World Without Stars

Some recent work suggests that most galaxies have too many gamma-ray bursters, such that most planets get hosed every so often, making complex life practically impossible – as if it wasn’t already.  It seems that low levels of heavy elements (heavier than helium: “metallicity”) make this more likely, so that conditions were unfavorable in almost all galaxies for the first few billion years.

On the other hand, another recent paper suggests that there are many rogue stars outside of galaxies, flung there by gravitational interactions with giant black holes in galactic cores.  That and spindizzies.

Seems to me that forming in a galaxy might give a solar system enough heavy elements, while being flung into the intergalactic deeps would protect you from cosmic catastrophes like gamma-ray bursts.   Such stars might be good homes for complex life, especially a few billion years ago.

Interstellar travel is hard enough for us, but for these guys, it would be a bitch. That first step is a doozy.

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77 Responses to World Without Stars

  1. MawBTS says:

    I think I read this Asimov story.

    • gcochran9 says:

      No, you didn’t. Poul Anderson, of course. On that topic, fairly often I find that people remember books in idiosyncratic ways (that is to say, they remember it wrong). Not just the wrong author, which is not that big a deal, but substantial points or events in the book. Remember when we had comments from several people who were really sure that Jared Diamond never said (in GGG) that people from PNG were smarter – genetically smarter – than the rest of humanity? Yet he did: he’s that much of a schmuck.

      • Weltanschauung says:

        Or when I remembered Hans Zinsser in Rats, Lice, and History identifying the plague of Athens as typhus, when what he wrote was that it wasn’t typhus.

      • Steve Johnson says:

        To be fair to Diamond he puts it in the forward to set the tone for the rest of the book – “this book will be full of lies and half-truths”.

        Downright sporting of him.

      • Zippy says:

        Is it possible he was just pulling our leg when he said that? Or even letting on that he knows the whole thing is a con?

        • Patrick Boyle says:

          I don’t think so. I’ve read all the popular Diamond books and he always seems very serious to me.

          There are now several scholarly books that specifically are written to debunk Diamond. The best of these is ‘The Statues That Walked’. It seems that just about everything that Diamond wrote about Easter Island was wrong. Diamond spent all his time in PNG. He had never actually been to Rapa Nui. Trust him on PNG wildlife, especially birds, but for other parts of the world, he’s an old fashion ‘armchair philosopher’.

      • Patrick Boyle says:

        Gee, Dr. Greg you must be the world’s leading authority of Sci-Fi plots and characters. Do you dress up and attend the conventions?

      • tequoia says:

        I think you’re wrong; the top commenter here could have been thinking of anything but it’s probably not a Poul Anderson story. Nightfall predates probably everything else you’re thinking of, however, and it’s also rather likely the commenter has at least heard of the comical clone Krikkit.

        While these settings do not match the technical specifics, for literary purposes they are far and away the most commonly known examples of an alien civilization in a seemingly completely isolated solar system, likely what this person thought he was after. I would place good odds on it being either one of those two.

        Also, no one is bothering to lol about the overzealousness of the implications in the sciencemag article linked? If you assume complex alien life of some sort or even abiogenesis required an ozone layer…

        • gcochran9 says:

          Nightfall is not set in an extra-galactic system – it’s more like Philadelphia. But he should have been thinking of a particular story by Poul Anderson that is indeed set in such a system, one with a billion-year-old civilization. The title of that book is, of course, World Without Stars.

  2. JayMan says:

    For such a species, any space travel outside their solar system is intergalactic travel. That is one heck of a first step.

  3. jamisonr says:

    I suppose the high frequency of gamma-ray bursts throughout could help answer Fermi’s paradox, no?

    I remember reading that one of those bursts possibly caused a mass extinction on earth some 400m years ago by messing with the ozone and screwing with the climate.

  4. AppSoCRes says:

    One more reason among so many others to dismiss that piece of scientific hocum, the soi disant “Drake Equation”. Almost as big a humbug as anthropogenic global warming. There are a lot of really unique things about the only planet we know to have developed intelligent (sort of) life. Among others are: (1) It’s out on the edge of an arm of a spiral galaxy. (2) It’s in the rather narrow spherical section around the right kind of star so that large amounts of liquid water are possible. (3) It has a molten iron core creating a magnetic field that prevents its atmosphere from being blown away by the solar wind. [Sorry, Mars, you didn’t make the cut.] (4) It has a very large moon revolving close enough to act as a stabilizing influence on axial tilt and hence moderate seasonality and climate. Current models of how the moon formed suggest that this is a very rare occurrence indeed. Kepler, considering the relative sizes and spacing of earth, moon and sun, called total solar eclipses — which basically became possible about the time our first hominid ancestors appeared on the planet and will cease to occur within a couple of million years — one of God’s greatest gifts to mankind.

