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Notes & Queries 4/8/10

Project Ozma’s Anniversary

It was just fifty years ago today, April 8, 1960, when Frank Drake launched Project Ozma by turning the Green Bank, WV dish toward Tau Ceti. In a reminiscence of the project written for Cosmic Search magazine, Drake recalls the initial sense of anticipation, followed by examination of the chart recorder, which returned nothing but noise. When Tau Ceti set in the west, Drake and team pointed the telescope at Epsilon Eridani. Let Drake tell it:

A few minutes went by. And then it happened. Wham! Suddenly the chart recorder started banging off scale. We heard bursts of noise coming out of the loudspeaker eight times a second, and the chart recorder was banging against its pin eight times a second. We had never seen anything like this before in all the previous observing at Green Bank. We all looked at each other wide-eyed. Could it be this easy? Some people had even predicted that the most rational extraterrestrial signal would be a slow series of pulses, as that would be evidence of intelligent origin. (No one had any idea about the existence of pulsars then.)

An exciting moment, and one that led to further debate:

Suddenly I realized that there had been a flaw in our planning. We had thought the detection of a signal so unlikely that we had never planned what to do if a clear signal was actually received. Almost simultaneously everyone in the room asked “What do we do now?” Change the frequency? Well, the most likely source of a spurious signal was the earth, and we could check that out by moving the telescope off the star and seeing if the signal went away. So we proceeded to do that, and as we moved off the star, sure enough the signal went away. So we pointed back at the star. The signal did not come back. Wow. Was it really from the star, or had it been from earth and had it turned off about the time we moved off the star? There was no way to know. And there was all that adrenaline flowing and no way to apply all that excitement and energy in a useful way.

Image: The Howard Tatel Radio Telescope at the National Radio Astronomy Observatory, Green Bank WV. SETI pioneer Dr. Frank Drake used this 85 foot diameter antenna for Project Ozma, the first modern microwave search for intelligent extra-terrestrial signals, in 1960. Credit: SETI League.

It was about ten days later, with newspaper reporters already asking about the unusual signal, that the Project Ozma team was able to determine that the noise was man-made radio interference. Drake persevered, and from April to July the 26-meter NRAO radio telescope studied the 21-centimeter emission line (1420 MHz) of cold hydrogen, looking for the kind of patterned pulses that would reveal intelligence. No unusual signals turned up, but Drake had set the era of modern SETI detection attempts in motion. A second Ozma project was managed by Benjamin Zuckerman and Patrick Palmer starting in 1973, also at Green Bank, surveying about 650 stars during a four-year period with the same result as the original.

Interlacing Art and Science

Those of you in the New York area will want to take advantage of a panel on art and astronomy that will be held tonight at Central Booking in Brooklyn (111 Front St., Gallery 210). Interstellar flight specialist Greg Matloff and the artist C Bangs will be on the panel, along with Denton Ebel (American Museum of Natural History) and Ari Maller (New York City College of Technology). I’m just finishing Matloff and Bangs’ new title Paradise Regained: The Regreening of Earth (Copernicus, 2009), written with NASA’s Les Johnson. I’ll have more on the book in a subsequent post, but for now I’ll simply mention how C Bangs’ elegant artwork complements the book’s central argument, that space resources can help us revive our tired planet.

Image: Message Plaque Rainbow Hologram, by C Bangs.

How do art and science interact? From Central Bookings’ news release:

Human history has been greatly influenced by our collective image of the cosmos. Today, art and astronomy continue to interact, witness the uproar of the American public when NASA planned to prematurely de-orbit the Hubble Space Telescope. Many artists have utilized Hubble images and those taken by other modern telescopes. Conversely, art also influences astronomy. After the success of the recent movie Avatar, an on-going search for Terrestrial planets circling our near stellar neighbors Alpha Centauri A and B has been dubbed “the search for Pandora.” The universe has been considered to be many things: a divine construction, a machine and a mathematical exercise. But in his 1937 vintage science-fiction classic Star Maker, British author/philosopher Olaf Stapledon speculates that our cosmos (and all others) might be the work of a divine artist.

Bangs’ work has graced books like Matloff’s The Starflight Handbook and has appeared in permanent collections including the Library of Congress, NASA Marshall Space Flight Center and the Chrysler Museum. Matloff continues to explore our prospects for travel both within and without the Solar System in books and scientific papers. The panel will convene at 6:30 this evening and should be well worth the modest $5 entrance fee.

