(Phys.org)—Black holes are known to have many unique properties,such as that they allow nothing—not even light—to escape after falling in. A lesser known but equally bizarre property is that black holes appear to "know" what happens in the future in order to form in the first set. However, this unique property arises from the way in which black holes are defined, and which has motivated some physicists to explore alternative definitions.
Source: phys.org