Astronomers, astrophysicists, other scientists, and even ordinary people always believed that we can’t be alone in the Universe. Why would such an apparently infinite portion of spacetime and matter exist only for Earthlings? Whether the Universe was created by a supernatural and divine being or not, it seems impossible the scenario of Earth being the only planet that hosts life.
But life on other planets doesn’t necessarily mean advanced civilizations that travel the galaxies in super-fast spaceships. Alien life can also be primitive and by the “hunter vs. prey” model as we often see on our planet: wolves hunting deers, birds eating worms, and so on.
However, let’s try to be optimistic. Let’s suppose that in our Universe that measures at least 93 billion light-years in diameter, there are alien civilizations that far surpassed any primitive state.
The ultimate question is this: how long would it take for them to send a response to us?
Long story short: at least 3,000 years
Harvard astronomers Abraham Loeb and Amir Siraj thought about the question and started research for finding an answer. They calculated that it would take humanity a minimum of 3,000 years to receive a reply from any highly intelligent green fellows from far away. Of course, this first implies that humanity will have to send some sort of transmission towards the aliens.
The astronomers relied on the Copernican Principle, which states that humans and the Earth are representative of the norm instead of an outliner. Their study is titled “Intelligent Responses to Our Technological Signals Will Not Arrive In Fewer Than Three Millennia,” and it is being considered for publication.
Abraham Loeb declared, as quoted by Universe Today:
The Copernican principle asserts that we are unlikely to live at a privileged time and so the likelihood of another habitable planet like Earth going right now through an analog of our first century of radio communication, given a few billion years of its history, is below one part in ten million,
Therefore, a response is expected only within a large enough volume, containing more than ten million stars.
Giving the distances between stars and not to mention galaxies that defy human comprehension, another problem emerges. The alien civilization “waving” at us could be long gone until we receive their message. Or even vice versa: humanity could become extinct until our message arrives at the aliens.
First of all, let’s all hope that technologically advanced aliens really are there, somewhere.
The new study was published online, and you can see it here.