“Finding a civilization dead due to war or climate change will hopefully convince us to get our act together and avoid a similar fate,” observes Abraham Loeb, chair of the astronomy department at Harvard University, founding director of Harvard’s Black Hole Initiative. “But it would be even more remarkable if radar imaging or flyby photography near an interstellar relic within the solar system would show signs of an advanced technology that our civilization had not mastered as of yet. There is no better lesson to learn than that of civilizations that had developed advanced technologies up to the point of self-destruction.”
“When exploring habitable worlds around other stars, we might therefore find planets with burnt-up surfaces, abandoned mega-structures or planetary atmospheres rich with poisonous gases and no sign of life,” says Loeb. “Even more intriguing is the possibility that we will find technological relics flying through our solar system with no detectable functionality, such as pieces of equipment that lost power over the millions of years of their travel and have turned into space junk.
The rate of growth of new technologies is often proportional to past knowledge, leading to an exponential advance over time, continues Loeb in Scientific American. This explosive process implies that very quickly after a civilization reaches technological maturity, it will develop the means for its own destruction through climate change, for example, or nuclear, biological or chemical weapons. Developments of this type, over mere hundreds of years, would appear abrupt in the cosmic perspective of billions of years. If such self-destruction is common, this could explain Fermi’s paradox, which asks “where is everybody?”—and could imply that relics of dead civilizations should be abundant in space.
How much debris exist in interstellar space would depend on the abundance of technological civilizations and the scope of their aspirations for space exploration. Based on Kepler satellite data, we know that about a quarter of all stars host a habitable Earth-scale planet. Even if a small fraction of all habitable Earths led to technological civilizations like our own during the lifetime of their stars, there might be plenty of relics out there in the Milky Way for us to explore.
Image credit: nuclear war event with thanks to Shutterstock.com
Top 10 Most-Viewed Headlines of 2018