There may be trillions of alien civilizations out there
A new study suggests that we may not be alone in the universe. In fact, it might be crowded, as there may be trillions of alien civilizations.
The question of whether or not we are alone in the universe is one of the oldest questions known to man, but a new research paper printed in the journal Astrobiology suggests that we may be asking the wrong question. Instead, it might make more sense to ask how crowded is the universe?
The paper comes from astronomers Adam Frank and Woodruff Sullivan, and it theorizes that not only are alien civilizations probable, they may number in the billions, even trillions.
“What we showed was the ‘floor’ on the probability for a civilization to form on any randomly chosen planet,” Frank, a University of Rochester physics and astronomy professor, told The Huffington Post. “If we are the only civilization in cosmic history, then that what we calculated is the actual probability nature has set. But if the actual probability is higher than that floor, then civilizations have happened before.”
Naturally, there are a few caveats to that. To begin with, Frank and Sullivan are considering the universe as a whole, from start to its eventual finish. The universe is estimated to be around 13 billion years old, and it could last for billions – even trillions of years still. The Earth alone is around 4.5 billion, and the earliest signs of life are believed to have begun in the first billion years. By comparison, the first human ancestor, homo-erectus, is just 1-2 million years old. The written language, however, is just over 5,000 years old.
Given the mind-numbingly vast expanse of space and the relatively minuscule time it takes sentient life to grow into a civilization capable of leaving its planet, there could have already been an incalculable number of civilizations that rose, had a lengthy tenure, and died off. When you start to think of it like that, it seems almost obvious that not only are we not alone, we probably weren’t first either.
“Even if you are pretty pessimistic and think that you’d have to search through 100 billion (habitable zone) planets before you found one where a civilization developed, then there have still been a trillion civilizations over cosmic history!” Frank wrote. “When I think about that, my mind reels — even if there is just a one in a 100 billion chance of evolution creating exo-civilizations, the universe still has made so many of them that we are swamped by histories other than our own.”
It makes logical sense that there may be life in the universe, but Frank and Sullivan go even further and offer an equation to help prove it.
The equation is based on an older formula from astronomer Frank Drake, a SETI astronomer who in 1961 developed an equation that showed the likelihood of alien civilizations. His equation became known as the “Drake Equation,” and it uses life on Earth and the growth of the solar system as the proof, then expands that for the universe. Frank and Sullivan take that equation and add it to the past and present of the cosmos.
Drake’s Equation is buoyed in part by the recent discoveries from the Kepler space telescope, which is designed to help find Earth-like worlds. By any measure, it has been a success. Its most recent findings added a possible 1,200 new planets to the list, nine of which may be Earth-like.
Even if Kepler never finds a true Earth-like planet with conditions that match those of Earth, it is confirming one huge variable: most stars have a planetary system.
That’s something that many have theorized about, but Kepler is helping to show that planetary systems around stars are the norm. That in turn vastly increases the number of planets that can be found within the Goldilocks zone of a star, the area a planet can orbit where it is not so hot that the liquid boils away, or so cold that it freezes. That makes it ideal for nurturing life.
“The universe is more than 13 billion years old,” said Sullivan, a member of the astronomy department and astrobiology program at the University of Washington. “That means that even if there have been 1,000 civilizations in our own galaxy, if they live only as long as we have been around — roughly 10,000 years — then all of them are likely already extinct. And others won’t evolve until we are long gone.
“For us to have much chance in finding another ‘contemporary’ active technological civilization, on average they must last much longer than our present lifetime.”
Of course, just because there are potentially trillions of alien civilizations littered throughout the history of the universe, that doesn’t necessarily mean we will ever meet one. The universe is very big and very old, and it will go on for a long, long time. Even if humans continue for hundreds of thousands, even millions of years, we may never meet any one. The odds of that happening though are improving.