A child on a swing can keep the swing in motion by repeatedly standing up and squatting down. This movement changes the frequency of the swings and amplifies them. This simple concept—known as parametric amplification—finds use also in modern quantum physics.
One hundred years after Albert Einstein shared it with the world, the general relativity is waiting for its last confirmation: direct observation of gravitational waves. These ripples in the curvature of spacetime are created when a massive object accelerates. Typical examples of such systems are binary neutron stars or black holes; as the two stars (or… Continue reading Seeing ripples in spacetime