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SETI@Home Revisits Its 100 Best Signals

cmbrothe writes "The Planetary Society is running an article about SETI@Home's plan to revisit its 100 most promising signal candidates. The article also outlines the criteria for selecting the candidates."

12 of 327 comments (clear)

  1. formula for likelihood of life by guidobot · · Score: 5, Insightful
    The formula used to rank the different stars according to the likelihood that they would host a communicating civilization is:

    score= N*(bv-bv0)*exp(0.5*(bv-bv_sun)^2)/(par+0.01)^3

    where

    N is a normalizing factor, 1.65x10^7
    bv is b-v color
    bv0 is b-v color of the bluest star in the catalog (-0.41)
    bv_sun is the b-v color of the sun (+0.65)
    par is the parallax in milliarcseconds

    How exactly do you test the validity of a formula like this?

    1. Re:formula for likelihood of life by SETIGuy · · Score: 3, Insightful
      Maybe we were't clear, low scores are better. (I didn't have a chance to review Amir's article before it went out. In fact, I haven't read it yet. Does that mean I'm a real slashdotter?)

      When you get down to it this "star score" is fairly arbitrary. I outght to know, I invented it. If you take out the Gaussian term, it reduces to the number of stars in our sample closer to the sun than the star being scored that are also bluer than the star being scored.

      I threw in the Gaussian term as a "we like stars like the sun" term.

      But it's OK for this "star score" to be somewhat arbitrary. The "star score" represents how interesting the star is to us, not a literal interpretation of the probability of life existing around that star. A "how probable is life there" score doesn't really exist.

  2. Re:Playing the Odds by Nintendork · · Score: 3, Insightful
    As an afterthought on the possibility of intelligent life, think about this. There was life on Mars. They're thinking there might be life on Europa. That's 3 different bodies producing life (Found thus far) in our solar system alone.

    -Lucas

  3. Re:Suppose we get a signal... by Nintendork · · Score: 3, Insightful
    You didn't see Contact, did you? The aliens send the blueprints for making a transport used to communicate with them in real time.

    Who says two way communication is the only way we can take advantage of the finding? If they're more advanced than us at the time in their history when the signal was sent out into the cosmos, we'll learn a lot just by listening.

    Imagine if 50 years ago, they could watch our current TV programs, listen to our current radio broadcasts, read the internet.

    Hell, even if we don't advance because they're at the level we were at in the 20s, a LOT would change because aliens would be FACT instead of FICTION.

    -Lucas

  4. Window of contact by hpeg · · Score: 4, Insightful

    I can't believe that people are still looking for signs of extraterrestrial intelligence, hooing to make contact one day.

    Stanislaw Lem once described the window of contact as the tiny amount of time in a planet's life that an intelligent life form has to evolve far enough to create enough noise around their planet that will be picked up as non-static background noise, until its civilisation dies the entroy death.

    Even if we picked up something now, it would only be a tiny flicker of something that existed millions of years ago, with no hope of us ever meeting whoever created this glimpse of order in the chaos of the universe.

    We are alone out there. Confined by the same rules that hold our universe together into a tiny section of space and time. The best we can hope for is to become nomads, travelling to near systems in the hope of making them inhabitable when this sun gives out. If we haven't fallen into the ashes until then.

    1. Re:Window of contact by mmacdona86 · · Score: 5, Insightful

      As others have pointed out, we could pick up something that existed a few score or a few hundred years ago, and that would certainly be interesting.

      Even knowing there was intelligent life somewhere else millions of years ago--and if the signal was millions of years old, it would necessarily represent an extremely advanced civilization, powerful enough to transmit a signal to another galaxy--would be extremely interesting scientifically and philosophically.

      Finally, it is only conjecture that the "Window of Contact" is brief. For all we know, once civilizations get to a certain point of development, they last forever, and slowly but surely colonize all the inhabitable parts of their galaxy.

  5. Re:Would they detect themselves? by szquirrel · · Score: 3, Insightful

    Now, let us suppose that a civilization with a similar technology to ours was located on a planet around Proxima Centauri, and let us suppose they did exactly as we did in our transmissions at Arecibo. Would that signal have been found by SETI@Home?

    SETI isn't looking for a person-to-person call necessarily, just for some scrap of evidence of intelligent life. By that criteria our planet has been spewing out transmissions like crazy for the last 70 years or so. If we find someting like that, then we at least know where to start looking for a "Hello, World!", or where to start sending our own.

    --
    Never approach a vast undertaking with a half-vast plan.
  6. Re:Hi SETI people.... by Waffle+Iron · · Score: 3, Insightful
    Maybe the space aliens have a cure for cancer already?

    Better still, what if the aliens have figured out how to upload your mind out of your meat body and into something more permanent.

    We could all become IMMORTAL. Bwa ha. Bwa haha. Bwahahahahah!

    Joking aside, contacting aliens would be a much more significant event than curing cancer. We already have a more than effective way to replenish the population on this planet.

  7. Re:Hi SETI people.... by Idarubicin · · Score: 5, Insightful
    Me? I'll spend my spare CPU cycles trying to find a drug combination to cure cancer.