Universe in a Black Hole

Theoretical physicist Nikodem Poplawski describes the gravitational field of a black hole in a new paper in Physics Letters B, modeling the radial geodesic motion of a massive particle into such an object. Both Schwarzschild and Einstein-Rosen black holes are considered legitimate mathematical solutions of General Relativity, but in both cases, we can see only the outside of a black hole, leading Poplawski to question whether our universe might be itself inside a wormhole associated with a black hole within a much larger universe.

This is mind-bending stuff, and I can only quote the author:

“This condition would be satisfied if our universe were the interior of a black hole existing in a bigger universe. Because Einstein’s general theory of relativity does not choose a time orientation, if a black hole can form from the gravitational collapse of matter through an event horizon in the future then the reverse process is also possible. Such a process would describe an exploding white hole: matter emerging from an event horizon in the past, like the expanding universe.”

Are astrophysical black holes concealing universes that formed when the black holes themselves did? The concept is that a white hole is connected to a black hole by a wormhole — an Einstein-Rosen bridge — and the new paper suggests that all black holes in our cosmos may contain such wormholes. One intriguing possibility is that such a theory might help us resolve problems with black hole information loss, the notion that all information about matter is lost as it passes over the event horizon. And it might just help us explain cosmic inflation.

The paper is Poplawski, “Radial motion into an Einstein-Rosen bridge,” Physics Letters B, Vol. 687, Issues 2-3 (12 April 2010), pp. 110-113.

Geoff Marcy on Habitable Worlds

With 205 planets already discovered, Geoff Marcy and the California Planet Search team have plenty of accomplishments to look back on, and as Marcy told a recent interviewer, Kepler is working beautifully, offering unprecedented measurements of the stars it’s monitoring. The short interview adds to the excitement of future Kepler discoveries, but Marcy is cautious about getting too far out in front of actual science. Will we find an Earth-like planet soon? Marcy:

It’s presumptuous to predict that Kepler will find Earth-like planets. We may find that Earths are a dime a dozen or we might find that they are a rare treasure. We might even find zero Earth-like planets, which would be a spectacular result and suggest that our planet is an extraordinary contradiction to the norm.

If we do find Earth-like planets, it will take more than a year to identify them. Kepler needs to observe a planet passing in front of its star three times in order to confirm its existence. For a planet with the same orbit as the Earth, that’s over three years to wait.

Image: Planet hunter Geoff Marcy. Credit: University of California at Berkeley.

It’s good to see this dash of realism, along with the reminder to keep our personal biases out of the search:

I think it’s important to remain unbiased. As scientists, we need to make sure to keep an open mind so that we can faithfully report our findings and avoid over-interpreting our data. We can make mistakes if we want a certain answer badly. Quality data are most important, so I try to stay calm, vigilant, and self-critical.

A brief look at interplanetary exploration offers plenty of evidence for the value of scientific detachment. How many times have we been confounded by what our space probes have found, from the volcanoes of Io to the bizarre geysers of Enceladus? The good news about Kepler is that the recently reported CCD problem is minor (Marcy calls it an ‘inconvenience,’ nothing more), and that we’re within a few short years of finding answers that will flesh out our understanding of the cosmos and the incidence of terrestrial worlds.


Comments on this entry are closed.

  • Mark Phelps April 8, 2010, 11:27

    Hi Paul,

    This may be of interest,http://culturingscience.wordpress.com/2010/04/07/the-discovery-of-animals-living-without-oxygen-and-its-implications-for-the-evolution-of-life/
    another modification of the terms of the Drake Equation….has there been a serious study of the equation and the manifest variables that you are aware of?..might be time for one….



  • philw1776 April 8, 2010, 12:03

    Kudos to Drake. It took stones to make the experiment when he did. That said, shortly thereafter was the era of SETI overpromise. Once we had META, we’d have a survey that had a good shot at finding signals. Then, once we had BETA we’d REALLY have a good shot, and so on. Reminds me of Minsky, et.al. and the decades of overhype on AI.

    Now after a half century of SETI with more powerfull tools than conceived in the 60s and 70s, once again scientists are confounded by nature’s perverse indifference. Other than the unexpected discovery of lots of interstellar organic chemistry and the expected discovery of exoplanet systems, we’re not much further ahead when FERMI posted his question. Very humbling.

