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Space Science

Should SETI Be Looking For Lasers Instead? 694

Posted by timothy
from the mutant-sharks-come-free dept.
colonist writes "Frank Drake, creator of SETI's famous equation, says the detection of extraterrestrial radio signals won't work, because Earth's own radio signal will only be around for 100 years. More and more of Earth's communications use cable and satellites, with no radio-frequency leakage to space. Instead, we should be looking for intentional signals in the form of high-powered lasers that could 'outshine the sun by a factor of 10,000'. Meanwhile, Paul Davies writes that we should be conducting SETI in our DNA. In turns out that an alien message designed to last millenia should be 'inside a large number of self-replicating, self-repairing microscopic machines programmed to multiply and adapt to changing conditions', otherwise known as living cells. Are we the message?"
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Should SETI Be Looking For Lasers Instead?

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  • Optical SETI (Score:5, Interesting)

    by Space cowboy (13680) * on Tuesday August 10, 2004 @05:12AM (#9927414) Journal

    Optical (ie: laser detection) SETI has been up and running for a while now (see Optical SETI overview [seti.org] for example). Drake ought to declare an interest though, since he's one of the investigators on the project.

    It's a reasonable argument, but it's far harder to set up optical "listening" posts than radio ones. It cost me about 1000 uk pounds (WHY is the pound symbol banned from /. ?) to set up a SETI listening post [gornall.net], including all the costs from dish/low-noise-amplifier through receiver and PC. Setting up an optical one is waaay more expensive. Optics in general are far more expensive than radio components, and large-scale ones are extortionate :-(

    The counter argument of course is that to detect laser light, the remote civilisation have to be pointing their laser at us, whereas with radio it doesn't matter since it's not a directed beam. Against that you have to offset the time-period over which transmissions of either kind could be made...

    The chances of getting a radio contact may be a few orders of magnitude lower than getting an optical contact, but since the chances of me setting up an optical SETI station are precisely 0, the chances of getting 'the' signal with radio is infinitely greater than with optics, at least for me :-)

    Simon
    • Re:Optical SETI (Score:5, Interesting)

      by selderrr (523988) on Tuesday August 10, 2004 @05:22AM (#9927458) Journal
      a very stupid question from a non-engineer : is it not possible to have non-directed optical signals ? Some sort of 'ambiet laser'. I understand that you'd have to go low voltage in order not to burn everything around you, but aren't pulsar stars some sort of ambient light beacon ? ? And how about we set up SETI to search for radioactivity residue slung into space ??
      • Re:Optical SETI (Score:5, Insightful)

        by BarryNorton (778694) on Tuesday August 10, 2004 @05:31AM (#9927487)
        A diffuse source contradicts with LASER, but yes, it's possible. But in order for it to be detected over ambient light it would have to be something huge and noticeable like a pulsar - I'd hate to see their electricity bill, these aliens of yours ;)
        • Re:Optical SETI (Score:5, Informative)

          by FireFury03 (653718) <slashdot@nexus[ ]org ['uk.' in gap]> on Tuesday August 10, 2004 @08:27AM (#9928019) Homepage
          A diffuse source contradicts with LASER

          Not necessarilly. A LASER does 3 things:

          1. Produces a narrow beam of light
          2. Produces monochromatic light
          3. Produces coherent light

          Monochromatic light is produced by gas-discharge tubes (e.g. sodium lights, etc) - nothing special here.

          You can produce a narrow beam of light using a point lightsource and mirrors/lenses.

          Now, the special bit - your normal light bulbs produce incoherent light - you get lots of photons emitted but their waves aren't synchronised, so they interfere destructively with eachother. By contrast the light you get off a LASER is coherent - all the waves are synchronised, so they interfere constructively, making the light appear brighter.

          So if you want to create a omnidirectional optical light beacon, rather than using a normal light bulb and ending up with the photons randomly interfering with eachother destructively, it makes more sense if you can synchronise the wave fronts so they expand away from your light source in neat coherent spheres.

          (I have no idea if the technology exists to do this ATM - it seems like a rather complex problem)
          • Re:Optical SETI (Score:5, Interesting)

            by Hal-9001 (43188) on Tuesday August 10, 2004 @09:01AM (#9928242) Homepage Journal
            A LASER does 3 things:

            1. Produces a narrow beam of light
            2. Produces monochromatic light
            3. Produces coherent light


            Actually, condition 3 is the only one that is necessarily true of all lasers. There are solid-state lasers with very wide bandwidths, thereby violating condition 2, and it is easy to expand or diffuse a laser beam, thereby violating condition 1.

            To be honest, there is little point in creating an omnidirectional laser source, at least for SETI purposes, because that only degrades the signal-to-noise ratio. However, if you want to do so, it's pretty trivial: shine the laser beam into a high numerical-aperture microscope objective, and the wavefronts that emerge beyond the focal point will be an excellent approximation of ideal spherical waves.
          • Re:Optical SETI (Score:4, Interesting)

            by boicy (547781) on Tuesday August 10, 2004 @09:11AM (#9928312) Homepage
            "By contrast the light you get off a LASER is coherent - all the waves are synchronised, so they interfere constructively, making the light appear brighter."

            Hmm, not actually sure if this is correct. This is going back a bit but I think:

            Laser stands for Light Amplification by the Stimulated Emission of Radiation.

            A LASER doesn't produce light because of waves contructively interfering. The light is amplified by the absorbtion and emission of photons at specific wavelengths.

            There are two types of photon emission, spontaneous and stimulated.

            Spontaneous emission occurs when an electron in an atom "jumps" from a higher quantised state to a lower one giving up energy. This energy is emitted as a photon. This is what happens in street lights, electrons fall back to a lower energy level and that corresponds exactly to the wavelength of the orange light we see. The photon can be emitted in any direction.

            Stimulated emission occurs when an atom absorbs a photon causing an electron to move to a "higher" state but in this case the electron can immediately jump back to it's lower state. This causes two photons to be emitted in exactly the same direction as the original photon was travelling.

