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Space

Simulation Pinpoints the Most Likely Spots For Life In the Milky Way (sciencemag.org) 86

sciencehabit writes: Our home galaxy isn't as hospitable to life as you might think. Cosmic radiation, supernova explosions, and collisions with small galaxies make much of the Milky Way too hellish for biology. But a detailed new simulation locates quiet and fertile cosmic neighborhoods, including a surprising locale: wispy streams of stars flung far beyond the main body of the Milky Way.
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Simulation Pinpoints the Most Likely Spots For Life In the Milky Way

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  • And when we finally discover life elsewhere it's not where we expected it to be.

  • The drake equation is a thought experiment of literally unknown variables. This entire simulation is a joke.
    • I don't think it has anything to do with the Drake equation.

      • But the same statement still applies.

        Its not a simulation, that implies some sort of basis in reality.

        This 'simulation' is no more realistic than a simulation in a video game. Its based entirely on made up BS with no actual science behind it. HINT: people calling themselves scientists or people say that are practicing science all the time when they don't know what the word means.

        This is fantasy, not science. There used to be an entire cable tv channel devoted to this, now it please Wrestling or something

        • The DE is the Fermi Problem [wikipedia.org].
        • This 'simulation' is no more realistic than a simulation in a video game.

          I don't know about that: racing and flight simulators do take things like physics and weather into account. Farming sims have a firm basis on reality, by means of being boring, hard work.

        • But the same statement still applies.

          Does it? Where does it state that they made up all their numbers?

          Its based entirely on made up BS with no actual science behind it.

          No actual science? How did you come to that conclusion? You checked, did you, that they used no science at all? Or did you count all the science and find out that they didn't use enough?

          Did they, perhaps, accidentally simulate gravity using an inverse-cube law?

    • Most variables have become known to some degree in the last few years, namely the number of planets per star, the size distribution of planets, fraction of planets in the habitable zone, etc. see http://arxiv.org/abs/1508.0120... [arxiv.org] (it does not use the Drake equation).

      The unknown in the Drake equation is the fraction of habitable planets in which life (or a intelligent civilisation) arises, which probably remains speculation until either >3 civilations have been found or civilations have been ruled out fo

      • by sycodon ( 149926 )

        400 billion stars in our Galaxy, 100 billion galaxies in the Universe (that we can guess at). So even with ONE Planet for each star the odds of intelligent life out there is overwhelming.

        • Except that the consideration of uniformity at and up to the boundaries of sight around 13 billion LY away implies that the visible cosmos is only a small fraction of the whole thing, which is at least 100-200 times larger (length scale) that the visible portion. Which means that you are underestimating everything by at LEAST a millionfold. To quote Adams:

          Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to

      • by sudon't ( 580652 )

        Most variables have been figured out? We have no idea how life began! It's possible that it might take more than a planet simply orbiting in a Goldilocks zone for life to arise. It may be that an axial wobble is needed to create seasons, and that a moon might be necessary to create tides. If that's the case, a lot of relatively unlikely events have to first take place. How many planets have all that going on? Even if we knew how many planets did have all that going on, it would still tell us nothing, becaus

        • That's what I said.

          An optimist could also argue that we have some rough idea how life began, at least on Earth. We do have some pieces of evidence of how it went from A to B.

    • by sudon't ( 580652 )

      I agree. The Drake Equation makes predictions based on a sample of one, and with no knowledge of how life even begins. But this simulation really says nothing except that, these areas of the galaxy are safer for life, therefore we ought to look here when looking for life. They're simply attempting to map out those regions.

  • far, far away?

  • by surfdaddy ( 930829 ) on Thursday December 10, 2015 @03:28AM (#51093593)

    Well, we are carbon life forms and we are looking at the situation from our perspective. I would say the chances of these simulations being accurate are vanishingly small. Do we REALLY understand how and where life forms? Being carbon-based, is it really realistic to assume any and all life is like us, formed like us (even if our other assumptions about our own formation are correct)? At one time we thought we were the center of the universe, right here on earth. We also thought that Mars has always been dry, and we thought that Pluto would be a featureless cold world. And THAT's only assumptions within our solar system!

    You can be pretty confident that this "detailed new simulation" isn't very accurate at all.

    • So we should assume that most life will be non-carbon-based? How does that make more sense?
    • by stevelinton ( 4044 ) <sal@dcs.st-and.ac.uk> on Thursday December 10, 2015 @04:03AM (#51093671) Homepage

      The simulation is probably accurate, the summary article not so much. The simulation answers a rather more nuanced question -- something like "where in the galaxy could Earth;s history possibly have been replayed?" Some places there aren't enough heavy elements, others there are too many supernovae, or near-misses with other stars. Yes, life could evolve in other places, maybe -- on a neutron star, or in the complex magnetic structures in gas clouds near the central black hole or ..... but, although the article suggests it, that is not really the question being answered by the simulation here. Also note that elements much heavier than iron are pretty rare everywhere. Even if you could identify a feasible biochemistry based on iridium or something, there is very unlikely to be enough iridium anywhere for it to evolve.