    • clathrus says:

      “Almost as big a humbug as anthropogenic global warming.”

      Thanks for putting that near the beginning of your comment. Saved me and likely many others valuable seconds.

      • Ursiform says:

        If you can get past that gratuitous, irrelevant, and uninformed comment he actually makes some good points.

        It’s a little like the Diamond problem. His books contain a wealth of information, and he makes many interesting observations. Unfortunately, his blind spots cause him to draw sweeping conclusions that often aren’t supported by the facts.

        • AppSocRes says:

          Gratuitous and irrelevant perhaps; but hardly uninformed. The most important factors determining earth’s climate (and weather) are (1) the magnitudes of solar radiation reaching earth; (2) the axial tilt of the earth in relation to the ecliptic (summer/winter anyone) and (3) the precessions of that tilt and other second order variations in it that seem to be responsible for the geologically recent ice ages that the earth has experienced. [I’m sure both of you are better acquainted with the widely accepted theory of Milankovitch cycles than is an ignorant lout like myself.] All these variable factors that are are more significant than any other immediately varying variables in determining weather and climate yet both are ignored in all the “climate change” models I’ve run across.

          I also worked while finishing up my Ph.D. with the type of system dynamics models that are used to build climate climate change models. I very quickly learned that these models are usually incredibly sensitive to extremely small variations in pararmeters, e.g., the “butterfly effect”. Before the models are of any use, empirical research is needed to appropriately fine tune these parameters. This has not been done for many if not most of the parameters in these models, e.g., there are still arguments over whether increasing water vapor in the atmosphere is governed by a positive or negative feedback loop!!!

          And the statistical methods that are used to estimate parameters are shockingly naive, e.g. moving averages to estimate temperature trends instead of ARIMA or more advanced methods. [To be fair, one piece of published research did use ARIMA and found that average global temperature variations over the past several decades show an underlying random walk, not an increase.]

          To prevent problems like this these models require massive amounts of sensitivity testing and evaluation. I have seen no evidence of this being done. Instead, whenever a prediction fails to materialize or some phenomenon appears to support recent global warming, parameters are altered post hoc to “explain” why. A recent example was the wonderful ability of these models to explain recent movements in Antarctic ice. At least until it was determined empirically that the flows were due entirely to volcanic activity.

          But let’s avoid such picky theoretical criticisms. Just compare the predictions of current conditions these modelers of AGW were making ten or fifteen years ago with actual current conditions. They’re all laughable failures.

          • ursiform says:

            OK, misinformed.

            1. Different cycles and effects occur over different time periods. The cycles you cite don’t explain near term trends.

            2. Many independent models predict similar trends due to what you call “AGW”. Few if any serious attempts to model global climate predict a contrary trend.

            3. There is an observed long-term correlation between greenhouse gas levels and global temperature. People are dumping greenhouse gasses into the atmosphere, and atmospheric levels are increasing. Don’t need a complex model to guess a trend.

            4. Global climate change models are intended to model long-term changes. They aren’t designed to predict weather in two years.

            5. Most climate models predict increased variability in weather; increased variability in weather (e.g., winters with a lot of blizzards) is not evidence against their predictions.

            6. “AGW” is a theory, not a mathematical theorem. It can’t be proven, only deduced to be likely to be correct. See, i.e., evolution, relativity, quantum mechanics …

            7. Arguments against “AGW” strike me as similar to arguments against evolution. Evolutions suggests D evolved from A. “But there is no intermediate form!” OK. here’s B. “But there’s no intermediate form between B and D!” OK, here’s C. “But there’s no intermediate form between C and D!” Repeat forever …

          • simontmn says:

            I’m always amazed by the confidence of AGW advocates considering that their predictions keep being falsified.

          • ursiform says:

            I hear a lot more claims about predictions being falsified than examples of actual predictions from climate models that have been falsified. Keeping in mind that the models predict long term trends, not conditions in any specific future year.