            Essentially a LASER works by putting mirrors round a cavity and multiplying the photons by bouncing them back off the mirrors and into the emitting atoms thereby causing a "chain reaction" to take place where two become four etc.

            The reason that you get monochromatic light (normally) is that the wavelength of the photons produced is exactly related to the energy levels in the atom producing them. The reason you get coherent light is because the photons are travelling in the same direction.

            IWAPIU (I was a physicist in Uni) and built a Nitrogen LASER for my final year project. That was a good 8 years ago now though.

      • Re:Optical SETI (Score:5, Informative)

        by Zarhan (415465) on Tuesday August 10, 2004 @05:37AM (#9927510)
        very stupid question from a non-engineer : is it not possible to have non-directed optical signals ? Some sort of 'ambiet laser'

        Um, yes. Just take a look at your closest lightbulb. There's your omnidirectional light source right there. One might actually consider variable stars as messages from outer space...

        In the interests of mentioning something real that actually exists, take a look at 802.11 over IR [wi-fiplanet.com]

        Lasers are used for point-to-point links because there is usually an intended recipient. All of the energy goes to that single, intended direction. However, there shouldn't be anything to stop creating ambient monocromatic light source..
        • Re:Optical SETI (Score:5, Informative)

          by moonbender (547943) <moonbender@gmai[ ]om ['l.c' in gap]> on Tuesday August 10, 2004 @08:26AM (#9928017)
          One might actually consider variable stars as messages from outer space...
          Pulsars are rapidly rotating neutron stars with periods less than ~3.75s. When they were first discovered at the radio telescope at Jodrell Bank, England, their origin was unknown and they were thought to possible be signals from extraterrestrials. As a result, the first pulsar was named LGM-1, with LGM standing for "Little Green Men."
          (source [wolfram.com])
      • by hashwolf (520572) on Tuesday August 10, 2004 @06:28AM (#9927668)
        how about we set up SETI to search for radioactivity residue slung into space ??

        Sure, radioactive sludge thrown in space is a sure sign of intelligence.

      • Re:Optical SETI (Score:3, Informative)

        by JRIsidore (524392)
        Well, besides the lightbulb others already mentioned there actually is a kind of ambient laser - the random laser. It differs from others that you don't have a cavity but a little sphere (or a cloud) of the active medium. On their way out of it the photons get scattered, but also amplified by stimulated emission. This type of laser usually radiates in all directions. Here's some more information about them: random lasers [complexphotonics.org]. Look under publications, there are 2 papers on the 2nd page.
      • by slew (2918)
        Since radio waves and light are basically the same (electromagnetic waves), the problem is not that of possibility, but basically an energy issue...

        photon energy is proportional to frequency

        So for a given amount of energy you can get either more photons at a lower frequency or fewer photons at a higher frequency.

        Since visible light is in the THz range (10^12) and radio waves are in the say MHz range (10^6), that's a factor a million less photons emitted per unit of energy.

        Since we are essentially detect
    • Re:Optical SETI (Score:5, Informative)

      by Anonymous Coward on Tuesday August 10, 2004 @05:22AM (#9927460)
      £
    • by Amiga Lover (708890) on Tuesday August 10, 2004 @05:42AM (#9927530)
      I'm not really sure I want to be looking to make contact with aliens who are pointing FRICKEN LASERS at us.
    • Re:Optical SETI (Score:5, Informative)

      by jez9999 (618189) on Tuesday August 10, 2004 @05:56AM (#9927578) Homepage Journal
      WHY is the pound symbol banned from /. ?

      I believe the answer would be because Slashdot only supports the lower 128 bits/characters of ASCII because the upper or extended 128 bits/characters are not standardized. Or rather, there are too many standards - hundreds of them - used by different people and countries to represent various different characters. Perhaps Slashdot should support the most common of them, ISO-8859-1 (Latin-1), in which the code for the UK pound symbol is 163... but Unicode will probably be supported before that happens. In short, Slashdot sucks a bit. :-)

      As an AC showed in reply to this thread, you can display the UK pound symbol using its HTML equivalent '&pound;' - producing £.
    • Quantum SETI (Score:5, Interesting)

      by essreenim (647659) on Tuesday August 10, 2004 @06:06AM (#9927615)
      With the promise of quantum communication, it is conceivable that (if Quantum communication is indeed feasible) we should be focussing our optical light search on specific photons of light.

      Anyone know about beam splitting entangled pairs etc. Many moons ago, Einstein, Podolski, and Rosen carried out there unusual experiment whereby the they observed what is now known as quantun weirdness. A photon in an entangled state could be split using a sophisticated 50:50 beam splitter. Each split photon could travel off in opposite directions and appear to be twins, in the sense that any change in behaviour of one would instantly (exactly synchronized regardless of distance!!!) be felt by the other, its twin.
      Evidence that this was no fluke is gathering thanks to continuing experiments, yet it is still not in stone.

      My reasoning is that if this phenomenan is genuine, it could be one way extraterrestrials would chose to contact us. Why not. They send a conventional optical signal, only this time encased in a surrounding cylindar of light, thus allowing for the entangled photons charateristic properties to be influenced only by this cylinder of light. Allot can till go wrong so conceivably, the 'ET's' would send a large stream of such light cylinders- the centre of which is a stream of entangled photons. That way any measurement of the entangled photon would cause an immediate change to its twin (The twin photon - of entangled pair)would presumably be archived on the alien world bouncing back and forth in a cavity (not unlike the cavities we use today - only presumably far more advanced.) So, once change is observed, an immeditae alarm bell is triggered. The ET's can know instantly someone/something has comeinto contact with their signal. Just like Earth SETI, the ET SETI would categorise all their findings and have mant false positives. They would probably already have chartered the area of space to which they send a signal. They may know the only objects (meteorites, stars, planets, commets...) that are likely influences over the transmitted light signal. Hence, if we Earthlings intercept the light in a very manufactured manner (i.e fire a encoded light signal of our own into theres, they are likely to get some unusual data back at there end - instantly.