    Very noble of you. Among other things, I have spent my own time, not my computer's, working on cures for cancer. (Right now I'm back at school.) I could have been earning much better money pushing paper--actually, I took a 25% pay cut to do cancer research.

    You know what? I was running SETI@Home on my computer at the time. And I don't feel guilty about it. Maybe there was a better use for those cycles, but I think of it as a sort of hobby for my computer. People who spend their spare time watching football, or playing with electric trains, or painting--forget what their computers are doing, shouldn't they be working on 'more relevant' problems?

    Breast cancer killed my best friend's mother this summer. I would love to see a cure for cancer, as well as for any number of other diseases--Alzheimer's runs in my family, and my uncle has diabetes. But if fear of death is to set all of our priorities, leaving no room for a sense of wonder and exploration--what's the point of living?

    If you really want to help people in a tangible way, please--go out and give blood. Not just after a terrorist attack, but every two months. Or volunteer at a food bank. Not just at Thanksgiving, or Christmas, but year round. Write a cheque to a charitable organization. If you can't afford that, write a letter to your government representative--tell them what their funding priorities should be.

    --
    ~Idarubicin
  8. Re:Playing the Odds by C14L · · Score: 3, Insightful

    I'm telling myself that it's not going to happen, but what if more than one of those 100 candidates turns out to be the real thing. What a shocker that would be!

    In fact, that could be quite beneficial for humanity. Humans tent to identify themselfs by what they not are. In other words: If a group of people has some kind of "enemy" or "opposite", it usualy becomes more united. That does allways happen and on any scale. So hopefully, when we discover extraterrestial civilizations, people may begin to define themselfs more as "humans" and less than citizens of different countries.

    Thinking that over... if they don't find any signal, they should make up one! Anyways, nobody will be able to validate it, if it comes from some 1000 Lightyears away...

  9. What about our future? by SiliconEntity · · Score: 3, Insightful

    The interesting part about attitudes towards SETI is what they say about our own future. What is happening with our civilization? Where will we be in 100 years? In 1000?

    Many people are pessimistic. They think we're bad and getting worse. They expect that we will destroy ourselves soon, or sink into a dark age, or otherwise lose the ability to communicate with the stars. So they can imagine a galaxy full of life but not much of it communicating at any given time.

    But let's suppose that things continue on as they have. Look at the grand sweep of human history. We see a continual growth of capability and power. Even a poor person today in the West has technology which would have been unavailable to the richest person in the world 100 years ago.

    Imagine that this continues to happen. Technology not only advances, it speeds up. The next 100 years bring more changes than the last 1000 years. Nanotechnology, biotech, AI, physics advances; we could be living like gods in 100 years.

    And let's assume that social trends continue. Racism and sexism was ubiquitous 100 years ago. Now they are recognized as great evils. As our power grows and our moral sensitivity increases, we will want to help those less fortunate than ourselves. We will end poverty and suffering among humans, because it will be easy compared to the power we have. We will turn to the higher animals, and do what we can to improve their lives as well.

    And we will turn outwards. We will reach out into the galaxy with communications and explorations. It will take centuries, millennia, but as our capabilities grow we will eventually find even the great interstellar distances easy to cross. We will search the galaxy for life, ready to cherish and protect anything that we find. And if we could meet a culture less advanced than our own, we would do what we could to ease their suffering while still respecting their chosen path.

    This may seem like an absurdly optimistic vision, but it's nothing different from what has happened in the past! Anyone who looks with clear eyes at the record of human history and who extrapolates it forward should see this as a very plausible and likely future path. The reason that it's not explored much in literature is because there aren't that many dramatic possibilities in a world which is as much improved over the present as our own world is over the past.

    The point is that if this is the likely path for a civilization, it would suggest that other cultures in the galaxy would also be spreading outward and would probably be here by now. The fact that we don't see them, that we stumble along and still suffer great and preventable catastrophes, suggests that really life is not so prevalant in the galaxy after all.

    So ironically, both the optimistic and the pessimistic view of humanity's future suggest that SETI won't work. The pessimists believe that any advanced culture will wipe itself out; and the optimists believe that such a civilization will spread through the galaxy and render aid to less developed worlds. Either way we won't find intelligent signals on our expensive radio telescopes.

    1. Re:What about our future? by meehawl · · Score: 3, Insightful

      Anyone who looks with clear eyes at the record of human history and who extrapolates it forward should see this as a very plausible and likely future path.

      This is delusional optimism. Anyone who looks with clear eyes at the record of human history (and pre-history) sees that localized human socieities follow a predictable pattern of expansion followed by dieback. Sometimes the cause is external -- war or invasion or disease or climate. Sometimes the cause is internal: stasis, political disorganization, social transformation, resource exhaustion. Every single piece of available evidence points to this conclusion -- yet you somehow manage to convince yourself of some privileged exceptionalism that will enable your society to endure? I have a bridge you might be interested in...

      The various human civilizations that have energed since the Holocene were lucky to be existing in an especially mild inter-glacial period not characterized by hyper-aridity. This is a special and situational set of circumstances that cannot be exxpected to continue indefinitely.

      --

      Da Blog