Carl Sagan on SETI

By Phil Plait | April 28, 2011 8:11 am

After I posted about SETI this morning, I found this video on YouTube. The master of communicating science, Carl Sagan, explains why we need to listen to the skies.

Tip o’ the radio dish to reddit.


Comments (25)

  1. davidlpf

    Damn that man is still wise to this day.

  2. Yeah, I always thought the best thing about active SETI was the search itself, not the potential discovery…which would probably be twisted and spun and frakked up by the usual bunch of clowns into something meaningless and divisive anyway.

    At least the search was a symbol of hope.

  3. You know I ‘m one of those people who believes that there likely is no alien intelligence anywhere near us, if at all, but I still support SETI whole-heartledly. Partially, because that is the scientific thing to do (my beliefs are falsifiable since finding aliens would disprove it), but partially because I would rather be wrong in this instance. I would rather there were aliens out there somewhere, and that we find them, than we be completely alone in the entire universe. Unfortunately, it’s just that the best evidence and arguments I can think of currently supports the latter more.

  4. Larry

    The second-to-last sentence of Dr. Sagan’s narration, “We are a little lonely…” is key to understanding SETI. As Arik Rice [3] also admits, SETI is really about how we view our place in the Universe. That isn’t science, although it certainly is a search.

    The scientific thing to do is use Occam’s Razor to choose the simplest explanation for the null observation of any hint of ET: they aren’t there.

  5. BJN

    I’m not big on new missions to the Moon, but I’ve given money to support SETI.

    In our self-centered perspective we all tend to put great stock in our technological prowess, and we presume that “intelligent” life will inevitably be technological. We can only really search for species that are very similar to ourselves and that’s a tremendous handicap. It’s not really surprising that we don’t find ourselves when we look to the stars. We’re very likely a flash in the pan. Our species is causing a great extinction event on this planet and our own survival in any meaningful sense of species longevity is very much in question. Silence in the stars may just be evidence that our kind of intelligence isn’t really viable.

  6. Messier Tidy Upper

    @ ^ BJN : Perhaps we’re only semi-intelligent? 😉

    Intelligence has degrees and is relative y’know.

    FWIW, I’m in favour of a Lunar return – and much more when it comes to space exploration, human & robotic, private and government, plain & simple.

    Lets go out and do these things not just because they’re hard but because we learn and benefit and increase our understanding by doing so.


    Superluminous clip. Thanks.

    I was looking for Sagan videos on youtube & posted a few earlier myself – see :

    Yet hadn’t seen this one. Love it. :-)

    PS. Sorry about the inevitable typos, drunk as & crazy – or is it just the rest of the world? 😉

  7. Linda

    Does anyone know what those strange creatures are at ~3:15 ?

    Nice video! CS really knew how to tell a captivating story :-)

  8. Bob
  9. Lewis

    The two-legged creatures are from a documentary by Stephen Hawking
    I found the best part of the documentary was the thought of aliens living inside a star. I always thought that was ridiculous until I read Flux by Stephen Baxter – worth a look too.

  10. Steve Metzler

    4. Larry:

    The scientific thing to do is use Occam’s Razor to choose the simplest explanation for the null observation of any hint of ET: they aren’t there.

    I’m willing to bet they’re there. It’s just that the distances involved are so immense. Say the nearest intelligence is a mere 500 LY away (and I don’t even know if we’ve discovered any viable exoplanets that close to us yet). They haven’t even seen any of our electromagnetic signals yet. And then it would take another 500 years for us to see their response.

  11. Mike

    In my opinion, we have only been searching for such a short time. At this point, I don’t think we have enough information to say whether there are not, for sure, any intelligent alien life forms out there.

    With the time frames and distances involved, there’s to much left open to question, in my mind.

  12. DLC

    I hate the Drake Equation.
    That noted, there are enough stars out there that the lowest side estimates for the Drake Equation make it a number very close to unity as a probability.
    Given that, the idea of listening for them seems like a good idea. probably anything within say, 200,000 LY. Or more. It’s so hard to tell how quickly life could develop elsewhere.
    And you can’t write off planets not in the “cinderella zone” (another thing I hate), either, because life may not be limited to our kind of life. It’s entirely possible that life could develop based on other reactive chemicals.

  13. Matt B.

    Linda, I think they come from a TV special that was on a couple years ago that talked about what alien life might be like. I’m pretty sure it was based on a book that came out around the same time, but that’s as good as my memory is on that. I can’t remember who wrote the book.

  14. Wedge


    Cinderella? I think that is the wrong tale about a not too hot, not too cold soup 😉

  15. toasterhead

    10. Steve Metzler Says:
    April 28th, 2011 at 4:32 pm

    They haven’t even seen any of our electromagnetic signals yet.
    And they won’t, unless we beam some signals directly to them. Our leaking radio and TV waves dissipate into the background radiation after a light year or two. To pick them up from as close as Alpha Centauri, you’d need a radio antenna almost half the size of Neptune:

  16. frankenstein monster

    The scientific thing to do is use Occam’s Razor to choose the simplest explanation for the null observation of any hint of ET: they aren’t there.

    simple as in the theory with minimum information-theoretic complexity. not simple as in the most simple-minded answer.

    and given our own existence, and the physics and chemistry of the universe, there would be much more negative results needed to make an a priori highly improbable hypothesis “we are an unique exception in the entire lifeless universe” to be the most probable answer.

  17. frankenstein monster

    Silence in the stars may just be evidence that our kind of intelligence isn’t really viable.

    And what kind of intelligence would there be else ? Any intelligent being would learn
    about the world around it works. an then start to use things in its environment to further its goals. Because that is, what is intelligence for.
    And that means technology.
    And vice versa. a thing that does not know or care to understand the world around it, can not be considered intelligent.

  18. Troy

    I have mixed feelings about SETI. Articles about it have never really excited me that much. I do think they should continue it because anything detected would have such overwhelming significance. It is also relatively cheap and there are spin offs in improving scanning algorithms and the like. In addition, it spawned the concept of networked computers on the Internet used as a huge supercomputer as a screen-saver.

  19. SLC

    In the previous thread, I mentioned that the late biologist Ernst Mayr had opined that intelligent life would probably be very rare in the universe. This was part of a debate on the subject between him and Carl Sagan. Needless to say, Dr. Sagan was rather more optimistic on the subject then was Dr. Mayr.

  20. Matthew Saunders

    “People need a sacred narrative. They must have a sense of larger purpose, in one form or another, however intellectualized. They will find a way to keep ancestral spirits alive.”

    –E. O. Wilson

    Simply beautiful video, Carl, who thought that religion was an essential meat, is able to capture and transmit awe and wonder so well.

  21. Dark Jaguar

    My biggest issue with SETI is if they are even capable of detecting any of those signals even if they are out there. How weak would those radio signals be after travelling the distances involved and how sensitive are their antennas?

  22. Gary Ansorge

    9. Lewis

    ,,,or Sun Diver by David Brin,,,

    I read an article several years ago in which the researcher(dang! can’t recall his name) had created plasmas that were both self sustaining and self replicating. Don’t remember the details.

    A blog commenter remarked that possibly the real reason we haven’t heard anything with SETI is that everyone is transmitting in compressed, digital code. To SETIs instruments, he suggested, it would look like noise.

    That seems too easy an explanation for me but maybe he’s right.

    Gary 7

  23. Carl Sagan on SETI | Bad Astronomy | Discover Magazine great ideas for this world!


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