  • Zen Blade April 8, 2010, 12:11

    some great stuff in this post… The universe within a universe… or universe to another universe… omg, that would make a lot of sense (from my lay person’s perspective)

  • Athena Andreadis April 8, 2010, 13:07

    There seems to be a slippage between “earth-like” (aka small and rocky, vs big and gassy) and “habitable” planets. The last term is formally meaningless, although its default implied meaning is “habitable by humans” or, at least, lifeforms very similar to us. Planetary system models as well as the secondary moon systems of the gas giants indicate that we will almost certainly find small, rocky planets (our solar system has four of those, not counting Jupiter and Saturn’s large moons or the asteroid and Kuiper belt objects). Whether they also prove habitable in the narrower anthropomorphic sense is another story.

    As for the holographic rendition of the human couple… I wonder if aliens will surmise that we have bluish spheres as part of our anatomy (and the gender-specific placement of the globes is unintentionally funny).

  • Administrator April 8, 2010, 13:53

    Mark Phelps writes:

    has there been a serious study of the equation and the manifest variables that you are aware of?..might be time for one….

    Yes indeed. In fact, numerous tweaks of the basic Drake equation have been made over the years. Claudio Maccone has recently been quite active in studying how we could improve the equation, but he is not alone. Here’s an earlier piece I did on this:


    but there are others in the archives.

  • kurt9 April 8, 2010, 14:05

    Speaking of the recently discovered anoxic animals, what power level of metabolism do they have? Is it comparable to, say, reptiles? Can a non-oxygen metabolism be bio-engineered that has the same power density and output as human or mammalian metabolism?

  • kurt9 April 8, 2010, 14:11

    I suggest the following classifications:

    1) “Rocky” planet – a rocky or terrestrial planet in any orbit around a star.
    2) “Earth-like” planet – a rocky planet roughly Earth-sized in the habitable orbit around the star.
    3) “Habitable” planet or “garden” planet – an Earth-like planet that is actually habitable to humans and other terrestrial life. This means the right temperature, right atmospheric pressure and composition, right rotational period, and other myriad characteristics that would make it a nice place to live if we could get to it.

  • Adam April 8, 2010, 15:58

    Hi kurt9

    Look up anoxic energy cycles in humans – most animals in fact – and you’ll see there’s already an anoxic metabolism. Runs alongside the oxic one. We use it when the oxic runs out, which it does during a sprint for example.

  • Duncan Ivry April 8, 2010, 17:40

    I’m glad, Geoff Marcy takes such a “calm, vigilant, and self-critical” approach to his planet hunt (I know how easy it is being overly enthusiastic).

    Regarding Poplawski’s hypothesis of our universe in a wormhole associated with a black hole in a universe …
    Is it so easy being accepted as a scientist by, well, taking certain theoretical solutions to the equations of Einstein’s general theory of relativity — a.k.a. wormholes –, for which until today there is not the smallest observational evidence, and playing around like crazy? I’m not against speculation in the area of physics — on the contrary –, but these young physicists should find enough research topics which are a *little* bit more useful. If I only consider what has been mentioned here on Centauri Dreams …

    But perhaps it is only Poplawski’s version for the media.

  • James M. Essig April 8, 2010, 18:42

    Hi Folks;

    If indeed our universe exists within a worm hole exhausting to produce a white hole, then perhaps super massive and rapidly rotating blackholes could be used as door ways to other universes.

    If the space time distortion near the center of rapidly rotating supermassive black holes typically found on galaxies is too great to permit an entering craft to survive, perhaps even larger black holes could be gradually constructed such as ones with a trillion solar masses or perhaps even a quadrillion solar masses that would permit safe transport.

    By the way, I am convinced that black holes exist and the occasional papers published to the effect that they do not exist are just plain rubbish conceptually in my own opinion.

  • Eniac April 8, 2010, 20:05

    Earth-like, to me, means kurt9’s number 2: rocky and small, but much more like Earth than Mars or Venus, in terms of size and insolation (or should that be instellation?). As for number 3, habitable as in “get out of the ship, open your visors, and take a good sniff”: Remember that free molecular oxygen implies life, so any such planet would already be inhabited, by microbes, at least.