      Anyway, lets face you can't have an interest in SETI without being imaginative.

      All Im tring to say is.

      1) If I were a highly advanced ET, I would use Quantum entaglement (if it is indeed feasible) to transmit photons of light.

      2)I believe we should start sending entangled photons of light, encased in our own manufactured cylinders of background light, out into space.

      3)I hope SETI read this.

      • Re:Quantum SETI (Score:3, Informative)

        by Anonymous Coward
        That's an interesting idea, but what the Einstein, Podolski, and Rosen's experiment showed was "spooky action at a distance", not instant data transmission at a distance. It is true that reading the state of one of the entangled photons coming out of their device uniquely determines some qualities of the other photon (that is, WE now know something about the other photon), but the other observer doesn't get any information from us this way.

        EPR were just freaked because it seemed to them that a signal that
    • by Anonymous Coward

      as /. users rush to see who can excel the other at sophistry. The rules are simple.

      Comment on the physics and applicability of technology that has never been seen and wrangle and argue about how to build machines for which there is no conceivable power source.

      Players must say as little in as many words as possible. It must also sound scientific and advanced. For lessons on how to do this, watch Star Trek.

      Lastly, players must never admit that they don't know what they are talking about. By admit

  • by Anonymous Coward on Tuesday August 10, 2004 @05:13AM (#9927418)
    The message only contained two words:

    FIRST POST!
  • by Anonymous Coward on Tuesday August 10, 2004 @05:13AM (#9927419)
    Are we the message?

    I guess that's akin to leaving a flaming bag of poo on the doorstep.
    • Ever seen Casshern? (Score:3, Interesting)

      by lingqi (577227)
      Erm, granted probably not (btw Casshern [yahoo.co.jp] is a movie released recently in Japan. See here [penny-arcade.com] (bottom of page) for a PA rant on it.)

      That's almost exactly what the movie suggests: that we are a message and we can pass the same message onward. Won't say too much lest I ruin the movie for yall though, as much as I realize it has but a small chance of ever making it to the states. (wonders about the prospects of Cutie Honey in the same vein.)

  • by miknight (642270) on Tuesday August 10, 2004 @05:14AM (#9927422) Journal
    "We apologise for the inconveniance."
  • Are we the message? (Score:5, Interesting)

    by EachLennyAPenny (731871) on Tuesday August 10, 2004 @05:14AM (#9927425) Homepage
    Is a message allowed to read itself?
    • by Anonymous Coward
      no that violates the DMCA
    • Yes (Score:3, Funny)

      by Kjella (173770)
      ...just don't shoot the messenger.

      Kjella
    • I guess in Soviet Betelgeuse, messages from advanced alien civilisations read YOU! (wince - sorry, first ever slashism - and hopefully the last)
    • by 3dr (169908) on Tuesday August 10, 2004 @09:56AM (#9928727)
      Anthropomorphic messages want to read themselves.

      A comment on the intro bit... Searching for an easily controlled and powerful phenomenon, like electromagnetic radiation, is a smart tactic at least for starters. As the tech gets more sophisticated in terms of control and detectability (LASERs), the challenge is greater.

      But who is this Paul Davies guy, and whose ass did he pull the SETI-in-DNA idea from? SETI has always been on the edge of SciFi-fringedom, but the jump from that to finding encoded messages in DNA leaves no shred of credibility. Here's why:

      "The Bible Code". What the Bible Code showed us is that given a sufficiently large text, you can pretty much find anything you want. Your birthday, apocolyptic predictions, SETI-in-DNA ideas, etc. By changing the search algorithm (ignoring punctuation and vowels is the equivalent method used in the Bible Code for searching Hebrew IIRC) you artificially expand the chances of finding a self-confirming data sequence.

      This isn't science -- it's a parlor trick.
  • by Tjebbe (36955) on Tuesday August 10, 2004 @05:15AM (#9927427) Homepage
    Maybe we should consider the possibility that we are part of a device to perform some calculation to find the answer to a certain big question.
    • Re:message of means? (Score:5, Informative)

      by Scarblac (122480) <slashdot@gerlich.nl> on Tuesday August 10, 2004 @07:04AM (#9927737) Homepage

      Maybe we should consider the possibility that we are part of a device to perform some calculation to find the answer to a certain big question.

      Actually, in my opinion, Kurt Vonnegut is the real master of "perhaps humanity only exists for a very stupid reason" stories.

      Especially the sub-stories of his sf author character Kilgore Trout often have that theme - humanity exists only to train the hardiest microbes in the universe, because hyperintelligent rays of light want to help organic life travel the universe and only microbes could do that, etc.

      In one of KV's books (spoilers for "Sirens of Titan"!), there is an intelligent alien who brings a message from his side of the universe to the only other intelligent species in the whole universe, millions of light years away. Half way, his ship breaks down, the alien manages to land on the moon we know as Titan. He needs a replacement part to fix his ship. His home planet sends the part, but this of course takes a long time; but the thing they can do faster than light is influence the thoughts of the monkeys that live on a planet nearby.

      As the millennia pass by, the monkeys evolve under the influence of the far-away aliens, eventually building huge pyramids and the like in patterns that meant "almost there now" to the alien who was watching from some moon, eventually producing an extremely complex story line, including many wars, the stock market, the development of space travel, and fashion, that ends in a human going to Titan with a weirdly shaped piece of metal adorning his neck.

      This is of course the replacement part for the alien, who can thus continue his travels. Humanity has served its purpose of producing the spare part, and is left to its own devices.

      Eventually the alien reaches the other side of the universe, to deliver the message to the only other intelligent species in the universe. It said "Hello there".

      I love Kurt Vonnegut. Adams must have read quite a few of his books.

    • I'm not playing with myself, I'm conducting research into my DNA to find out if I'm part of a device to perform some calculation. So far, I've calculated that Hustler magazine has 104 pages, plus or minus a 5% margin of error and a few staples.
  • by toomin (793701) on Tuesday August 10, 2004 @05:16AM (#9927429)
    Then we hardly need a whole lot of computers to see them!
  • Somewhere I read that some flu viruses might be of alien form. Indeed, they seem to be the ideal organisms built for space travel. So why don't we search for alien messages in their DNA too?

