Are we alone in this universe? A group of researchers from Oxford says no and has calculated when we will encounter extraterrestrial civilizations – and why they might be greedy.
Oxford – Astronomers have long been on the lookout for traces of extraterrestrial life on other planets. But a team of researchers at Oxford University believes it will be millions of years before mankind can actually come into contact with alien civilizations. They have made estimates of where these civilizations are in our universe, how much they have taken so far, and how long it will ultimately be before we actually encounter them.
The research group led by the economist Robin Hanson has published its results in a study that was published in the Astrophysical Journal . On the basis of various factors, such as the age of the earth as well as the period and history of the universe, they have analyzed why humanity developed comparatively early in the era of the universe and what that means for possible contact with extraterrestrials.
Extraterrestrial life: humanity is comparatively young
Current estimates suggest that the universe is approximately 13.8 billion years old. Our solar system and the earth, on the other hand, were only formed about 4.5 billion years ago. The development time would mean that life can only develop on very long-lived stars and planets, such as red dwarf exoplanets. In relation to this, our evolutionary time corresponds to just one percent of the life span of long-lived planets. That would mean that 99 percent of the advanced life forms in our universe will not emerge until after today.
But why did humanity develop so incredibly early? The research team from Oxford found an answer to the question: “Greedy” extraterrestrial civilizations would suppress the evolution of possible competitive civilizations in the later course of time. What at first sounds like the plot of a Star Trek film is the core of the study from Oxford. The researchers differentiate between “greedy” and “quiet” aliens. The latter, like the people at this point in time, only live on their planet and would therefore be very difficult to track down in the entirety of the universe.
Aliens: The greedy owns the universe
Sometimes “quiet” but “greedy” alien civilizations can develop. This happens about once in a million galaxies. These “greedy” aliens then expand beyond their own home planet and enlarge their area of influence over several star systems. At the same time, they also prevent the spread of other, more technologically advanced civilizations. “Greedy” aliens could rule the entire universe within a few billion years.
Should the development actually take place like this, then the ratio of “greedy” to “quiet” civilizations should be 10,000 to 1. It is therefore very unlikely that another “quiet” civilization has ever lived in the history of our galaxy. If at this point in time another “quiet” civilization still lives somewhere in the Milky Way, which we do not yet know about, the ratio should even be 10 million to 1.
Contact with aliens: first date in 200 million years at the earliest
But our galaxy is only a tiny part of the universe. If it can be assumed that “greedy” aliens spread at half the speed of light, then they already control 40 to 50 percent of the universe today. Despite everything, the research team assumes that humanity will not encounter a “greedy” extraterrestrial civilization at the earliest in 200 million to 2 billion years – provided that humanity still exists. (ij)