  • NS April 8, 2010, 21:23

    I was too young in 1960 to be aware of Project Ozma but I do recall reading about it a few years later. At a time when the only ideas of extraterrestrial intelligence I’d heard of were connected with UFOs, it was exciting to find out that an actual scientist had conducted a much more plausible investigation. It triggered what has become my lifelong interest in SETI.

  • Adam April 8, 2010, 21:29

    Hi James

    Tidal forces are pretty minor going through the centre of a rotating black-hole’s ring-singularity for BHs above about ~1 million solar masses. An E-R bridge would be even milder since the maximum space-time tides are at the event horizon AFAIK. Since tidal forces decline with the inverse cube of the Schwarzschild radius, that’s good news for Galactic Core black-hole traversal – if E-R bridges form instead of the standard Kerr-Newman metric’s ring-singularity. All such end-points of gravitational collapse are fiendishly hard to compute, so I’ll reserve judgement as yet, but the white-hole cosmos on the other side of the event horizon sounds interesting.

  • Adam April 9, 2010, 6:16

    FYI the radial tidal force at the event horizon – the interface between Universes if an E-R bridge forms – is (c/Rs)^2, where c is lightspeed and Rs is the Schwarzschild radius of the Black Hole. Rs is roughly 3 km per solar mass. Thus a 100,000 solar mass black-hole, a small Galactic core BH, would produce a radial acceleration of just 1 m/s^2 per metre of the infalling object. So the Milky Way’s monster, at 4.2 million solar masses, would only exert trifling tidal forces on an infalling object, and M87’s 12 billion solar mass BH would barely be noticed by an infalling planet, let alone a human body, for example.

    At the other extreme if one could be reinforced against 1,000 gees of tidal forces, then a ~3,000 solar mass BH would be survivable for a human. A 1 mm long person made of diamond, for example, could easily endure the 1,000,000,000 gee tidal forces of a solar-mass black-hole, though the smallest collapsars are expected to be ~3 solar masses and up.

  • Eniac April 9, 2010, 23:50

    “A 1 mm long person made of diamond”
    Now, that would be an interesting person to be :-)

  • Eniac April 10, 2010, 11:43

    I don’t get this: What goes in a black hole can never come out again, almost by definition. Would that not mean that any ERB with a BH at one end would have to 1) be traversable one way only, and 2) Have something different from a BH at the other end. A “white hole”? What is that, anyway? I have never seen it characterized in any way. Would it have things coming out instead of going in?


  • Duncan Ivry April 10, 2010, 17:44

    I have read Poplawski’s paper “Radial Motion into an Einstein-Rosen Bridge”, and, as far as I can see, the hypothesis of our universe in a wormhole associated with a black hole in a bigger universe looks like this:

    Remark: Please insert “as far I can see” nearly everywhere.

    Poplawski takes two theoretical solutions of the equations of Einstein’s general theory of relativity, a Schwarzschild black hole, and an Einstein-
    Rosen bridge (a.k.a. wormhole), and associates them with each other (don’t ask me how). And, of course, these objects exist in an universe, as everything does. Having gone through (difficult to understand) mathematical calculations, he concludes, that the two solutions are indistinguishable for distant observers. This is the usual phenomenon that things, including photons, can enter a black hole, but cannot leave it. Here “distant” is equivalent to “outside the event horizon”.

    Poplawski admits that his theory has the problem, that an observer staying outside is not able to make observations in order to check the real motions of particles falling into the black hole. The theory is not falsifiable, as some would say.

    Except … when an observer enters the black hole, or is already inside. And here comes the important turn: We — as observers — would be already inside the black hole under *what* condition? For example: *if* our universe — our whole universe including us as observers — were already inside a block hole. Yeah!

    One minor point: Poplawski started with a universe containing a wormhole associated with a black hole; in the example condition this black hole would contain *our* universe; without magic, Poplawski has our universe in a wormhole associated with a black hole in a bigger universe. Hypothetically!

    Does Poplawski’s paper state, that our universe may be situated in … I won’t repeat it? No, it does not. It states, that the pertinent assumption would be sufficient for his theory. But the abstract does, and the responsible person for the abstract is a certain editor S. Dodelson, and there is a (C) 2010 Elsevier. Shame on them!

    At the end of his paper Poplawski speculates about time reversion in Einstein’s general theory of relativity leading to an exploding white hole leading to an universe born from the matter coming out of the white hole’s event horizon … having my tongue hanging out. Speculations!

