For two galaxies accelerating away from each other one might in an "in principle" manner think of a tether connecting these two galaxies. Some sufficiently capable ET then manages to build this tether continually out of a magnetic material that passes through coils and the Faraday effect kicks in. This is not exactly eternal, for eventually these ETs will run out of resources in their galaxy, but it does seem to suggest dark energy could be mined.
There is however no "free lunch" per se here. https://physics.stackexchange.com/questions/257476/how-did-the-universe-shift-from-dark-matter-dominated-to-dark-energy-dominate/257542#257542 so you can read this without me having to spend the next hour typing this up again. This all stems from the Hamiltonian constraint NH = 0 which then has a kinetic and potential part. The eternal accelerated expansion is then just a way that ever more negative gravitational potential energy generates ever more kinetic energy. LC On Tuesday, April 2, 2019 at 3:23:48 PM UTC-6, Mason Green wrote: > > It appears as though it would indeed be possible to build a device powered > by dark energy. Such a device could keep running forever (as long as the > universe keeps expanding forever and vacuum decay doesn’t occur) and be > able to survive (or prevent) the heat death of the universe. Even proton > decay would not present a problem; new protons could always be created from > the energy generated. > > So far I’ve thought of two possible classes of device that could do this. > The first is the “giant atom”, consisting of two spheres of equal but > opposite charge orbiting each other at an extremely long distance (long > enough that dark energy becomes significant). At such a distance, dark > energy would cause the objects’ orbits to spiral further and further apart. > On the other hand, because the objects are charged, they radiate away > energy as they orbit, and this radiation provides a braking force that > would cause the objects to spiral closer together. If the two effects are > perfectly balanced, the orbits would be stable and the system would keep > radiating away energy forever—energy extracted from the acceleration in the > universe’s expansion. > > The second device consists of an extremely long spring. Due to dark > energy, the spring experiences a fictitious force pulling it apart. This > force is stronger when the spring is fully extended, due to the longer > distance between the ends. Thus an oscillating spring would experience an > oscillating force, and have energy continually added to it, increasing the > amplitude of its oscillations. To keep the string from breaking, a > mechanism for extracting energy from the spring would have to be added, and > if energy is extracted at the same rate it is added the system would be > stable. > > As far as I know, neither of these devices has been proposed before in the > literature; I might have been the first person to come up with them. > > Perhaps we should look for signs of these devices being constructed, in > the event highly advanced alien civilizations might be constructing them. > Any civilization that constructs such a device would probably qualify as > Type IV. With infinite energy it’d be possible to do an endless variety of > things: run a universal dovetailer, or resurrect the dead (simply by > resurrecting every person who COULD have ever existed, a set that obviously > includes every person who DID actually exist), etc. > > -Mason Green -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
