommunication and have formed…a club of communicating intellects of which we have only just qualified for membership and are probably now having our credentials examined. In view of the present chaotic political and economic situation of the world, it is not by any means certain that we would be accepted.” (The Origin of Life, 1967)

Lee J. Rickard and I have put forward a scenario for eventual entrance of Earth into the Galactic Club in our paper published in 1988 (Lee J Rickard is a radio astronomer and I am a biogeochemist). We proposed that at some future time, our terrestrial civilization might achieve sufficient maturity to proceed with a program to detect so-called leakage radiation - the electromagnetic TV, radio and other broadcast signals that are inadvertently sent out into space (military radars are the strongest, a possible universal signature of a late stage primitive civilization).

This proposed program has a critical distinction from virtually all of observational SETI: detecting a targeted beacon from ET requires that they intended to send one. The absence of evidence it not necessarily evidence of absence, if intention is lacking. On the other hand, for a relatively short time, primitive civilizations like us leak radio waves to space, unintended signals that we could potentially detect.

The technical requirements for a galaxy-wide search are dictated by the size of the radio telescope, with the detection range proportional to the effective diameter of the telescope. A large enough radio telescope situated in space could potentially set meaningful upper limits on the rate of emergence of primitive Earth-like civilizations (‘N/L’ in the Drake equation), without ever actually detecting the leakage radiation of even one ET civilization.

But just how big a telescope is required for this project, and at what cost? Our 1988 paper provided such estimates: a dish diameter on the order of 500 kilometers, at a cost of roughly $10 trillion. Perhaps the cost has come down somewhat (but note the estimate was in 1988 dollars). This is surely a project with a vanishingly small chance of implementation in today’s world. I could only conceive of a demilitarized newly mature planetary civilization, call it Earth-United (Finally!), with any intention of implementing such an ambitious project that has no apparent immediate practical benefits. Then and only then would we successively detect a message from the GC, presumably faint enough to be only detectable with a huge radio telescope in space.

On the other hand, the GC may be monitoring biotically-inhabited by remote Bracewell probes that have programmed instructions. Such a probe would plausibly be now hiding in the asteroid belt (as Michael Papagiannis once suggested). If the GC exists, there was ample time to set up this surveillance system long ago. Surveillance probes so situated in planetary systems would send welcoming signals to newly mature civilizations, with the potential for a real conversation with artificial intelligence constructed by the GC, if not reconstructed biological entities.

If this proposed surveillance system is absent, we should expect the GC to use highly advanced telescopes to monitor planetary systems that have prospects for the emergence of intelligent life and technical civilizations. These alien telescopes could use gravitational lenses around stars. Planetary system candidates to the GC could expect to receive continuous beacons, but the signals would be very weak or disguised so that they would only be decipherable by newly mature civilizations that just pass the entrance requirements. The problem with this scenario is there would be a fairly long communication delay with the GC, because they would be so far away. Nevertheless, reception of a rich message from the GC is possible. The material and/or energy resources needed for these signals to be recognized must correspond with great probability to a newly ripe mature civilization. Hence, cleverness in itself cannot be the criteria for successful detection and decipherment, otherwise a brilliant scientist on a primitive civilization might jump the GC protocol.

I submit that if we want to enter the Galactic Club, the challenge lies in reconstructing our global political economy. A few minor side benefits should result, like no more war, no more poverty, a future for all of humanity’s children with a substantial proportion of biodiversity intact. We should not expect the Galactic Club to save us from ourselves.

Explore further: SpaceX launches supplies to space station (Update)

More information: Reference: Schwartzman, D. and L.J. Rickard, Being Optimistic about SETI, American Scientist, 76, No.4, 364-369.

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User comments : 22

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lhsmithnet
5 / 5 (5) May 24, 2010
I like the article. Can someone seriously explain why the threat of a nightmare ET encounter is a joke? What if ETs are silent because the universe is a dangerous place? What if they could care less about us and are only concerned about avoiding each other? That seems to me like a fourth explanation for the Great Silence, unless it's just hilarous to everyone and I'm not getting it.
LKD
1 / 5 (3) May 25, 2010
"Carbon emissions to the atmosphere continue to climb, even though presently available renewable technologies such as wind turbines exist and are sufficient to completely replace our unsustainable energy infrastructure."