    Bottom line: There is a lot of media hype around Poplawski’s paper, the paper does not justify the hype, and Poplawski now had his Andy Warholian (more than) fifteen minutes of fame.

  • kurt9 April 11, 2010, 0:56

    The recently discovered anoxic animal life is powered by hydrogenosomes, which are similar to mitochondria. Think of hydrogenosomes as the anoxic version of mitochondria. In terms of evolution, mitochondria came first, which means that this discovery of animal life based on hydrogenosomes tells us nothing about the origin of the eukarote. This, in turn, means that it has little significance with regards to the commonality of life, especially complex life, in the galaxy. The commonality of complex life in the universe is entirely based on the occurrence of the hydrogen hypothesis of endosymbiosis.


    Here are the take-home quotes:

    “The hydrogen hypothesis is a very clever model that is intended to explain the origins of eukaryotes,” says Sogin. “In my opinion, this area of research is on the one hand very exciting but on the other hand lacks meaningful molecular sequence data capable of proving anything about the validity of the hypothesis. I think the transformation from aerobic mitochondria to metabolisms based upon anaerobic hydrogenosomes has little or nothing to do with the origins of eukaryotes.”

    “What is clear to me is that hydrogenosomes have arisen multiple times in the evolutionary history of protists, and in fact might even be an inevitable consequence of a eukaryote moving into an anaerobic niche,” says Sogin.

    You still have to have the mitochondria in the first place and, if the hydrogen hypothesis of endosymbiosis is correct (I think it is), then complex life is likely to be exceedingly rare in the galaxy (and universe).

  • Duncan Ivry April 11, 2010, 14:36

    kurt9: “… You still have to have the mitochondria in the first place and, if the hydrogen hypothesis of endosymbiosis is correct (I think it is), then complex life is likely to be exceedingly rare in the galaxy (and universe).”

    Interesting! Just thinking …

    May be, it’s time to consider what should be done if the above is true. Alien civilizations would be so rare in the universe, that we will most probably never communicate with them, or they may not exist at all.

    Deep space exploration and interstellar possibilities will nevertheless make sense, but perhaps should be approached a little bit differently.

    Just thinking further: in the long run seeding empty planets and stimulating simple life on other planets.

  • kurt9 April 11, 2010, 15:15

    Duncan Ivry,

    I read “Power, Sex, and Suicide” by Nick Lane about a year and a half ago. It is about mitochondria. He talks about endosymbiosis and the hydrogen hypothesis. He also talks about the role of mitochondria as a driver in the evolution of larger and more complex organisms, once the initial eukaryote had formed. This book made quite an impression on me. I highly recommend it.

  • Duncan Ivry April 11, 2010, 19:14

    kurt9: Power, Sex, and Suicide, by Nick Lane

    Thank you, I will put this book on my list.

  • Ron S April 11, 2010, 21:55


    There’s black holes, and then there’s black holes. The distinguishing feature of a BH is an event horizon. However, for a putative wormhole, things get a bit weird. First off it must be said that the type of BH you need to construct a wormhole is likely impossible since there are negative energy conditions and you would need the mass to be in the shape of a rapidly-spinning cylinder. There may be other topologies that also work, but this way beyond my ability.

    If you have a whole lot of magic and you manage to construct one of these monstrosities, using it is a bit tricky. As you note, it is a BH after all. From the outside all you see (visually) is a BH (event horizon). You can’t approach it any which way; you need ideally need to line up along the center of its spin axis. The warp is very strong, so when you get to the event horizon you are definitely going in. Except, in this case there is (speculatively) a bundle of world lines that pass through the throat. I believe that inside the throat you are effectively weightless and can continue without doing much (except to steer, since all bets are off if you get too far off-center).

    At the far end, your inertial motion should fling you out of the wormhole, with a limiting velocity that may be identical to the one on your initial approach. To an observer near the exit point it will seem as if you emerge from the event horizon, but this is not actually the case since there is a similar throat entrance at that end. If someone were to shine a flashlight at one end into the throat, the light may be visible to a observer at the other end, if also on-axis. This, again, is highly speculative.

