the bending of light by a gravitational body was predicted by albert einstein in 1912, a few years before the publication of general relativity in 1916 (renn et al. 1997). the ring effect was first mentioned in the academic literature by orest khvolson in a short article in 1924, in which he mentioned the “halo effect” of gravitation when the source, lens, and observer are in near-perfect alignment. einstein remarked upon this effect in 1936 in a paper prompted by a letter by a czech engineer, r w mandl , but stated