It could take a while for humans to hear from aliens from the vast universe – another 1,500 years in particular.
Astronomers from Cornell University deconstructed the Fermi paradox and paired it with the mediocrity principle to form a new equation, which concludes that E.T. probably wouldn’t phone home for at least 1,500 years.
“We haven’t heard from aliens yet, as space is a big place — but that doesn’t mean no one is out there,” said study author Evan Solomonides, explaining that until that time, it holds possible for humanity to seem alone despite actually being not.
Yet it’s worth waiting for about 60 generations.
“If we stop listening or looking, we may miss the signals. So we should keep looking,” he added.
If We Aren’t Alone, Why Haven’t We Found Others Yet?
The authors combined the Fermi paradox and mediocrity principle to suggest that the planet might hear from alien life when about half of the Milky Way galaxy has been reached in around 1,500 years.
The Fermi paradox is a contradiction perplexing scientists and sci-fi fans for a long time now: if there are billions of Earth-resembling planets in the galaxy, why haven’t aliens initiated contact or visited us yet?
The so-called mediocrity principle, on the other hand, was proposed by Copernicus in the 16th century and states that nothing may really be special about us – Earth’s physical characteristics aren’t unique, its natural processes are aplenty through the cosmos. Thus, aliens are unlikely to chance upon us for a good while.
Humans are not one to give up in the search for extraterrestrials. For decades, we have been releasing signals via TV broadcasts as well as radio signals into space, which travel from the planet for 80 years at the speed of light.
Solomonides believes that aliens would probably find these transmissions indecipherable, needing to decode light waves into sounds and afterwards parse 3,000 languages of humanity to understand the message.
At any rate, these broadcast signals managed to touch each star within 80 light-years from the sun, with the NASA’s Kepler mission noting that they have arrived at 2,326 verified exoplanets.
It’s All About Distance
The numbers, said Solomonides, make the Fermi paradox “counterintuitive.”
The Milky Way alone, while not notably large compared to other galaxies out there, is already massive beyond one’s imagination. Humans have been sending out signals only for the past eight decades, as well as discovered around 0.125 percent of the galaxy they belong to.
According to the authors, we should let the signals reach half of all the Milky Way’s solar systems in order for them to be picked up. Even then, though, there may be a tiny percentage of alien life capable of understanding and replying to our own messages.
SETI Institute Senior Astronomer Seth Shostak said that one might not expect to gather any signals until someone knows humanity exists right here.
“That means the noise we can make as a society has to have reached them,” he said.
Solomonides presented the paper at the June 16 meeting of the American Astronomical Society in San Diego, California.
Photo: NASA Goddard Space Flight Center | Flickr