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Title: Life versus dark energy: How an advanced civilization could resist the accelerating expansion of the universe

Abstract

We present that the presence of dark energy in our universe is causing space to expand at an accelerating rate. As a result, over the next approximately 100 billion years, all stars residing beyond the Local Group will fall beyond the cosmic horizon and become not only unobservable, but entirely inaccessible, thus limiting how much energy could one day be extracted from them. Here, we consider the likely response of a highly advanced civilization to this situation. In particular, we argue that in order to maximize its access to useable energy, a sufficiently advanced civilization would chose to expand rapidly outward, build Dyson Spheres or similar structures around encountered stars, and use the energy that is harnessed to accelerate those stars away from the approaching horizon and toward the center of the civilization. We find that such efforts will be most effective for stars with masses in the range of $$M\sim (0.2-1) M_{\odot}$$, and could lead to the harvesting of stars within a region extending out to several tens of Mpc in radius, potentially increasing the total amount of energy that is available to a future civilization by a factor of several thousand. Lastly, we also discuss the observable signatures of a civilization elsewhere in the universe that is currently in this state of stellar harvesting.

Authors:
ORCiD logo [1]
  1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, IL (United States)
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP)
OSTI Identifier:
1462730
Alternate Identifier(s):
OSTI ID: 1637151
Report Number(s):
arXiv:1806.05203; FERMILAB-PUB-18-254-A
Journal ID: ISSN 2212-6864; 1677930; TRN: US1902209
Grant/Contract Number:  
AC02-07CH11359; FG02-13ER41958; SC0009924
Resource Type:
Accepted Manuscript
Journal Name:
Physics of the Dark Universe
Additional Journal Information:
Journal Volume: 22; Journal Issue: C; Journal ID: ISSN 2212-6864
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS

Citation Formats

Hooper, Dan. Life versus dark energy: How an advanced civilization could resist the accelerating expansion of the universe. United States: N. p., 2018. Web. https://doi.org/10.1016/j.dark.2018.09.005.
Hooper, Dan. Life versus dark energy: How an advanced civilization could resist the accelerating expansion of the universe. United States. https://doi.org/10.1016/j.dark.2018.09.005
Hooper, Dan. Thu . "Life versus dark energy: How an advanced civilization could resist the accelerating expansion of the universe". United States. https://doi.org/10.1016/j.dark.2018.09.005. https://www.osti.gov/servlets/purl/1462730.
@article{osti_1462730,
title = {Life versus dark energy: How an advanced civilization could resist the accelerating expansion of the universe},
author = {Hooper, Dan},
abstractNote = {We present that the presence of dark energy in our universe is causing space to expand at an accelerating rate. As a result, over the next approximately 100 billion years, all stars residing beyond the Local Group will fall beyond the cosmic horizon and become not only unobservable, but entirely inaccessible, thus limiting how much energy could one day be extracted from them. Here, we consider the likely response of a highly advanced civilization to this situation. In particular, we argue that in order to maximize its access to useable energy, a sufficiently advanced civilization would chose to expand rapidly outward, build Dyson Spheres or similar structures around encountered stars, and use the energy that is harnessed to accelerate those stars away from the approaching horizon and toward the center of the civilization. We find that such efforts will be most effective for stars with masses in the range of $M\sim (0.2-1) M_{\odot}$, and could lead to the harvesting of stars within a region extending out to several tens of Mpc in radius, potentially increasing the total amount of energy that is available to a future civilization by a factor of several thousand. Lastly, we also discuss the observable signatures of a civilization elsewhere in the universe that is currently in this state of stellar harvesting.},
doi = {10.1016/j.dark.2018.09.005},
journal = {Physics of the Dark Universe},
number = C,
volume = 22,
place = {United States},
year = {2018},
month = {9}
}

Journal Article:

Figures / Tables:

Figure 1 Figure 1: A cartoon summarizing the prospects for an advanced civilization to transport usable stars to a central location, assuming that such efforts begin in the present epoch (t = 0). Blue, yellow and red symbols represent stars with masses of 2, 1 and 0.2$M$ , respectively. The colored linesmore » denote the (co-moving) distances those stars have travelled after 1 Gyr, 10 Gyr or 100 Gyr, adopting a maximum speed of 10% of the speed of light and assuming that approximately 100% of the collected energy is converted into kinetic energy of the star ($η$ = 1). The results shown apply to the case in which each star is encountered as it begins its main sequence evolution. The thick black line in the $t$ = 100 Gyr frame represents the horizon at that time in cosmic history. Very distant stars with either very low or high masses will not be collected, as they will either fall beyond the cosmic horizon or evolve beyond the main sequence before reaching their destination.« less

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Works referencing / citing this record:

Habitable Zones around Almost Extremely Spinning Black Holes (Black Sun Revisited)
journal, January 2020

  • Bakala, Pavel; Dočekal, Jan; Turoňová, Zuzana
  • The Astrophysical Journal, Vol. 889, Issue 1
  • DOI: 10.3847/1538-4357/ab5dab

    Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.