          • kai says:

            Looking at the longer trend you can (100 year let’s say, not much more if you want to have both temperature record and significant rise of co2), the models don’t do a good job on average, given the curve they have to fit (quite simple) and the number of parameters to adjust (quite a lot). Lately, they did so poorly that much lower estimates of temp/co2 sensitivity (this is not a division, relax 😉 ) do a come back in mainstream climate science. If the lower sensitivity (2c or less per doubling) get more and more likely, global warming will slowly fade into irrelevance. It is already, in fact…Unfortunately, I would have been happier to see it exposed as a scam, some of the scaremongers were extremely annoying and I don’t like the neopuritan green movement, even if I have a lot of respect for earlier versions focussed on species preservation…
            But no, it will not ends with a bang but with a whisper…like such things so often do…

      • jamesd127 says:

        Compare climate model projections made sixteen years ago, with what has happened since.

        They are wildly wrong.

        Temperatures have been flat since then, and global sea ice has increased substantially.

        Variations between models were slight. Difference between model and reality, huge.

    • petrus says:

      The Drake “equation” is actually a mathematical identity, and therefore has no content at all.

    • John Hostetler says:

      Cool about the eclipses – I assume this is about changing distances between the three bodies – can you explain what eclipses were and will be like 5 million years into the past and future?

      Was Kepler referring to the intellectual spur that eclipses represent (in addition to esthetic element)? I mean, of course he couldn’t have known that ‘divine providence’ provided total eclipses for something very close to the regnum of Hominidae, and neither before nor after.

      • Ursiform says:

        Five million years doesn’t make a lot of difference. In the past, total solar eclipses were more common, and in the distant past the moon appeared much larger than the sun. Over time the moon will appear smaller and smaller and there will be more annular eclipses and fewer total eclipses. In a few hundred million years the moon will never appear as large as the sun, and there will be no more total eclipses.

  5. Philip Neal says:

    Interesting developments. Will they necessitate further embellishment of the Malaysian flag before you have the new t-shirts printed?

  6. dave chamberlin says:

    I really enjoyed this book “Rare Earth, Why complex Life is Uncommon in the Universe”. Peter Ward wrote it and the reviews are here. It was a fun read, I know a lot of readers here appreciate a heads up on an original non fiction book.

    • Patrick Boyle says:

      Thanks for the recommendation. I read Ward’s book on oxygen levels and the dinosaurs a few months ago. I liked it very much but I wondered if it was valid.

    • dave chamberlin says:

      The long and short of it is we don’t have any idea how common or uncommon complex life is in the universe. Peter Ward doesn’t know and all the writers of science fiction sure don’t know. Carl Sagan, bless his old stoner heart, would use the Drake equation to sell that their has got to be thousands, maybe tens of thousands of intelligent races out there, so what are we waiting for, lets get a move on and get out there and meet em.

      Fermi nailed it in one short sentence asking some other physicists shooting the shit about news stories on extra terrestrial aliens, “Where are they?”

      It is all we have to really go on. We are on the cusp of leaving this blue ball (OK, theoretically but we are getting close) and the planet Earth has harbored complex life for around a half a billion years, why on earth if we are getting ready to shove off, has no one else in 500,000,000 years ever come here to make this place their home? One of those factors in the Drake equation have to be very close to absolute zero, to keep us all alone in that insanely long time span. Yea, there are other possibilities like every time life gets intelligent enough to become intelligent to go out exploring they kill themselves in a cataclysmic frenzy (another stoner idea from Sagan) but I don’t buy it. Peter Ward talks about the hypothetical possibilities the way they should be talked about, he is a serious scientist, not just another schmuck trying to write a non fiction best seller. It’s fun to wonder about the big picture, that is one reason why i liked his book.

      • athEIst says:

        Does he cover the most common “science fiction” answer–they came, they got a glimpse of us, and they quarantined several cubic light years around the sun.

  7. dearieme says:

    Why do all discussions such as this tend to assume that complex life must be much like our goodselves?

    • Count Doofus says:

      Because life in earth show remarkable similarity even when stem from far different groups.
      See thylacosmilus e smilodont, and a zillion of mouse-looking creature.
      Intelligent behavior is shown to appear in very different animals, from octopus to raven to dolphin, but civilized intelligent behavior is a pure human brand.
      The environment suitable for life is very probably the same in all universe. Same environment, same external evolutive pressure, same look.

      On totally different point, dearieme, have you italian origins?

  8. a very knowing American says:

    So maybe SETI should be looking for advanced civilizations (Dyson spheres, or whatever) in intergalactic space?

  9. ziel says:

    That first step is a doozy.

    Haha – I finally got it.

  10. Cpluskx says:

    What would sky look like on a planet orbiting a rogue star? All black except the star?

    • JayMan says:

      Night time sky would indeed be all black on such a planet save for other objects in solar system and any possible stellar companions.

