EINSTEIN AND GENERAL RELATIVITY

The general theory of relativity, published by Albert Einstein in 1915, is one of the cornerstones of modern physics. It is a theory that describes the gravitational interactions, generalising and overcoming the previous theory of Isaac Newton, developed almost three centuries earlier.
General relativity has revolutionised the concept of gravity, which after Einstein is no longer a force able to propagate instantaneously, like Newton thought. Instead, it is the effect of the curvature of spacetime, which is transformed from a simple stage to a lead actor.

Einstein’s most spectacular predictions include often counter-intuitive phenomena. One example is the dilation of time near an intense gravitational field, or the effect known as “gravitational lensing”, which predicts the curvature of starlight around massive objects (with the consequent deformation or multiplication of the source in the eyes of the observer). But the solutions to the equations of general relativity also predicted black holes (similarly considered merely mathematical curiosities up to a certain point, but whose existence in nature is almost certain today) and gravitational waves. The first historic observation of the latter, in 2015, represented the final confirmation of perhaps the most iconic theory o fphysics of the last century.