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A View of the Deepest Future

Adam Crowl first appeared in Centauri Dreams not long after I opened the site to comments about nine years ago. His insights immediately caught my eye and challenged my thinking. I have always admired auto-didacts, and Adam is an outstanding example: “I don’t work in this field nor did I especially train in it,” he writes. “I did physics/maths/engineering study but my astrophysics, astrodynamics, planetology and interstellar propulsion knowledge is self-taught.” The list of books in the various disciplines — as well as science fiction — by which he did this will, I hope, become a future Centauri Dreams article. Adam writes the Crowlspace blog, is active in Project Icarus, the re-design of the 1970’s Project Daedalus fusion starship now in progress at Icarus Interstellar, and is a frequent participant on this site, often pointing me to papers I would otherwise have missed. The one he discusses today is, typically for Adam, a true mind-bender.

by Adam Crowl


The long-term fate of Life in this Universe is rarely contemplated. A few landmark studies, by Freeman Dyson, then Fred Adams, Peter Bodenheimer & Greg Laughlin, have looked into Deepest Time, long after Matter itself fails and the Void becomes unstable. How far can biological Life extend into the Long Dark? A study by Robin Spivey extends Life’s tenure, in neutrino-annihilation warmed Ocean Planets, to 1025 years – and Beyond. That’s 100 times longer than the 1023 years we’ve reported here previously and some 1,000 trillion times longer than the time the Universe has presently existed. If the current Age of the Universe was a clock tick – a second -, then those 1025 years would be 20 million years.

Spivey discusses his new finding here: Planetary Heating by Neutrinos: Long-Term Habitats for Aquatic Life if Dark Energy Decays Favourably [Open Access article]. Outer-shell electrons of 56Fe (iron) inside the cores of Ocean-Planets become ‘catalyzers’ of Inverse Photo-Neutrino Process (IPP) reactions, annihilating neutrinos and creating a steady heat-flow sufficient to warm the planet at ~0.1 W/m2. This Figure, published in the paper, illustrates the flow:


Perhaps coincidentally, the inexorable processing of stellar materials in Type Ia Supernovae leads to a chemical mixture which makes Earth-like planets. Each Type Ia Supernova masses about 1.4 Solar Masses, or about half a million Earths, with the ejecta debris being mostly iron, then oxygen and silicon. Earth-stuff. Thus the ‘ashes’ of stars can produce a multitude of Ocean Planets.

To quote Spivey:

Observations have determined that the ejecta of a typical SNIa are, by mass, 18% oxygen, 15% silicon, 13% iron, and 49% nickel (almost all in the unstable form 56Ni which decays radioactively to 56Fe), along with smaller amounts of carbon, calcium, sulphur and magnesium. Elements emerge from SNIa in strata, with the lightest occupying the outermost layers. This provides the oxygen-rich outermost shell with the best opportunities for reacting with hydrogen in the interstellar medium, resulting in the formation of water molecules. On cooling to temperatures found in deep space, ice XI is obtained, whose ferroelectric self-aggregation may be relevant to comet formation [38-40]. The bombardment of protoplanets with comets would be important to the formation of oceanic planets, deferring the delivery of water to their surfaces.

Notice that the iron component is 62% by mass, thus the very large core in the illustration. Quoting Spivey again:

Based on the composition of type Ia supernova ejecta, a hypothetical oceanic planet of one Earth-mass is projected to consist of a large iron core of radius ~4240 km surrounded by a silicate mantle of thickness ~1300 km through which heat would be transported by advection. External to this inner mantle would be an outer mantle of ice consisting of strongly convective ice VI and VII phases of combined depth ~320 km. A liquid ocean ~50 km in depth covered by a solid crust of ice Ih upwards of 50 m in thickness would overlie the hot ice mantles.

Spivey’s new paper focuses on how the supply of neutrinos can be maintained at the right density to keep planets warm for the maximum amount of time. He posits several, as yet, unobserved processes – the decay of dark energy into neutrinos in less than ~70 billion years and the accelerated decay of black holes, also preferably into neutrinos. Other researchers have posited the existence of ‘sterile’ neutrinos, which Spivey shows improves the characteristics of the neutrino halo surrounding a Galaxy cluster, enabling planets to be warmed in a life-friendly manner in a sphere of 400 thousand light-years radius.

