How to really look for aliens

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Two scientists summarize the challenge for finding alien life in the universe.

Look for high amounts of oxygen and mid-infrared energy, the second of which has already produced some candidates.

A recent large survey by the Wide-field Infrared Survey Explorer (WISE) satellite did identify five red spiral galaxies whose combination of high MIR and low near-ultraviolet luminosities are inconsistent with simple expectations from high rates of star formation. A conventional explanation for these observations, such as the presence of large amounts of internal dust, has not been ruled out, however. Such peculiar objects deserve follow-up observations before we explore whether they might represent the signatures of galaxy-dominating species.

The article is very thoughtful, however, and outlines in detail the issues and problems the research faces. We might, in a few decades, have the capability to answer this question, but then, the aliens might be alien enough to still be undetectable. Or they might not exist at all.


  • Cotour

    Timing is everything.

    I think that the numbers alone, sans any search for “life sign” atmospheric conditions indicate that there has to be somewhere in the universe other life forms, even intelligent life forms. The numbers are just tooo big to assume otherwise. The problems as we have spoken about before is the timing, meaning how two advanced civilizations tend to over lap / exist in time and distance / proximity.

    Any advanced intelligence IMO , and most all other intelligent beings if they do exist in the universe have to be more advanced than us, has got to have the ability to be invisible to all who are looking for them if they so desire. And maybe not even if they desire, their technology will probably be so advanced that we would probably not be able to detect it anyway.

  • LocalFluff

    In order to try to nuance your arguments somehow, I would argue that some lifeforms can get very advanced (which certainly can be hard to find or even imagine), but that this is not necessarily in opposition to there being ETI’s around too which are as primitive as we are. They could rise independently regularly. We did it in 4½ Bn years and there are about 200 Bn stars in the Milky Way.

    Secondly, we still use wheels and fire although they are ancient inventions. Radio technology will likely prevail for a long time for different purposes. If I’m not mistaken, most of the photons in the Universe are microwave radio emissions, it is physics which cannot be ignored by anyone going forward after having once having discovered it.

    And thirdly, the infrared mentioned here I think refers to waste heat from industrial processes, something which is unavoidable because of thermodynamics. They have to emit it in order to do anything useful as in lowering entropy locally (construction).

    So it is funny that we haven’t found any company! But in the next few years huge telescopes are coming online, and SETI efforts are steadily increasing. I think that “because we haven’t looked enough” is a valid answer today. In another ten years without any hint of ETI, it will be harder to get away with that answer.

  • Cotour

    My main observation about this subject is not that it is unlikely that there are no other “intelligent” life forms / civilizations around it is the overlap of two or more life forms who can detect each other divided by time.

    Lets assume that it takes aprox. 400 years between the beginning of a technology trend and the point in the future where you become “invisible” to other civilizations due to highly advanced progression of your technology.

    400 year technology / civilization detectable overlap divided by the aprox. 10 billion year age of the Milky way?

    4.5 billion year age of our solar system?

    13.7 billion year age of the universe itself?

    A very, very thin window of opportunity for one to detect the other.

    This is of course assuming that the development of technology leads to something that indeed becomes something that can not be detect by lower level civilizations.

    Thats a pretty thin slice.

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