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What If There Are No Extraterrestrial Civilizations?

Remember SETI@Home? A few years ago, the distributed network that enabled analysis of radio signals using the spare resources of home computers gained quite a bit of attention. Supporters of the program claimed that we would know very soon whether there is, indeed, extraterrestrial intelligence in the universe, if only there was adequate computing power to make sense of radio waves reaching the Earth from outer space. The universe should be teaming with beings that use radio waves to communicate, they reasoned, so with some analysis of signals already being gathered by radio telescopes, it shouldn’t take long to hear from ET.

It’s been almost eight years now, and SETI@Home has listened to the entire sky visible from the Arecebo telescope it gets to piggy back space on. Still there has been no signal heard from outer space. There hasn’t even been a hopeful candidate for further examination in over two years.

So, it seems that the time has come for us to ask the question: What if there are no extraterrestrial civilizations? What if no one else in the measurable universe is communicating using radio waves of the sort we’re searching through?

There’s a lot of space out there, and a lot of planets on which alien civilizations could take route. If getting life to the point where communicates using electromagnetic devices like ours is something common, surely we ought to have detected a signal by now.

The idea posited by Star Trek of a universe teeming with advanced civilizations seems less likely than it did back in 1999. Intelligence as we know it on other planets seems more likely to be extremely rare, or not to exist at all. Perhaps the creatures on these planets are intelligent but not technological. Perhaps they aren’t intelligent at all. Perhaps even multicellular life is an oddity.

Perhaps, in spite of the presumption by scientists like Carl Sagan that we ought not to be, we on Earth really are quite special in the universe.

With every day that SETI@Home searches and finds nothing, it becomes more reasonable to assume that we may never know if other civilizations exist in the universe. We can now see planets around other stars, but they are silent planets. Whether that’s by choice or by dearth of anyone to talk is not something any telescope has the resolution to determine.

The distances to other solar systems are far too vast for us to travel without sucking a great deal of energy out of the Earth, so it makes sense to keep on listening. It does not make sense anymore, however, for our popular mythology to rest upon the presumption of aliens in spaceships with galactic empires coming by our planet to say hello.

7 thoughts on “What If There Are No Extraterrestrial Civilizations?”

  1. Michael Martine says:

    This question is known as the Fermi paradox. Our own understanding of this is limited by our current or anticipated levels of technology. In Star Trek’s time, we thought that in the future we’d still be sending meatbodies out in tin cans, and the idea of a technological singularity or Matrioshka brain was not even a gleam in anyone’s imagination.

    Now that we can imagine such things, some are postulating the answer to the Fermi Paradox is that alien civilizations are post-singularity and are practically undetectable like a conventional pre-singularity civilization. This is what Charles Stross does in his novel, Accelerando.

  2. James Brown says:

    No I don’t think its time to give up yet.

    You say that it’s been eight years now that SETI@Home has listened to the entire sky but I assure you that it’s nothing like the entire sky. On my very small SETI system (www.SETI.Net) I have calculated the possible number of ‘channels’ I could look at and it turns out to be 12 million and each one of those requires about an hour of staring. Do the math.

    I’m sure that the humankind is very special, how could I think otherwise but that doesn’t preclude other very special intelligence’s out there waiting for contact.

  3. Peregrin Wood says:

    Hey, I didn’t say it’s time to give up. I think that it’s time to rethink the presumption that there are alien civilizations. We can always say that we’d find the extraterrestrials if we just had this next technology, and then the next technology, and then the next, but it starts to get a lot less plausible after a few years.

  4. Ralph says:

    I’ve heard that our radio telescopes are still really only sensitive enough to detect a message from another star system if the message is being beamed directly at us. We need better radio telescopes if we want to detect other civilizations talking to each other (probably over relatively short distances) by radio.

  5. HareTrinity says:

    Agreeing with the “let’s not give up” side.

    There is the very slim chance, if the universe isn’t infinite, that we are the only planet with life. However, even if the universe isn’t infinite it is unimaginably HUGE (diagrams are all very good, but it’s difficult enough to truly picture Earth mentally to scale, let alone things many billions of times bigger than our solar system).

    Continuing small programmes aimed “just in case” gives people hope, hope in science and a more realistic look at the universe we live in.

    There’s one quite famous photo from a leaving telescope of Earth. Shown as one tiny slightly off-coloured pixel in the massive thing.

    ALL of our wars, homicides, genocides, deaths, successes, lives, opinions, cultures and history exist on a slightly off-coloured pixel only.

    More or not it’s worth remembering that the universe is massive and that we’re sharing one dot of it.

  6. Xlp Thlplylp says:

    Do you know how pitifully small and underfunded SETI is? Sagan once wrote, “Science arouses a soaring sense of wonder,” but the journalistic approach to science is an open sore in science education. It leads to the perspective that all science efforts are equally well-funded and well-staffed at the highest level, and unlimited technological resources are being brought to bear on them. SETI is largely a volunteer effort. Anyone who knows the least bit about maintaining computing grid systems can see the huge disparity between the few racks of computing systems at SETI headquarters, and the thousands of systems donated by users on the internet.

    Maybe instead of rethinking our presumption about the existence of extraterrestrials, the editorial “we” might rethink its presumptions about how science is done come from a journalistic or a scientific perspective.

  7. Xlp Thlplylp says:

    The obligatory parting shot should have been:

    Maybe instead of rethinking our presumption about the existence of extraterrestrials, the editorial “we” might rethink whether its presumptions about how science is done come from a journalistic or a scientific perspective.

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