Experimental studies of black holes: status and future prospects Black holes (BHs) are regions of space-time where gravity is so strong that not even light can escape. Einstein's general theory of relativity (GR) predicted their existence, and observational evidence for BHs has grown significantly over the past century. Three experimental techniques, based on interferometry, have enabled breakthroughs in understanding BHs. These techniques allow for the investigation of space-time near BH event horizons. Recent advancements in interferometry have provided strong evidence for BHs with masses ranging from 10 to 10^10 solar masses. The Event Horizon Telescope (EHT) has detected the 'shadow' of a BH, confirming predictions of GR. The Galactic Center, with its dense star cluster and compact radio source SgrA*, provides a unique opportunity to study BHs. Observations of stellar orbits and radio emission have confirmed the presence of a BH with a mass of about 4.3 million solar masses. The EHT's image of SgrA* shows a shadow consistent with GR predictions. The GRAVITY interferometer has measured BH masses in distant AGN and quasars, providing insights into the co-evolution of BHs and galaxies. Gravitational wave observations have detected mergers of stellar BHs, providing experimental evidence for their existence. These studies highlight the importance of interferometry and gravitational wave astronomy in understanding BHs and their role in the universe. Future research will focus on further testing GR and exploring the nature of BHs in extreme conditions.Experimental studies of black holes: status and future prospects Black holes (BHs) are regions of space-time where gravity is so strong that not even light can escape. Einstein's general theory of relativity (GR) predicted their existence, and observational evidence for BHs has grown significantly over the past century. Three experimental techniques, based on interferometry, have enabled breakthroughs in understanding BHs. These techniques allow for the investigation of space-time near BH event horizons. Recent advancements in interferometry have provided strong evidence for BHs with masses ranging from 10 to 10^10 solar masses. The Event Horizon Telescope (EHT) has detected the 'shadow' of a BH, confirming predictions of GR. The Galactic Center, with its dense star cluster and compact radio source SgrA*, provides a unique opportunity to study BHs. Observations of stellar orbits and radio emission have confirmed the presence of a BH with a mass of about 4.3 million solar masses. The EHT's image of SgrA* shows a shadow consistent with GR predictions. The GRAVITY interferometer has measured BH masses in distant AGN and quasars, providing insights into the co-evolution of BHs and galaxies. Gravitational wave observations have detected mergers of stellar BHs, providing experimental evidence for their existence. These studies highlight the importance of interferometry and gravitational wave astronomy in understanding BHs and their role in the universe. Future research will focus on further testing GR and exploring the nature of BHs in extreme conditions.