It has long been an unspoken tenet of astrobiology that in the absence of confirmed alien technologies it’s necessary to imagine some.

This is far from a frivolous pursuit. Rather, it is an attempt to resolve one of the more baffling aspects of human existence, generally summed up as the Fermi Paradox.

In 1950 the famous nuclear physicist Enrico Fermi came up with an interesting point. Given the size and age of the Milky Way, he said, any alien civilisation just a bit cleverer than humanity should by now have had ample time to explore and colonise all of it.

Why, then, with the obvious exception of a couple of dozen befuddled folk in America’s more agricultural states, has no one ever seen evidence thereof?

Scanning the skies for the sounds of extraterrestrial radio broadcasts – the basis of the long-running Search for Extra Terrestrial Intelligence (SETI) project – has thus far turned up squat. Other research avenues, at least since Fermi’s implicit challenge, have focussed on the search for technological evidence.

If ET is out there, the logic runs, she or he or it must have somehow arrived wherever there is, and must be somehow surviving – and for those things to happen, some type of whizzbang alien machinery must be involved

To read more, click here.