    More peculiarities:
    * There is (more) speculation as to where the wormhole will exit (corresponding spacetime coordinates) once the wormholes is born, and whether there is a consistent notion of proper time during the wormhole’s life.
    * When you enter a wormhole, someone measuring its mass will see it increment by your mass. There is no notion of the mass returning to its former value from that spacetime perspective since there is, after all, an event horizon. The reverse happens, at the observing end, when a mass emerges. This plays all kinds of games with the notion of mass-energy conservation.
    * The wormhole’s diameter needs to be wide enough that the tidal forces don’t crush you during entry (transition to the interior).

    Beyond this, all I can say is go consult an expert, provided you keep in mind that there are no experts on wormholes, just mathematical extrapolations that are quite likely non-physical. Hopefully I haven’t made too many mistakes in the above coarse description.

  • Eniac April 12, 2010, 23:43

    You still have to have the mitochondria in the first place and, if the hydrogen hypothesis of endosymbiosis is correct (I think it is), then complex life is likely to be exceedingly rare in the galaxy (and universe).

    I don’t follow this logic. Why would endosymbiosis be rare? It happens all the time in biology. Corals have endosymbionts. Lichens have endosymbionts. As I understand it, the hydrogen hypothesis provides a very good reason for the endosymbiosis leading to eukaryotes, and thus should make it more, not less, plausible. Am I missing something?

  • ljk April 13, 2010, 22:08

    philw1776 said:

    “Kudos to Drake. It took stones to make the experiment when he did. That said, shortly thereafter was the era of SETI overpromise. Once we had META, we’d have a survey that had a good shot at finding signals. Then, once we had BETA we’d REALLY have a good shot, and so on. Reminds me of Minsky, et.al. and the decades of overhype on AI.”

    Phil, you are mistaking overpromise for what was then a virtual
    revolution against the status quo.

    Thanks to a potent combination of Western religions who more or less
    rejected the idea of anyone else existing in the Universe beyond Earth
    (yes I know there were exceptions to the rule, but the overall feeling
    was either we were it or if there were others, we were still the Special
    Ones), the monomaniacal and well-funded efforts of one Percival Lowell
    who insisted there was a race of ancient and highly advanced beings
    on Mars building massive canals to quench their parched and dying
    cities, and most influence of all, the sighting of strange objects in our
    skies which became the UFO phenomenon or craze (I consider that to
    be the People’s way of saying they believed there were beings on other
    worlds even if the so-called authorities said otherwise), mainstream
    science tended to frown upon the idea of aliens in any form back when
    Drake was doing his thing.

    To think of and act upon a scientifically plausible way to look for other
    intelligences in the Milky Way galaxy and right after that come up with
    a mathematical formula to figure out how many celestial neighbors we
    might have – even though most of the factors were guesswork – that was
    indeed a stone-taking act.

    Guys like Drake and Sagan felt that in such an ancient Universe there HAD
    to be lots of older and wiser voices out there talking to each other. Some
    of them might even want us in their Galactic Club. And we had the means
    to do so: Radio. And most of the astronomers poo-poohed using their
    big expensive toys for such things (Sir Bernard Lovell told Cocconi and
    Morrison they couldn’t play with his 250-foot radio telescope in England
    to look for aliens).

    So put that all together and you don’t have overhype (at least not until a
    few decades later), you have a brave pioneering group saying with all those
    billions of stars and billions of galaxies it is crazy to think we are the only
    ones in the Cosmos so let’s tune in with our newfound abilities and see
    who or what is out there!

    So if you want to jump on the hubris and and egocentric behavior of
    humanity, go after their endless view that they are the Center of
    Everything despite the fact that we have known for a while now just
    how vast the Cosmos is and how tiny we are.

    SETI has only been happening for half a century now in a galaxy 10
    billion years old. A lot of SETI programs were sporadic and short
    and probably aimed at the wrong places, so how can you or anyone
    else expect us to have success so soon? Now THAT is hubris.

    So be patient and stop whining about a bunch of past SETI efforts that
    were probably nice tries but not enough.

    And thank Drake and Sagan and all those pioneers who bravely brought
    us out of the Dark Ages of extraterrestrial life studies.

  • ljk September 2, 2010, 7:58

    SETI at 50

    Fifty years after the Search for Extraterrestrial Intelligence (SETI) started, efforts have yielded no evidence of other civilizations, but the search continues.

    Jeff Foust reports on the past and future of SETI as discussed at a recent event.


  • ljk September 21, 2010, 20:47

    SETI 2060, Do We Make Contact By Then?

    Analysis by Ray Villard

    Mon Sep 20, 2010 08:22 AM ET