A huge investment into the search for intelligent alien life has renewed public interest in the question of whether we’re alone in the universe. Paul Davies tells Late Night Live why he’s sceptical of the current search, and why he thinks we should look for ‘life as we don’t know it’ on our own planet. For Professor Davies, the big question is whether Earth-like planets are likely to have life on them.
‘If life does pop up obligingly in Earth-like conditions, no planet is more Earth-like than Earth itself, so shouldn’t life have started many times over right here on our home planet? How do we know it didn’t? Has anybody actually looked?’ asks Davies.
You don’t know how it ticks, you’ve got to delve into its biochemical innards to work that out, and if you go looking for life as we know it, you’re not going to discover life as we don’t know it,’ he says.
There’s plenty of room at the bottom for microbial life that would be radically alternative to known life.
If these microbes were found, it would be obvious from their biochemistry that they could not possibly have had a common origin with the rest of life on Earth, Professor Davies says.