The World Year of Physics goes into its final month with a Big Bang — a 12-hour marathon Webcast on Thursday that hops from Geneva to Egypt, from Jerusalem to Venice, from London to the South Pole. From 6 a.m. to 6 p.m. ET, physicists and educators will hold forth on time travel and neutrinos, the legacy of Albert Einstein’s theories and the puzzles yet to be solved. And along the way, even MSNBC.com will come in for a little of relativity’s reflected glory. Our interactive presentation on “Putting Einstein to the Test” is one of the winners in the Pirelli Relativity Challenge for the best multimedia presentations explaining special relativity. The contest, which is presenting its awards at the Telecom Future Center in Venice on Thursday, drew about 250 entries from 40 countries.