The existence of Dark Matter itself has been called into question by physicists, such as Mordechai Milgrom, who think the evidence for invisible Dark Matter can be equally well explained by modifying Newtonian Gravity to have a minimum gravitational acceleration. This Modification of Newtonian Dynamics (MOND) theory neatly explains the structure of galaxies, but hasn’t been as successful on a cosmological scale. Intriguingly if Galactic haloes are made of sterile neutrinos, then MOND and Dark Matter physics are equivalent in outcomes: Reconciliation of MOND and Dark Matter theory with giant ‘Neutrino Stars’ forming around each large Galaxy. Spivey suggests that a key research priority is determining the properties of neutrinos, to confirm the IPP heating mechanism. Such neutrino studies are important for refining the Standard Model of particle physics – and possibly discovering new physics, such as the masses of the various neutrinos, something not predicted by the Standard Model.

Spivey’s most audacious suggestion is the strategy that Life should adopt in the next few aeons to extend its lifespan. Unfortunately for Life in this Galaxy, our local Group of Galaxies is insufficiently massive to form a large enough neutrino ‘star’ before Dark Energy spreads galaxies too far apart. To survive, Life in our Local Group needs to emigrate to the Virgo Super-Cluster. Although our Milky Way is heading towards Virgo at ~200 km/s, cosmic acceleration, from Dark Energy, is presently pushing us away from Virgo at ~1,000 km/s. Thus we need to launch towards Virgo faster than the Dark Energy pushing us away. Yet the reward is 10 trillion trillion years of Habitable planetary environments, which may well be worth intergalactic migration.

Spivey suggests using antimatter rockets to launch modest payloads. Essentially small Life-seeds, like those proposed by Michael Mautner to seed Life in our own Galaxy, but launched on intergalactic journeys of a hundred or more billennia. Whether the cosmic-ray flux between the Galaxies can be endured for geological epochs is presently unknown and while I wouldn’t rule it out, it seems unlikely at best. A good reference, available online, is still Martyn Fogg’s “The Feasibility of Intergalactic Colonisation and its Relevance to SETI”, which suggests how a mere 5 million year intergalactic voyage might be survived by a bio-nanotech seed-ship.

But we’ve discussed other options in these pages previously. In theory a tight white-dwarf/planet pair can be flung out of the Galactic Core at ~0.05c, which would mean a 2 billion year journey across every 100 million light-years. A white-dwarf habitable zone is good for 8 billion years or so, enough to cross ~400 million light-years. It’d be a ‘starship’ in truth on the Grandest Scale. Perhaps other Intelligences have begun their preparations earlier than us and we should look for very high-velocity stars leaving the Milky Way and Andromeda’s M31. Over the next aeon we might observe many, many stars flinging towards Virgo from the nearby Galactic Core black-holes.

Comments on this entry are closed.

  • Montie June 23, 2014, 16:48

    Hello, Adam. It’s Montie from the Jovian Society(and SpaceX, and Mars, etc). this remind sme of a talk given by Robert Bradbury, about how it might be possible to continue on to a degree where the worry is dealing with the heat death of the Universe.


    That is part 1 of 3, if you are interested. I exchanged a few emails with him in 2001, and learne donly recently of his passing.

  • Adam June 23, 2014, 16:59

    Hi Montie
    Robert Bradbury was a Giant of ideas, with his Matrioshka Brain concept being one of the largest easily conceivable inhabited structures ever proposed. He assumed the physical possibility of the Singularity, but what if he was mistaken? Spivey is a Singularity-sceptic and so I think contemplating the long-term options for biological life is worthwhile, this side of the Singularity.

