'There is no conflict between quantum physics and gravity': Physicists prove Einstein's 'happiest thought' holds true at quantum scales

For the first time, physicists have measured a quantum effect predicted in 1927, confirming that Einstein's equivalence principle holds at the quantum scale. Using ultracold rubidium atoms split into two paths, one in free fall and one suspended, researchers recorded interference patterns matching theoretical predictions within 2.5%. The findings suggest no conflict between quantum mechanics and general relativity, opening doors to deeper tests involving gravity and quantum superposition.