Black Hole Collisions Are More Common than Previously Thought

By listening to gravitational waves, or tiny ripples in the fabric of space-time, an international team of astronomers that includes Columbia professor Maximiliano Isi has roughly doubled the total number of black-hole collisions ever identified, to nearly four hundred.

The new observations, using data from detectors in the states of Washington and Louisiana, as well as in Italy and Japan, have enabled the researchers to refine measurements of the universe’s expansion rate, discover two unique types of black holes, and determine multiple pathways by which black holes are created.