  • Geoffrey Hillend June 23, 2014, 18:30

    I don’t agree with the IPP process or Inverse Neutrino Photo processes. It does not seem to be supported by quantum physics. Neutrinos like Dark Matter are only weakly interactive with baryons or matter particles, the fermions and bosons which is why they are difficult to detect. Most of them pass right through the Earth and not enough of them interact with matter to cause the heat needed to heat a planetary core. Trillions of them pass right through the Earth and not enough of them interact with matter to cause the heat needed to heat a planetary core. Trillions of them pass through our body every second. We detect them when they collide with a nucleus of an atom such as the atoms in water in the Super-Kamiokande detector. When a muon neutrino hits the nucleus of a water atom, a cone of Cherenkov light is emitted from the nucleus in the form of muons and an electron neutrino collision with a nucleus with emit a cone of electrons with positrons so neutrinos are only indirectly detectible. P. 70 Scientific American, the Edge of Physics, special edition
    Furthermore, I don’t think there is a large enough cross section or particle interaction for enough neutrino an anti-neutrino annihilation for them to be a significant heat source in a planetary core. It sounds like a process than might happen in stars, gas or the quantum vacuum zero point energy of space.


    All that is needed to heat the core of a planet is a large iron core. Our Earth has a large iron core which is partially liquid. It is mostly heated by extreme pressure, friction and the radioactive decay of radioactive isotopes.


  • Geoffrey Hillend June 23, 2014, 18:57

    Excuse me for the error. Neutrino heating from neutrino and anti-nuetrino annihilation is supported by quantum physics. It occurs in the accretion disks of black holes. It also occurs in radio active decay but the pressure in friction of an iron core causes most of the heat there. Stars emit most of the neutrinos.

  • Geoffrey Hillend June 23, 2014, 19:02

    www. mnras.oxfordjournals.org/concent/410/4/2302.full

  • Adam June 24, 2014, 2:47

    Hi Geoffrey
    Spivey makes his argument for the specific process in the paper. Best read it to learn more. Iron-56’s outer shell electrons provide numerous narrowly spaced transitions which can be excited by a W-mediated reaction with neutrinos sufficiently often to warm a planet. Or so the numbers imply.

  • torque_xtr June 24, 2014, 3:59

    If the planetoid is massive enough and has a thermoinsulating atmosphere, than the liquid water might be supported py proton decay itself, which extends the habitat existence into 10^34 years range..

    (further calculations make this unlikely. The object needs to be very massive, more like the stellar mass object formed from a very chemically evolved medium. If it has 1 solar mass, it is composed f ~10^57 nucleons, and 10^16 of them decay every second, providing a megawatt of heat, so the only place for such habitat would be somewhere quite deep inside black dwarfs, in a thin layer of cold water sandwiched somewhere between surface and high pressure ices. And this layer would very likely be deficient in heavy elements because of gravitational separation, and unstable because collisions with the black dwarf surface would temporarily vaporize it, even the 10-km asteroid would give a punch more like the Moon-forming collision. And then again, the heating in stellar remnants and other massive objects depends on the Unknown Physics…) The decay of dark matter particles, concentrated inside such objects by the intense gravity, now seems more reliable and probably even more long-lived because it is not limited by the rest energy of planetoid mass, but by the quantity of available dark matter…

  • Brian Swiderski June 24, 2014, 4:29

    Thinking about such Deep Time causes me to then think in the opposite direction and wonder, are there exotic lifeforms from earlier epochs in the universe whose conditions would have been extremely hostile to Life As We Know It (LAWKI), but that have managed to survive into the present era of “normal” matter through means as clever as those laid out here for LAWKI to survive into the Long Dark?

    I would urge people who research these topics to think about that question, and try to imagine what such structures might be and how we might be able to detect them. We can already look for Dyson Spheres to a minimal extent, but those would be extremely familiar civilizations compared to the weirdos who would be survivors of times when the universe was hot and dense. What might an intelligence do to locally maintain Early Universe conditions in the present era, and how could we detect such environments?

  • swage June 24, 2014, 6:03

    Particle physics isn’t a strong point of mine. Physics isn’t a strong point of mine. However, as far as i understand it, this is very, very theoretical work. There are too much unknowns, especially with respect to Dark Energy (and to a very secondary extend Dark Matter and ‘singularities’), to make a conclusive statement in these timescales at this time. Some people speak of a cosmological crisis (a crisis of modelling) and i am inclined to agree.