    • viruses and non-eukaryotes have to be too efficient with their DNA. Anything not needed will get discarded
      • Well, probably there is still some room for some message, like "Alien XXX please fix your software" or something like this :-)

        Some advanced viruses such as bacteriophages of the family Leviviridae, can reach almost 300 Kbp (kilobase pairs) which should be enough to store some additional data.

    • Pay attention: irony ahead.


      We don't need to search there.

      Quoted from the article: The cargo would be designed to infect, without harm, any DNA-based life it encountered.


      There, they KNOW that we are a DNA-based life form, universally sprung from a watery solution, the salty sea. Like we all know, that harmless DNA can be engineered quite easily. That's why I don't understand that all the rocks from the moon (and mars) are in quarantine

  • by selderrr (523988) on Tuesday August 10, 2004 @05:16AM (#9927431) Journal
    yup. And the message is 41,99999999 (ad finitum)
  • by Effugas (2378) * on Tuesday August 10, 2004 @05:17AM (#9927434) Homepage
    We dump pretty enormous amounts of energy at RADAR wavelengths, 24/7, across the night sky. That'll stop approximately when we have no fear of hostile aircraft showing up at our borders.

    You know, never.

    --Dan
    • Even if there would be no fear of hostile aircraft, radar would be used to track civilian aircraft, birds, etc.
    • by Inexile2002 (540368) * on Tuesday August 10, 2004 @05:38AM (#9927516) Homepage Journal
      What a letdown to discover alien RF signals and find out their message was "ping". It would be undeniably cool to discover them, but if all we discovered was RADAR signals there would be no message to decypher.
      • Detecting a simple content-free transmission would be a great start as you at least have somewhere to focus your investigation.
        After that it's probably just a matter of looking hard enough.
  • Satellites? (Score:5, Insightful)

    by earthman (12244) on Tuesday August 10, 2004 @05:17AM (#9927435)
    And exactly since when do satellite uplink transmissions stop at the satellite? The uplink is a radio wave, albeit a directed one. It might still be possible to pick up an alien uplink signal.
    • by prockcore (543967) on Tuesday August 10, 2004 @05:59AM (#9927590)
      And exactly since when do satellite uplink transmissions stop at the satellite? The uplink is a radio wave, albeit a directed one. It might still be possible to pick up an alien uplink signal.

      Fuck... if aliens are anything like us, the signal is going to have DRM all over it.. you know, to ward off space pirates.
  • by torpor (458)
    Oh sure, yeah, right. DNA is the frickin' solution to everything, isn't it?

    Next thing you know, all those conspiracy nutters who say we are "Children of the Gods" will be being appointed to national agencies ... sheesh.

    Look, if someone knows something about space aliens, then OUT WITH IT!! Why the American people have put up with Area 51 for so long without any sort of culpability being required of their government, I do not know. Of the people and for the people, my ass.

    Of the Grey Overlords, and For
    • by Lord Kano (13027)
      Why the American people have put up with Area 51 for so long without any sort of culpability being required of their government, I do not know.

      Simple, regardless of whatever else has gone on there; they have developed some really cool technology that has kept our country safe and free.

      The U2, SR-71, F-117A and B2 were all flown at Area 51 during tests. Who knows what other cool shit [abovetopsecret.com] is out there. Guess we'll find out in 40 years.

      LK
      • by Zocalo (252965)
        Is it just me, or does that "Aurora" on the web page at abovetopsecret you linked to look suspiciously like the Scramjet NASA has been very publically testing recently? The one they have a photo of a few planes down (Hyper-X)... I think they are probably one and the same somehow.

        That's not to say there isn't some other cool shit at A51 we won't be seeing at airshows for a few decades of course. :)

    • Yet another case of SciFi blazing the trail for (suspect) science. In War in Heaven [amazon.com] (1998), the final book of the follow up trilogy to his still largely overlooked classic Neverness, David Zindell writes:

      "Because this secret is part of the Elder Eddas," Danlo said. "And the Eddas are believed to be encoded only in human DNA."

      In truth, no one knew what the Elder Eddas really were. Supposedly, some fifty thousand years ago on Old Earth, the mythical Ieldra had written all their godly wisdom into the hum

  • Is EM not the most likely medium for wide-beam transmission? Lasers are completely ridiculous... it's a tight beam transmission taken to an extreme. We have no idea how other civilizations could be reaching out... perhaps they're using gravity waves, or perhaps they've discovered some sort of faster-than-light system of communications which they have been signaling other races with but we are too ignorant to perceive. In all likelyhood EM is the best way of reaching out to other civilizations, and while
  • user reg bypass (Score:4, Informative)

    by Krafty Koder (697396) on Tuesday August 10, 2004 @05:24AM (#9927464)
    seti in dna [smh.com.au] article : bugmetnot [bugmenot.com] is your friend
  • Albeit, there's a lot of non-coding DNA in Eukaryotic cells, but I wonder how many generations a random mutation would endure in that region unchanged. Those regions probably have a purpose re: the conformation of the DNA, among other things.

    While using SETI on our genetic code might be helpful in identifying patterns and so forth, the notion that another creature would talk to us that way seems a little far fetched.
  • by MisterLawyer (770687) <mikelawyerNO@SPAMgmail.com> on Tuesday August 10, 2004 @05:27AM (#9927471)
    I for one welcome our DNA-speaking, laser-shooting overlords. :-D
  • by JoeShmoe (90109) <askjoeshmoe@hotmail.com> on Tuesday August 10, 2004 @05:30AM (#9927479)
    "When all you have is a hammer, everything starts to look like a nail"

    Next thing you know, we will look for SETI in the burn pattern of a tortilla...or maybe in the reflection from a store window...

    Is anyone getting my point here?

