Einstein's theory of relativity has passed the most rigorous test to date، this time withstanding the super-strong gravitational field of a supermassive black hole، as the Technical Times said. This is the latest in a series of demonstrations of Einstein's 103-year-old theory of general relativity applied in the most extreme circumstances. Previously، scientists have proven that Einstein's explanation of how the universe works stands in the face of highly dense neutron stars and mysterious particles called ghost neutrinos. They also found an entire galaxy that bends space itself and، in 2015، discovered gravitational waves، ripples in the fabric of space-time. An international team of scientists studying Sagittarius A*، the supermassive black hole at the center of the Milky Way، has found that، even in the vicinity of the strongest gravitational field in the galaxy، Einstein's relativity applies. The team specifically examined S2، a star that circles Sagittarius A*، and measured its velocity and orbit as it came to its closest point to the black hole. They found that S2 behaved exactly as Einstein predicted. At such a close distance to an object with a much stronger gravitational field، the star exhibited a phenomenon called gravitational redshifting. The study، which is published in the Astronomy & Astrophysics journal، is the culmination of more than a quarter of a century of observation by a team of experts led by Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics at Garching، Germany. Genzel says this is the second time the team observed S2 making its closest pass to Sagittarius A*. However، they were able to make observations at unprecedented resolutions with the development of new instruments. "We have been preparing intensely for this event over several years، as we wanted to make the most of this unique opportunity to observe general relativistic effects،" says Genzel.