Please don't pontificate on something you have no comprehension of. Not only is this wholly off topic, but wind and solar can NOT replace our power sources. Unless of course you wish us to return to tribal life. In that case, yes, you are correct. Of course when that happens, people will be dying from easily avoidable deaths caused because of lack of heating and cooling, lack of clean water, lack of sewage treatment, pretty much everything that allows us to live past 20 years old.
deterred
5 / 5 (2) May 25, 2010
Be careful when you make statements about people pontificating on something they have no comprehension of. It shows how much you really may or may not know about the topic.
The statement on renewable technologies is completely on topic, the point of the paragraph was that our primitive energy production methods, non renewable sources which cause significant environmental damage, is one of the reasons ET might see us as a primitive species.
And as far as energy needs, I assert that renewable energy sources can indeed replace our current energy needs without forcing us to return to "tribal life". There is no question that the current installed base of renewable energy production is a long ways from meeting those needs, and even the cleanest of them do have their own environmental problems, but the planet does have more than enough energy sources in the way of solar and wind, they also include hydro, geothermal, tidal, biomass, etc… to support our standard of living.
LKD
1 / 5 (1) May 25, 2010
I apreciate your respectful tone. I disagree with you about evironmental policy, but this is not the place for such. It would detract from a interesting topic. :)

If ET is showing up here, we are primitive no matter how you look at it, as we ourselves can not leave LEO at present. Our prefered energy source has nothing to do with that, and to throw in an environmental note is just rediculous preaching. I am pretty sure that if we traversed space in coal engines, they would be astonished by our engineering, not decrying our lack of technological advancement. I know I would be impressed if an oil burning starship made it out of a solar system.

This is a really stunning post I read on the topic of aliens, it makes far too much sense to me: http://www.space....#p452902

I really recomend you read it, whether you agree or not, it has some interesting points to consider.
deterred
5 / 5 (1) May 25, 2010
Yes, it is an interesting topic, and I did follow / like the link you provided…

However, I don't see that David's including energy source along with military spending and people dying from preventable causes as detracting from it. Rather I do see it as a valid possible explanation of why an ETI might think we are primitive. As valid as any guess as we don't really know what a potential alien visitor would consider primitive. Those aspects of our society may be perfectly normal and acceptable to a technologically advanced space fairing species.

But mostly I was challenging the assertion that he has no comprehension of the realities of energy, as, his claim does not contradict my (academic energy engineering studies combined with several real world energy related projects) understanding of the potential in renewable energy.

And yes, I certainly would be impressed by an effective coal fired space craft :)
lhsmithnet
not rated yet May 25, 2010
You're missing the point, humans. The question is, what do you think our planetary policy should be with regard to contacting ET? Generalizing from the Human species, and the foregoing discussion in particular, we cannot rule out the possibility of ET having an unnatural obsession with Gilligan's Island. All in favor say aye?
LKD
1 / 5 (1) May 26, 2010
"But mostly I was challenging the assertion that he has no comprehension of the realities of energy"

Potentially we can build solar arrays in space and beam energy back to earth using microwaves. This isn't about potential, but his remark that we can switch to all renewable now.

"even though presently available renewable technologies such as wind turbines exist and are sufficient to completely replace our unsustainable energy infrastructure"

No they aren't. There is no math to back this up. It's pure fiction. Solar is still in its infantcy, Wind is sporadic at best, and what pray tell do we do at night? In 50 years? I'd say it's possible with space based power generation and reasonable leaps in nano technology and superconductors, but now? No. It's not possible.

And don't suggest burning bio, that is what coal and oil are, biomass from 60 million years ago. ;)
deterred
5 / 5 (1) May 26, 2010
Not fiction:
http://en.wikiped...umption:

"89 PW[55] of solar power falls on the planet's surface. While it is not possible to capture all, or even most, of this energy, capturing less than 0.02% would be enough to meet the current energy needs."

"This isn't about potential, but his remark that we can switch to all renewable now."

I did read it as potential, he did not say we could switch right now, just that the technology for it exists today. No we can not switch over immediately, it would require a huge series of infrastructure projects.

"Wind is sporadic at best, and what pray tell do we do at night?"

That's a storage and distribution problem, not all that difficult to solve today. Smart grids and converting electricity to Hydrogen are just a couple of examples of things we can start implementing today.