    "For centuries, mankind has searched for evidence of God, in the skies, in the stars, in animals and in himself." Now do a search and replace s/God/aliens/ and ask if this is really any more a sensible statement. Not to mention, if we do find aliens, are we their peers, or are they our gods?

    Final thought of the day...from what I can understand, our solar system is rather young compared to other galaxies out there. And apparently there are hundreds of planets capable of supporting life (our life, that's not even counting life that forms in some environment we consider hostile). Well if that's the case, and life/evolution is as easy as the theories make it sound (all it takes is heat and time)...then why isn't the universe like something out of Star TRek with hundreds of alien species flittering about, dropping in to violate the prime directive, establish moonbases, and so forth? Think about it.

    - JoeShmoe
    .
    • by Anonymous Coward on Tuesday August 10, 2004 @06:10AM (#9927623)
      Regarding your final question: this question has been asked and pondered before by Enrico Fermi in 1950. See this Nature article for an extensive discussion on the subject: www.nidsci.org/pdf/nature_v409.pdf. I particularly like the list of canonical answers:

      There are no aliens, and there never have been. Humanity is unique in the Universe.

      There have been plenty of aliens, but civilizations only moderately more advanced than ours always blow themselves up in nuclear wars.

      The lifespan of an alien civilization is only a few million years. They visited us ten million years ago, and will turn up again in ten million years time, but there is nobody around at the moment.

      Aliens exist, but interstellar travel is impossible because of relativistic limits on the speed of light, or because living creatures cannot survive it.

      Aliens exist, but are not interested in interstellar travel.

      Aliens exist and have interstellar travel, but they are not interested in contacting us.

      Aliens exist, but galactic law forbids any contact with us because we are too primitive, or violent.

      Some aliens see it as their duty to eliminate all other forms of life that come to their attention.
      Any technological civilization will develop radio and TV, attract their attention, and be eliminated11. They are on their way now.

      They are here already (the preferred answer on the Internet s UFO pages).

    • Let's see, you are comparing our solar system to other galaxies? You must realize that the scale of a solar system in relation to the scale of a galaxy is unbelieveably small, right? Ie., there are a (suitably big number) of solar systems in our galaxy alone.

      Think of it this way, when you look at a picture of a galaxy, and you see the fuzzy white haze, that haze is (to quote Dr. Sagan) billions and billions of stars.

      Now step back, and look at a Hubble Deep Field photo. What do you see? A (suitably lar

    • by boicy (547781) on Tuesday August 10, 2004 @07:24AM (#9927792) Homepage
      "then why isn't the universe like something out of Star TRek"(sic)

      The author Iain M. Banks [iainbanks.net] has discussed this issue throughout his "Culture" series of books. He suggests that perhaps there are galazy spanning civilisations out there, but that they are evolved enough to leave us alone until we reach a level as a species where we can be considered for inclusion in the galactic community.

      Why would they need to do anything as unsubtle as establishing moonbases when they could have invisible ships 30 kms long able to control every single tv screen on this planet from outside the orbit of Jupitor? :)

      In fact, one of his short stories from the collection The State of the Art [iainbanks.net] is about what happens when the Culture use Earth as part of a control group. An excellent read.

      Of course this is sci-fi but you get the drift. If anyone is interested I would go as far as saying that for thought provoking Sci-Fi, Iain M. Banks is the man to beat at the moment.

      Here he is in an interview at scifi.com [scifi.com] talking about his writing. And here is the man with a few introductory notes [onetel.net.uk] on the Culture for the unitiated - I just picked this site from the top of google so I hope they don't mind me posting here :P

    • then why isn't the universe like something out of Star TRek with hundreds of alien species flittering about, dropping in to violate the prime directive, establish moonbases, and so forth?

      Maybe the universe isn't old enough. Seriously! Stuff like carbon, iron took multiple generations of stars (birth-to-supernova) to produce. Intelligent life that appeared approximately before the existence of Sol/Earth would have lived and died without the means to forge swords, much less spaceships. I believe our star

    • Star Trek and a lot of SF is based on faster-than-light travel. One of the real possibilities is that the universe just doesn't permit this, and travel to the stars will always be prohibitively slow.

      From an SF writer's viewpoint, this doesn't led to very interesting stories, so most of them have assumed some solution to the FTL problem. A few, such as Ursula LeGuin, have written stories in an "Einsteinian" universe, but have added the gimmick that FLT communication turns out to be possible. This does le
  • by hool5400 (257022) on Tuesday August 10, 2004 @05:31AM (#9927486)
    Aliens with frickin' laser beams on their heads?

    Because that would rock.
  • In turns out that an alien message designed to last millenia should be 'inside a large number of self-replicating, self-repairing microscopic machines programmed to multiply and adapt to changing conditions', otherwise known as living cells. Are we the message?"

    Nice idea. But, IMHO, it is not the 'Magic Encrypted Formula' hardcoded into whatever finally rendering the even more magical 42. What about the hypotheses that the system that the instances based on that DNA create is covering (for sure alternati
  • The real alien DNA (Score:5, Interesting)

    by mikeophile (647318) on Tuesday August 10, 2004 @05:34AM (#9927497)
    is in our mitochondria. [brown.edu]
    • by drmike0099 (625308)
      This may actually be more logical than that article. How would aliens know that we even had DNA, as opposed to what might be a variety of other possible arrangements? How did they know that we primarily use ATGC instead of the other, much less common, nucleotides, so that it would have gone unnoticed? Did they just get really really lucky?

      Or, could it be that they thought some sort of DNA-based lifeform was out there somewhere, whatever nucleotides it was using. They could then send out their own self-
  • SETI on DNA (Score:2, Funny)

    by trifakir (792534)
    CCAA MADE INCH INAA AAGT CAGT TCCT CGCT

    That is to fool the lameness filter. It counts the capitals or something like this.

