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posted by martyb on Friday June 22 2018, @02:25AM   Printer-friendly
from the star-wars:-where-combatants-toss-stars-at-each-other dept.

How an Advanced Civilization Could Stop Dark Energy From Preventing Their Future Exploration

For the sake of his study, which recently appeared online under the title "Life Versus Dark Energy: How An Advanced Civilization Could Resist the Accelerating Expansion of the Universe", Dr. Dan Hooper considered how civilizations might be able to reverse the process of cosmic expansion. In addition, he suggests ways in which humanity might looks[sic] for signs of such a civilization.

[...] This harvesting, according to Dr. Hooper, would consist of building unconventional Dyson Spheres that would use the energy they collected from stars to propel them towards the center of the species' civilization. High-mass stars are likely to evolve beyond the main sequence before reaching the destination of the central civilization and low-mass stars would not generate enough energy (and therefore acceleration) to avoid falling beyond the horizon.

For these reasons, Dr. Hooper concludes that stars with masses of between 0.2 and 1 Solar Masses will be the most attractive targets for harvesting. In other words, stars that are like our Sun (G-type, or yellow dwarf), orange dwarfs (K-type), and some M-type (red dwarf) stars would all be suitable for a Type III civilization's purposes.

[...] Based on the assumption that such a civilization could travel at 1 – 10% the speed of light, Dr. Hooper estimates that they would be able to harvest stars out to a co-moving radius of approximately 20 to 50 Megaparsecs (about 65.2 million to 163 million light-years). Depending on their age, 1 to 5 billion years, they would be able to harvest stars within a range of 1 to 4 Megaparsecs (3.3 million to 13 million light-years) or up to several tens of Megaparsecs.

In addition to providing a framework for how a sufficiently-advanced civilization could survive cosmic acceleration, Dr. Hooper's paper also provides new possibilities in the search for extra-terrestrial intelligence (SETI). While his study primarily addresses the possibility that such a mega-civilization will emerge in the future (perhaps it will even be our own), he also acknowledges the possibility that one could already exist.

Kardashev scale. One parsec is equivalent to a distance of approximately 3.26156 light years. Corrections made above.


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  • (Score: 2) by ElizabethGreene on Friday June 22 2018, @05:37PM (2 children)

    by ElizabethGreene (6748) Subscriber Badge on Friday June 22 2018, @05:37PM (#696854) Journal

    >> a relatively negative energy density stored within a physical substrate

    (I am not an expert on this topic.)

    For an Alcubierre drive I don't know if that's a show stopper or not. You do need both the positive and negative energy density, a massive metamaterial structure might be the ticket. If you can achieve the desired effect with a low enough frequency (wavelength in tens of meters) it's not inconceivable to make the spacecraft in or part of the resonator.

    It would be cool to see a 10 Megahertz multi-gigawatt split-ring resonator (from a safe distance)(assuming it didn't rattle the fillings out of your head)(and give your cancer cancer).

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  • (Score: 2) by Immerman on Friday June 22 2018, @05:57PM (1 child)

    by Immerman (3985) on Friday June 22 2018, @05:57PM (#696864)

    I'm no expert either, and while I understand the basic geometries involved, I have only the vaguest concept of why negative energies are absolutely required to create them.

    However, if negative energies are necessary, then I strongly suspect that any substantial quantity of matter, with it's incredible positive energy density, in those regions that require a negative energy density would render them unsuitable. Moreover, you're talking about regions of space that are folded in on themselves with such extreme curvature that even subatomic particles would be torn apart by the immense tidal forces - I doubt any physical metamaterials could survive (though perhaps some sort of "metaenergy" structure could.

    Another potential problem is that the entire metastructure would have to exist *within* the "warp field", since anything outside the field will be left far behind as soon as you start moving FTL.

    • (Score: 2) by VLM on Friday June 22 2018, @07:22PM

      by VLM (445) Subscriber Badge on Friday June 22 2018, @07:22PM (#696902)

      There are other LARP issues with FTL such that traditionally its inside a ship that can control it, but its sometimes pretty tricky to control a field from inside it. Think of how easy it is to charge two capacitor plates using all kinds of gadgetry from the outside of the plates, and its a bit trickier to charge two plates from between two plates without generating an even stronger tidal field in between the plates than exists outside it. Of course "FTL field" might be as simple as manipulating a magnetic field, although I suspect it would not.

      My guess is a FTL thingie would be more stargate like, a huge and energetically expensive space station, where small stuff goes in a big object and magically disappears, reappearing perhaps FTL hopefully a really long distance away.

      Something often mentioned is how poor of a job solar cells do further away than earth orbit. Yet, if you can keep them cool (which can be tricky) then solar cells within the orbit of Mercury or something really pump out the watts.

      If I were doing realistic hard sci fi I'd put my theoretical solar powered star gate around Mercury.

      Also some of those solar systems with extremely large planets in extremely close to their star orbits would probably look absolutely delicious as a resource provider for a solar powered star gate civilization.

      Now the point of this ramble is if I were doing SETI stuff, assuming solar powered star gates exist, THEN I'd be pointing my SETI antenna at those recently discovered planetary systems with huge planets in close orbit to stars.

      Assuming of course we're not all being fooled by the oldest "Warp drive" trick in the sci fi book, that being close to grav fields screws up warp travel.

      Also I would assume that any research on this is classified. Something that can go faster than light outside normal space ... is not just faster than light, but is outside normal space and that would make it awesome (well, from some perspectives) for everything from logistics to weapons of mass destruction to paratrooper delivery service.

      So mixing this all up, we can "prove" grav fields do or do not F up solar powered star gates by pointing SETI antennas at likely exo species Space Marine base locations to determine if those otherwise ideal locations are, or are not, swarming with alien space marines. Assuming we can identify space marines from this distance. Extrapolating from my experience in the Army with Marines, admittedly a long time ago, we would need to detect excessive quantities of pr0n liquor and hooah.