The Butterfly Effect of Intelligence on the Cosmos
The butterfly effect is a concept in the theory of chaos describing how tiny, initial changes in a complex system can result in massive, consequences. The metaphor coined by Edward Lorenz in the 1960s, suggests that a butterfly flapping its wings in Brazil could, through a chain reaction, trigger a tornado in Texas, highlighting extreme sensitivity to initial conditions.
A butterfly is a minor mover drawn from the natural world. But an intelligent technological civilization with major computational resources, could “flap its wings” in a deliberate fashion so as to accomplish a major goal. The related effect could serve as a technological signature of intelligence in the cosmos, one of many that I discussed in a new podcast interview of the “The Basement/The Why Files”, available at the following link:
In particular, consider our future in which the Sun will inevitably brighten up and boil off all liquid water on Earth’s surface, turning it into a desert within a billion years through the greenhouse effect, as predicted here.
To avoid this doomsdays scenario and keep the Earth habitable, our descendants might embark on a cosmic engineering project which will aim to grow the orbital distance of the Earth from the Sun at the necessary rate. This task can be accomplished by tugging the Earth gravitationally by another body which orbits the Sun and resonates intermittently with the orbits of the Earth and Jupiter.
Each time the currier body flies past Jupiter, it may “steal” a tiny amount of orbital energy through a gravity assist. As this “butterfly” then returns to the proximity of Earth, it can “donate” that energy during a close flyby, nudging Earth’s orbit slightly outward. This scheme relies on gravity assists and orbital resonances to transfer energy from a massive outer planet, like Jupiter, to Earth. By timing these flybys to be resonant and always transfer energy with the same sign, the effect can be amplified over hundreds of millions of years — much like pushing a child on a swing at just the right moment to increase its height.
This cosmic engineering project to save humanity could involve selecting and equipping suitable Asteroid or Kuiper Belt objects with technological engines so that they will serve as the required “butterflies,” swinging periodically by the Earth and then Jupiter. This could raise the orbit of Earth significantly, but only lower Jupiter’s orbit by a tiny amount, since Jupiter is 318 times more massive than Earth.
The mass of these “butterflies” can be chosen so as to expand the Earth’s orbit by just the right amount over a billion years to maintain a constant solar flux on Earth’s surface over that period. This would mean tailoring the Earth-Sun separation to scale as the square root of the solar luminosity.
Searching for such a scaling among habitable planets around other stars can be used to detect the signature of advanced technological civilizations which chose to engage in similar cosmic engineering projects. If this idea was popular among our siblings in the family of intelligent civilizations within the Milky-Way galaxy, then it would result in an overabundance of Earth-mass planets in the habitable zone around old Sun-like stars as these stars evolve along the red giant branch of the Hertzsprung-Russel diagram — an inevitable consequence of the natural evolution of these nuclear fusion furnaces.
***
Cosmic engineering projects might not be restricted to planetary systems. Given the accelerated expansion of the Universe, intelligent civilizations which were used to communicating with each other across cosmological distances might have decided to propel themselves closer together so that they would not be pulled apart and lose contact with each other in the distant future due to the accelerated expansion. Could we identify the related motions or artificial clustering of sources in cosmological data sets? I showed As in a paper here that the power required to move a star at a constant speed across cosmological distances can be supplied by the nuclear energy production in the star. Assuming that a significant fraction of this power is emitted in the infrared, the Webb Telescope will be able to detect a single stellar-mass object propelled at a constant speed out to a distance of about 30 million light years times the speed in units of 10,000 kilometers per second. Discovering the non-gravitational clustering and dynamics of many such sources would provide evidence for a new phenomenon of cosmic engineering on large scales.
***
This paper was inspired by an email exchange that I had with Freeman Dyson in 2011 (as documented here). Back then, I published a paper here which calculated that in a trillion years from now, all extragalactic light sources will cease to be visible due to the accelerating expansion of the universe. Future astronomers would therefore be stuck looking only within their own galaxy. Not only would the absence of extragalactic sources make for a lonely universe, but it would deprive future astronomers of the tools that we have used to arrive at our current understanding of cosmology, such as extragalactic supernovae and the cosmic microwave background (CMB) radiation. Despite this, I suggested an observational signature by which these astronomers could still derive the standard cosmological model: hypervelocity stars.
In our correspondence, Freeman as the “ultimate optimist” suggested a means by which future civilizations could avoid this fate. He proposed that a civilization could harness the gravitational energy of a group of galaxies in some way as to pull together colossal collections of galaxies before they were thrown apart from each other by cosmological expansion.
Two years before I was born — in 1960, Freeman conceived here of civilization-scale engineering project, currently labeled as a Dyson Sphere, a megastructure which intends to harvest much of the energy output of a star by its resident civilization.
