If advanced alien life exists in our universe, it's likely to be at the 'very young' stage.
This is according to Harvard astronomer, Dimitar Sasselov, who came up with the theory to explain something known as the 'Fermi Paradox'.
The paradox refers to the fact that there are billions of galaxies in the observable universe, each with up to a trillion stars, and perhaps trillions of habitable planets.
But, despite such worlds being so abundant, and life on Earth has been able to thrive, we've still been unable to find aliens.
Sasselov, however, says that doesn't mean they don't exist – they just haven't evolved yet.
One week it's we haven't found any any aliens because they're all extinct due to climate change, and the next week it's we haven't found any any aliens because they're in a very young stage of evolution. What a bunch of bull puckey. To read more, click here.