Hi,I've read that even Newton's law suggests a degree of gravitational lensing (at least in the context of the 1919 eclipse observation that confirmed GR) - but that GR predicted that the amount of bending of a light path would be exactly twice that predicted by Newton. See here (http://en.wikipedia.org/wiki/Tests_o...y_the_Sun).Can anyone talk me through why it's exactly twice (noting I'm not really a maths person).Thanks