      • AppSoCRes says:

        Can that be correct? The magnitude, brightness, and distance of distant objects, e.g., galaxies, which constitute by far the vast majority of “stars” observable in earth’s night sky, would be one set of determinants of what will appear in the night sky of a planet. The other major set of determinants would be the obscuring effects of light radiation from the rogue star, the opacity of the planet’s atmosphere, and the inter-stellar dust density in the rogue star’s neighborhood. Given the near uniform distribution of galaxies and the isotropic nature of space, the night sky of an earth-type planet in a rogue solar system should usually be just as bright and “star”-spangled as earth’s night sky. Olber’s paradox will be as true or false anywhere — except perhaps in galactic cores and near massive objects as it is in the vicinity of our solar system. Am I missing something here?

        • Cloudswrest says:

          Only four galaxies, outside the Milky Way, are visible to the naked eye. The Large and Small Magellanic Clouds, Andromeda and (just barely in ultra dark skys) Triangulum. They appear as fuzz balls and their surface intensity is much dimmer than stars.

        • JayMan says:

          Only about 200 or so stars are brighter than magnitude 3, which is a bit brighter than the Andromeda Galaxy appears, if that gives you any idea. And what Cloudswrest said. Objects would be visible, but they wouldn’t stand out. Much about the sky would be unknown to these people before they invented telescopes.

        • gcochran9 says:

          “galaxies, which constitute by far the vast majority of “stars” observable in earth’s night sky”

          Clearly you grew up on a planet of an extragalactic star somewhere in the Virgo Cluster. We can still accept your donations – allow for the alien transaction fee.

          • ApPSocRes says:

            Not totally fair, if you are willing to allow telescopes. I’m assuming that any intelligent species would eventually invent these, e.g. for military purposes. Sooner or later someone would accidentally look at the night sky and notice hundreds, if not thousands, of small bright objects. Larger scopes would reveal these to be galaxies and nebulae.

          • ursiform says:

            “I’m assuming that any intelligent species would eventually invent these, e.g. for military purposes.”

            For what purpose do you think Hans Lippershey tried to sell his first telescope?

  11. Cloudswrest says:

    Long gamma ray bursts last for tens of seconds and occur when massive stars burn out, collapse, and explode. …

    … That seconds-long flash of radiation itself wouldn’t blast away life on a nearby planet. Rather, if the explosion were close enough, the gamma rays would set off a chain of chemical reactions that would destroy the ozone layer in a planet’s atmosphere.

    On BOTH sides of the planet? How’s that work?

    • AppSoCRes says:

      The current theories of planet formation suggest that, unless locked by tidal forces, planets will rotate. This means that if one is stripped of a large part of its atmosphere by a gamma ray burster, the planet’s surface will, over time be uniformly exposed to (probably) massive levels of radiation.

  12. Count Doofus says:

    Thinking on preceeding posts in this blog, it seems that mouse-look is the most evolutionary valid. it goes from common rat to elephant shrews to opossum.
    All hail the mouse-shape!

  13. melendwyr says:

    A while ago I attended a series of talks given by my local university’s astronomy program. Among the topics discussed was a gamma ray burst, detected, in the late 90s, that caused a detectable (but ecologically not noticeable) ionization of the upper atmosphere and creation of nitrogen compounds. That wasn’t the surprising part.

    The neutron-starquake that caused the burst occurred on the very edges of our ability to observe – on the horizon of our universe. Billions of years ago, billions of light-years away. What would it have done to our planet if we’d been a few dozen galaxies closer to it?

    I always laugh inside when I hear or read some pompous fool talking about how our universe is tuned to permit life. Not only is the argument generally incorrect, it’s specifically wrong: this universe is unspeakably hostile to living things, perhaps more so than we can comprehend.

    • j says:

      Perhaps humanity’s first task should be to create some kind of gamma ray shield. May be densely packed crystals… We must also seed the whole universe so life would have a greater than zero probability to survive somewhere.

      • gcochran9 says:

        Supposedly the mechanism is ozone destruction: just keep seven years of food in a cave, along a nuclear-reactor powered terrarium/aquarium in which you preserve the flora and fauna you want to reintroduce: everything from diatoms to venison, I meant to say deer. And people, traditionally about 10 females for each male. Supplement with a sperm bank. The cave has to be defensible: everyone else is going to want in. Doesn’t have to be real deep, but you do want to keep out of the UV while the ozone is out of commission.

        It’s cheap, really: perhaps we’re already doing it, in the same way that we do all the prudent anti-disaster stuff.

        • j says:

          If we are already doing it, I hope we are following Dr Strangelove’s blueprint and the females are super attractive.