    • Stars predominately form He (which is chemically inert), C, N, O (see CNO-cycle), a bit of Fe as well as a little bit of heavier elements from supernovae. Therefore life anywhere will most likely be formed of a combination these elements just because of their abundance.

      • Stellar composition isn't uniform. Some stars formed with few heavy elements (lithium and up) because there weren't as many supernovas around before they were forming.

    • by delt0r ( 999393 ) on Thursday December 10, 2015 @08:03AM (#51094091)
      Well really bad scifi aside (Dr Who, star trek). A proper look at elemental abundance and chemical properties, something that we do know with a lot of accuracy, non carbon based life forms are a pipe dream. The only proposed element is silicon, and it is shit. Total shit. It simply does not form the range of compounds you need. Does not have any kind of useful solvent. doesn't naturally form anything interesting even in the slightest. And where you have silcon you have carbon. In fact silicon is far more prevalent on earth than carbon, yet life only uses it for shells of some diatoms.

      Compare to carbon, where we have giant clouds of interesting organic molecules just floating around in space, that can bond to itself and other elements in an infinite range of ways with and equally diverse range of properties. Water is a *very* good and strong solvent and highly polar. But in a pinch i guess say methane may work as a solvent. But it wouldn't be as good as water.

      In short there are very good reasons to believe all life in this universe will be carbon based. But lets not forget, that gives a huge scope for varation from what we see here on earth. With equal certainty all alien life will not be biocompatible with us. If we found anything with DNA, RNA etc, it would be very strong grounds to suspect common origin.

      Some people i work with here, are astrobiologist. Honestly carbon is as impressive as a bable fish.
      • silicon ... Does not have any kind of useful solvent.

        Compare to carbon, where we have giant clouds of interesting organic molecules just floating around in space, that can bond to itself and other elements in an infinite range of ways with and equally diverse range of properties. Water is a *very* good and strong solvent and highly polar. But in a pinch i guess say methane may work as a solvent. But it wouldn't be as good as water.

        I don't see what water (as a solvent or otherwise) has to do with the carbon vs. silicon issue. The interactions between water and carbon-based life are mainly due to other elements such as hydrogen, oxygen and nitrogen in organic compounds, not the carbon backbone itself.

        If water were such a great solvent for organic compounds, then I'd be very afraid to drink any...

        • by delt0r ( 999393 ) on Thursday December 10, 2015 @12:56PM (#51095321)
          So a solvent is important for moving things around. Mobility of compounds in other words. It turns out that some form of general mobility is always required, otherwise it would just sit there doing nothing. Without mobility nothing can spontaneously from. Water is again much like carbon, especially unique. However it is true that other solvents are possible. The most likely being liquid methane, because it can plausibly exist.

          It should also be noted that *no one* has came even close to the most basic set of metabolism for anything other than carbon based life, in a water based solvent.
        • by amorsen ( 7485 )

          If water were such a great solvent for organic compounds, then I'd be very afraid to drink any...

          Selection bias. Water is an almost universal solvent. Everything we see is stuff that is left behind after water dissolves the rest, so to us, water does not seem very potent.

    • I am not sure how life forms, but I can tell you that the ratio of elements on the planets are governed by a common set of physics that should be consistent throughout the universe. It seems probable that carbon based life forms predominate.
    • Well, we are carbon life forms and we are looking at the situation from our perspective. I would say the chances of these simulations being accurate are vanishingly small. Do we REALLY understand how and where life forms? Being carbon-based, is it really realistic to assume any and all life is like us, formed like us (even if our other assumptions about our own formation are correct)?

      Someone asks this question every time this topic comes up.

      Of course we don't understand how life forms. Yes, it's possible l

    • by Ranbot ( 2648297 )

      Well, we are carbon life forms and we are looking at the situation from our perspective. I would say the chances of these simulations being accurate are vanishingly small. Do we REALLY understand how and where life forms? Being carbon-based, is it really realistic to assume any and all life is like us, formed like us (even if our other assumptions about our own formation are correct)? At one time we thought we were the center of the universe, right here on earth. We also thought that Mars has always been dry, and we thought that Pluto would be a featureless cold world. And THAT's only assumptions within our solar system!

      You can be pretty confident that this "detailed new simulation" isn't very accurate at all.

      It's funny you bring up Pluto, because I was thinking about how the surprising processes at work there, far from the warmth of a star show we have very little basis for predicting things in the universe. Any large body that can internally retain heat in it's core has the potential for a stable environment to support life.

  • Life tends to favor binary stars. Our single sol is the anomaly.

    • by KGIII ( 973947 )

      [citation needed] for the first sentence. No, I'll need actual proof, not speculation.

      • There are many things modern Science / scientists are ignorant about. Whiteholes, the 6 fundamental forces (strong intergalactic and weak intergalactic), Life all over the universe, hell, let alone life in our (own) solar system.

        Your fallacy is assuming Science is the only way of knowing truth. Science, the CCW system, only removes falsehood. The polar opposite CW system adds truth and is not based on proof.

