Albert Einsteinâ€™s been having quite a few weeks! First his â€œimaginary elevatorâ€� thought experiment was confirmed with unprecedented precision, then his theory of relativity was shown to create gravitational lenses as expected even in other galaxies. And today, we learn that a central tenet of relativity still holds even at gravitational extremes. Itâ€™s no annus mirabilis, but it ainâ€™t bad.
Todayâ€™s news, which appears in the journal Nature, concerns the equivalence principal, which roughly