I mostly agree with you on the biomass end, though from a carbon perspective it is closer to neutral as crops suck in carbon.
LKD
1 / 5 (1) May 27, 2010
Something is wrong with your link, if you could, would you repost it? I would appreciate it very much.

If we could store electricity like that, then nuclear plants wouldn't have to be used to pump water up hill of a hydro dam. We could also store lightning strikes. Battery technology is still in the greek era. If this could be overcome, then I would be MUCH more amicable to non-poluting earth power sources.

Could, yes, but we would deaden the planet. SEGS is huge, and desertifies the acres below it and produces half the power of a nuclear plant best case.

Is anyone proposing underground?

My point isn't that its not theoretically possible, but that it is physically impossible to do so. There aren't enough mine-able rare earth's to make all the turbines needed to give power to all people. Just like that we can't convert to all nuclear because there isn't enough plutonium.

My hope is:http://www.physor...4356.htm
Or Fusion. I want every human to have power.
deterred
not rated yet May 27, 2010
So there is. Looks like it included the ':' I placed at the end. Try this:
http://en.wikiped...sumption

Hmm, I get a 404 not found for your link...

There are many ways to store energy far more efficiently then traditional batteries, fuel cells, super capacitors, ... But most, tend to be _real_ expensive (though that's starting to change some.)

Overall I'm for Fusion, at least in theory. I'm also in favor or solar stations above the atmosphere beaming energy back, even if only for the reason that it promotes more activity outside the gravity well :)

"...aren't enough mine-able rare earth's..."

But wouldn't that mean their are not enough to make all the needed coal / gas / nuclear / etc... generators?

Regardless I don't think any one source, renewable or not covers the planets needs, but any non renewable will run out someday and today many of the alternatives are much more capable and cost effective than most people give them credit for.
deterred
not rated yet May 27, 2010
OK, I solved your link, had to place an 'l' at the end of htm...

Yeah, that idea rocks. But, while I still think the author's comment was appropriate, I agree our debate on is it possible or not has strayed _way_ off topic, so maybe we should move it over to that link, or perhaps to http://www.physor...765.html
LKD
1 / 5 (1) May 28, 2010
Nice link. I like that technological process. I'll have to see if I can find out more about that.

Yes, there aren't enough rare earths for any current process to supply 6 billion. But I think that if we go for the most efficient, it'll hold us over until we finally get the best source; whether space, subsurface, or fusion.

Very much so. They are improving a great deal. I want to know what happens when Nano technology finally become aplicable to real products. It should be exciting.
Skeptic_Heretic
not rated yet May 28, 2010
The statement on renewable technologies is completely on topic, the point of the paragraph was that our primitive energy production methods, non renewable sources which cause significant environmental damage, is one of the reasons ET might see us as a primitive species.


Why would an ET care about how we change our habitat? How do you affix value to the habitat of Titan or Mars? Just as we don't live on Mars, they don't live here.

If anything they might prefer what we're doing as the world would be more habitable for their form of life in increased temperature humidity and carbon content.

You cannot presume to judge the motives and operational ethics of other humans most of the time, what makes you think aliens are going to be anything like us at all?
Chef
5 / 5 (2) May 29, 2010
IMO Having "Radio Silence" should almost be a given. If there is a civilization at the technical level of Humans, then I would think they would also be using the VHF & UHF bands like we do, but for SETI and others we don't listen to these because of our own noise broadcasting from Earth. Also, we have to take in account of how long Radio wave comm will be used. We are already looking at Entanglement for comm use, and if this becomes reality in say 50 years, there would only be relatively short window to hear us, or us of them.

Skeptic_Heretic
not rated yet May 29, 2010
there would only be relatively short window to hear us, or us of them.
And this is probably the best explanation for the "Great Silence".
Tangent2
1 / 5 (2) May 29, 2010
... Also, we have to take in account of how long Radio wave comm will be used. We are already looking at Entanglement for comm use, and if this becomes reality in say 50 years, there would only be relatively short window to hear us, or us of them.