        You're like a blind man asking for proof of color -- the only valid proof is experience. You'll g

  • ....the entire local area that's received radio broadcasts of Slim Whitman, obviously. https://www.youtube.com/watch?... [youtube.com]
  • Supernovae as risk (Score:5, Interesting)

    by Framboise ( 521772 ) on Thursday December 10, 2015 @04:24AM (#51093701)

    The research focuses on risks for life linked to cosmic radiation produced by supernovae (and massive stars in general).

    This is only one of the risks. In dense regions of galaxies stars perturb the planetary orbits sufficiently frequently to destroy any climate stability. The solar system has been lucky not to have a star nearing the whole solar system in the last 4 billions years, such that even the outer planet orbits are near from circular.

    On the other hand it is not difficult for life to screen strong cosmic radiation, such as
    in the ocean and deep in the earth crust where most of the biomass exists. So the argument of cosmic radiation killing all life is probably wrong.

    • by wonkey_monkey ( 2592601 ) on Thursday December 10, 2015 @05:38AM (#51093837) Homepage

      On the other hand it is not difficult for life to screen strong cosmic radiation, such as in the ocean and deep in the earth crust where most of the biomass exists.

      And that's why I'm staying in the basement.

    • Building stargates aside, the problem with radiation is tied to the problem with magnetic moments. The radiation from the local sun alone is enough to make life anywhere from pretty unlikely at all to pretty unlikely to evolve into a rich ecology if the planet in question hasn't got enough of a magnetic field to provide a radiation shield from both cosmic rays and the solar wind. Without it, atmosphere is just blown away by the solar wind and cosmic rays reach the surface in abundance. The solar magnetic

      • by delt0r ( 999393 )
        You don't' really need a magnetic field. Earth for example has 10 metric tons per sq meter of atmosphere to protect you. And it does. Also even without a magnetic field an atmosphere can easily last billions of years, see venus. It is easy to imagine a set of parameters that would result in stable liquid water for billions of years, that requires no such magnetic field. As for moons... There is a big difference between alien life and multicellular alien life. It took a long time for that to get of the groun
        • I agree that this is controversial, but it is by no means a slam dunk that it isn't necessary. And if it isn't, it makes it more likely that a moon-forming atmosphere stripping collision is needed (or else bombardment by comets or whatever you think is needed for an ocean). And then there are the issues associated with radiation. The point is that there may be some subtleties associated with the requirements for life that mean that high radiation zones (sustained) are indeed inimical to life. Or (sure)

  • Observer bias (Score:5, Insightful)

    by argStyopa ( 232550 ) on Thursday December 10, 2015 @09:05AM (#51094233) Journal

    If the premise of the study is to highlight the risks of near stellar neighbors and cluttered neighborhoods, of COURSE the conclusion will be that remote systems are 'safer'.

    This is like asking a cancer doctor where it's safest to live, and getting the answer "in a sealed lead-lined vault"....yes, disregarding the need for air, water, and food, and only focusing on the cancer risk, that's probably great.

    While we simply don't KNOW the primary drivers of life generation (or the Drake equation would be a lot less hand-waving), and while yes, there's a danger of nearby stellar events, one might also consider:
    - our solar system didn't just appear ex nihilo: the heavier elements present suggest that our system formed from nova or supernova remnants. A more cluttered stellar neighborhood is going to have more of such events. While these events would be indeed dangerous (likely exterminatory) for nearby life, life might regrow with such staggering frequency that the stellar scales are outmatched
    - radiation: dangerous, sure, but we exist because of mutations. LIFE is based on mutation. (And hell, there's persuasive evidence here on earth that living with higher level of background radioactivity actually increases life span; then again, that could also be a raised average due to selective weeding by same.) A higher-radiation environment is not necessarily inherently bad for life, and may actually accelerate the mutative processes.

    These are just a couple of reasons that inner regions might be better. A lot of it is simply guesswork at this point.

  • by tomxor ( 2379126 ) on Thursday December 10, 2015 @09:12AM (#51094257)

    Forget the summary or the article, the title makes no sense... "pinpoint" and "likely" are pretty close to antonyms of each other... that's like saying a weather simulation has pinpointed where it's going to rain next week.

  • It is thought life evolved in deep ocean near vents. In a hiP hiT environment you dont need many enzymes (protein catalysts) to drive metabolic and protein synthesis reactions. Life then migrated to more hostile environments after evolving enzymes. These hostile environment include hot and cold temperatures, low pressure, solar radiation, free oxygen and parasitic viruses.

    I could see in life evolving in the interior ocean of an ice moon in a more hostile solar system. Then evolve mechanisms to surviv
    • It is also thought life evolved in fresh water. It is also thought that life evolved amidst the clays. It is also thought.....

      All thoughts about this are conjecture.

  • So small, unregarded yellow suns in uncharted backwaters of the unfashionable end of the spiral arms of the Galaxy is actually where it's really at. Who knew?

  • Remember this old SPI game? Journey to the center of the map and collect "Wisdom Chits" pick up the "X" wisdom chit and you go hostile!

  • "Cosmic radiation, supernova explosions, and collisions with small galaxies make much of the Milky Way too hellish for _our type_ of biology"

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