A New Meeting?
Patience is a virtue, regardless of whether you’re waiting in line at the airport...or waiting to finally talk with an alien.
Case in point, Cornell astronomers say that, due to the sheer size of the Milky Way, it will take a while (about 1,500 years) before Earthlings can reasonably expect to hear back from any extraterrestrials who could’ve picked up transmissions from Earth.
"We haven't heard from aliens yet, as space is a big place – but that doesn't mean no one is out there. It's possible to hear any time at all, but it becomes likely we will have heard around 1,500 years from now," says astronomy student Evan Solomonides from Cornell University.
Solomonides is co-author of a new study that analyzes what's known as the Fermi Paradox. In his work, he uses calculations to help uncover the reason that humanity has yet to hear from any little green men (or women).
The Fermi paradox argues that it’s strange that humans haven't yet heard from aliens because, in this vast galaxy with about 100 to 400 billion stars, there has to be some life form out there. Indeed, according to basic probability, given the size and scope of our universe, advanced alien life does exist.
But Solomides says this might actually be the problem – the galaxy is just too vast. As such, it will take a long, long time for communication to happen.
"Even our mundane, typical spiral galaxy – not exceptionally large compared to other galaxies – is vast beyond imagination," says Solomonides. "Those numbers are what make the Fermi paradox so counterintuitive."
But even if Earthlings feel alone sometimes, it doesn’t necessarily mean they are alone—after all, human broadcasts that could be picked up by our alien friends in the Milky Way have only been transmitted for 80 years (in the form of TV and radio signals). Since they've only been broadcast for 80 years, the transmissions would have only reached a radius of 80 light-years from Earth.
To put that in perspective, 1 light-year is around 9.5 trillion kilometres (5.88 trillion miles). That is a pretty long way, but the Milky Way is a staggering 100,000 light-years across. Not all hope is lost, but extraterrestrial enthusiasts will need to take a chill pill for a bit.