“SO, WHERE is everybody?” Nobel laureate Enrico Fermi reportedly quipped to fellow physicists in 1950, when discussing why we haven’t seen any signs of alien civilisations if, as many believe, our galaxy is teeming with life. Now, a maths model may have an answer to Fermi’s paradox.
Rasmus Bjork of the Niels Bohr Institute in Copenhagen, Denmark, has calculated that eight probes – travelling at a tenth of the speed of light and each capable of launching up to eight sub-probes – would take about 100,000 years to explore a region of space containing 40,000 stars. When Bjork scaled up…
