New theory on why we have not seen aliens: they got bored and went home

Scientists have long pondered why, given the hundreds of billions of planets in the galaxy, we have seen no compelling evidence of intelligent life existing beyond Earth.

- Ian Sample Science editor

Now researchers are mulling an intriguing possibility: if aliens exist, their technology may be only marginally better than ours. Having explored their cosmic neighbourhood for a while, they simply got bored and could not be bothered to continue, making it difficult to detect them.

That scenario, described in a new paper, embraces the principle of “radical mundanity”, which shuns the notion of extraterrestrials zipping around the universe after harnessing physics beyond our comprehension.

Instead, it proposes a Milky Way that is home to a modest number of civilisations with technology not wildly more advanced than our own.