It seems that after all, we may not bee the only intelligent civilization in the known universe
In 1961, astrophysicist Frank Drake came up with an equation that calculates the number of advanced civilizations likely to exist in the Milky Way galaxy. Today, researchers have remodeled the equation using new data from the Kepler satellite. The results are fascinating.
Scientists have concluded that human beings aren’t the only intelligent civilization in the universe after a recent revision of the famous Drake Equation of 1961. The equation estimates the number of potential intelligent civilizations in the universe.
Scientists adapted the Drake Equation with data from NASA’s Kepler satellite on habitable planets in the cosmos. Researchers modified the Drake Equation from detailing the number of extraterrestrial civilizations that exist now, to about the chance of our civilization being the only one ever existed.
The new research indicates that unless the odds of intelligent lifeforms evolving on habitable planets are extremely low, life on Earth is not the only one that evolved to an advanced stage.
Scientists explain that the chance of an advanced civilization developing would need to be less than one in 10 trillion, for our civilization to be the only intelligent one in the known universe.
However, data obtained from Kepler changes everything placing the odds at a much higher percentage, meaning that technologically advanced civilizations are likely to have evolved at a certain point in the life of the universe.
A New Empirical Constraint on the Prevalence of Technological Species in the Universe
Researchers turned to the specific question, ‘‘Has even one other technological species ever existed in the observable Universe?’’
Adam Frank, professor of physics and astronomy at the University of Rochester and co-author of the paper stated that: ‘The question of whether advanced civilizations exist elsewhere in the universe has always been vexed with three significant uncertainties in the Drake equation.
‘We’ve known for a long time approximately how many stars exist.
‘We didn’t know how many of those stars had planets that could potentially harbor life, how often life might evolve and lead to intelligent beings, and how long any civilizations might last before becoming extinct.’
‘Thanks to Nasa’s Kepler satellite and other searches, we now know that roughly one-fifth of stars have planets in ‘habitable zones,’ where temperatures could support life as we know it.
‘So one of the three big uncertainties has now been constrained.’
However, a question that remains a puzzle is how long civilizations might have survived.
‘The fact that humans have had a rudimentary technology for roughly ten thousand years doesn’t really tell us if other societies would last that long or perhaps much longer,’ he explained.
However, authors of the study Frank and Woodruff Sullivan of the astronomy department at the University of Washington discovered that they could eliminate that term altogether by simply expanding the question.
“Rather than asking how many civilizations may exist now, we ask ‘Are we the only technological species that has ever arisen?” said Sullivan. “This shifted focus eliminates the uncertainty of the civilization lifetime question and allows us to address what we call the ‘cosmic archeological question’—how often in the history of the universe has life evolved to an advanced state?” (source)
Frank and Sullivan mixed things up, refreshing the Drake equation. Instead of taking a guess at the odds of intelligent life developing, they calculated the change against it occurring for humanity to be the only known advanced civilization out there. Researchers calculated the chance between a universe where mankind has been the sole experiment in civilization and another one where other advanced civilizations might have developed before the rise of advanced lifeforms on earth.
“Of course, we have no idea how likely it is that an intelligent technological species will evolve on a given habitable planet,” says Frank. But using our method we can tell exactly how low that probability would have to be for us to be the ONLY civilization the Universe has produced. We call that the pessimism line. If the actual probability is greater than the pessimism line, then a technological species and civilization have likely happened before.” (source)
Sullivan and Frank calculated how unlikely would it be for advanced life to exist if there has never been another one developing somewhere in the ten billion trillion stars in the universe or even among our own galaxy’s hundred billion stars. This approach changed the way we look at the Drake equation and the likelihood we are alone in the universe.
“One in 10 billion trillion is incredibly small,” says Frank. “To me, this implies that other intelligent, technology producing species very likely have evolved before us. Think of it this way. Before our result, you’d be considered a pessimist if you imagined the probability of evolving a civilization on a habitable planet were, say, one in a trillion. But even that guess, one chance in a trillion, implies that what has happened here on Earth with humanity has, in fact, happened about a 10 billion other times over cosmic history!” (source)
However, on a smaller scale, the universe is less extreme. Researchers speculate that another technologically advanced species likely evolved on a habitable planet in our galaxy if the odds against it are better than one chance in 60 billion.
“The universe is more than 13 billion years old,” said Sullivan. “That means that even if there have been a thousand civilizations in our own galaxy if they live only as long as we have been around—roughly ten thousand 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 of success in finding another “contemporary” active technological civilization, on average they must last much longer than our present lifetime.”
“Given the vast distances between stars and the fixed speed of light we might never really be able to have a conversation with another civilization anyway,” said Frank. “If they were 20,000 light years away, then every exchange would take 40,000 years to go back and forth.” (source)
Franck and Sullivan point out in their revolutionary study that even though there aren’t other advanced civilizations in the Milky Way, the results of the study have a profound scientific and philosophical meaning.
Journal Reference: University of Rochester