Perfect black holes are versatile mathematical tools. Just don’t mistake them for the real thing.
Computer simulations and custom-built quantum analogues are changing what it means to search for the laws of nature.
Gravitational waves have opened up new ways to test the properties of black holes — and Einstein’s theory of gravity along with them.
For decades, physicists have struggled to create a quantum theory of gravity. Now an approach that dates to the 1970s is attracting newfound attention.
Two leading candidates for a “theory of everything,” long thought to be incompatible, may be two sides of the same coin.