        • melendwyr says:

          You’re leaving out the acid rain issue… as well as the difficulties of so much of Earth’s biosphere dying that it sharply reduces the oxygen content of the atmosphere.

          If you think you’ve come up with a simple solution to a problem, there’s a good chance you’ve gotten something wrong.

    • gcochran9 says:

      The physical laws allow carbon-based life, but with slight changes they would not. “Tuned” is as good a word as any.

      • melendwyr says:

        So? In order for the argument to work, we’d have to demonstrate that alternative physics would be less hospitable to life. Life, not carbon-based life. Our ability to derive working models from fundamental postulates isn’t advanced enough for us to do this.

        For all we know, our reality is relatively deprived because of its total lack of merielon, which the overwhelming majority of potential life is founded upon.

        • gcochran9 says:

          Well now, you’re being silly. We already know that other kinds of life are possible: we could construct something that could replicate itself, if we tried hard. Something that could live in a wider range of environments than carbon-based life. But it’s hard to see how life that used FETs, or vacuum tubes, or gears a la Babbage engine, could evolve in the first place.

          Of course we don’t really know how carbon-based life evolved either, but the warm little pond idea isn’t totally crazy.

          • melendwyr says:

            You’re talking about alternate forms of life within our known physics, Dr. Cochran. The ‘tuning’ argument ignores whatever kinds of life might be possible in the entire space of possible physics. We don’t know if there are alternatives, and if there are, we don’t know whether they would be worse or better than our system for life.

            That’s why the argument isn’t just wrong, it’s stupid. It’s made by people who want to think that there’s something special about our world, probably because some benevolent superbeing made it so.

    • dave chamberlin says:

      I would like to expand on melendwyr’s comment because I think it a good jumping off point for what is most probable. Suns are energy giving but they are not life giving whatsoever, instead they are extremely adept at quickly killing complex life. Simple life may or may not be freakishly rare, we simply don’t know. It might be frequently located in places like Europa, Jupiter’s moon that has an ocean of liquid water below it’s frozen surface. What is looks probable from what little we know is life is freakishly rare, complex life is freakishly rare squared, and intelligent life is freakishly rare cubed.

      • jamesd127 says:

        The chemistry of Titan differs substantially from what would be expected if only nonliving processes are at work. If life on titan, probably life pretty much everywhere. Complex life, however, requires substantial amounts of oxygen, to give single celled organisms an incentive to group together for defense and attack. Probably requires a large moon to avoid climate extremes from time to time. It is likely oxygen worlds are very rare.

  14. MawBTS says:

    I always laugh inside when I hear or read some pompous fool talking about how our universe is tuned to permit life.

    Noses are also fine-tuned to hold up spectacles.

  15. franklindmadoff says:

    Greg, Henry, and company:

    In case anyone is interested: I compared aggregated data state-wide from’s “genetic census of america” to non-hispanic white (NHW) life expectancy (and other measures) over on my in a long-ish blog post. I found that by using three of their european “ethnicities”, namely Great Britain, Ireland, and Western Europe, as a share of total european ethnicities I could account for ~53% of the variance in NHW life expectancy (significant variance amongst states) and ~84% if I added in current NHW smoking rates (amongst other findings).

    I suspect this more quantitive genetic approach is probably more accurate and more robust than using self-reported ancestry measures and the like (as in the US census), although I see these reported ethnicities as fairly crude proxies for particular populations that happened to settle or immigrate here in the main (not to mention other issues with representativeness and the like)….

  16. athEIst says:

    Seems like a solar system would be greatly altered by being “flung”. Would “flung” solar systems be noticeably different from non-flung solar systems other than being out in the darker?

    • gcochran9 says:

      As long as it didn’t get too close to something that radiated strongly, being flung would have no effect at all. Bird navigation might be screwed up, eventually.

      • athEIst says:

        Bird navigation might be screwed up, eventually..

        • gcochran9 says:

          Birds use the stars in navigation: new constellations -> you fly east for the winter.

          • athEIst says:


          • a very knowing American says:

            Slightly more complicated, at least for indigo buntings. They aren’t born with a map of constellations in their heads. Instead they learn which part of the sky the other stars rotate around. Right now that’s Polaris. 13000 years ago it was Vega. So precession doesn’t mess them up. And in a planetarium they can learn to use any old star as “North” if it’s made the center of rotation. Of course on a planet outside the galaxy, with no visible stars, indigo buntings would be screwed.

            Stephen T. Emlen. 1975. The stellar-orientation system of a migratory bird. Scientific American

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