Probing the Nature of Black Holes: Deep in the mHz Gravitational-Wave Sky

Understand

Black holes are unique among astrophysical sources: they are the simplest macroscopic objects in the Universe, and they are extraordinary in terms of their ability to convert energy into electromagnetic and gravitational radiation.

• Our capacity to probe their nature is limited by the sensitivity of our detectors.
• The LIGO/Virgo interferometers are the gravitational-wave equivalent of Galileo's telescope.
• The first few detections represent the beginning of a long journey of exploration.