  • by Mr.Cookieface (595791) on Tuesday August 10, 2004 @05:40AM (#9927522)
    One day when I was reading about some possible candidates of stars that were likely to develop earth like planets, I thought it would be cool to send the spark of life their way so that it could possibly spread throughout the universe. I was thinking about what kind of genetic capabilities we would have in 1000 years if we keep up the pace we're at right now.

    I think we would probably be able to program organisms from scratch by that point, so what kind of organisms would you send to establish life on a distant planet? It would probably start off small, or virus like, but would need to be preprogrammed to evolve into something more complex. Since the evolution would be random, you really couldn't determine the outcome after billions of years.

    Then it occurred to me that if we were going to go through all this trouble for a slight chance that these packets of life might just thrive and grow some brains, we would probably put some kind message in there. Then it occurred to me that we could possibly be the product of such a plan.

    It is possible that the structure of the genetic code itself is an artificial creation of an advanced race. Maybe we should examine the fossil record to look for patterns in the earliest life on the planet. Maybe humans got an evolutionary speed pass to intelligence. Who knows? At any rate understanding the underlying structure of genetic programming would be necessary for understanding the rational behind choosing one structure over another. Just like programmers develop an understanding of the language they program in, perhaps we'll see some calculated order to it all.

  • by hcdejong (561314) <hobbes@NOSPAM.xmsnet.nl> on Tuesday August 10, 2004 @05:51AM (#9927562)
    In ST:TNG, of course! This episode [rotfl.com.au]
  • by JWSmythe (446288) * <jwsmythe@@@jwsmythe...com> on Tuesday August 10, 2004 @05:51AM (#9927564) Homepage Journal
    I think we're really looking in all the wrong places. We're putting human assumptions on alien life.

    We assume they would be using radio communication, or that they'd bother with a high-power laser. What if their communication is completely different. Like, something we haven't even considered to be a possibility yet, even in SciFi.. In a transmission media we don't even realize, we may be receiving communications from them, but we simply don't have the equipment to hear it.. We can't even decipher what any other creature on this planet is trying to communicate, why should we even be so egotistical to thing that not only would we know how to receive their communication, but have the vaugest idea of what they're saying.

    I thought the idea of SETI was that we'd pick up an omni-directional broadcast, with some alien saying "here we are, can anyone hear me" A laser would be directional. It would have to be intended for Earth, and would need to be tracking many years ahead of where we are. We aren't broadcasting the same signal, why would they? There could be many planets near by with the same idea of listening, but if no one's talking, there's no communcation.

    Maybe pulsars aren't just some celestial event, maybe they're beacons, and when we're ready to go to them, we'll find more information. But for now (and the next hundred+ years), we won't be going anywhere near them. Like, we haven't even managed to get a person to the next planet yet. There isn't enough "push" to develop to the next level. Imagine if every country spent their military budget on developing space travel. we'd alerady have a flag on Pluto, along with a bunch of empty beer cans from tourists.

    But no, we waste our resources blowing each other up, or making sure we're on the virge of it every day. Remember the cold war? Ya, 40 years of "I'm going to kill you all", just for it to fall apart, and both sides realize that those people we were so scared of for so long aren't really that bad.

    I grew up knowing the Soviet Union was the evil Red Army, who had so many weapons pointed at us because they hate us so much. Now, thanks to the fall of the Soviet Union, and the rise of the Internet, I now frequently talk to a Russian, and really, he's a nice guy. I've seen some beautiful pictures around where he lives, where not too long ago I would have believed was a frozen wasteland.

    If only all of our governments would give up on this nonsense and cooperate in things, or better yet, ditch the whole "This is ours, you can't play with it" mentality, we'd make a lot more progress.

    [rant mode off]
  • by hankwang (413283) * on Tuesday August 10, 2004 @05:54AM (#9927572) Homepage
    The sun radiates with about 2e25 watts per steradian. That's of course an incredible amount of light, so the idea is to use fewer watts within a very narrow angle. The claim is that one can achieve 2e29 W/sr that way.

    The divergence of a laser beam is, assuming ideal optical components, mostly dependent on the diameter of the beam where it starts. You can take a big telescope and let the light pass through in the opposite direction, so let's say, a diameter of 4 meters. For visible light, that will generate a beam with a divergence of 1e-14 sr. So, to get to 2e29 W/sr, you need a laser with a power of no less than 2e15 watts. (Compare this to a mid-size electrical power plant at 1e9 watt...)

    Yes, there exist lasers that can generate ultrashort pulses in the near-infrared, with such a high peak energy, say 100 femtoseconds (100 fs=1e-13 s) and 100 joules per pulse, so there you have our desired fluence.

    Unfortunately, such lasers can only fire something like one shot per second. If you really want to appreciate the high peak power, you need a camera with a shutter time of 100 fs. Imagine looking at the sky with such an ultrafast camera. The chance that you actually manage to catch a flash from this laser is virtually zero, unless you have a way to know when the flash is going to come. Someone who is looking at a nearby star and expecting flashes is more likely to have an aperture time of 0,1 seconds or so in order to capture any photons at all. At 0,1 seconds aperture time, the laser is no longer 10,000 times more bright than the nearby star (that is, our sun), but rather 1e8 times weaker.

    So, it is unlikely that this is going to word, assuming that someone is looking at us anyway.

  • by droleary (47999) on Tuesday August 10, 2004 @06:08AM (#9927616) Homepage
    Maybe someone can enlighten me, because I never understood why SETI got much effort at all. Any random signal we could eavesdrop on seems like it would likely becoming from a planet like ours, transmitter on a surface that is moving around an axis that is moving around a sun that is moving around a galaxy. Radio waves might cut a fair (if increasingly faint) arc into the Universe under such conditions, but a laser? Wouldn't that make it a pressing assumption that aliens knew we were here? And I don't mean just "here here" but "there here": contact in a manner that accounted for our movements over the time scales it would take for a directed signal to reach the planet. I mean, pick any random star of billions in the night sky and assume a planet around it had intelligent life on it. Now where exactly would you point your beacon so that it actually hit that target? And why is it we think we're on the receiving end of such improbable attention?
  • by nimblebrain (683478) on Tuesday August 10, 2004 @06:51AM (#9927722) Homepage Journal

    It's bizarre. The universe could be teeming with life, or it could be utterly, completely barren save for us, and both alternatives would look pretty much the same to us.