I think you hit the nail right on the head with that one Chef, well put indeed! I would say our best chances of contact at this point is when the governments finally give full disclosure as I am almost certain that they still have contacts with select races.
Quantum_Conundrum
3 / 5 (2) May 30, 2010
Please don't pontificate on something you have no comprehension of. Not only is this wholly off topic, but wind and solar can NOT replace our power sources. Unless of course you wish us to return to tribal life. In that case, yes, you are correct. Of course when that happens, people will be dying from easily avoidable deaths caused because of lack of heating and cooling, lack of clean water, lack of sewage treatment, pretty much everything that allows us to live past 20 years old.


Human beings currently use 1/10875th as much power as the Solar Constant for Earth's cross-sectional disk.

People don't have a problem with governments establishing transportation infrastructure, such as roads, bridges, levees, and dams, but for some reason, they have a problem with government involvment in energy production.

We could easily phase in pure solar for residential through government grants, loans and tax credits.
Quantum_Conundrum
3 / 5 (2) May 30, 2010
You cannot presume to judge the motives and operational ethics of other humans most of the time, what makes you think aliens are going to be anything like us at all?


Good comment.

Assuming they exist, the "dominant intelligent" species of an alien world might be something completely and utterly un-recognizable to us. It could literally be anything from a shape-changinging collective of microbes to snails, to giant squid-like creatures, to reptilians, to even some other life form (I.E. an AI experiment gone bad...such as the Borg...)

They might breathe methane and nitric oxide, instead of O2 and CO2. Who knows.

They might be a highly sophisticated species capable of "networking" with all other life on their planet, much like the "Avatar" aliens, in which case a Tree might be the most intelligent life form on the planet...

Or, depending on atmospheric and gravitational environment, they might even be a winged predator species...
Quantum_Conundrum
1 / 5 (1) May 30, 2010
I actually find this article incredibly humorous.

The author speaks in a faith-based manner concerning his "Galactic Club" of allegedly advanced aliens, and this "blind" game of meeting the criteria of entering that club.

I submit that the criteria has been presented in plain sight for entering the true "Galactic club" run by the ultimate "Extra-terrestrial Intelligence," not that God is an alien, because he isn't, but that he isn't of this world.

Nay, but there IS a way to join the "Galactic Club" known as the Kingdom of God, and this is done through our Lord and Savior Jesus Christ.

Now the author of the article has heard all this, in whom we have eye witness accounts of Jesus, who came to earth, but he does not believe in that which was seen and handled with hands. But he believes in a "Galactic club" of benevolent aliens waiting to welcome him into it's fold.

Whereas the criteria enter the TRUE club is to "take up the Cross and follow Jesus."
antialias_physorg
1 / 5 (1) May 31, 2010
What if ETs are silent because the universe is a dangerous place?


1) ET might be using something other than electromagnetic waves to communicate.

2) If they have faster-than-light travel then sending capsules is better than sending EM messages (sending EM messages between solar systems is pointless because of the time lag, anyways)

3) If they use EM then they are likely using some form of _directed_ radiation (think: lasers). In this case every solar system could be busily communicating with every other one and we'd never know - because we are not in the line of sight.

4) E.T. could have better amplifiers than we do and so the messages they send could be below our ability to register them (if they originate from planets then they will be outshined by the local star in our dishes)

5)...

Current SETI is assuming they use EM and that they are wastefully broadcasting everything at ridiculous energies in all directions.
These are foolish assumptions.
gwrede
1 / 5 (1) May 31, 2010
Talking about GC means Schwartzman believes that Darwinian evolution only works at the intra-planetary scale.

That is, does he think that the GC is just another irc channel for advanced civilisations who have a priori decided that they'll never visit each other, because that will only lead to competition and war?

I'd say that sooner or later someone gets advanced enough to build a superior military fleet. Heck, even ants and bacteria do it, so why wouldn't aliens?

Believing that advanced cultures cultivate lofty ideals and principles, is as naive as when I as a child thought that grown-ups aren't childish, selfish, lying back stabbers.
antialias_physorg
1 / 5 (1) May 31, 2010
As for why extraterrestrials (if they know we are here) haven't made contact: Why would they? Do we make contact when we go bird watching? No. We try to hide as much as possible so as not to disturb their natural reactions.

If ET is even a bit more intelligent than us then they'll see us as we see animals: An interesting object to study.

What would be in it for them in making contact? Nothing. They'd just have to deal with a bunch of (to them) retards clinging to their ankles and setting up a cargo cult.

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