In our correspondence, Freeman suggested searching for anomalous clustering of galaxies to detect such “cosmic engineering.” In response, I mentioned two possible observational signatures of cosmic engineering: redshift surveys and the Sachs-Wolfe effect. Redshift surveys use galaxies to trace the distribution of matter on large scales throughout the Universe. By the Sachs-Wolfe effect, if some advanced civilization pulled together an cluster of galaxies far bigger than “normal” superclusters, then we could detect it from the energy lost by CMB photons as they climb out of the cluster’s enormous gravitational potential well. Signatures of anomalous clustering are not actually observed in either type of surveys, but Freeman noted that given the trillion-year timescale of the problem, “we have plenty of time to start doing it ourselves.”
Below is the full scope of our email correspondence in 2011.
Avi Loeb:
Dear Freeman,
In 2002 I wrote a paper about the long-term future of our Universe (Phys.
Rev. D65, 047301, 2002). Back then, you asked me in an e-mail to let you
know if I have any interesting follow-up thoughts on the subject.
Attached is a short paper that I had just submitted for publication on the
same subject. I would love to hear any comments you might have about it.
With best wishes,
Avi
Freeman Dyson:
Dear Avi,
Thank you for sending the paper. I found nothing wrong with it.
It presents a dismal picture of the future awaiting our descendants.
Since I am an incurable optimist, I raise the question, how much this
future could be changed by a large-scale intervention of intelligent life.
A very rough estimate indicates that large-scale “cosmic engineering”
could be feasible. Using available gravitational energy as the motive
power, roughly ten percent of the mass from one percent of the observable
universe could be collected within a volume small enough to remain
permanently bound together gravitationally. The collection could be done
in a single Hubble time and could then be maintained with small active
adjustments. So, our descendants would stay in communication with a
hundred million galaxies instead of only one. It is also possible that
some of our more advanced colleagues elsewhere in the universe already
began this process. We should look out for evidence of large-scale
coordination of gamma-ray bursts or other phenomena indicating high
velocity movement of large masses. It would be interesting to examine
such possibilities in detail. Thank you for the suggestion. Yours ever,
Freeman Dyson.
Avi Loeb:
Freeman,
Your underlying assumption is that intelligent beings prefer as much
company as possible. I can only say that as I get older, I prefer to stay
away from other people as much as possible, since I have the feeling that
I heard it all. Extrapolating to the distant future, I am entirely
complacent with us being surrounded by vacuum and protected by an event
horizon. Aside from the benefit of not having any distractions, this
will reduce the risk of a hostile invasion by another civilization.
Yours,
Avi
Freeman Dyson:
Each to his own taste. History without hostile invasions would be very
boring. FD.
Avi Loeb:
Putting prejudice aside, we already have relevant data for testing your
proposition about “cosmic engineering” on very large scales. SDSS provided
us with a map of the distribution of galaxies out to a redshift of z=0.3
(and SDSS III is now reaching farther out). The biggest bound systems in
the survey are clusters of galaxies, containing at most ~10^{15} solar
masses or ~1000 galaxies each. The existence of clusters is fully
consistent with the initial conditions we detect in the microwave
background at redshift z=1000. Since the initial conditions are Gaussian,
it should be easy to identify “cosmic engineering” in the form of a rare
over-dense region (supercluster) containing many more than ~1000 galaxies.
A region compact enough to bind a million galaxies against cosmic
acceleration would have imprinted an anomalously large Sachs-Wolfe effect
on the microwave background or would have induced unusually high peculiar
velocities. We do not see anomalies of this magnitude. The biggest
supercluster in our vicinity is the Shapley supercluster, but it is
expected to be dissolved in the future by the cosmic acceleration according
to the calculation in
Munoz, J, & Loeb, A. “The Density Contrast of the Shapley Supercluster”,
MNRAS, 391, 1341
Of course, it is possible that the Shapley supercluster is still “under
construction”, or that “cosmic engineering” operates on much smaller
scales.
Avi
Freeman Dyson:
That is disappointing. On the other hand, if our colleagues have been
too lazy to do the job, we have plenty of time to start doing it
ourselves. FD.
*******
In this essay, I featured four amazing watercolors from a series created by the celebrated artist, Greg Wyatt. These watercolors incorporate inspiring statements by Giordano Bruno and Marsilio Ficino. This is the eighth in a sequence of essays, where Greg and I collaborate on the interface between art and science. The first essay in this series, titled “Music of the Cosmic Spheres,” appeared here; the second essay, titled: “Cosmic Waterfalls in Spacetime Cliffs,” appeared here; the third titled “Missing Elements in the Cosmic Jigsaw Puzzle,” appeared here; the fourth essay, titled: “Why Do We Exist?”, appeared here, and the fifth titled “Inspiration from the Stars”, appeared here, the sixth titled: “We Might Understand How the Cosmos Works Before We Understand How Life Works”, appeared here, and the seventh titled “Will the Human Survive for Billions of Years”, appeared here.
ABOUT THE AUTHOR
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.
Professional website:
https://lweb.cfa.harvard.edu/~loeb/
Social media:
https://avi-loeb.medium.com/
https://www.youtube.com/@ProfessorAviLoeb
https://open.spotify.com/show/1zhndXkvSY2b8FdjspFpCd
https://x.com/ProfAviLoeb