    Its good to build future scenarios based on what seems possible and think about that, but one should keep in mind that we are not currently in a position to make really conclusive statements about stellar evolution in these dimension at this time. Based on this its not surprising that there are various competing models for the ‘end of the universe’ as such floating around the scientific community, all perfectly credible.

    We should of course be aware of any and all ‘worst case’ scenarios at all time.

  • Mike Lockmoore June 24, 2014, 12:10

    Sure, this posting is based on very speculative physics, but it’s a fun little thought experiment nonetheless. Wonderful stuff you’re sharing here, Adam. Count me as a fan!

  • ljk June 24, 2014, 12:31

    Mysterious X-ray Signal Intrigues Astronomers

    June 24, 2014

    A mysterious X-ray signal has been found in a detailed study of galaxy clusters using NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton.

    One intriguing possibility is that the X-rays are produced by the decay of sterile neutrinos, a type of particle that has been proposed as a candidate for dark matter.

    While holding exciting potential, these results must be confirmed with additional data to rule out other explanations and determine whether it is plausible that dark matter has been observed.



    “We know that the dark matter explanation is a long shot, but the pay-off would be huge if we’re right,” said Esra Bulbul of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. who led the study. “So we’re going to keep testing this interpretation and see where it takes us.”

    Full article here:


  • Michael June 24, 2014, 13:07

    Surely on those time scales the Universe would have become so large that neutrinos would be very dilute indeed. I am also dubious about the iron (planet sized) been a absorber of these elusive particles as well. Probably better to live on the edge of a black hole and feed off the energy radiated by in falling dark or normal matter.

  • swage June 24, 2014, 15:00

    Oh, absolutely. Its very important to do this kind of scenario development, as it helps to understand the universe.

  • Geoffrey Hillend June 24, 2014, 16:36

    Adam W bosons are part of the weak nuclear force or radioactive beta decay. Scientists already know about the heat creating processing in planets including large ion cores. Half of the heat in the Earths core is generated from the decay of radioactive isotopes which emit alpha, beta and gamma particles. Some of the energy of the collisions of alpha, beta and gamma particles “is converted into the thermal movement of atoms.” Wikipedia, Earths internal heat.
    This process is from the linear energy transfer or momentum of the radiation. The rotation or vibration of the atoms corresponds to heat. I think Neutrino interaction with the atoms are small since they are weakly interacting so they are only responsible for a small fraction of heat. It’s mostly the alpha, beta and gamma decay which cause the heat.
    I don’t want to get into the details of this process because I am not a nuclear physicist but the momentum of the radioactive particles through linear energy transfer cause elastic and inelastic scattering, neutron capture and decay, nucleus excitation and decay etc.

  • ljk June 24, 2014, 16:39

    Perhaps when galaxies start merging as the Milky Way and Andromeda galaxies will do in a few billion years, not only can beings from one galaxy move to the stars of the other but even as they spread apart in their cosmic dance, the stellar islands often produce long streams of stars between them along with a literal explosion of stellar births.

    Perhaps during those long eras beings can “hop” along the star streams from one galaxy to the other, having a supply of star systems along the way instead of relatively empty intergalactic space.

    Perhaps that is why we have yet to be aware of any visitors from Messier 31 or other members of the Local Group, as they are awaiting the merger to save time and money.


    Perhaps we should examine those colliding galaxies with long star streams between them to see if their is any activity such as Cherenkov radiation which is supposed to indicate a starship moving at relativistic speeds or a preponderance of what look like red dwarfs (Dyson Shells).

    If beings do continue to compete for space and resources on a galactic scale, then intergalactic migration may make sense.

  • Geoffrey Hillend June 24, 2014, 16:43
  • Adam July 1, 2014, 4:31

    Hi Geoffrey
    I’m well aware of present-day geophysical heat sources (and some more speculative options), but Spivey isn’t suggesting that’s where the current heat is coming from. Neutrino-heating will kick-in in later aeons, long after geophysical sources are tapped out.