Two of the most important tenets in all of physics are Quantum Mechanics and the General Theory of Relativity. A team of researchers from the University of California at Berkely demonstrated with great precision that gravity changes the flow of time, a concept fundamental to the Theory of General Relativity. The phenomenon, sometimes referred to as "Gravitational Redshifting" because the oscillations of the matter waves slow down or become redder when tugged by gravity, was tested by taking advantage of a principle of quantum mechanics: that matter is both a particle and a wave. While in the past, airplane and rocket experiments have proven that gravity makes clocks tick more slowly — a central prediction of Albert Einstein's General Theory of Relativity — this new experiment utilized an atom interferometer to measured this slowdown 10,000 times more precisely than before.