    Communication modes: Our communications are getting more focused, more noiselike (anyone remember what 300 bps sounded like compared to 56K compressed?), less tangible. Maybe the signal came 500 years ago. We couldn't have heard it. Couldn't have. At least the Professor on Gilligan's Island had a radio - coconuts wouldn't have worked. You can't hear radio without a radio (or finely-tuned braces). Who knows what the next physics breakthrough in modes of communication will be? Something quantum? Gravity-related? When it arrives, and if it's better, we'll switch over to it wholesale, and guaranteed we don't have receivers for it at present. Who knows what aliens would be sending their messages with?

    Lucky in the life lottery: Perhaps it's easy for life to take hold on a planet, but maybe we're lucky to have had relatively complex creatures survive the multiple catastrophes. Folks sometimes theorize that Jupiter has protected us from some major calamities just by being big and in a further orbit, acting as dustbuster. Maybe life was seeded here from elsewhere. Wouldn't even have to be an organism - just a decayed crappy chunk of RNA-esque material would do for initial seeding purposes, and it would only have to happen once - one intact chunk out of millions of rocks. It took a heck of a long time to evolve multicellular organisms - the number just boggles the mind. Perhaps it's just that hard to evolve anything past single-cell organisms.

    Planets: There seem to be a significant number of planets around. The program Celestia keeps a semi-current list of the detected planets and systems (so you can have fun visiting). Some of them, though, seem like there are gas giants way too big, or way too close to the sun, or are in a funny configuration. That's likely not conducive to life.

    Age of the universe: I'm guessing, according to an increasing number of observations of late (mostly from the Hubble), that the universe is a lot older than we've been theorizing over the past few decades. The older it is, the more likely extraterrestrial life becomes.

    The Ultimate Find: If we found someone, something out there, it would be the greatest discovery... well, practically ever. At least, "are we alone?" is something we've been asking for so long, and actually having a definitive answer would be amazing.

    I think the voyages to Mars and (soon) Titan will inspire a new generation. Gads, if we can be that surprised in our own solitary back-yard...

    I don't know if we'll find anything out there. I remain hopeful, but I certainly don't have "faith" in anything being out there.

    -- Ritchie

  • by tfb (49770) on Tuesday August 10, 2004 @07:09AM (#9927749)
    The idea here seems to be that at some point we'll just decide to abandon the whole RF spectrum because we have better mechanisms of comminucating. This is implausible to the point of silliness. We *will* have better mechanisms, but the RF specrum is still there, and still as usable as it ever was, and if no one is using it, why, it will be very cheap. So people *will* use it, of course.

    Imagine, for instance, that UHF TV goes away, and non one wants the spectrum any more. Now you can build a local TV system for the cost of a transmitter (which you can get as cheap surplus). So lots of people will do that, so there will be lots of use of the UHF spectrum. It will just be by people doing more interesting thigns than it was before.
    • The exact point isn't that we won't use RF at all, but that we won't use RF high power brodcasting. It takes a lot of power for signals to leave our magnetosphere, and currently there is nothing stronger than a conventional UHF TV signal: it's broadband, and the AM video carrier often is a blistering million+ watts.

      The odds of a million watt AM carrier surviving a trip light-years across space is pretty good.

      Compare that to a signal from most personal communications devices, the likely long-lasting legac
    • by jefp (90879)
      Yeah, it's silly. In fact our civilization will keep on radiating more and more RF until we have fully saturated the airwaves with encrypted spread-spectrum signals from trillions of separate low-power sources. To an outside observer this would basically look like thermal noise peaking at microwave frequencies.

      SETI@Home and other SETI searches skip right past sources like this, but guess what: ten years ago an astronomer named Walter Sullivan wrote up his observations of intense thermal microwave emissio
  • In our DNA, my ass (Score:3, Insightful)

    by Oligonicella (659917) on Tuesday August 10, 2004 @08:27AM (#9928018)
    Yet another bogus attempt to inject some credence to that hoary ghost of ID. No, there is no "message" in our DNA other than the message of how to make and use cell parts.

    This is the last friggin' retreat the ID'ers can have. The last bastion of that stupid concept of "irreducible complexity". Couldn't have your way with the eye? Couldn't make the flagellum work for you? Now, trying to encode some decipherable message in the DNA? Yeesh.

    Been watching that Star Trek movie too many times.
    • by sharkdba (625280)
      Yet another bogus attempt to inject some credence to that hoary ghost of ID. No, there is no "message" in our DNA other than the message of how to make and use cell parts.

      And what makes you so sure of this? I'm not suggesting there is a message coded in our DNA, but if there is a possibility, it should be explored. After all there are many parts of DNA which scientists have NO IDEA what they are for.

      Your type of flat denial is what held science back for many years throughout human development.
  • Bible Codes (Score:3, Funny)

    by Black Parrot (19622) on Tuesday August 10, 2004 @08:41AM (#9928103)


    > Meanwhile, Paul Davies writes that we should be conducting SETI in our DNA.

    Let's see, we're looking for an unspecified message in an unknown language spelled out in an unknown coding... Yeah, I bet you can 'find' any kind of message you want in there, just like the silly Bible Codes thing. The only surprise is that k00ks haven't already been making their claims.

  • by east coast (590680) on Tuesday August 10, 2004 @08:45AM (#9928131)
    You bullheaded humans think you have it all down pat, don't you?

    The sad truth is that my planet found your planet from the leaked signal of an '802.11b' device owned by Dave Stewart in Provo, Utah as he was attempting to download a copy of Blue Oyster Cult's Don't Fear The Reaper song. But soon no other intelligence will be able to find your planet due to the decline in the P2P that was a beacon in the long dark night of space. You see, it's the legal dickering of the RIAA that is more a threat to your society than high powered lasers... so sad.
  • by Captain_Chaos (103843) on Tuesday August 10, 2004 @08:59AM (#9928233)

    More and more of Earth's communications use cable and satellites, with no radio-frequency leakage to space.

    Why would there be no radio-frequency leakage to space using satellites? Some of the signal sent down to earth probably bounces back to space. More importantly, most of the radiation beamed up to satellites goes right into space! There's no way those beams are so narrow that they only hit the satellite's receiving antenna...

  • by gooru (592512) on Tuesday August 10, 2004 @09:09AM (#9928300)

    Meanwhile, Paul Davies writes that we should be conducting SETI in our DNA. In turns out that an alien message designed to last millenia should be 'inside a large number of self-replicating, self-repairing microscopic machines programmed to multiply and adapt to changing conditions', otherwise known as living cells. Are we the message?

    This was a Star Trek: TNG episode. I distinctly remember Romulans, Klingons, the Federation (and perhaps a couple other species) all fighting over some secret weapon they had discovered in human DNA when it turned out to be a holographic image of a common ancestral species that had seeded the planets. It was probably the second season.

  • Replicators (Score:3, Interesting)

    by Perl-Pusher (555592) on Tuesday August 10, 2004 @09:45AM (#9928590)
    It turns out that an alien message designed to last millenia should be 'inside a large number of self-replicating, self-repairing microscopic machines programmed to multiply and adapt to changing conditions', otherwise known as living cells. Are we the message?"

    If we were the message, it would have long ago mutated as to be undecipherable. The message was destroyed by SG-1 and the those gray aliens in last seasons Stargate. Seriously, DNA wouldn't be my choice, but a self replicating nanobot designed to reproduce with extreme fidelity would be more suitable for a message. Unfortunately, uncontrolled replication could have disastrous results.

  • For the record (Score:3, Informative)

    by Durandal64 (658649) on Tuesday August 10, 2004 @10:03AM (#9928810)
    Paul Davies is a creationist. Sorry, but I'm not going to take the advice of a guy who honestly thinks the universe is 6,500 years old.
  • Interesting.... (Score:3, Interesting)

    by gillbates (106458) on Tuesday August 10, 2004 @10:19AM (#9928978) Homepage Journal

    How would we know if there was a message in our genomes? Presumably ET would make it easy for us to spot. Some sort of in-your-face pattern would be best, something that stood out from the random scatter of genetic letters.

    I would posit that an ET intelligence smart enough to create a pattern in our DNA would also be smart enough to make the evidence of their existence readily apparent to even those without the ability to decode DNA. I mean, if the point of sending a message is to communicate, why would you require such sophisticated techniques to understand it, with the attendant risk of misinterpretation?

    Replace ET with God, and you've got a good paraphrase of the "intelligent design" argument for God's existence.

    I think what irks me the most is the assumption that aliens are trying to contact us. When we think about communication, there are some interesting principles:

    1. The sender of a message fulfills some need in sending the message. Perhaps it is a call for help; perhaps "they" need some more friends.
    2. A message is always sent with a reasonable expectation that the recipient will be able to understand it.
    3. The sender usually wants some sort of response from the recipient, even if it is merely an acknowledgement.
    This leaves us with some fundamental problems regarding ET's contacting us with "sophisticated" techniques:
    • An alien intelligence seeking to make contact with other civilizations would probably choose the most easily recognized form of communication, not one which required sophisticated technology or a considerable degree of intelligence to decode.
    • What purpose would such a message serve? If they are more advanced technologically, why would they contact us - we don't have anything that they need? If less so, then we would be able to decode their messages with ease.
    • If "they" are sending messages, then surely they must already know, or strongly suspect, our existence. If this is the case, then why don't they already know how to communicate with us?
    It would seem to me that if aliens were trying to contact us, we would have known it by know. I suspect that if SETI discovers any "intelligent signals", we'll come to discover that they were not intended for us to decode. Perhaps some alien military communications, or ARIA (Alien Recording Industry Association) encrypted music broadcasts, etc...

    Just a rhetorical exercise here: Would God qualify as the sender of such a message?

    • The fact that mankind is the only animal with free will and moral choice is an in-your-face pattern represented nowhere else in the known universe. Furthermore, this is easily recognized by the message recipient (mankind).
    • The desire for a loving relationship is the reason for communication.
    • Our existence is certain to the one who created us.

    With what we know now, only our Creator would possess the knowledge of our existence, the desire to communicate, and the means to do so. I wonder if this occurs to the SETI team, or if they are trying to find God in outer space...

  • No, no, no (Score:4, Funny)

    by Vinnie_333 (575483) on Tuesday August 10, 2004 @10:47AM (#9929331)
    No no no! Aliens communicate through a series of large stone monoliths! Don't you guys pay attention?
  • by cr0sh (43134) on Tuesday August 10, 2004 @05:34PM (#9934331) Homepage
    Those interested in SETI should read the following:

    The Law of Accelerating Returns by Ray Kurzweil [kurzweilai.net]

    It offers a very well reasoned argument as to 1) why the technological singularity must occur, and 2) why SETI is likely a failure. Actually, I would suggest reading Vernor Vinge's writings on the singularity, then read Kurzweil's work above.

    One should then read the story (posted at k5?) called "The Metamorphisis of Prime Intellect".

    Finally, read Albert-Laszlo Barabasi's book "Linked" (network theory), Kevin Kelly's "Out of Control" and Steven Johnson's "Emergence" (emergence theory), and Stephen Wolfram's "A New Kind of Science" (The Principle of Computational Equivalence).

    There are many more references, both fictional and non-fictional (for entertainment purposes only, I also suggest the anime "Serial Experiments: Lain") - but these which I have listed detail a staggering breadth of information which, after you have digested it and left it to simmer in your mind, just might change your opinions and worldview in radical directions.

    Lastly - a plea for help: Does anybody here know of any papers or references from reputable sources which discuss why the singularity can't occur, or is wrong in some manner? I have only read one side of the debate, and I would like to hear the other.

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